Structure-dependent biological activities of food-related stilbene derivatives isomers

Resveratrol, piceatannol and pterostilbene are stilbene derivatives in which two aromatic rings linked by an olefin bridge. Many stilbene derivatives have proven beneficial to human health, acting on risk factors for cancer, on cardiovascular and neurodegenerative diseases, on diabetes, and on osteoporosis. All these monomeric polyphenols are particularly prone to oligomerization processes through oxidative coupling, originating complex structures such as dimers or oligomers that may be responsible for their beneficial effects. These natural oligomers present stereogenic centers, that could play a pivotal role in the interaction of this class of molecules with biological targets. In this study, isomers of these compounds were synthesized, purified, and tested as for their ability to inhibit enzymes relevant to glucose metabolism (such as brush-border glucosidase and pancreatic alpha amylase), and to control inflammatory response in a suitable Caco-2 cell model. Results highlight the requirement for peculiar structural features as for eliciting individual effects, both in terms of the polymerization state of these phenolics and in terms of their three-dimensional structure.