Ivana Correa Ramos Leal

• Federal University of Rio de Janeiro

Perillyl alcohol is a monoterpene known for its potent antitumor activity. In this study, we focused on esterification reactions of perillyl alcohol catalyzed by the immobilized enzyme Novozym 435 from Pseudozyma antarctica. Initially, the reaction conditions using a molar ratio of 1:4 (2:5 mmol of monoterpene: 10 mmol of octanoic acid), 40 mg of N...

Citronellyl esters present broad applications in the cosmetic, pharmaceutical, and food industries due to their organoleptic and biological properties. Lipase-catalyzed acylation of citronellol has been a suitable way to obtain these natural esters on a high scale. This work describes the lipase-catalyzed acylation of citronellol through esterifica...

Research into natural products has led to the discovery of new drugs. This work shows relevant data on the antibacterial activity of Ocotea notata leaves. Dichloromethane fraction (DF) from leaves of O. notata showed antibacterial activity at the concentration of 512 μg/mL against strains of Staphylococcus. The DF was fractionated to investigate bi...

Monoacylglycerols are eco‐friendly and inexpensive emulsifiers with a range of applications. The traditional synthetic route is not eco‐friendly, while enzymatic catalysis offers milder reaction conditions and higher selectivity. However, its application still is limited due to the costs. In this context, endophytic fungi can be source to new bioca...

Objectives This work investigated the acute antinociceptive effect of a synthetic chalcone, 4-dimethylamino chalcone (DMAC), as well as its effects on vincristine-induced peripheral neuropathy (VIPN) in mice. Methods The inhibitory activity of myeloperoxidase was assessed by measuring HOCl formation. Formalin and hot plate tests were used to study...

The aim of this study was to evaluate the effects of a coating formulation involving whey protein isolate (WPI) and garlic essential oil (GEO) on the internal quality and microbiological and sensory attributes of quail eggs stored for 28 days at room temperature. Unwashed quail eggs (171) were divided into treatments of uncoated eggs (UE), WPI-coat...

The objective of the study is to evaluate a new proposal for a coating based on corn starch (CS) enriched with basil essential oil (BEO) to overcome the rapid deterioration of quail eggs under nonrefrigerated conditions. One hundred and seventy-one quail eggs were divided into treatments of uncoated eggs (control), eggs coated with CS, and eggs coa...

The ability of Stemphylium lycopersici immobilized in MCM 48 zeolite structure as biocatalyst for ω-transamination reactions was evaluated. The conversion capacity for rac -1-methylbenzylamine, and also rac -1,2,3,4-tetrahydro-1-naphthylamine was verified in order to ascertain the potential of this biocatalyst in relation to the bioconversion of am...

Compounds that reduce or neutralize free radicals have been evaluated for use as nutraceutical or antioxidant additives in processed foods. This study aimed to enzymatically produce ascorbyl oleate and assess its biological properties. The synthesis was performed under previously maximized conditions (L-ascorbic acid/oleic acid 1:9 molar ratio, 70...

Monoterpenes, such as beta-pinene, are secondary metabolites widely used in the flavors and fragrance industries and can have their structure altered to enhance their applicability, such as producing epoxides, which are used as intermediaries for pharmaceuticals. Epoxides are commonly synthesized by the use of inorganic acids as catalysts, although...

A rare dihydoxyflavan-epicatechin proanthocyanidin, entcassiflavan-(4β→8)-epicatechin, was isolated from Dalbergia monetaria, a plant widely used by traditional people from the Amazon to treat urinary tract infections. The constitution and relative configuration of the compound were elucidated by HR-MS and detailed 1D- and 2D-NMR measurements. By c...

Studies involving the transformation of lignocellulosic biomass into high value-added chemical products have been intensively conducted in recent years. Its matrix is mainly composed of cellulose, hemicellulose and lignin, being, therefore, an abundant and renewable source for obtaining several platform molecules, with levoglucosan (LG) standing ou...

Monoterpenes are secondary metabolites widely used in the flavors and fragrance industries and can have their structure altered to enhance their applicability, such as producing epoxides, which are used as synthetic blocks for pharmaceuticals. Epoxides are commonly synthesized by the use of inorganic acids as catalysts, although the acid medium ind...

Biocatalytic transesterification is commonly carried out employing lipases in anhydrous organic solvents since hydrolases usually prefer hydrolysis over acyl transfer in bulk water. However, some promiscuous acyltransferases can catalyze acylation in an aqueous solution. In this study, a rational design was performed to enhance the acyltransferase...

The ethanolic extract and five fractions from Eremanthus crotonoides (DC.) Sch. Bip., Asteraceae, leaves were tested by the agar dilution method against sixteen bacterial strains acquired from hospital infection sites and 12 strains from the American Type Culture Collection. A total of 26 human pathogenic strains were inhibited by the dichlorometha...

Endothelial dysfunction in obesity plays a key role in the development of cardiovascular diseases, and it is characterized by increased vascular tonus and oxidative stress. Thus, this study aimed to investigate the vasodilatory and antioxidant activities of Mandevilla moricandiana ethyl acetate fraction and subfractions. Vascular effects were inves...

Ocotea notata (Lauraceae) is popularly known as white-cinnamon. Ocotea species have several medicinal uses, especially for treating chest pain, rheumatism and wounds. The present study aimed to analyze the chemical composition of O. notata n-hexane fraction, in addition to its anti-mycobacterial and immunomodulatory activities. The n-hexane fractio...

The flavonoid rutin presents several pharmacological effects, despite this, its application in the pharmaceutical industry can be significantly limited by its low bioavailability. The development of lipophilic derivatives by esterification of hydroxyl groups with fatty acid chains may be an effective strategy to change their physicochemical propert...

Objective The present report describes the enzymatic acylation of umbelliferone with different vinyl esters as acyl donors biocatalyzed by the commercial lipase Novozym® 435, and the investigation for their antibacterial activity against ATCC and clinical strains isolated from hospital infection sites. Results The umbelliferone esters (1–5) were s...

Arginase catalyzes the hydrolysis of l-arginine into l-ornithine and urea, acting as a key enzyme in the biosynthesis of polyamines. Leishmania growth and survival is dependent on polyamine biosynthesis; therefore, inhibition of Leishmania arginase may be a promising therapeutic strategy. Here, we evaluated a series of thirty-six chalcone derivativ...

Humiria balsamifera is used in traditional medicine as anthelmintic, expectorant, to treat hepatitis, diarrhea, hemorrhoids; to cure chronic wounds; and to alleviate toothaches. This species occurs in Jurubatiba shoal, Rio de Janeiro state-Brazil, a rich region which offers a variety of promising bioactive product sources. The present study focuses...

Monoacylglycerols (MAGs) are amphiphilic compounds with many applications such as emulsifiers, solubility agents and chiral building blocks. They are currently produced by alkaline glycerolysis under high pressure and temperature, resulting in low yields and by-products formation. Lipase-catalyzed processes are alternative tools that may lead to a...

The chemical composition and biological properties of citronella essential oil were modified by the enzymatic esterification reaction of the major monoterpenic alcohols with cinnamic acid. The almost complete conversion of geraniol and citronellol present in the citronella (Cymbopogon winterianus) essential oil, into geranyl (99%) and citronellyl (...

The aim of this study was to perform the isolation and characterization of vasodilatory flavonoids from Tapirira guianensis Aubl. (Annacardiaceae) leaves. In this context, ethyl acetate fraction (EA fraction) was obtained and subjected to fractionation batches by HSCCC affording: myricetin 3-O-α-L-rhamnopyranoside (myricitrin, 1); quercetin 3-O-(6”...

Dalbergia monetaria is an Amazonian plant whose bark is widely used to treat urinary tract infections. This paper describes a bio-guided study of ethanolic extracts from the bark and leaves of D. monetaria, in a search for metabolites active against human pathogenic bacteria. In vitro assays were performed against 10 bacterial strains, highlighting...

Tuberculosis (TB) still constitutes a threat to public health in various regions of the world. The existing treatment is long and has many side effects. The need to identify new anti-TB compounds and also adjuvants to control exacerbated inflammation in severe TB cases is relevant. Therefore, the objective of this study was to evaluate the anti-myc...

Cancer is one of the most prevalent diseases worldwide and the natural products could be a source of bioactive compounds. Passiflora mucronata (PM) belongs to a very known vegetal genus, although, there are no studies about cytotoxic activity or isolated compounds. Different extracts from PM were obtained by liquid-liquid partition (P), Soxhlet (So...

The specie Ocotea notata (Nees & Mart). Mez is a tree with 5 meters high, that can be found in restinga regions in the Brazilian coast. This study describes a phytochemical investigation, total phenolic content and the antioxidant activity of extracts and fractions by DPPH and ORAC. Phenolic content revealed equivalent concentration between evaluat...

Glycosylated flavonoids, caffeoylquinic acid and 3,5-dicaffeoylquinic acid have been identified in the ethyl acetate partition from the crude ethanol extract of Tocoyena bullata (Rubiaceae) leaves. The fraction containing the mixture of flavonol rutin and a tetraglycosylated flavonoid showed 89.2% inhibition and the mixture of isoquercitrin and 3,5...

Flavonoids are one of the most important and diversified phenolic groups among products of natural origin. An important property of this metabolite class is the antioxidant action. This study evaluated the antioxidant and cytotoxic activities and oxidative stress of transesterification products of the flavonoid rutin, catalyzed by Novozym® 435. The...

NMR1H and 13C spectrum of rutin diacetate. (DOC)

HMBC H-C correlation signals of rutin diacetate. (DOC)

Antioxidant evaluations by the ORAC method. (XLS)

Effect of rutin and reaction mixture (monoacetate and diacetate) on the production of reactive oxygen species (ROS). (XLS)

H-C correlation signals of rutin diacetate and monoacetate. (XLS)

Citotoxicity assays. (XLS)

Background: P. mucronata (Pm) comes from South America, Brazil and is characterized as "Maracujá de Restinga". It is used in folk medicine for its soothing properties and in treating insomnia. Objective: The present study for the first time analyzed the antioxidant and cytotoxicity of the hydroalcoholic leaves extract and fractions from Pm. Met...

Red algae of the genus Laurencia J. V. Lamouroux are found in tropical and subtropical regions throughout the world and are an extremely rich source of active secondary metabolites with diverse structural features. In the present study, 6 sesquiterpenes (obtusol, (−)-elatol, dendoidiol, debrome-elatol, triquinane, and obtusane) isolated from Lauren...

Aims: To screen twenty microorganisms for ω-transaminase activity by the kinetic resolution of rac-1-phenylethylamine, followed by testing rac-amines of pharmaceutical interest with bulky substituents and, to conduct the asymmetric synthesis of a chiral amine. Methods and results: Stemphylium lycopersici was selected as the best biocatalyst. By...

In this work lipase CaLB was immobilized on functionalized Pd-SiO2 nanoparticles in order to simplify the DKR of α-methylbenzylamine. Hybrid biocatalysts showed immobilization efficiencies of 82%, 80% and 76% when containing 1, 5 and 10% of Pd respectively. On DKR reaction values of ee > 99% and conversion of 82% were found with only 1% of Pd, gene...

In general, Passiflora species have been reported for their folk medicinal use as sedative and anti-inflammatory. However, P. caerulea has already been reported to treat pulmonary diseases. Severe pulmonary tuberculosis (TB), common in MDR cases, can lead to deleterious inflammation and high mortality, encouraging new approaches in drug discovery....

The aim of this research was to perform a phytochemical study of the methanol leaves extract of T. guianensis (MET) guided by vasodilatory and antioxidant activities. The chemical profile of MET and the ethyl acetate fraction (EA fraction) was determined by HPLC-UV-MS and EA fraction guided fractionation by reverse-phase chromatography. The vasorel...

Acmella oleracea, commonly known as jambú, is a great source of spilanthol, a secondary metabolite responsible for different kind of biological activities, such as the antioxidant, antimicrobial, cytotoxic and anti-inflammatory bioactivities. The purpose of this work was to evaluate spilanthol content in A. oleracea plants obtained from three diffe...

Two commercially available and widely used enzymes, the parent Thermomyces lanuginosus lipase (TLL) and the shuffled phospholipase A1 LecitaseTM (Lecitase Ultra), were encapsulated in AOT/isooctane reverse micelles and evaluated regarding their structure and activity. Preparations were also tested as effective biocatalysts. Small-angle X-ray scatte...

Natural products extracted from plants represent a valuable source of new bioactive substances. Many studies describe the potential of plant products for the treatment of cardiovascular diseases. Species of the Mandevilla genus have been studied for their biological activities, mainly as antioxidant, anti-inflammatory, and vasorelaxant. However, th...

Microbial lipases have great industrial interest. However, few studies explore the potential of endophytic fungi, micro-organisms that apparently not cause any damage to your host1, as production source of these enzymes. Our research group isolated many endophytic fungi associated with some plant species, which may represent important sources of pr...

The fruits of Pilosocereus arrabidae (Cactaceae) is found in the Grumari shoal, located in the Rio de Janeiro state, Brazil and, several studies have already highlighted the importance of consuming its fruits. This work aims to investigate the physical, mineral and physicochemical properties of its fruits as well as to establish the knowledge about...

Packed bed reactors can be used as an interesting alternative on the bioreduction of β-ketoesteres mediated by immobilized microorganisms. Here in, we report our results on the bioreduction of ethyl 3-oxohexanoate by immobilized Kluyveromyces marxianus cells and tert-butyl 3-oxobutanoate by immobilized Rhodotorula rubra cells under continuous flow...

Several microorganism strains were used to reduce 2,2,2-trifluoroacetophenone (1) and 4 '-Br-2,2,2-trifluoroacetophenone (3). Immobilized cells of Geotrichum candidum in calcium alginate led to conversion and enantiomeric excess higher than 99%. By using immobilized G. candidum cells under continuous flow conditions, the same conversion and enantio...

In this work, microemulsion-based organogels (MBGs) containing lipase are reported as an efficient catalytic system for monoacylglyceride (MAG) synthesis. More specifically, Candida antarctica lipase B (CaLB) was immobilized on an MBG matrix (MBG CaLB) formed with (hydroxypropyl)methyl cellulose as a gelling agent, and this catalyst revealed high c...

The development of chemo-enzymatic reaction under continuous flow conditions is an emerging area where biotechnology and organic chemistry can joint efforts in order to develop better process. Here in we report our effort on the development of a continuous flow approach to the synthesis of Odanacatib intermediate using a combined batch and continuo...

Gram-positive bacteria are the most common cause of skin infection in hospitalized patients, with Staphylococcus aureus being the principal pathogen responsible for deaths. A series of poly-oxygenated chalcones was synthesized and assayed for anti-staphylococcal activity. Hydroxylated chalcones were more effective in the inhibition of microbial gro...

In this work, a three-step chemo enzymatic cascade reaction is reported for 1-monoacylglycerols from glycerol derived from biodiesel industry under continuous-flow conditions. Glycerol protection was performed using H 2 SO 4 /SiO 2 (2.5 %w/v) solid catalyst and acetone, generating 87 % of solketal under 55 °C at 0.1 mL/min with glycerol–acetone rat...

Cancer chemotherapy is an important strategy to treat this leading cause of death worldwide and plants may constitute a source of new antineoplastic agents. This work fractionated the ethanolic extract of Jacaranda puberula leaves and studied the in vitro antitumoral action and some toxicological effects of the most bioactive fraction. Cell lines r...

The use of glycerol derived from biodiesel industry is an important development to add value to this actual waste. Several products can be obtained from glycerol, but acetins are very interesting molecules with a wide range of applications in pharmaceutical, cosmetics, food, and fuel industry. Herein we report our results on biocatalyzed batch and...

Calophyllum brasiliense is a rich source of bioactive coumarins, xanthones and biflavonoids. The aim of the study was to compare the phenol contents and the antioxidant activity of C. brasiliense extracts obtained by conventional and supercritical fluid extraction (SFE) methods, as well as the quantification of crude extracts and (−)-mammea A/BB yi...

Chemical methods for the synthesis of sugar esters require the use of high temperatures in the presence of alkaline catalysts resulting in undesirable by-products and low regiosselectivity. Sugar-based fatty acid esters are non-ionic, biodegradable, odorless, non-irritating, non-toxic surfactants widely used pharmaceuticals, cosmetics, detergents,...

Lecitase Ultra was immobilized on Amberlites XAD2 and XAD4, through physical entrapping under conventional stirring or ultrasound irradiation, and characterized by standard techniques. The resulting immobilized biocatalysts were utilized in the valorization of an acidic food-derived residue from a palm oil refining process to produce monoacylglycer...

Diacylglycerol oil has been increasingly recognized by its good nutritional properties and therefore, different technologies have been developed for obtaining it. The present work focuses on the diacylglycerol production by hydrolysis reaction of the palm oil using the PS IM and TL IM commercial lipases as biocatalysts under ultrasound irradiation....

The present work focuses on the oleic acid epoxide production by using PSCI Amano Lipase as biocatalyst in the reaction. An experimental design (central composite design - CCD) adopting surface response was applied to this purpose. Reactions were performed in a shaker equipment and different variables were investigated, such as temperature (25-55 d...

Bumelia sartorum (Sapotaceae) is used ethnomedicinally for treatment of several diseases, including diabetes mellitus. The aim of this work was to investigate the hypoglycemic effect of B. sartorum extracts, rich in polyphenolic compounds, and the possible mechanisms of action. Assessment of B. sartorum hypoglycemic activity was performed from the...

The lipase catalyzed sugar ester synthesis is an interesting strategy for producing biodegradable, non-ionic surfactants. The main disadvantage of this protocol is the long reaction time required for achieving moderated to good yields. Here, we report the esterification of steric hindered fructose derivative where important variables for batch cond...

Silica immobilized lipases have been prepared and utilized in the valorization of fatty acid-derived food waste streams under continuous flow conditions. Findings demonstrate that better conversions could be obtained when compared with commercially available immobilized enzymes.

The aim of this study was to compare the yield and biological potential of Piper regnellii extracts obtained by supercritical fluid extraction (SFE) and by conventional method. The extracts were characterized by the HPLC technique according to the structure type of conocarpan and eupomatenoid-5 neolignans. SFE was performed at temperatures of 313 a...

Biodegradable, biocompatible and nontoxic nonionic surfactants are widely used in food, pharmaceutical and industrial applications being commonly produced based on alkaline-catalyzed chemical glycerolysis of natural oil and fats at high temperatures and elevated pressure under nitrogen atmosphere. In this work we have optimized a biocatalytic conti...

Free fatty acids are used in many cases for the production of soaps, candles and assist processing of rubber products, but we believe that new process technology should be developed to produce products with higher added value. Monoacylglycerols (MAGs) are nonionic surfactant, highly hydrophobic and has been used as controlled release systems for dr...

Microorganisms were used to reduce 4-bromoacetophenone to (S)-4-bromophenylethanol and (R)-4-bromophenylethanol. After a fractional factorial design to identify the important variables for this reaction, Geotrichum candidum provided 98.9% conversion with >99% e.e. of the (R)-isomer, while Rhodotorula rubra led to 97.6% conversion with 98.8% e.e. of...

The esterification reaction mediated by lipases was investigated applying both microwave irradiation and conventional heating in order to evaluate the existence of nonthermal microwave effects on the biodiesel synthesis. All transformations were conducted at 40 °C in both Monowave 300 and CEM Discover instruments that allowed accurate internal reac...

Diacylglycerols (DAG) are commonly used in different purity levels for food, medicine and cosmetic industries. Several approaches are found over the literature on DAG production under lipase-catalyzed reactions among which are highlighted: glycerol sterification, vegetable oils’ glycerolysis and selective hydrolysis. Results obtained palm oil parti...

a b s t r a c t Recognition that trans and saturated fats have negative health effects drive researchers to develop alternative systems that can structure liquid oils into semi-solid plastic pastes for food applications. Monoacylglicerols (MAG) can be used as a promising molecule to achieve this structuring so we have optimized a biocatalytic batch...