Artur M S Silva

• Managing Director at University of Aveiro

The Front Cover depicts a female Anopheles spp. mosquito, the vector of Plasmodium falciparum and perhaps the most iconic image associated with the fight against malaria, which inspects the structure of a new indole scaffold with promising activity against blood-stage malaria parasites, under the moonlight (the vector has a nocturnal feeding habit,...

This study aimed to evaluate the systemic effects of resveratrol in a functional bread to prevent diabetes complications in vivo

The World Health Organization aims to stop the rise of diabetes by 2025, and diet is one of the most efficient non-pharmacological strategies used to prevent it. Resveratrol (RSV) is a natural compound with anti-diabetic properties, and incorporating it into bread is a suitable way to make it more accessible to consumers as it can be included as pa...

The present investigation aimed to examine the therapeutic potential of the new coumarin derivative bis(4-hydroxy-2H-chromen-2-one) coumarin (4HC) against breast cancer. For this purpose, the effects of 4HC treatment on the proliferation of MCF-7 breast cancer cells and on MCF-10a non-cancerous cells were evaluated using a fluorescent assay. Cell c...

Opuntia fruits are recognized for their richness in nutrients and in bioactive compounds, being also highly appreciated by consumers as a juice. Nevertheless, without further processing, prickly pear juices have a short shelf-life, hampering their commercial use. In this work, thermal (TP) and high-pressure (HPP) pasteurization were applied to juic...

Olive leaves are an alternative source of bioactive compounds, such as hydroxytyrosol (HT) and oleuropein (OLE), which do not compete with the food chain. Olive phenolic compounds have gained much attention due to their bioactive properties, and their use as a food ingredient to improve food quality has been widely exploited. Indeed, HT is recognis...

Evaluate the systemic effect of functional bread with resveratrol to prevent diabetes complications in vivo.

Trans-resveratrol (RSV) is recognised as a bioactive ingredient in the development of functional foods. Its stability, solubility, and bioavailability constraints can be overcome by delivery systems, not yet tested in foods. This study aims at evaluating the impact of two delivery systems on the stability, antioxidant activity, bioaccessibility and...

Two new oleanane-type triterpene glycosides, 3˗O˗β˗D˗glucopyranosyl˗28˗O˗[β˗D˗glucopyranosyl˗(1→2)˗β˗D˗xylopyranosyl˗(1→6)˗β˗D˗glucopyranosyl]medicagenic acid (1) and 3˗O˗β˗D˗glucopyranosyl˗28˗O˗[β˗D˗glucopyranosyl˗(1→6)˗β˗D˗glucopyranosyl˗(1→2)˗ β˗D˗xylopyranosyl]oleanolic acid (2), named capitatosides A and B respectively, were isolated from the...

This chapter focus on the developments concerning the strategies used in the synthesis of 1,4‐diazepane derivatives reflecting selected relevant examples described in the literature between 2005 and the end of 2020. Chiral 1,4‐diazepanes can be synthesized by asymmetric reductive amination, one of the most important reactions used to prepare chiral...

Abiotic stresses, such as those induced by climatic factors or contaminants, and biotic stresses prompted by phytopathogens and pests inflict tremendous losses in agriculture and are major threats to worldwide food security. In addition, climate changes will exacerbate these factors as well as their negative impact on crops. Drought, salinity, heav...

Introduction: Spirocyclic scaffolds are an exceptional tool in drug design, allowing fine-tuning of a molecule's conformational and physicochemical properties. As it expands and diversifies, so does the number of therapeutics that contain this core. Several spirocyclic drugs are already marketed, and considerably more have shown promising results....

Chromones is a family of oxygen heterocyclic compounds whose synthetic versatility and broad spectrum of bioactive properties has been widely reported over the past decade. The increasing number of publications related to the synthesis of this heterocyclic system highlights diverse synthetic approaches, using different starting materials, with nove...

The depletion of the stratospheric ozone layer due to natural and/or anthropogenic causes decreases the amount of UV-B radiation filtered, and consequently increases the risk of potential damage to organisms. In the Mediterranean region, high UV-B indices are frequent. Even for species typical of this region, such as the olive tree, the progressive...

Usually, chalcones are not luminescent, although their derivatives with push-pull patterns of substitution may present fair quantum yields. Intramolecular hydrogen bonding between a hydrogen donor (–OH or –NH) and the chalcone carbonyl promotes Excited State Intramolecular Proton Transfer (ESIPT). If the dye is fluorescent, the emission can derive...

Neutrophils are polymorphonuclear leukocytes recruited to sites of acute inflammation, in response to pathogen invasion and tissue injury. The modulation of their activity, especially oxidative burst, may be important to control the inflammatory process. 2-Styrylchromones (2-SC) are derived from chromones and despite their recognized multiple biolo...

Phloroglucinol is a powerful antioxidant compound and an active pharmaceutical ingredient used in the management of intestinal spasms. In this report, we describe the interaction of γ-cyclodextrin with phloroglucinol to readily form a solid inclusion compound with 1:1 by co-dissolution and freeze-drying. Solid-state characterisation using FT-IR, th...

Nowadays, leishmaniasis constitutes a public health issue in more than 88 countries, affecting mainly people from the tropics, subtropics, and the Mediterranean area. Every year, the prevalence of this infectious disease increases, with the appearance of 1.5–2 million new cases of cutaneous leishmaniasis and 500,000 cases of visceral leishmaniasis,...

The quality control of a commercial gasoline includes the assessment of several physical-chemical properties. The main objective of the present work is to investigate the simultaneous use of NIR and ¹H NMR data to accurately estimate 13 of those characteristics [i.e., density, vapour pressure, percent evaporated at 70 °C, percent evaporated at 100...

Asparagopsis armata Harvey is a red alga native from the southern hemisphere and then introduced in the Mediterranean Sea and the Atlantic Ocean, including the Azores Archipelago, where it is considered an invasive alga. Some studies show that the extracts exhibit antimicrobial and antifouling activities, and it is incorporated in some commercializ...

Agroforestry by-products have gained rising attention in recent years as they represent inexpensive and abundant raw materials that are a source of added-value chemicals, e.g., for food and pharmaceutical applications, as well as for bioenergy generation. Pinus pinaster Ait. bark extracts are consumed worldwide for their cardiovascular benefits, wh...

Chromones (4H‐chromen‐4‐ones) contemplate a naturally occurring class of compounds widely distributed in Nature, particularly in plants. This singular ring system has emerged as a privileged scaffold in medicinal chemistry, mainly due to its unique structural features, diverse biological activities, and pharmacological properties. Throughout the pa...

Glycogen phosphorylase (GP) is a key enzyme in the glycogenolysis pathway. GP inhibitors are currently under investigation as a new liver-targeted approach to managing type 2 diabetes mellitus (DM). The aim of the present study was to evaluate the inhibitory activity of a panel of 52 structurally related chromone derivatives; namely, flavonoids, 2-...

Type 2 diabetes (T2D) is the most common form of diabetes, and the number of people with this metabolic disease is steadily increasing worldwide. Among the available antidiabetic agents, α-glucosidase inhibitors are the most effective at reducing postprandial hyperglycaemia (PPHG), one of the main characteristics of T2D. However, most of the studie...

Styrylchromones (SC) are a group of oxygen-containing heterocyclic compounds, which are characterized by the attachment of a styryl group to the chromone core. SC can be found in nature or can be chemically synthesized in the laboratory. As their presence in nature is scarce, the synthetic origin is the most common. Two types of SC are known: 2-sty...

Citrus are economically important fruit crops to which infectious diseases like citrus canker caused by Xanthomonas citri subs. citri, citrus variegated chlorosis caused by Xylella fastidiosa, “huanglongbing” associated with the presence of Candidatus liberibacter species, anthracnose caused by Colletotrichum gloeosporioides and citrus black spot c...

Microwave irradiation has become a popular heating technique in organic synthesis, mainly due to its short reaction times, solventless reactions, and, sometimes, higher yields. Additionally, microwave irradiation lowers energy consumption and, consequently, is ideal for optimization processes. Moreover, there is evidence that microwave irradiation...

Alzheimer's disease (AD) is a chronic neurodegenerative disease and represents the major cause of dementia worldwide. Currently, there are no available treatments capable to deliver disease-modifying effects, and the available drugs can only alleviate the symptoms. The exact pathology of AD is not yet fully understood and several hallmarks such as...

N-heterocycles, both saturated and unsaturated, are ubiquitous biologically active molecules that are extremely appealing scaffolds in drug discovery programs. Although classical synthetic methods have been developed to access many relevant N-heterocyclic scaffolds, representing well-established and reliable routes, some do not meet the needs of su...

In recent years, more attention has been paid to natural sources of antioxidants. Flavonoids are natural substances synthesized in several parts of plants that exhibit a high antioxidant capacity. They are a large family, presenting several classes based on their basic structure. Flavonoids have the ability to control the accumulation of reactive o...

Warionia saharae Benth. & Coss. (Asteraceae) is an endemic species of North Africa naturally grown in the southwest of the Algerian Sahara. In the present study, this species’ hydromethanolic leaf extract was investigated for its phenolic profile characterized by ultra-high-performance liquid chromatography coupled with a diode array detector and a...

In recent decades, fungi-derived naturally occurring quinazolines have emerged as potential drug candidates. Nevertheless, most studies are conducted for bioactivity assays, and little is known about their absorption, distribution, metabolism, and elimination (ADME) properties. To perform metabolic studies, the synthesis of the naturally occurring...

Pyrazoles and their reduced form, pyrazolines, are considered privileged scaffolds in medicinal chemistry, owing to their remarkable biological activities, physicochemical properties and occurrence in many low-molecular-weight compounds present in several marketed drugs (e [...]

DNA is one of the most exciting biomolecules in nature for developing supramolecular biofunctional nanoarchitectures owing to the highly specific and selective interactions between complementary Watson‐Crick base pairing. Herein, simple and one‐pot synthetic procedures have been implemented for producing a library of DNA nucleobase derivatives endo...

Previously unreported anthraquinone, acetylpenipurdin A (4), biphenyl ether, neospinosic acid (6), dibenzodioxepinone, and spinolactone (7) were isolated, together with (R)-6-hydroxymellein (1), penipurdin A (2), acetylquestinol (3), tenellic acid C (5), and vermixocin A (8) from the culture of a marine sponge-associated fungus Neosartorya spinosa...

Highlights - A novel chiral (s)-carvone dihydrazone (s-CHD) have been hemi-synthetized from the natural (s)-carvone, the major compound of caraway’s seeds essential oil and oxalyldihydrazide (ODH). - Enantio-pure (s)-carvone dihydrazone (s-CHD) is structurally characterized by Single-crystal X-ray diffraction, 2D-NMR spectroscopy and chiral LCMS...

Introduction: Peptidomics is an emerging field of omics sciences using advanced isolation, analysis, and computational techniques that enable qualitative and quantitative analyses of various peptides in biological samples. Peptides can act as useful biomarkers and as therapeutic molecules for diseases. Areas covered: The use of therapeutic pepti...

Benzimidazole-based boranils were designed and synthesized in order to assess the influence of halogen substituents on their optoelectronic properties. All compounds are photoluminescent in solution and solid state. Compared to the free ligands, the new boranils emit at a lower wavelength, by elimination of the excited-state intramolecular proton t...

Seaweeds are one of the largest producers of biomass in the marine environment and a source of multiple bioactive metabolites with valuable health benefits. Among these, phlorotannins have been widely recognized for their promising bioactive properties. The potential antitumor capacity of Fucus vesiculosus-derived phlorotannins remains, however, po...

The development of novel anticancer agents is essential to finding new ways to treat this disease, one of the deadliest diseases. Some marine organisms have proved to be important producers of chemically active compounds with valuable bioactive properties, including anticancer. Thus, the ocean has proved to be a huge source of bioactive compounds,...

Highlights-A novel chiral (s)-carvone dihydrazone (s-CHD) have been hemi-synthetized from the natural (s)-essential oil and oxalyldihydrazide (ODH).-Enantio-pure (s)-carvone dihydrazone (s-CHD) is structurally characterized by Single-crystal X-ray diffraction, 2D-NMR spectroscopy and chiral LCMS analysis.-The (s)-CHD exhibited an antigrowth potenti...

Ulva macroalgae species are recognized to be an underexploited source of key nutrients, including proteins, fibers and minerals. The present work evaluated the nutritional value protein, ash, mineral composition, fat, fatty acid profile and dietary fiber of the green macroalgae Ulva rigida produced in an open land-based integrated multi-trophic aqu...

The contamination and bioavailability of deleterious metals in arable soils significantly limits crop development and yield. Aiming at mitigating Pb- and Al-induced phytotoxicity, this work explores the use of P25 titanium dioxide nanoparticles (nTiO2) in soil amendments. For that, Lactuca sativa L. plants were germinated and grown in the presence...

Polyfunctional N,O,O,N-type ligands such as the oxalyl dihydrazide (ODH) may induce formation of mono-, di-, and polynuclear complexes with natural monoterpene ketones, involving ligand bridging and Oxo-bridging. In this context, a novel chiral dihydrazone is designed through hemi-synthesis process by reacting oxalyldihydrazide (ODH) with (s)-carvo...

Recent studies indicate that plant polyphenols could be pointed as potential prebiotic candidates since they may interact with the gut microbiota, stimulating its growth and the production of metabolites. However, little is known about the fate of brown seaweeds’ phlorotannins during their passage throughout the gastrointestinal tract. This work ai...

According to the WHO, cancer was responsible for an estimated 9.6 million deaths in 2018, making it the second global leading cause of death. The main risk factors that lead to the development of this disease include poor behavioral and dietary habits, such as tobacco use, alcohol use and lack of fruit and vegetable intake, or physical inactivity....

2-Styrylchromones (2-SC) are a group of oxygen-containing heterocyclic compounds, which are characterized by the attachment of a styryl group to the C-2 position of their chromone core. Over the years, several biological activities have been attributed to 2-SC, such as antioxidant, anti-inflammatory, antimicrobial, antiviral, and antitumor activiti...

Calendula suffruticosa subsp. algarbiensis (Boiss.) Nyman is very common on the Portuguese coast, but it has only recently begun to be studied chemically and belongs to a genus of difficult taxonomic classification. To improve the knowledge on the chemical variability of this taxon and evaluate the possible use of this tool for taxonomical purposes...

The frequency of combined stress events is increasing due to climate change and represents a new threat to olive (Olea europaea) culture. How olive plants modulate their profile of metabolites under multiple stressing agents remains to unveil, although several metabolites affect plants' resilience, and olive production and quality. Young olive plan...

Four undescribed prenylated phenylbutyrolactones, aspulvinones R, S, T and U, were isolated together with the previously reported aspulvinones A, B′, H and 4-hydroxy-3,5-bis(3-methylbut-2-en-1-yl)benzaldehyde, from cultures of the marine sponge-derived fungus Aspergillus flavipes KUFA1152. The structures of the undescribed compounds were establishe...

Methylglyoxal is a dicarbonyl compound recruited as a potential cytotoxic marker, initially presents in cells and considered as a metabolite of the glycolytic pathway. Our aim is to demonstrate the inhibitory effect of 3, 3'-[3-(5-chloro-2-hydroxyphenyl)-3-oxopropane-1, 1-diyl] Bis (4-hydroxycoumarin) on the glyoxalase system, and indirectly its an...

A new series of benzodiazepines and chiral Schiff bases have been prepared by an in situ condensation of (S)-(-)-perillaldehyde, occurring naturally in the essential oil of Ammodaucus leucotrichus subsp. Leucotrichus, with various amines, hydrazines, and oxalyl dihydrazide. Pure enantiomeric compounds TK1-6 have been obtained in moderate to good yi...

Alzheimer’s disease (AD) is a complex multifactorial disorder, mainly characterized by the progressive loss of memory and cognitive, motor, and functional capacity. The absence of effective therapies available for AD alongside the consecutive failures in the central nervous system (CNS) drug development has been motivating the search for new diseas...

Novel substituted bis-(3-cyano-2-pyridone) derivatives were prepared via a powerful method using enaminonitriles push–pull dienes as key building blocks. The synthesis was performed in three steps from easily accessible starting materials in good yields. All target products were structurally elucidated by spectroscopic data. The reaction mechanism...

Sesbania bispinosa (Jacq.) W. Wight is a medicinal plant used by traditional healers from India and now introduced in southern Algeria, for which the chemical composition still needs to be uncovered. This work aimed to establish the chemical profile of this important medicinal plant and determine of the antioxidant effects of the 80% methanol extra...

Extreme climate events are increasingly frequent, and the 2017 summer was particularly critical in the Mediterranean region. Olive is one of the most important species of this region, and these climatic events represent a threat to this culture. However, it remains unclear how olive trees adjust the antioxidant enzymatic system and modulate the met...

Type 2 diabetes mellitus (DM) is a complex chronic disorder and a major global health problem. Insulin resistance is the primary detectable abnormality and the main characteristic feature in individuals with type 2 DM. Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of the insulin signaling pathway, which dephosphorylates insuli...

Microcystins (MCs), produced by Microcystis sp, are the most commonly detected cyanotoxins in freshwater, and due to their toxicity, worldwide distribution, and persistence in water, an improvement in the monitoring programs for their early detection and removal from water is necessary. To this end, we investigate the performance of three covalent...

Oleuropein (OLE) and hydroxytyrosol (HT) are olive-derived phenols recognised as health-promoting agents with antioxidant, anti-inflammatory, cardioprotective, antifungal, antimicrobial, and antitumor activities, providing a wide range of applications as functional food ingredients. HT is Generally Recognised as Safe (GRAS) by the European Food Saf...

The preparation of covalently linked manganese(III) meso-tetrakis(2,6-dichlorophenyl)porphyrin acetate to aminopropyl functionalized silica gel and its full characterization by standard spectroscopic methods including Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG) and scanning electronic microscopy (SEM) is described. The sup...

Coordination compounds of N,N’-di(4-bromophenyl)-4-hydroxycoumarin-3-carboximidamide (L1) were synthesized via the reaction of Cu (II), Co (II) and Zn (II) salts in molar ratio 1 : 1 in the presence of ammoniac as basic media. The Ligands and the complexes formed were characterized using FT-IR, UV-visible and fluorescence spectrophotometric analyse...

BACKGROUND The present work stands as an endeavor to uncover the ideal harvesting time of leaves in which they exhibits the maximum contents of bioactive molecules such as essential fatty acids, tocopherols and carotenoids. METHODS A large scale investigation was carried out for the leaves of Pistacia atlantica involving a large number of populati...

The medicinal use and/or use in the nutrition of plants growing in Portugal is common, although in many cases the validation of their health benefits is far away from being established. On the other hand, other plants have a high impact on the country’s economy and are at risk of being damaged by climate changes, a factor that should also be evalua...

Alzheimer’s disease (AD) is one of the most common types of dementia, especially in elderly, with an increasing number of people suffering of this disease worldwide. There are no available disease-modifying therapies and only four drugs are approved for the relief of symptoms. Currently, the therapeutic approach used for AD treatment is based on si...

The present work aimed at the valorization of biomass derived compounds by their transformation into new added-value compounds with enhanced antioxidant properties. In this context, betulinic acid (BA) was decorated with polyphenolic fragments, and polyhydroxylated (E)-2-benzylidene-19,28-epoxyoleanane-3,28-diones 4a–d were obtained. For that, the...

The present work evaluated the nutritional impact of macroalgae flours used as new ingredients in fermented sausages and the feasibility of using high-pressure processing (HPP) as a non-thermal pasteurization methodology to keep the quality attributes of the new food products. A commercial macroalgae mix was used in the formulation of new macroalga...

A series of 6H,7H-7-(4-Hydroxy-3-coumarinyl)[1]benzopyrano[4,3-b][1]benzopyran-6-ones 4a-g and 3-(2-hydroxybenzoyl)-2H-chromen-2-ones 5a-g derivatives were synthesized by reaction of 4-hydroxycoumarin with 2-hydroxyarylaldehydes 2a-f or 2-hydroxynaphtaldehyde 2g using different solvents and acid/base catalysts. The approach relies on a regioselecti...

The separation and purification of biologically-active compounds from natural sources is of interest because such molecules find wide application in the pharmaceutical sector and in other industrial areas. Roselle (Hibiscus sabdariffa) plants are a good source of anthocyanins, flavonoids, hydroxycitric acid, tartaric acid, ascorbic acid and hibiscu...

Aglaomorpha quercifolia (L.) Hovenkamp & S. Linds is an extensively used species in traditional medicinal systems in several areas of the world due to some important medicinal properties such as antioxidant, antibacterial, analgesic, and anti-inflammatory activities. In East Timor, different parts of this fern are used either as remedies or as food...

Two undescribed viomellein derivatives, xanthoelegansin and spiroxanthoelegansin, were isolated together with clavatol, sitosteanone, vioxanthin, xanthomegnin, viomellein, rubrosulphin, rubrosulphin diacetate, viopurpurin , ochratoxin A, ochratoxin A methyl ester, ochratoxin B and ochratoxin β, from cultures of the marine sponge-associated fungus A...

The most interesting chemistry published in 2019 on the synthesis of O- and S-6-membered heterocycles is reviewed. This personal overview is focused on the developments made on the synthesis of a large variety of natural compounds, specific reactions, and reagents for the preparation of natural and synthetic pyrans, chromenes and chromans, isochrom...

The most interesting chemistry published in 2020 on the synthesis of O- and S-six-membered heterocycles is reviewed. This personal overview is focused on the developments made on the synthesis of a large variety of natural compounds, specific reactions, and reagents for the preparation of natural and synthetic pyrans, chromenes and chromans, isochr...

Aims: Evaluate the ability of chalcones to scavenge hypochlorous acid (HOCl) and modulate oxidative burst. Background: The chemistry of chalcones has long been a matter of interest to the scientific community due to the phenolic groups often present and to the various replaceable hydrogens that allow the formation of a broad number of derivative...

Microencapsulated resveratrol (RSV) is a pertinent ingredient in functional foods to be used in the prevention and management of cardiovascular diseases. Gamma-cyclodextrin (γ-CD) was evaluated for its RSV inclusion ability. Inclusion procedures comprised mixing equal concentration of an aqueous solution of γ-CD with an ethanol solution of RSV and...

A family of iminoboronates was prepared through a one-pot multicomponent reaction, starting from boronic acid, anthranilic acid, and different salicylaldehydes. Their synthesis was straightforward and the complexes were obtained in good to excellent yields. Their photophysical properties were assessed in a diluted solution, and the complexes proved...

The pyrazole nucleus and its reduced forms, pyrazolines and pyrazolidine, are privileged scaffolds in medicinal chemistry due to their remarkable biological activities. A huge number of pyrazole derivatives have been studied and reported over time. This review article gives an overview of pyrazole derivatives that contain a styryl (2-arylvinyl) gro...

Hydroxytyrosol (HT) is an amphipathic functional phenol found in the olive tree, both in its leaves and fruits, in free or bound forms, as well as in olive oil and by-products of olive oil manufacture. The European Food Safety Authority recommends regular consumption of HT due to its several beneficial effects on human health, which are closely ass...

The Box-Behnken design was used to investigate the effect of three independent variables-time, temperature and solvent-to-solid ratio on the responses of total phenolics, total flavonoids, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and cupric ion reducing antioxidant capacity (CUPRAC) of date fruit methanolic extracts. Response surfac...