3d image of castalagin skeletal formula

castalagin ellagitannin hydrolyzable tannin oak chestnut wood anogeissus leiocarpus terminalia avicennoides diastereomer vescalagin glycosidic oak barrel aging wines castanea quercus fagaceae anthyocyanin flavonoid acutissimin topoisomerase ii rendering wine winemaking viticultural straw aging polysaccharides biosynthetic catabolism metabolism synthesis phytochemical pathway cycle substrate biogenesis mechanism herb natural enzyme herbalism bioprecursor endogenous precursor metabolite contractor phytoalexin plant