Review: Pharmacological effects of Capparis spinosa L.

Medicinal plants have been known as one of the most important therapeutic agents since ancient times. During the last two decades, much attention has been paid to the health-promoting effects of edible medicinal plants, because of multiple beneficial effects and negligible adverse effects. Capparis spinosa L. is one of the most common medicinal plants, used widely in different parts of the world to treat numerous human diseases. This paper aims to critically review the available scientific literature regarding the health-promoting effects of C. spinosa, its traditional uses, cultivation protocols and phytochemical constituents. Recently, a wide range of evidence has shown that this plant possesses different biological effects, including antioxidant, anticancer and antibacterial effects. Phytochemical analysis shows that C. spinosa has high quantities of bioactive constituents, including polyphenolic compounds, which are responsible for its health-promoting effects, although many of these substances are present in low concentrations and significant changes in their content occur during processing. In addition, there is negligible scientific evidence regarding any adverse effects. Different health promotion activities, as well as tremendous diversity of active constituents, make C. spinosa a good candidate for discovering new drugs. However these findings are still in its infancy and future experimental and clinical studies are needed

Induction, purification et caractérisation moléculaire d une quercétinase produite par Penicillium olsonii

Les quercétinases sont des dioxygénases à cuivre produites par différents champignons filamenteux lorsqu ils se développent en présence de flavonols. Elles appartiennent à la voie catabolique de la rutine et catalysent la décomposition de la quercétine en depside avec libération concomitante de monoxyde de carbone. Ce travail a porté sur une quercétinase produite par Penicillium olsonii. Une étude d induction, impliquant les composés phénoliques et les sucres appartenant à la voie catabolique de la rutine, a été entreprise pour comprendre la régulation de la production de l enzyme chez Penicillium olsonii. Cette étude a nécessité la mise au point préalable de la synthèse du produit de la réaction catalysée par la quercétinase, le depside. L enzyme a ensuite été purifiée et partiellement caractérisée. Enfin, une étude génétique a permis de séquencer le gène codant la quercétinase de Penicillium olsonii et d exprimer cette dernière de manière hétérologue chez Saccharomyces cerevisiae.AIX-MARSEILLE3-BU Sc.St Jérô (130552102) / SudocSudocFranceF

Diversion of a thioglycoligase for the synthesis of 1-O-acyl arabinofuranoses

International audienceAn arabinofuranosylhydrolase from the GH51 family was transformed into an acyl transferase by mutation of the catalytic acid/base amino acid. The resulting enzyme was able to transfer carboxylic acid onto the anomeric position of arabinose with complete chemo- and stereoselectivity. A wide range of acyl α-l-arabinofuranoses was obtained with yields ranging from 25 to 83%. Using this method, ibuprofen and N-Boc phenylalanine were successfully transformed into their corresponding acyl conjugates, expanding the scope of the reaction to drugs and amino acids

Modulation of the Activity and Regioselectivity of a Glycosidase: Development of a Convenient Tool for the Synthesis of Specific Disaccharides

The synthesis of disaccharides, particularly those containing hexofuranoside rings, requires a large number of steps by classical chemical means. The use of glycosidases can be an alternative to limit the number of steps, as they catalyze the formation of controlled glycosidic bonds starting from simple and easy to access building blocks; the main drawbacks are the yields, due to the balance between the hydrolysis and transglycosylation of these enzymes, and the enzyme-dependent regioselectivity. To improve the yield of the synthesis of β-d-galactofuranosyl-(1→X)-d-mannopyranosides catalyzed by an arabinofuranosidase, in this study we developed a strategy to mutate, then screen the catalyst, followed by a tailored molecular modeling methodology to rationalize the effects of the identified mutations. Two mutants with a 2.3 to 3.8-fold increase in transglycosylation yield were obtained, and in addition their accumulated regioisomer kinetic profiles were very different from the wild-type enzyme. Those differences were studied in silico by docking and molecular dynamics, and the methodology revealed a good predictive quality in regards with the regioisomer profiles, which is in good agreement with the experimental transglycosylation kinetics. So, by engineering CtAraf51, new biocatalysts were enabled to obtain the attractive central motif from the Leishmania lipophosphoglycan core with a higher yield and regioselectivity.</jats:p