Showing papers in "Progress in the chemistry of organic natural products. Progrès dans la chimie des substances organiques naturelles in 2007"

The trichothecenes and their biosynthesis.

Abstract: The trichothecenes are a group of naturally-occurring sesquiterpenoid epoxides which show a broad range of biological activity. They are powerful inhibitors of eukaryotic protein synthesis, are phytotoxic, insecticidal and toxic to animals, and some are among the most toxic nonnitrogenous compounds known to man. Several are commonly found in cereal grains, and the potential health risk from contaminated animal feed and human food is a major factor in stimulating research into this group of compounds. Since the isolation of the macrolide mixture, glutinosin t(1), was reported in 1946, the body of trichothecene literature has expanded to some 3000 publications

Synthesis pathways to Erythrina alkaloids and Erythrina type compounds.

Abstract: The history of erythrina research begins at the end of the 19th century. During the last two decades of that time extracts from species of Erythrina have been found to exhibit curare-like neuromuscular blocking activities which are caused by alkaloids occurring therein (1, 2, 3, 4).

Melanin, melanogenesis, and vitiligo.

Abstract: Melanins, pigments of diverse origin and chemical function, have been subjects of interest for a long time (Aristotle, in “Historia Animalia”, 315 B.C.). These natural cosmetics of skin, hair, and feathers usually occur in the form of insoluble fine granules in certain dendritic cells of the epidermis. The term melanin (μɛλαζ = black) is, however, misleading and confusing since not all biogenetically related pigments are black. The melanogenic enzyme, tyrosinase, is known to catalyze the biosynthesis of not only black but also red to brown, or even yellow pigments, e.g. pheomelanins (208, 266). On the other hand, the fascinating colors in the feathers of birds, skins of reptiles and fishes and the blue eyes in animals are optical phenomena due to diffraction, light absorption and scattering, interference, that are produced by melanin granules either in combination or not, with other pigmentary colors (94, 156) and by complex formation of the granules with heavy metals (21, 156).