Current Organic Chemistry - Volume 16, Issue 6, 2012

... Naturally occurring (poly)phenols are secondary metabolites that constitute an ubiquitous family of natural products, encountered in both plant1 and marine sources2. For illustration, the number of (poly)phenols isolated from the plant kingdom alone already amounts to several thousands (!) and this number still increases in a continuous and impressive manner. Fortunately, Mother Nature does not accomplish the combinatori Read More

Polyphenols having catechol (1,2-dihydroxybenzene) nuclei are strong in vitro antioxidants owing to their ability to rapidly reduce reactive oxygen species (ROS), bind transition metal ions as inert complexes and regenerate the potent chain-breaking antioxidant α -tocopherol. Polyphenols provide antioxidant protection to plants by acting as electron donors to peroxidases that reduce hydrogen peroxide into water. Polyphen Read More

Copigmentation is the main colour-stabilizing mechanism in plants and in food products of vegetable origin. It is a spontaneous and exothermic process that consists of the stacking of an organic molecule, called copigment, on the planar polarizable moieties of the anthocyanin coloured forms. Although this phenomenon has long been described, there are some aspects that are still not well understood or controversial lik Read More

The interactions between polyphenols and proteins have been long described from both nutritional and pharmaceutical perspectives, being relevant for some sensorial and biological properties. Several variables known to drive these interactions have been extensively assayed and are still being presently studied by some research groups. The different physical-chemical features influencing protein- polyphenol interactio Read More

Cinnamic acid and its phenolic analogues are natural substances. Chemically, cinnamic acids or the 3-phenyl acrylic acids, offer three main reactive sites: substitution on the phenyl ring, addition on the α ,β -unsaturation and reactions of the carboxylic acid. Owing to these chemical aspects, cinnamic acid derivatives received much attention in medicinal research as traditional as well as valuable scaffolds in recent synthetic bi Read More

For long manned space missions, regenerative life support systems must provide carbohydrates. In addition to the necessity to develop such fully closed systems, the formose reaction (FR), the alkaline polymerisation of formaldehyde using Ca(OH)2, seems to be the only current single-step method for the production of synthetic carbohydrates. The FR received much attention with regard to edible carbohydrate production d Read More

The present review provides a comprehensive summary of microwave-assisted preparation of five-membered azaheterocyclic systems, such as pyrrole, pyrazole, imidazole, triazole, thiazole, isothiazole, oxazole, isoxazole, oxadiazole, thiadiazole and tetrazole.