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d-Mannose: Properties, Production, and Applications: An Overview: An overview of d-mannose…

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d-Mannose: Properties, Production, and Applications: An Overview: An overview of d-mannose…

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Abstract

d-Mannose is a C-2 epimer of d-glucose, which is a natural monosaccharide. It can be obtained from both plants and microorganisms. Chemical synthesis and biotransformation of d-mannose from d-fructose or d-glucose by using d-mannose isomerases, d-lyxose isomerases, and cellobiose 2-epimerase were intensively studied. d-Mannose is an important component of polysaccharides and glycoproteins. It has been widely used in the food, pharmaceutical, and poultry industries, acting as the source of dietary supplements, starting material for the synthesis of drugs and blocking colonization in animal feeds. d-Mannose is a glyconutrient with high research value in basic science because of its structure and function. This article presents a review of current studies on sources, characteristics, production, and application of d-mannose.

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... Mannose is a natural monosaccharide, occurring in plants as well as microorganisms, usually as a constituent of mannan, hemicellulose, or cellulose [1]. Historically, mannose was used in the food industry as an alternative sweetener or to improve the texture of foodstuff, in cosmetics, or it was used as a feed additive [1]. ...
... Mannose is a natural monosaccharide, occurring in plants as well as microorganisms, usually as a constituent of mannan, hemicellulose, or cellulose [1]. Historically, mannose was used in the food industry as an alternative sweetener or to improve the texture of foodstuff, in cosmetics, or it was used as a feed additive [1]. Thanks to its ability to bind to specific biological receptors, mannose has been examined as a functional moiety of biosensors [2][3][4] and as the key compound for bacterial labels [5]. ...
... However, organisms are very sensitive to the right form of the mannose derivative structure. Mannose contains six carbons and appears in either a pyranose or furanose form [1]. Therefore, the synthesis of targeting nanocarriers requires high selectivity and exact reproducibility of the products. ...
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Thanks to their ability to bind to specific biological receptors, mannosylated structures are examined in biomedical applications. One of the most common ways of linking a functional moiety to a structure is to use an azide-alkyne click reaction. Therefore, it is necessary to prepare and isolate a propargylated mannose derivative of high purity to maintain its bioactivity. Three known preparations of propargyl-α-mannopyranoside were revisited, and products were analysed by NMR spectroscopy. The preparations were shown to yield by-products that have not been described in the literature yet. Our experiments showed that one-step procedures could not provide pure propargyl-α-mannopyranoside, while a three-step procedure yielded the desired compound of high purity.
... However, mannose metabolism is fundamental to cellular health. Mannose plays an important structural role as mannans, hemicellulose, and cellulose [8] in a variety of beans, fruits, and plants. At the cellular level, D-mannose and its derivatives are key metabolites for most glycosylation reactions. ...
... At the cellular level, D-mannose and its derivatives are key metabolites for most glycosylation reactions. Fascinating is the etymology of mannose-the name mannose is derived from the biblical word manna, the pivotal food source that sustained the Israelites during their arduous journey in the Sinai Peninsula [8]. This profound name seems fitting, given the critical contribution of mannose to cells through glycosylation. ...
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History suggests that tasteful properties of sugar have been domesticated as far back as 8000 BCE. With origins in New Guinea, the cultivation of sugar quickly spread over centuries of conquest and trade. The product, which quickly integrated into common foods and onto kitchen tables, is sucrose, which is made up of glucose and fructose dimers. While sugar is commonly associated with flavor, there is a myriad of biochemical properties that explain how sugars as biological molecules function in physiological contexts. Substantial research and reviews have been done on the role of glucose in disease. This review aims to describe the role of its isomers, fructose and mannose, in the context of inborn errors of metabolism and other metabolic diseases, such as cancer. While structurally similar, fructose and mannose give rise to very differing biochemical properties and understanding these differences will guide the development of more effective therapies for metabolic disease. We will discuss pathophysiology linked to perturbations in fructose and mannose metabolism, diagnostic tools, and treatment options of the diseases.
... Diabetes, inflammation [2], and urinary tract infections [3] can all be prevented and treated with D-mannose. D-Mannose is also frequently utilized as a major component or raw material in the manufacture of vitamins, D-mannitol, and antitumor medicines [4]. D-Mannose inhibited tumor development and might be used therapeutically for cancer treatment [5]. ...
... Epimerization (intercountry of epimers) and isomerization (intercountry between aldose and ketose) of carbohydrates can also be catalyzed by carbohydrate isomerases and epimerases. These proteins are extremely useful in industrial enzymatic carbohydrate conversions, which are more environment friendly than the chemical methods [4]. ...
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D-Mannose has great value in the treatment of chronic diseases. D-Mannose isomerase can catalyze the bioconversion of D-fructose to D-mannose. Therefore, a novel D-mannose isomerase gene (Strh-MIase) from Stenotrophomonas rhizophila strain IS26 was expressed, purified, and characterized for the industrial production of D-mannose. The specific activities of the Strh-MIase for D-mannose and D-fructose were 437.5 ± 0.8 U/mg and 267.2 ± 0.7 U/mg. Its optimal temperature and pH were 50 °C and 7.0. The enzymatic bioconversion produced 25 g/L D-mannose from concentration D-fructose (100 g/L) in 6 h by recombinant Strh-MIase, resulting in a final yield of 25%. Sodium phosphate inhibition has little influence on D-mannose production when a high concentration of D-fructose is used as substrate. We demonstrate that the metal ions improve the efficiency of D-mannose isomerase because of the enhancement of its thermostability. Moreover, the possible catalytic residues of Strh-MIase were identified by site-directed mutagenesis.
... Nevertheless, the hydrolysis of the açaí seed's linear mannan can produce mannose hydrolysates with higher purity, which is highly desirable for the industrial separation of mannose from other sugars [21]. Considering that mannose is a monosaccharide with applications in the cosmetic, pharmaceutical, and food industries [22], it is of high economic interest to avail the high mannan content of açaí seeds to produce mannose. ...
... Today, the most common raw materials for commercial production of mannose present much lower mannan content, such as palm kernel cake [21] with 29-38% [23], and softwood [24] with 7-15% of dry weight [25]. Processes for mannose production are based on the thermal, acid, or enzymatic hydrolysis of plant raw materials, which produce hydrolysates containing a mixture of monosaccharides [21,22]. Commercial production of mannose from palm kernel cake hydrolysate is carried out via enzymatic hydrolysis [21,26], while the sulfite pulping process is used to obtain this sugar from softwoods [24,27]. ...
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A critical environmental problem in the Brazilian Amazon-rainforest region is the annual generation of 1.4 million tons of açaí seeds as a waste from açaí-pulp production. This work evaluates the techno-economic viability and environmental impacts of four alternatives to avail açaí seeds: complete combustion for power generation, integrated production of polyphenols and electricity, and co-production of mannose, polyphenols, and electricity by two different routes. Incineration is the least profitable alternative and requires long-term payback for the considered capacity of 6000 kg/h of seeds. The alternative that prescribes co-production of polyphenols and electricity has sound economic and environmental performances but misses the opportunity to avail the mannan content of açaí seeds to produce mannose. The comparison of mannose-producing processes unveiled lower capital and operational costs in the single-step oxalic acid hydrolysis than the sequential sulfuric acid and enzymatic hydrolysis, resulting in a payback time of 2.7 years and an internal rate of return of 34.8%. It further evinces lower aquatic toxicity and acidification potentials, but greenhouse gas emissions are slightly higher than in the sulfuric acid case. The biorefinery is shown as a viable and sustainable waste valorization pathway for açaí seeds, which could help develop a circular bioeconomy in the Amazon region.
... As a high-value product, D-mannose production is a research hotspot in food and pharmaceutical industry. So far, a variety of methods such as chemical synthesis, microbial fermentation, biotransformation, etc. had been developed (Hu et al., 2016a). Each of these methods has its unique advantages. ...
... The traditional chemical preparation method uses molybdic acid or molybdate as a catalyst to prepare D-mannose by isomerizing D-glucose (Hu et al., 2016a). The researchers screened different types of molybdate catalysts and reaction conditions to increase the yield of D-mannose. ...
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D-mannose is a natural and biologically active monosaccharide. It is the C-2 epimer of glucose and a component of a variety of polysaccharides in plants. In addition, D-mannose also naturally exists in some cells of the human body and participates in the immune regulation of cells as a prebiotic. Its good physiological benefits to human health and wide application in the food and pharmaceutical industries have attracted widespread attention. Therefore, in-depth research on preparation methods of D-mannose has been widely developed. This article summarizes the main production methods of D-mannose in recent years, especially the in-depth excavation from biomass raw materials such as coffee grounds, konjac flour, acai berry, etc., to provide new ideas for the green manufacture of D-mannose.
... Studies have reported recovery of simple sugars, primarily glucose and fructose, using enzyme saccharification from commercial food and beverage wastes (Kwan et al., 2018;Park et al., 2009). Some additional examples of sugars produced during saccharification include xylose, found in xylan, arabinose, found in arabinoxylans (Gupta et al., 2013), galactose, found in milk products, mannose, produced during the depolymerisation of hemicellulose (Hu et al., 2016) and xylulose, formed as isomerisation of xylose during hydrolysis (Bhaumik and Dhepe, 2015). ...
... Recovery of sugar-rich effluents from anaerobic fermentation of food waste has been discussed in the literature and extraction of these reducing sugars could present an opportunity for valorisation (Dahiya et al., 2018). Sugars released in enzyme hydrolysis are ideal substrates for producing alcohols, organic acids and a wide range of biochemicals and biobased products (Sawatdeenarunat et al., 2016) with applications spanning sectors including food, beverage and pharmaceutical industries, as a source of dietary fibre and as a starting material in drug synthesis (Hu et al., 2016). However, a major challenge in the production of sugars is their separation from other sugars (Werpy et al., 2004). ...
Article
Anaerobic digestion is a promising technology as a renewable source of energy products, but these products have low economic value and process control is challenging. Identifying intermediates formed throughout the process could enhance understanding and offer opportunities for improved monitoring, control, and valorisation. In this review, intermediates present in the anaerobic digestion process are identified and discussed, including the following: volatile fatty acids, carboxylic acid, amino acids, furans, terpenes and phytochemicals. The key limitations associated with exploiting these intermediates are also addressed including challenging mixed cultures of microbiology, complex feedstocks, and difficult extraction and separation techniques.
... Перспективным терапевтическим подходом является использование антиадгезионных агентов, таких как D-манноза [10,14,17,21,22]. Термин «манноза» происходит от библейского термина «манна» [23]. ...
... Термин «манноза» происходит от библейского термина «манна» [23]. Согласно Библии, манна -некая сладкая субстанция, которую израильтяне получали во время передвижения по Синайскому полуострову [22]. D-манноза -природный сахар альдогексоза, отличаю щийся от глюкозы инверсией одного из 4 хиральных центров молекулы: атома углерода во втором положении. ...
Article
Worldwide, urinary tract infections (UTIs) are reported in 150-250 million people per year. Annual direct and indirect costs of UTIs for overall patients are estimated to be from $2.4 billion to $3.5 billion Uropathogenic Escherichia coli is the most common cause of UTIs. These bacteria have the ability to colonize urothelium, persist in epithelial cells, and form quiescent biofilms. This bacterial reservoir may provide a source for bacterial persistence and UTIs recurrence. Besides, recurrent UTIs may be caused by the translocation of other bacteria which originate from the gastrointestinal tract or reinfections due to external sources. Menopause and pregnancy are considered as complicating factors that predispose to UTIs. Oral vaccine OM-89 and D-mannose are specified in the European Urological Association guidelines among non-pharmacological methods for the prevention of recurrent UTIs in postmenopausal women. The rationale to the use of D-mannose in UTI prophylaxis is based on its competitive inhibition of bacterial adherence to urothelial cells due to binding of type 1 fimbriae expressed on the bacteria. Exogenous D-mannose is absorbed, but not metabolized by the human body and it is excreted intact in urine. In vivo and in vitro studies showed the ability of mannose-like molecules to provide a 2-fold reduction of bacterial load in the urinary tract after 4 intravesical instillations. Clinical studies also demonstrated a high efficacy of the six months course of oral mannose in the prevention of UTIs.
... It can cause high energy consumption, byproduct formation, complex downstream purification, and environmental pollution. By contrast, enzyme method can produce mannose at a mild condition with eco-friendliness and high efficiency, and has attracted increasing attention [15]. There are four main types of enzymes which produce mannose: D-mannose isomerase (EC 5.3.1.7), ...
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d-Mannose isomerase can reversibly catalyze d-fructose to d-mannose which has various beneficial effects. A novel d-mannose isomerase gene (PsMIaseA) from Pseudomonas syringae was cloned and expressed in Escherichia coli. The recombinant d-mannose isomerase (PsMIaseA) showed the highest amino acid sequence homogeneity of 50% with ManI from Thermobifda fusca. PsMIaseA was purified through Ni-NTA chromatography, and its specific activity was 818.6 U mg–1. The optimal pH and temperature of PsMIaseA were pH 7.5 and 45 °C, respectively. The enzyme was stable within a wide pH range from 5.0 to 10.0. It could efficiently convert d-fructose to d-mannose without any metal ions. When PsMIaseA was incubated with 600 g/L d-fructose for 6 h, the space-time yield of d-mannose reached 27.2 g L–1 h–1 with a maximum conversion ratio of 27%. Therefore, the d-mannose isomerase may be suitable for green production of d-mannose.
... D-mannose, a C-2 epimer of D-glucose, is an important monosaccharide for human metabolism, and it is primarily found in mannan, cellulose, and hemicellulose [113]. Dmannose has not been widely used as a starting material for synthesizing ILs: From 2011 to now, only a handful of reports can be found in the literature [32,33,80,100]. ...
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Carbohydrates represent a promising option in transitioning from oil-based chemical resources to renewable ones, with the goal of developing chemistries for a sustainable future. Cellulose, hemicellulose, and largely available monosaccharides already provide useful chemical building blocks, so-called platform chemicals, such as levulinic acid and hydroxymethyl furfural, as well as solvents like cyrene or gamma-valerolactone. Therefore, there is great anticipation for novel applications involving materials and chemicals derived from sugars. In the field of ionic liquids (ILs), sugar-based ILs have been overlooked for a long time, mainly on account of their multistep demanding preparation. However, exploring new strategies for accessing sugar-based ILs, their study, and their exploitation, are attracting increasing interest. This is due to the growing concerns about the negative (eco)toxicity profile of most ILs in conjunction with their non-sustainable nature. In the present review, a literature survey concerning the development of sugar-based ILs since 2011 is presented. Their preparation strategies and thermal behavior analyses, sorted by sugar type, make up the first two sections with the intention to provide the reader with a useful guide. A final overview of the potential applications of sugar-based ILs and their future perspectives complement the present analysis.
... Photosynthetic pigments present in microalgae cells show great potential as food supplements (Smetana et al., 2017). Moreover, some microalgae species present cell walls with a high content of mannose (Baudelet et al., 2017), which is a pentose that has been used in the food, feed, and pharmaceutical industries; and only a few vascular plants and microorganisms present a high content of mannose (Hu et al., 2016;Soares et al., 2016). ...
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The establishment of microalgae as a sustainable source of bioproducts requires a detailed evaluation of unit operations that compose a biorefinery. Biorefining of microalgal biomass is performed in sequence for obtaining a diversity of valuable compounds, but the optimum sequence of biorefining still under scrutiny. Herein, detailed modeling of unit operations was performed to enhance the extraction of neutral carbohydrates, crude lipids, and photosynthetic pigments from the wet biomass (slurry) of the microalga Scenedesmus obliquus BR003. Concentrated sulfuric acid hydrolysis resulted in an optimized extraction yield of 93% at temperature of 80 °C, 1.5 mol L-1 of sulfuric acid solution, and retention time of 120 s. Temperature and retention time were important parameters to increase the extraction of neutral carbohydrates using concentrated sulfuric acid. The efficiency of the multistage extraction of crude lipids was drastically decreased by high biomass-to-solvent ratios, and the use of proper mixing systems and longer mixing times increased the efficiency of this unit operation. The highest lipid content was achieved using orbital shaker (210.1 ± 10.9 mg g-1), retention time of 55 min, and biomass-to-solid ratio of 6.6% (w w-1). The extraction of chlorophylls a and b, and total carotenoids could be described by sigmoidal functions between the extraction yields and ratios of ethanol to the microalgal slurry, hence high levels of ethanol were required to efficiently extract them. The minimum ratio of ethanol to microalgae slurry necessary to efficiently extract photosynthetic pigments from the slurry of S. obliquus BR003 was 0.8:0.2 in volume, and this condition allowed the extraction resulted in extraction yields from 84 to 100%.
... Futhermore, weaning stress leads to intestinal damage and being more susceptible to pathogen infection (Hu et al. 2015;Wan et al. 2016;Che et al. 2017). TFE contains polysaccharides that are responsible for anti-inflammation and immunomodulation (Jiang et al. 2012;Hu et al. 2016). In agreement with a previous study (Lee et al. 2016), we found T. fuciformis extract could suppress the inflammatory response via reducing the levels of LPS-induced IL-1β, IL-6 and TNF-α. ...
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Context In-feed antibiotics are commonly used to improve growth and gut health of weaning pigs. Due to anti-microbial resistance by extensively using antibiotics, however, in-feed antibiotics have been banned in Europe and China. Tremella fuciformis is a traditional edible fungus in China. Recent studies have found that Tremella fuciformis extract (TFE) has anti-inflammatory, anti-cancer and immune-modulatory functions. Therefore, there is the potential to develop Tremella fuciformis as an alternative to antibiotics. Aims The study was performed to explore the effects of TFE on growth performance, and biochemical and immunological parameters of weaned piglets under lipopolysaccharide (LPS) challenge. Methods Forty-eight weaned piglets were assigned into two groups with six pens (four piglets per-pen), receiving a control diet or a control diet with 400 mg/kg TFE (TFE), respectively. After 28 days of the trial, two piglets per pen were selected to be injected with LPS (50 μg/kg of BW) or an equivalent amount of sterile saline. Blood samples were collected at 0 and 3 h after LPS challenge. Key results The results showed that TFE supplementation significantly increased the average daily gain (P < 0.05) and decreased the faecal score (P < 0.05) during the first week, improved the feed conversion ratio (P < 0.05) and BWt gain (P < 0.05) during the whole period. Piglets fed the TFE diet had higher plasma levels of white blood cells (P < 0.05) than that of piglets fed the control diet diet before the LPS challenge. Regardless of the dietary treatment, the LPS challenge significantly decreased the level of white blood cells, and increased the levels of red blood cells, haemoglobin, haematocrit, total protein, interleukin-1β and tumour necrosis factor-α (all P < 0.05). Regardless of the LPS challenge, however, the concentrations of total protein, interleukin-1β and tumour necrosis factor-α were decreased (all P < 0.05) in the plasma of piglets fed the TFE diet compared with the control diet diet. Conclusions In summary, the supplementation of TFE in the weaning diet could improve the growth performance and immunity of piglets. Implication TFE could be used as a bioactive substance for improving growth and immune response in pig production.
... In accordance with the report of Hu [31], who reported that UTI occurs in all age groups, the same trend was evident in this study as the six age groups to which the patients were grouped into had cases of UTIs. The highest incidence of UTI in this study was however observed in the elderly population within age groups 61-80 and 81-100 years with 62 (51.67%) patients; which is in line with the study of Cove and Almond [32] who reported that UTI cases are more predominant in the elderly population as against the younger generation. ...
Article
Infection of the urinary tract ranks as one of the most common infections affecting people worldwide and its treatment is made complicated by the rising incidence of antibiotic resistance. This study aimed to detect extended spectrum beta-lactamase (ESBL) genes and antibiotic resistance profile of uropathogenic Escherichia coli ( E. coli ) recovered from patients attending a University Teaching hospital in Nigeria. Uropathogenic E. coli isolates were obtained from the culture collection of Department of Microbiology and Parasitology of the University Teaching hospital for a period of four months (October 2019–January, 2020). Antibiotic susceptibility testing was done using the disc diffusion method while phenotypic ESBL production was detected using double disc synergy test (DDST). Detection of β-lactamase genes was done using Real-Time PCR. Forty-nine E. coli isolates were recovered from 120 urine samples, with 24 (49%) being ESBL positive. The resistance to antibiotics in the ESBL producers was: ciprofloxacin (100%), cefotaxime (100%), cefpodoxime (100%), tetracycline (95.7%), ceftazidime (56.7%), amoxicillin-clavulanate (50%), gentamicin (33.3%), and imipenem (0%). All the ESBL producers carried bla TEM , bla CTX-M-1 and bla CTX-M-9 , 75% (18/24) carried bla SHV , while bla CTX-M-2 , bla CTX-M-8 and bla CTX-M-25 groups were detected in 20.8% (5/24) of the isolates. There was co-occurrence of CTX-M, SHV and TEM β-lactamases in 79.2% (19/24) isolates, while five isolates (20.8%) co-harbored bla CTX-M and bla TEM . This study showed a high level of multidrug resistance and ESBL gene carriage in uropathogenic E. coli obtained in this study, suggesting a likely review of therapeutic options in the treatment of UTI to clamp down on the rising cases of antibiotic resistance.
... In the treatment of recurrent UTIs (Altarac and Papeš, 2014) Starting material for the synthesis of drugs and blocks colonization in animal feeds ( Xing et al., 2016). 6. ...
Article
The ethnomedicinal plant extract of Trillium govanianum was assessed for its antimicrobial activity and for the presence of phytochemicals to provide scientific support for its ethnomedicinal use. Ethanolic rhizome extract of the plant was used for the antibacterial study and displayed a maximum inhibition zone against a standard isolate of K. pneumoniae (16.66 ± 0.57) followed by an inhibition zone against clinical isolate of K.pneumoniae (16.33 ± 0.57) at 200 μg/disc. The antimicrobial activity of plant rhizome extract was observed against five pathogenic microbial strains, with both standard strains and clinical isolates viz. Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium and Pseudomonas aeruginosa. Standard analysis of phytochemicals in the plant showed the presence of flavonoids, cardiac glycosides, alkaloids, reducing sugars and saponins, however, tannins were found to be absent. In GC-MS profiling the plant rhizome extract showed the presence of important compounds possessing antibacterial, anticancer, antioxidant and antiinflammatory properties. DPPH and FRAP assays showed optimum antioxidant potential of the plant. Antimicrobial and phytochemical investigation of the plant rhizome extract revealed therapeutic potential of Trillium govanianum, thus scientifically supporting its ethnomedicinal use.
... D-mannose is found naturally in small quantities in numerous food sources, such as coffee, baker's yeast, egg white, fruits such as apples, cranberries and mangos, and also in legumes such as soybeans, kidney beans and peanuts. 19 It is absorbed in the upper gastrointestinal tract and excreted in the urine. 14 D-mannose may offer an alternative to antibiotic prophylaxis in women who experience RUTI and in turn to contribute to better antimicrobial stewardship in primary care. ...
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Introduction Recurrent urinary tract infections (RUTIs) have a significant negative impact on quality of life and healthcare costs. To date, daily prophylactic antibiotics are the only treatment which have been shown to help prevent RUTIs. D-mannose is a type of sugar which is believed to inhibit bacterial adherence to uroepithelial cells, and is already being used by some women in an attempt to prevent RUTIs. There is currently insufficient rigorous evidence on which to base decisions about its use. The D-mannose to prevent recurrent urinary tract infections (MERIT) study will evaluate whether D-mannose is clinically and cost-effective in reducing frequency of infection and symptom burden for women presenting to UK primary care with RUTI. Methods and analysis MERIT will be a two-arm, individually randomised, double blind placebo controlled, pragmatic trial. Participants will be randomised to take D-mannose powder or placebo powder daily for 6 months. The primary outcome will be the number of medical attendances attributable to symptoms of RUTI. With 508 participants we will have 90% power to detect a 50% reduction in the chance of a further clinically suspected UTI, assuming 20% lost to follow-up. Secondary outcomes will include: number of days of moderately bad symptoms of UTI; time to next consultation; number of clinically suspected UTIs; number of microbiologically proven UTIs; number of antibiotic courses for UTI; quality of life and healthcare utilisation related to UTI. A within trial economic evaluation will be conducted to examine cost-effectiveness of D-mannose in comparison with placebo. A nested qualitative study will explore participants’ experiences and perceptions of recruitment to, and participation in a study requiring a daily treatment. Ethics and dissemination Ethical approval has been obtained from South West-Central Bristol Research Ethics Committee. Publication of the MERIT study is anticipated to occur in 2021. Trial registration number ISRCTN 13283516.
... Mannose, a C2epimer of D-glucose, is considered a natural bioactive monosaccharide and one of the major carbohydrates of glycoprotein participating in N-glycosylation reactions [1]. Mannose can be obtained from both plants and microorganisms, while the majority of mannose comes from endogenous production [2,3]. Moreover, the physiological blood concentration of mannose in humans is about 50 microM derived from N-glycon processing [4]. ...
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Background: There is a handful of controversial data from observational studies on the serum levels of mannose and risks of coronary artery disease (CAD) and other cardiometabolic risk factors. We applied Mendelian Randomization (MR) analysis to obtain estimates of the causal effect of serum mannose on the risk of CAD and on cardiometabolic risk factors. Methods: Two-sample MR was implemented by using summary-level data from the largest genome-wide association studies (GWAS) conducted on serum mannose and CAD and cardiometabolic risk factors. The inverse variance weighted method (IVW) was used to estimate the effects, and a sensitivity analysis including the weighted median (WM)-based method, MR-Egger, MR-Pleiotropy RESidual Sum and Outlier (PRESSO) were applied. Radial MR Methods was applied to remove outliers subject to pleiotropic bias. We further conducted a leave-one-out analysis. Results: Mannose had no significant effect on CAD (IVW: odds ratio: 0.96 (95% Confidence Interval (95%CI): 0.71−1.30)), total cholesterol (TC) (IVW: 95%CI: 0.60−1.08), low density lipoprotein (LDL) (IVW: 95%CI = 0.68−1.15), high density lipoprotein (HDL) (IVW: 95%CI = 0.85−1.20), triglycerides (TG) (IVW: 95%CI = 0.38−1.08), waist circumference (WC) (IVW: 95%CI = 0.94−1.37), body mass index (BMI) (IVW: 95%CI = 0.93−1.29) and fasting blood glucose (FBG) (IVW: 95%CI = 0.92−1.33), with no heterogeneity for CAD, HDL, WC and BMI (all p > 0.092), while a significant heterogeneity was observed for TC (IVW: Q = 44.503), LDL (IVW: Q = 33.450), TG (IVW: Q = 159.645) and FBG (IVW: Q = 0. 32.132). An analysis of MR-PRESSO and radial plots did not highlight any outliers. The results of the leave-one-out method demonstrated that the links were not driven by a single instrument. Conclusions: We did not find any effect of mannose on adiposity, glucose, TC, LDL, TG and CAD.
... Xylitol has received global demand mainly due to its anti-cariogenecity activities, substitute of glucose for insulino-dependent diseases, pharmacological properties and high sweetening power [86]. Mannose, present in hemicelluloses extracted from softwoods, have large interest in chemistry, health, food and biotechnology with new profitable markets [87]. Finally furfural, which is produced by the catalytic dehydration of xylose, was considered as one of the best chemical synthons in synthetic organic chemistry. ...
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In this review, we highlight our recent developments on the formic acid refining of lignocellulosic biomass and how it can be an innovative way to produce sustainable hydrogen and fuels. There is a worldwide high demand for green energy and green chemistry endeavors to drastically slow down climate change in accord with the COP 21. This review mainly focuses on the deconstruction of the lignocellulosic biomass, using formic acid-based mixtures, into its 3 main components and how they can be the new resources for hydrogen, fuels, and products in the 21st century. We are underlining the natural carbon capture in the form of atmospheric CO2 concentrated into lignocellulosic biomass wastes from the forest and agricultural land sites and the subsequent low energy organic extraction of cellulose, lignin, and hemicelluloses. We illustrate in this review that our dependence on fossil fuels will be greatly reduced, and that atmospheric CO2, sunlight and water will provide safe energy and products for future generations. Graphic Abstract
... d-mannose is an epimer of d-glucose with the isomerization at the C-2 position [1]. It is in a free state in various fruit peels including orange, peach, and apple. ...
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d-mannose has exhibited excellent physiological properties in the food, pharmaceutical, and feed industries. Therefore, emerging attention has been applied to enzymatic production of d-mannose due to its advantage over chemical synthesis. The gene age of N-acetyl-d-glucosamine 2-epimerase family epimerase/isomerase (AGEase) derived from Pseudomonas geniculata was amplified, and the recombinant P. geniculata AGEase was characterized. The optimal temperature and pH of P. geniculata AGEase were 60 °C and 7.5, respectively. The Km, kcat, and kcat/Km of P. geniculata AGEase for d-mannose were 49.2 ± 8.5 mM, 476.3 ± 4.0 s−1, and 9.7 ± 0.5 s−1·mM−1, respectively. The recombinant P. geniculata AGEase was classified into the YihS enzyme subfamily in the AGE enzyme family by analyzing its substrate specificity and active center of the three-dimensional (3D) structure. Further studies on the kinetics of different substrates showed that the P. geniculata AGEase belongs to the d-mannose isomerase of the YihS enzyme. The P. geniculata AGEase catalyzed the synthesis of d-mannose with d-fructose as a substrate, and the conversion rate was as high as 39.3% with the d-mannose yield of 78.6 g·L−1 under optimal reaction conditions of 200 g·L−1d-fructose and 2.5 U·mL−1P. geniculata AGEase. This novel P. geniculata AGEase has potential applications in the industrial production of d-mannose.
... Mannose is an important sugar component of mannoproteins, celluloses and hemicelluloses. Arabinose and galactose can be derived from arabinogalactans, being highly ubiquitous in plants, and xylose from the xyloglucan backbone of the primary wall and the middle lamella [24,45]. These sugars were used as the sole carbon source in a solid medium culture of the two endophytes. ...
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Endophytic fungi that colonize the plant root live in an environment with relative high concentrations of different sugars. Analyses of genome sequences indicate that such endophytes can secrete carbohydrate-related enzymes to compete for these sugars with the surrounding plant cells. We hypothesized that typical plant sugars can be used as carbon source by root endophytes and that these sugars also serve as signals to induce the expression and secretion of glycolytic enzymes. The plant-growth-promoting endophytes Serendipita indica and Serendipita herbamans were selected to first determine which sugars promote their growth and biomass formation. Secondly, particular sugars were added to liquid cultures of the fungi to induce intracellular and extracellular enzymatic activities which were measured in mycelia and culture supernatants. The results showed that both fungi cannot feed on melibiose and lactose, but instead use glucose, fructose, sucrose, mannose, arabinose, galactose and xylose as carbohydrate sources. These sugars regulated the cytoplasmic activity of glycolytic enzymes and also their secretion. The levels of induction or repression depended on the type of sugars added to the cultures and differed between the two fungi. Since no conventional signal peptide could be detected in most of the genome sequences encoding the glycolytic enzymes, a non-conventional protein secretory pathway is assumed. The results of the study suggest that root endophytic fungi translocate glycolytic activities into the root, and this process is regulated by the availability of particular plant sugars.
... For glucose, all four OH groups are equatorially oriented. Mannose and galactose are important natural products mainly found in plant sources, 43,44 and they both are C-2 and C-4 epimers of glucose, respectively, where the OH group is axially positioned at C-2 in the former and at C-4 in the latter. From density functional theory calculations, the intramolecular HBs of these epimerically related glycolipids define conventional HBs which were reported to be more stable than the nonconventional ones. ...
Article
The lyotropic phase behavior of four common and easily accessible glycosides, n-octyl α-d-glycosides, namely, α-Glc-OC8, α-Man-OC8, α-Gal-OC8, and α-Xyl-OC8, was investigated. The presence of normal hexagonal (HI), bicontinuous cubic (VI), and lamellar (Lα) phases in α-Glc-OC8 and α-Man-OC8 including their phase diagrams in water reported previously was verified by deuterium nuclear magnetic resonance (2H NMR), via monitoring the D2O spectra. Additionally, the partial binary phase diagrams and the liquid crystal structures formed by α-Gal-OC8 and α-Xyl-OC8 in D2O were constructed and confirmed using small- and wide-angle X-ray scattering and 2H NMR. The average number of bound water molecules (nb) per headgroup in the Lα phase was determined by the systematic measurement of the quadrupolar splitting of D2O over a wide range of molar ratio values (glycoside/D2O), especially at high glucoside composition. The number of bound water molecules bound to the headgroup was found to be around 1.5-2.0 for glucoside, mannoside, and galactoside, all of which possesses four OH groups. In the case of xyloside, which has only three OH groups, the bound water content is ∼2.0. Our findings confirmed that the bound water content of all n-octyl α-d-glycosides studied is lower compared to the number of possible hydrogen bonding sites possibly due to the fact that most of the OH groups are involved in intralayer interaction that holds the lipid assembly together.
... As mannose is a reducing sugar, it is hypothesized that build-up of mannose in bound form with SALT inside the cell will result in increased cellular osmotic potential and thereby confers salinity stress tolerance to plants. However, in normal situation, the levels of free mannose are very low in the cell cytoplasm due to its fast metabolism which offsets our hypothesis 36 . Many of these pending queries can be addressed in future by taking insights from the structural analysis of SALT protein by our group and other researchers in the field. ...
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Abstract Salinity is one of the major stresses affecting rice production worldwide, and various strategies are being employed to increase salt tolerance. Recently, there has been resurgence of interest to characterize SalTol QTL harbouring number of critical genes involved in conferring salt stress tolerance in rice. The present study reports the structure of SALT, a SalTol QTL encoded protein by X-ray crystallography (PDB ID: 5GVY; resolution 1.66 Å). Each SALT chain was bound to one mannose via 8 hydrogen bonds. Compared to previous structure reported for similar protein, our structure showed a buried surface area of 900 Å2 compared to only 240 Å2 for previous one. Small-angle X-ray scattering (SAXS) data analysis showed that the predominant solution shape of SALT protein in solution is also dimer characterized by a radius of gyration and maximum linear dimension of 2.1 and 6.5 nm, respectively. The SAXS profiles and modelling confirmed that the dimeric association and relative positioning in solution matched better with our crystal structure instead of previously reported structure. Together, structural/biophysical data analysis uphold a tight dimeric structure for SALT protein with one mannose bound to each protein, which remains novel to date, as previous structures indicated one sugar unit sandwiched loosely between two protein chains.
... Considering the structure of mannose 25 , there's no binding site available for DSS, in other words, the direct binding of mannose to DSS is rarely possible. It was previously reported that mannose enters epithelial cells via the Na + -dependent transport system 26 . ...
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Metabolite alteration has been associated with the pathogenesis of inflammatory bowel disease (IBD), including colitis. Mannose, a natural bioactive monosaccharide that is involved in metabolism and synthesis of glycoproteins, exhibits anti-inflammatory and anti-oxidative activities. We show here that the circulating level of mannose is increased in patients with IBD and mice with experimental colitis. Mannose treatment attenuates intestinal barrier damage in two mouse colitis models, dextran sodium sulfate (DSS)-induced colitis and spontaneous colitis in IL-10 -deficient mice. We demonstrate that mannose treatment enhanced lysosomal integrity and limited the release of cathepsin B, preventing mitochondrial dysfunction and myosin light chain kinase (MLCK)-induced tight junction disruption in the context of intestinal epithelial damage. Mannose exerts a synergistic therapeutic effect with mesalamine on mouse colitis. Cumulatively, the results indicate that mannose supplementation may be an optional approach to the treatment of colitis and other diseases associated with intestinal barrier dysfunction.
... About 60 min after ingestion, it arrives unchanged in the urinary tract. D-mannose also has no effect on human metabolism after long-term use (16,17). ...
Article
Several studies, reviews and meta-analyses have documented that D-mannose use lowers the risk of recurrent urinary tract infections (UTI), but its role in the treatment of UTI/cystitis-related symptoms is unclear. In particular, no systematic review has analyzed the role of treatment with D-mannose in acute UTI/cystitis. In this paper, we systematically reviewed the published data on the effect of D-mannose, alone or in association with other compounds, on the typical symptoms of UTI/cystitis. PubMed/Medline and EMBASE databases were searched, from 1990 to January 2022, using combinations of the following keywords: 'urinary tract infections', 'cystalgia', 'recurrent next urinary tract infection', 'cystitis', 'mannose', 'mannoside', 'D-mannose', 'bacteriuria', 'pyuria', 'pyelocystitis' with the appropriate Boolean modifiers (Limits: Human, English, full article). Studies were selected for the systematic review if they were clinical studies and reported original data, the number of patients using D-mannose alone or in association with other treatments, and the number of patients with symptoms of UTI/cystitis at trial entry and after the follow-up period. A total of seven studies were identified. D-mannose was given alone in two studies, and was associated with cranberry extract, Morinda citrifolia fruit extract, pomegranate extract, fructo-oligosaccharides, lactobacilli, and N-acetylcysteine in the others. All studies reported that symptoms decreased after treatment with D-mannose. Despite the limitations of the studies, the consistent results observed among all studies give support to the general findings that D-mannose may be useful in the treatment of UTI/cystitis symptoms.
... Both, the presence of pre-slaughter stress and high pH u leads to higher mitochondrial stability and its respiratory rate, leading to decrease of myoglobin oxygenation and development of darker color in DFD beef (Wu et al., 2020). Lower level of D-mannose in the typical DFD beef could be due to lower levels of glycogen, which is source of glucose and D-mannose (Hu et al., 2016). ...
Article
This study explored the changes in postmortem metabolites of atypical and typical DFD beef using UHPLC-Q-TOF/MS. The longissimus thoracis muscles were categorized into normal, atypical DFD and typical DFD groups. The L⁎, a⁎, b⁎, glycogen and lactic acid contents were lower (P < 0.05) in typical DFD than normal beef. A total of 240 compounds were significantly different among groups. Levels of glycerol-3-phosphate, d-ribose-5-phosphate, d-glucose-6-phosphate, d-fructose-6-phosphate, alpha-d-glucose-1-phosphate and dihydroxyacetone phosphate were higher in atypical DFD than those in the normal and typical DFD beef and the contents of 9 amino acids were elevated in typical DFD. KEGG analysis showed that metabolomic changes were primarily related with ATP-binding cassette transporters, metabolism of purine, central carbon, glycine, serine and threonine, biosynthesis of aminoacyl-tRNA, digestion and absorption of proteins, metabolism of amino sugar and nucleotide sugar, pyrimidine, bile secretion and galactose. In conclusion, development of atypical and typical DFD meat results in differences at level of postmortem metabolite concentrations of different metabolic pathways.
... Mannose content of different biomass sources was summarized by Hu et al. [48]. Spent coffee grounds have the highest mannose content in literature (21.2% on dry weight basis), followed by baker's yeast (16%), Chinese jujube (12.9%), and orange peel (6.1%). ...
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In this study, for the first time, polyphenols are extracted using microwave-assisted deep eutectic solvents (MW-DES) from supercritical CO2 defatted date seeds under variable operating conditions. The best conditions consisted of choline chloride: formic acid (1:2 molar ratio), a solid to solvent ratio of 1/20 (g/mL) (0.75 g of dry biomass in 15 mL solvent), an extraction time of 50 s, and a microwave power of 400 W. The maximum polyphenols extraction yield was 128 g gallic acid equivalent/kg dry biomass (g GAE/kg) (which is the highest value ever reported in literature for date seeds extracts). The antioxidant activity of the optimum extracts was assessed with the DPPH and ABTS quenching capacities being equal to 27 and 145 mg trolox equivalent/g dry biomass, respectively. Mainly mannose and manno-oligosaccharides were solubilized during extraction. The highest yields were (obtained at 200 W, 120 s) 35.07 and 32.18 mg/g of dry biomass for mannose and manno-oligosaccharides, respectively. It was also observed that the total mannose (monomer and oligomer) release during the extraction increased linearly (r2 = 0.9951) with respect to microwave energy applied per gram of date seeds (J/g).
... This sugar is a dextrorotatory hexose aldehyde/aldose monosaccharide found in certain bacteria, fungi, and plants, and is rarely present in nature as a free monosaccharide. Nevertheless, it is a constituent of numerous simple and complex polysaccharides and is mostly found in nature as a component of mannan, hemicellulose, and cellulose in dietary fiber (Hu et al., 2016). For example, it constitutes the basic molecule of mannans, the reserve polysaccharides of some plant species (e.g., palm), or is associated with galactose (mannogalactans) to form gummy mucilages that protect the seeds of some plants (e.g., carob); they are widely used as stabilizers of food products such as ice cream and mayonnaise. ...
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In this study, the genomes of the Weissella (W.) beninensis, W. diestrammenae, W. fabalis, W. fabaria, W. ghanensis, and W. uvarum type strains were sequenced and analyzed. Moreover, the ability of these strains to metabolize 95 carbohydrates was investigated, and the genetic determinants of such capability were searched within the sequenced genomes. 16S rRNA gene and genome-based-phylogeny of all the Weissella species described to date allowed a reassessment of the Weissella genus species groups. As a result, six distinct species groups within the genus, namely, W. beninensis, W. kandleri, W. confusa, W. halotolerans, W. oryzae, and W. paramesenteroides species groups, could be described. Phenotypic analyses provided further knowledge about the ability of the W. beninensis, W. ghanensis, W. fabaria, W. fabalis, W. uvarum, and W. diestrammenae type strains to metabolize certain carbohydrates and confirmed the interspecific diversity of the analyzed strains. Moreover, in many cases, the carbohydrate metabolism pathway and phylogenomic species group clustering overlapped. The novel insights provided in our study significantly improved the knowledge about the Weissella genus and allowed us to identify features that define the role of the analyzed type strains in fermentative processes and their biotechnological potential.
... It can be used as a food supplement, biological recognition anchor in drug design, or blocking colonization in animal feeds. 22,23 It is also directly involved in the biological recognition of mannanbinding lectins that form part of the immune system, and its application for biobased nanocarriers is of vital importance. Mannose receptors are also expressed on alveolar macrophages, target for the treatment of diseases such as tuberculosis, or possess a critical role in phagocytosis through Ctype lectin membrane receptors. ...
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Sugar-based amphiphiles are a relevant natural alternative to synthetic ones due to their biodegradable properties. An understanding of their structure–assembly relationship is needed to allow the concrete synthesis of suitable derivatives. Here, four different mannose-derivative surfactants are characterized by pendant drop, dynamic light scattering, small-angle X-ray scattering, cryotransmission electron microscopy, and molecular dynamics techniques in aqueous media. Measurements denote how the polysaccharide average degree of polymerization () and the addition of a hydroxyl group to the hydrophobic tail, and thus the presence of a second hydrophilic moiety, affect their self-assembly. A variation in the of the amphiphile has no effect in the critical micelle concentration in contrast to a change in the hydrophobic molecular region. Moreover, high- amphiphiles self-assemble into spherical micelles irrespective of the hydroxyl group presence. Low- amphiphiles with only one hydrophilic moiety form cylindrical micelles, while the addition of a hydroxyl group to the tail leads to a spherical shape.
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Production of cellulosic ethanol from lignocellulosic biomass leads to the generation of a hemicellulosic hydrolysate during the feedstock pretreatment. This hydrolysate is rich in sugars, but also contains inhibitory compounds (mainly acetic acid and phenolic compounds) in concentrations that may be toxic to microbial growth. Currently, this side-stream of the cellulosic ethanol production process is processed as a waste, due to the lack of feasible alternatives for tackling the complexity of wood hemicellulosic hydrolysate. Thus, this work evaluated the ability of six microorganisms to metabolize the raw and detoxified hemicellulosic hydrolysate produced from Pinus taeda for the production of lactic acid, ethanol, xylitol, single-cell protein, lipids and carotenoids, with the aim of selecting a potential alternative for valorization of this side stream generated during the production of cellulosic ethanol contributing to the implementation of a sustainable advanced biorefinery. The tested microorganisms included a lactic acid bacterium, Bacillus coagulans; a probiotic bacterium, Lactobacillus salivarius; two oleaginous yeasts, Rhodosporidium toruloides and Saitoella coloradoensis; a thermotolerant yeast, Kluyveromyces marxianus; and a methylotrophic yeast, Hansenula polymorpha. L. salivarius, K. marxianus, and H. polymorpha showed promising ability to metabolize the partially detoxified hydrolysate (composed of (g/L): mannose, 29.27; glucose, 17.25; galactose, 6.18; xylose, 4.94; arabinose, 1.23; acetic acid, 7.99; formic acid, 4.86; levulinic acid, 4.04; 5-hydroxymethylfurfural, 0.74; total phenolic compounds, 0.40). On the other hand, the oleaginous yeasts and B. coagulans presented high sensitivity to the inhibitory compounds. L. salivarius produced lactic acid with high yield (1.1 g/g), which was limited by product inhibition. K. marxianus produced xylitol at 0.37 g/g xylose and ethanol at 0.19 g/g hexoses. Finally, H. polymorpha converted hexoses and acetic acid into single-cell protein with yield of 0.27 g/g. The production of lactic acid by L. salivarius proved to be a promising alternative for valorization of Pinus hemicellulosic hydrolysate in an ethanol biorefinery.
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Titanium oxide nanoparticles modified with D-(+)-mannose were obtained. In the process of their formation, they were conjugated with an active substance (tadalafil). The physicochemical properties of the obtained products were assessed, and the size and electrokinetic potential were determined using a dynamic light scattering technique. X-ray diffractometry was applied in order to define the crystalline properties, and Fourier-transform infrared spectroscopy was used to confirm the formation of the desired products. It was possible to obtain TiO 2 coated with D-(+)-mannose. The average size of nanoparticles was between 230 and 268 nm. The release of the active substance from the product over a time period of three hours was assessed against the reference material, which was not modified by D-(+)-mannose. The results indicate that covering titanium oxide nanoparticles with the modifying substance favours a slower rate of release for the active substance, which is the desired effect from a pharmacological point of view. The releasing of active substance from modified products was even 68% slower than that from the reference product. These modified titanium oxides are promising materials that may have found an application as drug carriers. Graphic Abstract
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An endo-1,4-β-mannanase gene (manB) from a Bacillus pumilus Nsic-2 grown in a stinky tofu emulsion was cloned and expressed in Pichia pastoris GS115. After characterized, the endo-1,4-β-mannanase (manB) show maximum activity at pH 6.0 and 50 °C with LBG as substrate and perform high stability at a range of pH 6–8. After applying for a shake flask fermentation, the specific activity of manB reached 3462 U/mg. To produce mannose, the soybean meal (SBM) was pretreated by biological fermentation for 11 days with Penicillium brevicompactum, and then hydrolyzed by manB. As a result, mannose yield reached 3.58 g per 1 kg SBM which indicated that 0.358% SBM was converted into mannose after hydrolyzation, and mean a total 20% mannan of SBM converting into mannose, while the control group demonstrated only 1.78% conversion. An effective β-mannanase for the bioconversion of mannan-rich biomasses and an efficient method to produce mannose with soybean meal were introduced. Graphic abstract
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The present supply of prebiotics is entirely inadequate to meet their demand. To produce novel prebiotics, a d-mannose isomerase (XpMIaseA) from Xanthomonas phaseoli was first produced in Komagataella phaffii (Pichia pastoris). XpMIaseA shared the highest amino acid sequence identity (58.0%) with the enzyme from Marinomonas mediterranea. Efficient secretory production of XpMIaseA (282.0 U mL-1) was achieved using high cell density fermentation. The optimal conditions of XpMIaseA were pH 7.5 and 55 °C. It showed a broad substrate specificity, which isomerized d-mannose, d-talose, mannobiose, epilactose, and mannotriose. XpMIaseA was employed to construct a one-pot three-enzyme system for the production of mannosyl-β-(1 → 4)-fructose (MF) using mannan (5%, w/v) as the substrate. The equilibrium yield of MF was 58.2%. In in vitro fermentations, MF significantly stimulated (≤3.2-fold) the growth of 12 among 15 tested Bifidobacterium and Lactobacillus strains compared with fructo-oligosaccharides. Thus, the novel d-mannose isomerase provides a one-pot bioconversion strategy for efficiently producing novel prebiotics.
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The synthesis of mannose is of great value because it is the only glyconutrient for clinical application. Here, we performed the enzymatic bioconversion of D-fructose to D-mannose using a recombinant thermostable N-Acyl-D-glucosamine 2-epimerase (ThMI) from Thermobifida halotolerans engineered strain. The enzymatic bioconversion produced 180 g/L D-mannose from high-concentration D-fructose (500 g/L) in 1 h by recombinant ThMI, resulting in a maximum bioconversion ratio of 35.8%. The recombinant resting cells at a density of 10 OD600 produced 157 g/L D-mannose from 500 g/L D-fructose in 1 h. These results suggest that the novel biocatalyst system developed in this study can be applied for large-scale industrial production of D-mannose.
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Background: Urinary tract infections (UTIs) are very common, affecting more than 7 million people worldwide. Whilst many people may only experience a single episode in their lifetime and are generally responsive to standard antibiotics, a significant proportion of adults and children (approximately 15% to 25%) are chronic symptomatic UTI sufferers. Certain population groups are at greater risk than others, such as immunosuppressed and people with chronic kidney disease. D-mannose is a sugar part of normal human metabolism found within most diets. The mechanism of action is to prevent bacterial adherence to the uroepithelial cells. The D-mannose-based inhibitors can block uropathogenic Escherichia coli adhesion and invasion of the uroepithelial cells. The bacteria are then understood to essentially be eliminated by urination. Early pilot studies on animals and humans have trialled concentrated forms of D-mannose (tablets or sachets) in doses ranging from 200 mg up to 2 to 3 g and found possible efficacy in reducing UTI symptoms or recurrence. Although the anti-adhesive effects of D-mannose have been well-established, only recently have we seen a small number of pilot studies and small clinical trials conducted. Objectives: To assess the benefits and harms of D-mannose for preventing and treating UTIs in adults and children. Search methods: We searched the Cochrane Kidney and Transplant Register of Studies up to 22 February 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. Selection criteria: We included RCTs measuring and reporting the effect of D-mannose, in any combination and any formulation, to prevent or treat UTIs in adults and children, females and males, in any setting (including perioperative). Authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria. Data collection and analysis: Data extraction was independently carried out by two authors using a standard data extraction form. Methodological quality of the included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another author. The certainty of the evidence was assessed using the GRADE approach. Main results: We included seven RCTs (719 participants) in adult females and males who had either acute cystitis or a history of recurrent (at least two episodes in six months or three episodes in 12 months) UTIs (symptomatic or asymptomatic). Two were prevention studies, four were prevention and treatment studies (two perioperative and one in people with multiple sclerosis), and one was a treatment study. Time periods ranged from 15 days to six months. No two studies were comparable (by dose or treatments), and we could not undertake meta-analyses. Individual studies reported no clear evidence to determine whether D-mannose is more or less effective in preventing or treating UTIs. D-mannose (2 g) had uncertain effects on symptomatic and bacteriuria-confirmed UTIs when compared to no treatment (1 study, 205 participants; very low certainty evidence) and antibiotics (nitrofurantoin 50 mg) (1 study, 206 participants; very low certainty evidence). D-mannose, in combination with herbal supplements, had uncertain effects on symptomatic and bacteria-confirmed UTI and pain when compared to no treatment (1 study, 40 participants; very low certainty evidence). D-mannose 500 mg plus supplements (N-acetylcysteine and Morinda citrifolia fruit extract) had uncertain effects on symptomatic and bacteriuria-confirmed UTIs when compared to an antibiotic (prulifloxacin 400 mg) (1 study, 75 participants; very low certainty evidence). Adverse events were very few and poorly reported; none were serious (mostly diarrhoea and vaginal burning). Overall, the quality of the evidence is poor. Most studies were judged to have unclear or high risk of bias across most domains. Data was sparse and addressed very few outcomes. The GRADE evaluation was rated as very low certainty evidence due to very serious limitations in the study design or execution (high risk of bias across all studies) and sparse data (single study data and small sample sizes). Authors' conclusions: There is currently little to no evidence to support or refute the use of D-mannose to prevent or treat UTIs in all populations. This review highlights the severe lack of high-quality RCTs testing the efficacy of D-mannose for UTIs in any population. Despite UTIs being one of the most common adult infections (affecting 50% of women at least once in their lifetime) and the growing global antimicrobial resistance, we found very few studies that adequately test this alternative treatment. Future research in this field requires, in the first instance, a single adequately powered RCT comparing D-mannose with placebo.
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Ascorbic acid (AA) is one of the foremost antioxidants. Unfortunately, its sensitivity to different external stimuli such as light, heat and oxygen are concrete limitations for its use. Various approaches have been investigated in order to circumvent this problem and enhance the stability of the active compound, besides promoting its use for different applications. In this investigation, AA was encapsulated in a vegetal protein-based matrix made up of gliadin, the prolamin obtained from wheat kernels, with the aim of proposing a novel nutraceutical formulation. The nanosystems were characterized by an average diameter of <200 nm and a negative surface charge of ∼-40 mV. The samples were not destabilized after incubation at different temperatures (up to 70°C) or after the pasteurization procedure. Suitable stability was also observed in NaCl 100 mM, as well as after cryodesiccation when 10% w/v of mannose was used. The gliadin nanoparticles showed the ability to retain high amounts of AA, promoting its prolonged release in PBS and under simulated gastrointestinal conditions. The nanosystems enhanced the antioxidant features of the compound as compared to its free form and preserved its chemical stability following UV exposition. The results demonstrate the potential application of the investigated nanoparticles as a novel nutraceutical formulation or as food fortificants.
Chapter
Functional sugars are some of monosaccharides, oligosaccharides, polysaccharides, and sugar alcohols with special care and superior physiological functions on people’s health. Within the emerging development of modern food industry, many functional monosaccharides have been recognized by the public due to the attractive benefits and crucial roles they play in daily life. Different from common monosaccharides named D-glucose and D-fructose used mainly for providing energy, other functional sugars, such as D-mannose, D-tagatose, and D-allulose, possess many excellent properties of low calories and low sweetness, providing vast applications in food, medicinal, and beverage industries (Huang et al. 2018a). For example, D-allulose, generally regarded as safe (GRAS) by the US Food and Drug Administration (FDA), showed physiological functions of suppressing postprandial blood glucose (Hayashi et al. 2010) and anti-hyperlipidemic (Matsuo et al. 2001) and anti-inflammatory effects (Moller and Berger 2003). D-Tagatose also exhibited antidiabetic and obesity effects (Lu et al. 2008), flavor enhancement, and prebiotic and anti-biofilm properties (Bertelsen et al. 1999; Oh 2007).
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Ovalbumin (OVA) is a globular protein found in hen’s eggs that has excellent nutritional and functional properties but is a major allergen. Previous studies have shown that ultrasound pretreatment combined with glycation (sonication-glycation) of OVA markedly reduced its IgG and IgE binding capacities and enhanced its antioxidant activity. In this study, the effects of sonication-glycation on a number of important functional attributes of OVA were studied: foaming, emulsifying, and digestibility. These processes significantly enhanced the foaming and emulsifying properties of OVA by increasing the exposure of hydrophobic residues at the protein surfaces. Moreover, reversed-phase chromatography indicated that sonication-glycation only caused a small decrease in OVA digestibility under simulated gastric and small intestine conditions, and that the level of IgG and IgE binding of OVA was exceedingly low after digestion. Furthermore, sonication promoted the glycation of OVA by increasing the number of exposed glycation sites, as determined by high-resolution mass spectrometry. These results imply that sonication-glycation is a promising method for improving the functional performance of food proteins, while also reducing their immunogenicity.
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D-Mannose can be used as a nutritional supplement due to its physiological functions. It can be directly converted from abundant D-fructose using mannose isomerase (MIase) as a biocatalyst. In this...
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Thromboembolic diseases are a major cause of mortality in human and the currently available anticoagulants are associated with various drawbacks, therefore the search for anticoagulants that have better safety profile is highly desirable. Compounds that are part of the dietary routine can be modified to possibly increase their anticoagulant potential. We show mannose 2,3,4,5,6-O-pentasulfate (MPS) as a synthetically modified form of mannose that has appreciable anticoagulation properties. An in silico study identified that mannose in sulfated form can bind effectively to the heparin-binding site of antithrombin (ATIII) and heparin cofactor II (HCII). Mannose was sulfated using a simple sulfation strategy-involving triethylamine-sulfur trioxide adduct. HCII and ATIII were purified from human plasma and the binding analysis using fluorometer and isothermal calorimetry showed that MPS binds at a unique site. A thrombin inhibition analysis using the chromogenic substrate showed that MPS partially enhances the activity of HCII. Further an assessment of in vitro blood coagulation assays using human plasma showed that the activated partial thromboplastin time (APTT) and prothrombin time (PT) were prolonged in the presence of MPS. A molecular dynamics simulation analysis of the HCII-MPS complex showed fluctuations in a N-terminal loop and the cofactor binding site of HCII. The results indicate that MPS is a promising lead due to its effect on the in vitro coagulation rate.Communicated by Ramaswamy H. Sarma.
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Sustainable industry practices and circular economy concepts encourage the transformation of production waste into by-products. Saccharomyces cerevisiae is widely used in fermentation industry worldwide, generating large amounts of spent yeast which is mainly directed to animal feed or discarded as waste. Instead of becoming and environmental problem, spent yeast can be directed to the extraction of valuable compounds such as mannans and mannan oligosaccharides (MOS). This review presents a compilation of the studies up to date regarding the different chemical, enzymatic, mechanical or physical processes addressed for mannans extraction and MOS production. Additionally, the existing studies on the chemical modification of mannans aimed to improve specific characteristics are also discussed. Finally, the more relevant bioactivities and potential applications of mannans, MOS and mannose are presented, together with products on the market containing these compounds.
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Abiotic stresses impose a huge threat to agricultural productivity and global food security. To counter this challenge, the precise identification of the right candidate gene (s) for conferring abiotic stress tolerance without compromising the growth and yield is crucial. OsSalT is identified as a salt stress responsive gene located on SalTol QTL of chromosome 1 of rice, however, there is no genetic evidence of its function and probable pathway of its regulation. To get better insights into its functioning, earlier we elucidated the structure of SALT protein at atomic scale {PDB ID (5GVY)} and solution state that provided key clues on the probable mode of its action. Herein, we report the modulation of OsSalT gene in response to various factors and its functional characterization. Results indicate that OsSalT operates through both abscisic acid and gibberellic acid-dependent pathways and is linked to the adaptive stress mechanisms of plants. Its overexpression in a model plant resulted in improved salinity and drought stress tolerance. The OsSalT transformed plants also showed vigorous root growth, early flowering, and better seed germination. The triggering of multiple responses by OsSalT suggested that modulation of such mannose-binding lectin could be a potential game-changer for the improvement of many crops in future.
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Desmodesmus sp.YT rich in bioactive substances exhibited impressive tolerance to various environmental conditions. To investigate the metabolism transformation influenced by salt stress in Desmodesmus sp.YT, biochemical compositions and comparative transcriptome were thoroughly explored in this research. Results showed that normal treatment (0‰ salinity) was beneficial for the production of biomass (up to 1.87 times) and protein (up to 1.46 times), compared with salt treatment. Furthermore, differentially expressed genes analysis revealed that vital genes involved in photosynthesis (light-harvesting complexs, LHCs; photosystem II oxygen-evolving enhancer proteins, Psbs), C3 photosynthetic pathway (fructose-bisphosphate aldolase, ALDO; fructose-1,6-bisphosphatase, PFK; phosphoglycerate kinase, PGK) and chlorophyll synthesis (coproporphyrinogen III oxidase, CPOX; porphobilinogen synthase, HemB) were significantly up-regulated in 0‰ salinity, leading to enhanced cell growth. Interestingly, salt stress stimulated the expression of cellulose synthase catalytic subunit A2 (CesA2) and starch synthase (GLGA), increasing the biosynthesis of cellulose (up to 3.23 times) and starch (up to 1.05 times). Results showed that Desmodesmus sp.YT cultured at freshwater could be applied as feed additives while microalgae grown in seawater had the potential for biofuel production for further mass cultivation.
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Phenolic compounds have long been of great importance in the pharmaceutical, food, and cosmetic industries. Unfortunately, conventional extraction procedures have a high cost and are time consuming, and the solvents used can represent a safety risk for operators, consumers, and the environment. Deep eutectic solvents (DESs) are green alternatives for extraction processes, given their low or non-toxicity, biodegradability, and reusability. This review discusses the latest research (in the last two years) employing DESs for phenolic extraction, solvent components, extraction yields, extraction method characteristics, and reviewing the phenolic sources (natural products, by-products, wastes, etc.). This work also analyzes and discusses the most relevant DES-based studies for phenolic extraction from natural sources, their extraction strategies using DESs, their molecular mechanisms, and potential applications.
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Given the difficulties of biodegradation of mesoporous silica nanoparticles (NPs), enrichment and penetration of tumor sites, and real-time monitoring of the treatment process, we developed a kind of mannose-doping doxorubicin-loading mesoporous silica nanoparticle (MSN-Man-DOX) and coated by polydopamine-Gd³⁺ (PDAGd) metal-phenolic networks, as well as modified by poly (2-Ethyl-2-Oxazoline) (PEOz), constructing a novel nanomedicine [email protected] Its pH-responsive charge reversal, photothermal, biodegradation, drug release, and nuclear magnetic resonance imaging properties were evaluated in vitro. Cellular uptake, tumor penetration, lysosomal escape properties, as well as cell safety and toxicity of the nanoplatform were investigated through cell experiments. Finally, the MRI, organ distribution, photothermal condition, and comprehensive anti-tumor therapy in vivo were evaluated comprehensively through animal experiments. Research results showed that [email protected] had outstanding tumor enrichment and penetration abilities, which can produce excellent treatment effects through the synergistic effect of chemotherapy and photothermal therapy (PTT) with the function of magnetic resonance imaging (MRI) contrast agent for disease monitoring. Besides, after finishing the therapeutic effect [email protected] can be biodegraded, so it had a good prospect of clinical application.
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Microalgae cultivation for exopolysaccharide production has getting more attention as a result of their high hydrocarbon biosynthesis skill. The aim of this study is to examine the exopolysaccharide production potential of different species of microalgae. In this context, exopolysaccharides were produced from Chlorella minutissima, Chlorella sorokiniana and Botryococcus braunii microalgae and the effects of carbon and nitrogen content in the growth medium and illumination time on exopolysaccharide production were analyzed statistically using Box-Behnken experimental design. In addition, techno-economic assessment of exopolysaccharide production were also performed by using the most productive microalgae and optimum conditions determined in this study. As a result of the experiments, it was seen that C. minutissima, C. sorokiniana and B. braunii produced 0.245 ± 0.0025 g/L, 0.163 ± 0.0016 g/L and 0.117 ± 0.0007 g/L exopolysaccharide, respectively. Statistically, it was observed that there was an inverse relationship between the exopolysaccharide production and investigated parameters such as illumination period and carbon and nitrogen amounts of culture mediums. The techno-economic assessment comprising microalgal exopolysaccharide (EPS) bioprocess was carried out, and it showed that the system can be considered economically viable, yet can be improved with biorefinery approach.
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Macromolecular/polymeric constituents of surfactants and their self-assembly in aqueous solutions play a key role in their technologically relevant application such as stabilization of foams and emulsions. However, such information on coffee-based surfactants is scarce. The present study is first-of-its-kind in elucidating the chemical and molecular fingerprints of surfactants derived from spent coffee grounds (SCG). Initial part of the study involved estimation of the total proteins and sugars, and monosaccharide composition of high (HMW) and low molecular weight (LMW) surfactants derived from dry and defatted SCG, which in turn is the residue obtained after hot water brewing of roasted Robusta and Arabica coffee granules. The HMW surfactants had higher protein and sugar contents that were directly related to their foamability and foam stability, respectively. Mannose and arabinose were the major sugars identified in HMW surfactants. LMW surfactants showed lower protein and sugar contents and absence of arabinose. Thus, only the HMW surfactants were subjected to MALDI-TOF mass spectrometry, LC-MS-MS based protein profiling, circular dichroism spectroscopy, and small-angle X-ray scattering. The presence of quercetin-sugar complexes, protease, transferase, and acylated proteins and a β-turn type protein secondary structure were detected in the SCG-surfactants. The transition from lamellar to rod-shaped micellar structures was observed when the surfactant concentration in aqueous solution was increased from a lower concentration to its critical micelle concentration (0.2% to 0.8%, w/v).
Article
Background The growth of the market for products derived from the açaí production chain, and the problems of the accumulation of residues from the process, intensified the demand for innovative strategies based on a circular bioeconomy model to value the industry, preserve the forest and the people who live in the Amazon. Thus, the demand for food inputs has stimulated the approach of full use of the açaí production chain for the production of mannose, polyphenols, and fatty acids. Scope and approach The objective of this brief comment is to update the reader on the potential of the açaí production chain for the development of food inputs, addressing its impacts, the development of technologies, and the challenges to implementing ecologies strategies and innovative in the Amazon region. The approach is centered on valuing the açaí production chain, based on a circular bioeconomy model, and applying ecological strategies to encourage the sustainable development of food inputs. Key findings and conclusions Products derived from the entire açaí production chain, for applications as food input, are very promising, as they have a global consumer market, with the potential to be competitive and attractive to investors. The circular bioeconomy model should leverage new routes for the recovery of waste for the production of mannose and polyphenols. Therefore, there are business, investment, and research opportunities to reduce environmental problems and increase the value of the açaí production chain.
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Background: Macrosolen parasiticus (L.) Danser, a hemiparasitic mistletoe plant was collected from the Bhadra Wildlife Sanctuary to determine its phytoconstituents and in vitro anticancer activities against PC-3 cancer cell lines. Materials and Methods: The collected samples were subjected to a hot extraction by using a soxhlet extractor. Investigation of phytochemicals was done by preliminary qualitative and GC-MS screening. In vitro anticancer activities on PC-3 cell lines were determined by MTT assay. Results: Preliminary phytochemical analysis revealed the occurrence of a variety of phytochemicals. GCMS screening of leaf methanol extract showed the occurrence of sixteen phytoconstituents, with valuable therapeutic uses. The identified major phytoconstituents were Dihydrochrysin (45.03%); 1,6-Anhydro-beta-D-glucopyranose (15.42%), and minor constituents were Adenosine,4'-de(hydroxymethyl)-4'-[N-ethylaminoformyl]-(0.95%); 4alpha-Phorbol 12,13-didecanoate (0.84%) and Agaricic acid (0.49%). The methanolic leaf extract showed moderate cytotoxicity on PC-3 lines at higher concentrations with IC 50 values of 448.7µg/ mL. while it had no cytotoxic effects on MEF-L929 non-cancerous cells. Conclusion: It is concluded that Macrosolen parasiticus contains a wide variety of secondary metabolites and also it proved a potential anticancer agent for PC-3 cells. Therefore, more research is required to determine its biological activities.
Article
Spent coffee grounds (SCG) are inexpensive materials with a complex composition that makes them promising feedstocks for a biorefinery. Here, conversion of SCG into a wide range of high value-added products (coffee oil, bio-ethanol, D-mannose, manno-oligosaccharide (MOS), cafestol and kahweol) using a novel integrated system was evaluated. The process involves oil extraction, MOS production by mannanase obtained from Penicillium purpurogenum, NaOH (Na) and hydrogen peroxide (HP) pretreatment for the degradation of lignin and phenolic compounds, diterpenes extraction, enzymatic hydrolysis, and fermentation, which can be performed using environmentally friendly technologies. Approximately 97 mL of coffee oil, 164 g of D-mannose, 102 g of MOS, 99 g of bioethanol and a dash of cafestol/kahweol were produced from 1 kg of dry SCG. Producing high-value co-products from SCG using an integrated approach as demonstrated here may be an efficient strategy to reduce waste generation, while improving the economics of the biorefinery production process.
Chapter
Hemicellulose present in lignocellulosic biomass can be converted into higher value-added products such as xylooligosaccharides and mannan oligosaccharides. These oligosaccharides have physicochemical and biological properties of great interest to several industry sectors, which has made them emerging molecules. They can be produced through chemical or enzymatic hydrolysis, focusing on high efficiency and income to fulfill market needs. The most well-known characteristic of these oligosaccharides is their action as prebiotics, since they are not digested by the human digestive system and can be used by the intestinal flora; however they present several other health benefits and technological uses. Nowadays, besides industrial production, research on novel production strategies is increasing, since these oligosaccharides have several advantageous properties and can be produced from a low-cost substrate.
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Molybdenum‐based catalysts have been widely studied in the epimerization of glucose to mannose. In this paper, several polymetallic molybdenum‐based catalysts were prepared and the high activity and selectivity of catalysts containing different divalent metal ions were investigated. Unlike most previous studies, there is no need to add acid to adjust pH in this reaction. It was found that the yield of CuAlMoO4 and CuAgAlMoO4 catalysts could be kept above 28.9 % at the epimerization of glucose reaction. Compared with soluble Cu3Mo2O9 catalysts, the prepared catalysts showed better stability and catalytic activity during the reaction process. It was found that the catalysts without copper had no catalytic effect or poor catalytic effect, and the valence state of copper ion changed before and after the reaction, indicating that copper ion played a very important role in the reaction. In this study, we have designed and synthesized a series of molybdenum‐based polymetallic catalysts, which displayed high yield and excellent selectivity without a requirement of additional acid to adjust pH. The results disclosed that the catalyst containing copper ion showed better catalytic performance than those without copper ion.
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The development and implementation of new amphiphiles based on natural resources rather than petrochemical precursors is an essential requirement due to their feedstock depletion and adverse environmental impacts. In addition, the use of bio-based surfactants can provide unique characteristics and improve the properties and versatility of the colloidal systems in which they are applied, such as emulsions. Here, the emulsification properties of a synthesized biocompatible mannose-based surfactant were investigated. Its behavior was evaluated in the presence of four different natural oils (castor, sunflower, olive and soybean) as well as two different aqueous phases (pure water and phosphate-buffered saline). The results highlighted their interest as surfactant in O/W nanoemulsions for all tested oil and aqueous phases, using a low-energy preparation protocol and relatively low surfactant concentrations. Furthermore, the mannose groups present on the polar head of the surfactant and adsorbed on the surface of the emulsion droplets were shown to retain their native biological properties. The specific mannose-concanavalin A binding was observed in vitro by the designed nanoemulsions, revealing the biorecognition properties of the surfactant and its potential applicability as a nanocarrier.
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D-mannose isomerase was cloned and characterized from a newly isolated actinobacteria strain, Thermobifida fusca MBL10003. The structural gene (manI) is predicted to encode a polypeptide of 407 amino acids with an estimated molecular mass of 43,900. Although the identity of the deduced amino acid sequence is not so high (45.7% to Salmonella enterica, and 38.5% to Agrobacterium radiobacter), the catalytic center appears has an essential structure that is conserved in the characterized homologs. It was a dimeric enzyme composed of two active monomer units. The optimal temperature and pH were 60°C and 8.0, respectively. The enzyme was stable up to around 60°C, and between pH 4 and 11. It showed activity on D-mannose and also on D-lyxose, but not on N-acetyl D-glucosamine, suggesting that it is functionally different from N-acyl D-glucosamine 2-epimerase despite the sequence similarity. Although Km value for D-mannose, 115 mM was similar to other mannose isomerase, kcat, hence kcat/Km was much higher than those. The enzyme was significantly inhibited by such divalent metal ions as Cu2+, Cd2+ or Ca2+, but it was not a metal-required enzyme for activity emergence.
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Use of antibiotics as an additive in poultry diets to improve growth has been discussed in relation to bacterial resistance and the development of new products and management practices. This study was carried out to test the efficacy of a new substance (Saccharomyces cerevisiae cell walls, var. Calsberg- SCCW) obtained from the brewery industry, added (at 0.1 and 0.2%) to broiler chicken diets (based on corn and soybean meal), on performance and intestinal mucosa development In Experiment 1 (carried out in litter-floor pens) the results revealed higher body weight gain for the total experimental period and higher villus height at 7 d of age for the birds fed 0.2% SCCW. In a field test using 44,000 broilers that received feed containing 0.2% SCCW, the results also showed higher body weight gain and better feed conversion for SCCW-supplemented birds. The present findings show that SCCW improved body weight gain in broiler chickens and that this effect can be attributed to the trophic effect of this product on the intestinal mucosa, because it increases villus height, particularly during the first 7 d of a chicken's life.
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Microbial infections are recognized by the innate immune system both to elicit immediate defense and to generate long-lasting adaptive immunity. To detect and respond to vastly different groups of pathogens, the innate immune system uses several recognition systems that rely on sensing common structural and functional features associated with different classes of microorganisms. These recognition systems determine microbial location, viability, replication and pathogenicity. Detection of these features by recognition pathways of the innate immune system is translated into different classes of effector responses though specialized populations of dendritic cells. Multiple mechanisms for the induction of immune responses are variations on a common design principle wherein the cells that sense infections produce one set of cytokines to induce lymphocytes to produce another set of cytokines, which in turn activate effector responses. Here we discuss these emerging principles of innate control of adaptive immunity.
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A mobile phase system comprising of ethyl acetate and propionic acid in 1:1 (v/v) ratio was identified as the most suitable green mobile phase for selective separation of maltose from fructose, dextrose, galactose, or mannose on precoated silica gel 60 HPTLC plates. The effect of presence of inorganic cations as impurities in the sample was examined for the separation of sugars. The chromatographic parameters like Delta R-F, separation factor (alpha), and resolution (Rs) of separated components of the mixture of maltose-fructose, maltose-dextrose, maltose-galactose, and maltose-mannose were calculated. The limits of detection for fructose, dextrose, and mannose were 7.5 +/- 0.41 mu g spot(-1) and for maltose and galactose were 1.5 +/- 0.09 mu g spot(-1). The proposed method is rapid, sensitive, and free from the use of toxic organic solvents and is therefore environmentally safe. Maltose has been selectively identified in the presence of fructose, dextrose, galactose, and mannose using scanning densitometry.
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Salmonella Enteritidis is one of the most prevalent foodborne pathogen, its main reservoir being considered the shell egg. As the concerns related to the increasing human salmonellosis cases grow, the need for an application of preventive methods either at the farm level or during the processing steps is crucial for a better control of the foodborne outbreaks due to the consumption of this specific food product. This review focuses on the application of preventive methods at the farm level, on preharvest step, in order to reduce the risk of shell eggs contamination with Salmonella, especially S. Enteritidis, through a better control of the laying hens’ infection with this pathogen. As postharvest methods, a 1st approach is the egg storage conditions and the prevention of Salmonella spp. growth and multiplication. In addition, shell eggs may be subjected to eggshell decontamination, to reduce the risk of foodborne outbreaks. Several of these latter mentioned methods are already authorized to be put in place in different countries, as it is the case in the United States of America and Canada. Their efficacy has been proven and their use is regarded by some as mandatory for ensuring shell eggs safety for the consumers.
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Polysaccharides containing uronic acids are of immense biological significance. Colorimetric methods using different chromogens have been explored for uronic acid estimation in polysaccharides but these methods counter numerous difficulties, when neutral sugars are present in substantial amount. The uronic acid content of cold water-soluble polysaccharide (CWSP) and hot water soluble polysaccharide (HWSP) isolated from Tinospora sinensis, widely known for marked therapeutic significance has been studied. The uronic acid was quantitatively estimated by spectrophotometric methods using carbazole, 3-phenylphenol and 3,5-dimethylphenol (DMP) vis-a-vis gas-liquid chromatography (GLC) analysis. Galacturonic acid in CWSP and HWSP was estimated as 1.41% and 1.20% respectively. The findings bring to light, the efficacy of chromogens and also reveal to what extent, they could be relied upon. The results also indicated higher specificity and selectivity of DMP over carbazole and 3-phenylphenol. However, GLC analysis despite time consuming remains finest method for precise estimation of uronic acids. Further, GLC analysis of alditol acetates indicated the monosugar composition of L-rhamnose, L-arabinose, D-mannose, D-galactose and D-glucose in molar ratio 0.178, 0.259, 0.140, 1.045 and 98.377 in CWSP and L-rhamnose, L-arabinose, D-xylose, D-mannose, D-galactose and D-glucose in molar ratio 0.608, 0.628, 0.978, 0.227, 0.111 and 97.448 in HWSP
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Effect of d-mannose treatment on different antioxidants, phenolics, protease activity, lipid peroxidation, DNA damage and cell death was investigated in coleoptiles of etiolated wheat seedlings. Modulations in these biochemical parameters were monitored up to 96 h after treatment at 24 h intervals. With accelerating effect on initial signs of cell death, i.e., appearance of long DNA fragmentation and no effect on initiation of terminal stage, i.e., internucleosomal nDNA fragmentation, mannose treatment (1 % = 56 mM) diminished the antioxidant activities in wheat coleoptiles. Mannose treatment decreased the catalase activity at all intervals, while APX and POD activities decreased at 72 h. Peroxidation of lipids increased at 72 h after mannose treatment. Levels of most of antioxidants, i.e., SOD, peroxidases and phenolics were raised during initial time period (24–48 h) of mannose treatment probably as an attempt to counter the stress effect. Protease activity gradually increased and protein content decreased with time in both treated and non-treated coleoptiles. Sharp decrease in CAT, APX and peroxidase activities and increase in lipid peroxidation at 72 h overlaps with apoptotic internucleosomal nDNA fragmentation in this organ. This coincidence points towards the importance of compromised antioxidant defense and involvement of reactive oxygen species in initiation of terminal stage of programmed cell death in wheat coleoptile. In conclusion, accelerating effect on DNA fragmentation and lipid peroxidation along with diminished antioxidant activities at the time of internucleosomal nDNA fragmentation, provide evidence for pro-apoptotic effect of d-mannose in wheat coleoptile.
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Background Peri-spinal subarachnoid (intrathecal; i.t.) injection of non-viral naked plasmid DNA encoding the anti-inflammatory cytokine, IL-10 (pDNA-IL-10) suppresses chronic neuropathic pain in animal models. However, two sequential i.t. pDNA injections are required within a discrete 5 to 72-hour period for prolonged efficacy. Previous reports identified phagocytic immune cells present in the peri-spinal milieu surrounding the i.t injection site that may play a role in transgene uptake resulting in subsequent IL-10 transgene expression. Methods In the present study, we aimed to examine whether factors known to induce pro-phagocytic anti-inflammatory properties of immune cells improve i.t. IL-10 transgene uptake using reduced naked pDNA-IL-10 doses previously determined ineffective. Both the synthetic glucocorticoid, dexamethasone, and the hexose sugar, D-mannose, were factors examined that could optimize i.t. pDNA-IL-10 uptake leading to enduring suppression of neuropathic pain as assessed by light touch sensitivity of the rat hindpaw (allodynia). Results Compared to dexamethasone, i.t. mannose pretreatment significantly and dose-dependently prolonged pDNA-IL-10 pain suppressive effects, reduced spinal IL-1β and enhanced spinal and dorsal root ganglia IL-10 immunoreactivity. Macrophages exposed to D-mannose revealed reduced proinflammatory TNF-α, IL-1β, and nitric oxide, and increased IL-10 protein release, while IL-4 revealed no improvement in transgene uptake. Separately, D-mannose dramatically increased pDNA-derived IL-10 protein release in culture supernatants. Lastly, a single i.t. co-injection of mannose with a 25-fold lower pDNA-IL-10 dose produced prolonged pain suppression in neuropathic rats. Conclusions Peri-spinal treatment with D-mannose may optimize naked pDNA-IL-10 transgene uptake for suppression of allodynia, and is a novel approach to tune spinal immune cells toward pro-phagocytic phenotype for improved non-viral gene therapy.
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Mannose in N-glycans is derived from glucose through phosphomannose isomerase (MPI, Fru-6-P ↔ Man-6-P) whose deficiency causes a congenital disorder of glycosylation (CDG)-Ib (MPI-CDG). Mannose supplements improve patients' symptoms because exogenous mannose can also directly contribute to N-glycan synthesis through Man-6-P. However, the quantitative contributions of these and other potential pathways to glycosylation are still unknown. We developed a sensitive GC-MS-based method using [1,2-13C]glucose and [4-13C]mannose to measure their contribution to N-glycans synthesized under physiological conditions (5 mm glucose and 50 μm mannose). Mannose directly provides ∼10–45% of the mannose found in N-glycans, showing up to a 100-fold preference for mannose over exogenous glucose based on their exogenous concentrations. Normal human fibroblasts normally derive 25–30% of their mannose directly from exogenous mannose, whereas MPI-deficient CDG fibroblasts with reduced glucose flux secure 80% of their mannose directly. Thus, both MPI activity and exogenous mannose concentration determine the metabolic flux into the N-glycosylation pathway. Using various stable isotopes, we found that gluconeogenesis, glycogen, and mannose salvaged from glycoprotein degradation do not contribute mannose to N-glycans in fibroblasts under physiological conditions. This quantitative assessment of mannose contribution and its metabolic fate provides information that can help bolster therapeutic strategies for treating glycosylation disorders with exogenous mannose.
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Large amounts of spent coffee grounds are discharged from food industries, for example, during the instant coffee manufacture. Although part of them is reused as compost and animal feed, most of the coffee grounds are burned as a waste. However, this material can be used as a biosorbent for xenobiotics removal. Spent coffee grounds were magnetically modified by contact with water-based magnetic fluid. This new type of magnetically responsive biocomposite materials can be easily separated by means of commercially available magnetic separators or strong permanent magnets. Magnetic coffee grounds can be used as an inexpensive magnetic adsorbent for the removal of water-soluble dyes. Seven dyes (crystal violet, malachite green, amido black 10B, Congo red, Bismarck brown Y, acridine orange and safranin O) were used to study the adsorption process. The dyes adsorption could be described with the Langmuir isotherm. The maximum adsorption capacities reached the value 73.4 mg of dye per g of dried magnetically modified coffee grounds for acridine orange; it corresponds to 276.6 lmol g -1 . This adsorbent can also be used for magnetic solid-phase extraction of crystal violet from extremely diluted solutions. To conclude, magnetic modification of spent coffee grounds resulted in the formation of a new, promising adsorbent for selected xenobiotics removal.
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Chromic acid oxidation of D-mannitol to mannose has been studied in aqueous media. The effect of promoter (PA, phen and bpy), micellar catalyst (SDS, TX-100 and CPC) and their combination is studied. All the reactions were performed under the condition [D-mannitol]T P [Cr(VI)]T. All the promoters accelerate the reaction rate and the rate is highest in presence of phen. In absence of a promoter the anionic surfactant SDS increases the rate followed by Triton TX-100. The cationic surfactant CPC retards the reaction in comparison to the reaction in aqueous media. Although phen is the best promoter in absence of any surfactant the catalyst combination of bpy and SDS produce a maximum rate enhancement.
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Poultry meat and eggs are important sources of human pathogens. Salmonella is a major cause of human foodborne infections following consumption of poultry products. The original ambition of the EU to eradicate zoonotic agents from the animal production chain has been tempered to reducing the infection pressure of specified zoonotic agents at all levels of the production chain. This can be done by a combination of pre-harvest, harvest and post-harvest measures. Feed additives constitute an important group of pre-harvest measures which can help in controlling Salmonella on the farm. Feed additives used for the control of Salmonella can be of different types, including antibiotics, prebiotics, probiotics and synbiotics. Public concerns regarding possible antibiotic resistance transfer lead to the ban of antibiotics as growth promoters in monogastric diets within the EU. Experimental and practical use of pre-, pro- and synbiotics, as well as volatile fatty acids as feed additives are discussed in this review. The effects of these additives on resistance to infection, on the extent of excretion and on the persistence of infection are reviewed. Attention is paid also to possible undesirable effects of some of these products. Taking into consideration the underestimated high level of contamination of poultry, the feed additives reviewed in this article can certainly play a valuable part in control strategies during the pre-harvest phase aiming at reducing the infection pressure and thus limiting the risk of contamination of poultry products.
Article
Crude mannose isomerase preparation from Xanthomonas rubrilineans S-48 which converts d-mannose to d-fructose was further purified by ammonium sulfate fractionation and DEAE-cellulose column chromatography. The specific activity of the purified enzyme solution was about 35-fold of original crude preparation. By using this purified enzyme solution, several enzymatic properties were investigated. (1) The Michaelis constant was 1.2 × 10⁻² M. (2) The enzyme was sensitive against temperature, but Ca⁺⁺ protected the enzyme to some extent from the effect of temperature. (3) The enzyme was stable in the pH range from 6 to 9. (4) The enzyme was not inhibited by glucose, xylose, mannitol, sorbitol, mannonic acid, mannuronic acid and so on, but strongly inhibited by d-arabinose and l-fucose, and Ki values of these inhibitors were 1.1 × 10⁻² M and 7.1 × 10⁻⁴ M respectively. © 1964, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.
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Results of a study are presented which was carried out in order to develop economic processes for recovering mannose or its derivatives from wood resources where it is a major component of mixtures containing other carbohydrates and lignin fragments. Five mannose chemicals were considered: D-mannose, the sodium bisulfite adduct of D-mannose, methyl alpha -D-mannopyranoside, sodium D-glycero-D-galacto-heptonate, and D-mannitol. The main achievement of this work was the development of processes for recovering sodium mannose bisulfite and methyl mannoside from several raw materials. Mannose was obtained by regeneration of sodium mannose bisulfite and converted to mannitol and sodium D-glycero-D-galactoheptonate using known procedures. Sodium annose bisulfite was prepared in nearly quantitative yield from the mannose component of spent sulfite liquor or from mannose-containing polymers by sulfurous acid hydrolysis and subsequent treatment with sodium hydroxide. Production of methyl mannoside involved hydrolysis of mannose-containing polymers by methanolysis concurrent with glycosidation. The economics and markets for these and other mannose chemicals are discussed. It has been shown that the bisulfite adduct separation route is rapid and inexpensive and is also the most favorable for regeneration of mannose. The methyl glycoside route could be used advantageously for converting dry polymer raw materials to industrial glycoside products.
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Mannose-binding lectin (MBL) is an important element of the innate immune defence system. The protein binds to the sugars present on many microbial surfaces and subsequently activates the complement system through a family of specific proteases called the MASPs (MBL-associated serine proteases). Studies of MBL binding to selected Gram-negative organisms suggest that the lipopolysaccharide (LPS) structure is of primary importance. For a range of clinically relevant organisms MBL binding leads to activation and cleavage Of C4 and C3, suggesting that this is a major pathway for opsonophagocytosis. MBL deficiency, resulting from three mutations in exon 1 and polymorphisms in the promoter region of the gene, is associated with both increased susceptibility to infections and autoimmune disease. Recent evidence indicates that the protein also modulates disease severity possibly by influencing cytokine production.
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Two fractions of polysaccharides, named PTPS-1 and PTPS-2, was extracted and purified from puerh tea by Sephacryl S-300 column chromatography. The physicochemical properties of these two polysaccharides were investigated by high-performance liquid chromatography (HPLC), Fourier Transform IR spectra, scanning electron microscope (SEM) and atomic force microscope (AFM). Analysis of chemical compositions (protein, neutral sugars, uronic acid and monosaccharide composition) suggested that they were both kinds of acid heteropolysaccharides bound with protein, and contained seven monosaccharides with different molar ratio. Meanwhile, evaluation of antioxidant activities by in vitro assays of DPPH, ABTS and FRAP showed that PTPS-1 demonstrated stronger antioxidant ability than PTPS-2. Similarly, PTPS-1 exhibited remarkable inhibitory potential on α-glycosidase in vitro, significantly stronger than that of PTPS-2 and acarbose. Moreover, the results from animal test indicated PTPS-1 possessed significant inhibition on postprandial hyperglycemia in diabetic mice compared with the model group.
Article
Aim: Study prebiotic properties of mannose and its effect on colonization resistance in experiments in mice. Materials and methods: Experimental dysbiosis was induced by introduction into non-linear mice of doxycycline hydrochloride. Prebiotic properties of mannose were studied by a single per oral administration to mice of increasing doses of preparation for a week compared with probiotics lactobacterin and bifidumbacterin. Lumen microflora was analyzed in feces. TNF-alpha level was determined by using a commercial kit OpTEIA ELISA Kit. Phagocytic activity of neutrophils and macrophages was studied in a cytochemical test of nitroblue tetrazolium reduction (NTT test) and by luminol-dependent chemiluminescence. Phagocytic activity and digestive ability of alveolar macrophages was studied. Results: The ability of mannose along with probiotic preparations bifidumbacterin and lactobacterin to restore the composition and numbers of indigenous microflora of mice under the conditions of experimental dysbiosis was revealed. Per oral administration of mannose and probiotic strains together with mannose was established to cause stimulating effect on functional activity of macrophages increasing ingesting and digesting ability of the cells and facilitates reduction of TNF-alpha levels. Conclusion: Mannose has prebiotic effect; the ability of mannose to induce expression of pro- and anti-inflammatory cytokines gives evidence of immunostimulating properties of the monosaccharide.
Article
The carbohydrate content of floral nectars of 12 Marantaceae species was analyzed by high-performance thin-layer chromatography (HPTLC). The main interest was not only to determine the sugar content of the nectar produced by the flowers but also to find potential differences within the genera and species. A total of 131 samples of this plant family, which grows in the tropical understory rainforest, were collected in the Golfo Dulce Region, Costa Rica, and analyzed. The nectar sugars found in the neotropical samples comprised melezitose, fructose, sucrose, glucose, and xylose (listed ascending in hRF values), whereof the main sugars were sucrose, glucose, and fructose. The nectars were successfully analyzed with regard to their individual sugar composition and classified according to their ratios. The overall mean sugar content of the studied species was 36%. The highest sugar contents of ≥40% were found in the nectar of the species Calathea lutea, Calathea donnell-smithii, Calathea marantifolia, Hylaeanthe hoffmannii, and Pleiostachya pruinosa. All species studied showed a ratio of sucrose to glucose and fructose between 1.3 for Calathealutea and 11.2 for Calathea donnell-smithii and, hence, were classified as sucrose dominated. HPTLC was found to be a good analytical method for nectar analysis, which took less than 1.5 h for 21 samples analyzed in parallel (ca. 4 min per sample).
Article
One-percent solutions of 2-deoxy-D-glucose, D-mannose, rafinose, L-sorbose, and 2-deoxy-Dribose were tested as potential fungicides in apple and peach fruit wounds inoculated with Botrytis cinerea and Penicillium expansum in apple and Monilinia fructicola in peach. Among the sugar analogs tested, only 2-deoxy-D-glucose was effective in controlling decay in inoculated apple and peach fruit. A slight reduction in lesion diameter was detected with L-sorbose and D-mannose. Radial growth of B. cinerea, P. expansum, M. fructicola, and Rhizopus stolonifer was completely inhibited in vitro when 2-deoxy-D-glucose was incorporated into a potato-dextrose agar medium at a 1.0% concentration. Severe alterations in fungal growth were also observed including excessive branching, shortening of the hyphal segments, and hyphal swelling. The sugar analog, 2-deoxy-D-glucose, shows promise as a treatment for postharvest diseases. Effective formulations that are safe to humans must be developed before this technology can be used commercially
Article
The equilibrium constant of the isomerization reaction between d-mannose and d-fructose which is catalyzed by a mannose isomerase from Streptomyces aerocolorigenes was obtained by using three methods over the temperature range from 1 to 40°C. It was found that the equilibrium constant was scarcely dependent on temperature, ΔH, the heat of the formation of d-fructose from d-mannose, being approximately zero. The standard free energy change, ΔG, and the standard entropy change, ΔS, of the reaction were calculated from the equilibrium constants at various temperatures and ΔH. The values of ΔG and ΔS at 25°C were −650 cal/mole and + 2.2 cal/deg·mole, respectively. By combining these thermodynamic data with those obtained for the isomerization reaction between d-glucose and d-fructose reported in the previous paper, ΔH, ΔG and ΔS for the isomerization between d-mannose and d-glucose were indirectly obtained to be +2220 cal/mole, +830 cal/mole and +4.6 cal/deg·mole at 25°C, respectively.
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