Synthesis of pure stereoisomers of benzo[b]thienyldehydrophenylalanines by Suzuki cross-coupling : preliminary studies of antimicrobial activity

Several benzo[b]thienyldehydrophenylalanines were synthesized from pure stereoisomers of the methyl ester of N-(tert-butoxycarbonyl)-beta-bromodehydrophenylalanine as an extension of our previously reported method for the synthesis of dehydrotryptophan analogues to dehydrophenylalanine derivatives. The latter were obtained in high yields by N-deprotection and bromination of N,N-bis-(tert-butoxycarbonyl)-(Z)-dehydrophenylalanine using TFA and NBS. This was carried out in two steps or in a one pot procedure resulting in different E/Z ratios. These compounds were coupled under Suzuki cross-coupling conditions [Pd(PPh3)4, Na2CO3, DME/H2O] with several boronic benzo[b]thienyl acids in good to high yields maintaining the stereochemistry of the starting materials. The best yields were obtained when the boronic acid was in position 7 of the benzo[b]thiophene and with the E isomer of the brominated dehydrophenylalanine. In some cases it was possible to increase the lower yields by changing the Pd source to PdCl2(PPh)2. A model dipeptide was prepared coupling a benzo[b]thienyldehydrophenylalanine with the methyl ester of alanine. Preliminary antimicrobial studies were performed with both isomers of one of the beta,beta-diaryldehydroalanines obtained. The results show that the compounds are selective and very active (very low MICs) against Gram positive bacteria (B. cereus and B. subtilis) the Z-isomer being more active. The compounds are also active against Candida albicans presenting similar MICs.Fundação para a Ciência e Tecnologia - POCTI/1999/QUI/32689, SFRH/BD/4709/2001

New perspectives of Juglans regia L. phytochemicals against Candida species

Opportunistic fungal infections have deserved special relevance in the last decades, presenting itself, a serious problem in terms of public health. Despite Candida albicans was considered the main agent responsible for those infections, other non-albicans Candida species have also been described in the last years [1-3]. Most of the species are susceptible to antimicrobial drugs, but recently it has been observed a growing number of microorganisms with drug resistance. Therefore, the discover/use of alternative therapies is crucial [4]. Juglans regia L. (walnut) leaves are commonly used in traditional medicine as antiseptic, antimicrobial and anti-inflammatory [5]; those benefits could be related with its richness in phenolic compounds [6]. In the present work, the antifungal potential of the hydroalcoholic extract prepared from walnut leaves was evaluated against a total of nineteen Candida strains (from the species: C.albicans, C.glabrata, C.parapsilosis and C.tropicalis), using the disc diffusion halo assay. All the tested strains were sensible to the plant extract. The obtained values of the inhibitory zones ranged between 0.9-1.4 cm, being the halo maintained after 48h. The observed antifungal activity is certainly related to the phenolic compounds previously determined in the extract [6]: five phenolic acid derivatives- caffeoylquinic and p-coumaroylquinic acid derivatives, two dimers and one trimer of procyanidins, twelve flavonols- quercetin, myricetin and kaempferol derivatives, and five taxifolin O-pentoside isomers; 3-O-caffeoylquinic acids and quercetin O-pentoside were the main phenolic compounds. Further studies are necessaries in order to elucidate the most active compounds and the specific role of each one. REFERENCES [1] Kim J, Sudbery P. (2011) J Microbiol. 49, 171-177. [2] Tsai P-W, Chen Y-T, Hsu P-C, Lan C-Y. (2013) BioMedicine. 3, 51–64. [3] Vázquez-González D, Perusquía-Ortiz AM, Hundeiker M, Bonifaz A. (2013) J Ger Soc Dermatology. 11, 381–94. [4] Kanafani ZA, Perfect JR. (2008) Clin Infect Dis - Antimicrob Resist. 46, 120–128. [5] Murray MT. (2004) 2nd ed. New York, NY. Random House. [6] Santos A, Barros L, Calhelha RC, Dueñas M, Carvalho AM, Santos-Buelga C, Ferreira ICFR. (2013) Ind Crops Prod. 51, 430-436.Instituto Nacional de Saúde Dr. Ricardo Jorg

Leaves and decoction of Juglans regia L.: Different performances regarding bioactive compounds and in vitro antioxidant and antitumor effects

Juglans regia L. (walnut) leaves are considered a source of healthcare compounds, and have been widely used in traditional medicine. Furthermore, they have been reported as a source of bioactive molecules such as the antioxidant phenolic compounds. In the present study, organic acids, mono and oligosaccharides, and tocopherols were analyzed in leaves and decoction (widely used for topical applications). Furthermore, the phenolic composition and bioactivity of walnut leaves was determined in its decoction and methanol extract. Malic acid, sucrose, alpha-tocopherol and 3-O-caffeoylquinic acids and quercetin O-pentoside were the most abundant organic acid, disaccharide, tocopherol isomer and phenolic compounds, respectively. Methanol extract presented higher antioxidant and antitumor potential than decoction; both samples did not show toxicity for non-tumor liver primary cells. This study provides a more complete characterization of phenolic compounds of walnut leaves, and as far as we know, this is the first time that the presence of procyanidins and taxifolin derivatives, as also tocopherols were reported in J. regia leaves.The authors are grateful to Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011). L. Barros and R.C. Calhelha also thank to FCT, POPH-QREN and FSE for their grants (SFRH/BPD/4609/2008 and SFRH/BPD/68344/2010, respectively). The GIP-USAL is financially supported by the Spanish Government through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063). M. Duenas thanks the Programa Ramon y Cajal for a contract

Boletus aereus growing wild in Serbia: chemical profile, in vitro biological activities, inactivation and growth control of food-poisoning bacteria in meat

Boletus aereus Bull. is a bolete, an edible mushroom frequently consumed all over the globe as a delicate mushroom, especially in Serbia, Portugal, Basque Country, Navarre, France and Italy. B. aereus was showed to be rich in carbohydrates (82.58 g/100 g dw), followed by proteins (7.86 g/100 g dw), ash (6.20 g/100 g dw) and fat (3.36 g/100 g dw). The most abundant sugar was identified as trehalose (11.28 g/100 g dw); three tocopherol isoforms (α-, β- and δ-tocopherols) were detected. Unsaturated fatty acids predominated over saturated fatty acids, with oleic and linoleic acids as the most dominant ones. p-Hydroxybenzoic (8.95 μg/100 g dw), p-coumaric (7.32 μg/100 g dw) and cinnamic (5.91 μg/100 g dw) acids were quantified, as also four organic acids: oxalic (0.69 g/100 g dw), citric (0.59 g/100 g dw), quinic (0.34 g/100 g dw), and fumaric (0.20 g/100 g dw) acids. The mushroom methanol extract showed in vitro antioxidant and antimicrobial activities, and successively inhibited the growth of meat contaminant bacteria, both at 25ºC and 4ºC, after 7 days of inoculation.The authors are grateful to Foundation for Science and Technology (FCT, Portugal) and COMPETE/QREN/EU for financial support to CIMO strategic project PEst-OE/AGR/UI0690/2011 and L. Barros contract. The authors also thank to SerbianMinistry of Education, Science and Technological Development for financial support (grant number 173032). The authors kindly thank to Nada Lazic for the harvest of the Boletus aereus sample

Antibacterial potential of northeastern Portugal wild plant extracts and respective phenolic compounds

The present work aims to assess the antibacterial potential of phenolic extracts, recovered from plants obtained on the North East of Portugal, and of their phenolic compounds (ellagic, caffeic, and gallic acids, quercetin, kaempferol, and rutin), against bacteria commonly found on skin infections. The disk diffusion and the susceptibility assays were used to identify the most active extracts and phenolic compounds. The effect of selected phenolic compounds on animal cells was assessed by determination of cellular metabolic activity. Gallic acid had a higher activity, against gram-positive (S. epidermidis and S. aureus) and gram-negative bacteria (K. pneumoniae) at lower concentrations, than the other compounds. The caffeic acid, also, showed good antibacterial activity against the 3 bacteria used. The gallic acid was effective against the 3 bacteria without causing harm to the animal cells. Gallic and caffeic acid showed a promising applicability as antibacterial agents for the treatment of infected wounds.The authors thank the Foundation for Science and Technology (Portugal) for financial support by the E. Pinho grant (SFRH/BD/62665/2009) and L. Barros grant (SFRH/BPD/4609/2000), and by the projects PEst-OE/EQB/LA0023/2013, PEst-C/CTM/UI0264/2011, and PEst-OE/EQB/LA0023/2013. Also, the authors acknowledge the financial support from FEDER through Programa Operacional Factores de Competitividade-COMPETE and to COMPETE/QREN/EU (CIMO strategic project 19 PEst-OE/AGR/UI0690/2011), and through the Project "BioHealth-Biotechnology and Bioengineering approaches to improve health quality", Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. The authors also acknowledge the project "Consolidating Research Expertise and Resources on Cellular and Molecular Biotechnology at CEB/IBB", Ref. FCOMP-01-0124-FEDER-027462

Edifícios de xisto no concelho de Peso da Régua

A pedra de xisto é um material natural e local comummente utilizado nas construções tradicionais do Concelho de Peso da Régua. Esta zona do Nordeste Português está inserida na região do Douro que é classificada como Património Mundial pela UNESCO. Os muros de divisão de terrenos, de suporte de terras e os edifícios de construção tradicional são os tipos de construção em que a pedra de xisto é o material dominante. Estas construções são parte integrante da paisagem e do património vernacular local, e por isso devem ser valorizados e preservados. Através deste trabalho de investigação foi possível realizar um levantamento dos edifícios de xisto existentes neste concelho, e reunir um conjunto de informações técnicas e construtivas que os caracterizam. Este artigo pretende divulgar informação técnica relativa a detalhes construtivos deste tipo de construção tradicional, focada principalmente nas suas especificidades estruturais. No contexto estrutural, as paredes de alvenaria de pedra de xisto são os elementos estruturais verticais principais. As dimensões e constituição das paredes, dos vãos de janela e de porta, dos cunhais e das padieiras são alguns dos aspectos técnicos e construtivos que merecem especial destaque, tendo em conta que podem influenciar de forma decisiva o comportamento estrutural deste elemento construtivo. Deste modo, pretende-se contribuir para o conhecimento deste tipo de construção, e disponibilizar informação base que possa suportar estudos futuros de modelação numérica e/ou ensaios experimentais do comportamento de paredes em alvenaria de pedra de xisto

Coprinopsis atramentaria extract, its organic acids, and synthesized glucuronated and methylated derivatives as antibacterial and antifungal agents

Despite the available data regarding antimicrobial activity of phenolic acids, studies dealing with the effects of their metabolites or derivatives are scarce. Therefore, the antimicrobial and demelanizing activities of Coprinopsis atramentaria extract, its organic acids, and methylated and glucuronated derivatives were evaluated. The antifungal activity was stronger than the antibacterial effects. In general, individual compounds (mostly organic acids) exhibited higher activity than the extract and even higher than the standards used in the assays. Methylated derivatives presented the highest demelanizing activity toward Aspergillus niger, A. fumigatus and Penicillium verrucosum var. cyclopium. The inclusion of methyl groups in the parental compound (CoAM1, CoAM2 and CoAM3) strongly increased antibacterial and antifungal activities of CoA, while the inclusion of acetyl groups (CoAGP) increased the antifungal activity but the antibacterial properties were maintained. For HA and CA, the inclusion of methyl groups (HAM1, HAM2, HAM3 and CAM) increased the demelanizing activity, but decreased the antimicrobial properties. The present work contributes to the knowledge of the mechanisms involved in the antimicrobial properties of organic acids namely, phenolic acids, usually present in mushrooms. Organic acids, and methylated and glucuronated derivatives could be used as antimicrobial agents.The authors are grateful to Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) for financial support to the Portuguese NMR network and to FCT and FEDER-COMPETE/QREN/EU for the financial support through the research project PTDC/AGR-ALI/110062/2009 and the research centres (PEst-C/QUI/UI0686/2011 and PEst-OE/AGR/UI0690/2011). S. A. Heleno (BD/70304/2010) also thanks FCT, POPH-QREN and FSE for her grant. The authors also thank Serbian Ministry of Education, Science and Technological development (grant number 173032) for financial support

Synthesis of tricyanovinyl-substituted thienylpyrroles and characterization of the solvatochromic, electrochemical and non-linear optical properties

Tricyanovinyl-substituted 1-(alkyl)aryl-2-(2´-thienyl)pyrroles 1 have been synthesized by direct tricyanovinylation reaction of 1-(alkyl)aryl-2-(2´-thienyl)pyrroles 2 using TCNE. The tricyanovinyl- derivatives 1 display dramatic reductions in both their optical and electrochemical band gaps relative to thienylpyrrole precursors 2. The solvatochromic behavior of compounds 1 was investigated in a variety of solvents. Hyper-Rayleigh scattering was used to measure the first hyperpolarizabilities β of the mentioned compounds. The β values show that the new compounds prepared could be used on the manufacture of materials with good non-linear (NLO) properties.Fundação para a Ciência e Tecnologia (FCT) - POCTI, FEDER (ref.POCTI/QUI/37816/2001)

Nutrients, phytochemicals and bioactivity of wild Roman chamomile: a comparison between the herb and its preparations

Roman chamomile, Chamaemelum nobile L. (Asteraceae), has been used for medicinal applications, mainly through oral dosage forms (decoctions and infusions). Herein, the nutritional characterisation of C. nobile was performed, and herbal material and its decoction and infusion were submitted to an analysis of phytochemicals and bioactivity evaluation. The antioxidant activity was determined by free radicals scavenging activity, reducing power and inhibition of lipid peroxidation, the antitumour potential was tested in human tumour cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture. C. nobile proved to be an equilibrated valuable herb rich in carbohydrates and proteins, and poor in fat, providing tocopherols, carotenoids and essential fatty acids (C18:2n6 and C18:3n3). Moreover, the herb and its infusion are a source of phenolic compounds (flavonoids such as flavonols and flavones, phenolic acids and derivatives) and organic acids (oxalic, quinic, malic, citric and fumaric acids) that showed antioxidant and antitumour activities, without hepatotoxicity. The most abundant compounds in the plant extract and infusion were 5-O-caffeoylquinic acid and an apigenin derivative. These, as well as other bioactive compounds, are affected in C. nobile decoction, leading to a lower antioxidant potential and absence of antitumour potential. The plant bioactivity could be explored in the medicine, food, and cosmetic industries.The authors are grateful to strategic project PEst-OE/AGR/UI0690/2011 for financial support to CIMO. R. Guimaraes, L. Barros and R. Calhelha thanks to FCT, POPH-QREN and FSE for their Grants (SFRH/BD/78307/2011, SFRH/BPD/4609/2008 and SFRH/BPD/68344/2010). The GIP-USAL is financially supported by the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063). M. Duenas thanks the Spanish "Ramon y Cajal" Programme for a contract