Photoprotection capacity of resveratrol on histidine oxidation

NEYRA RECKY, JAEL R.; DANTOLA, MARIA LAURA; LORENTE, CAROLINA

Congreso; Latinxchem; 2021

L-histidine (HIS) is an essential amino acid.Participation as coenzyme, in proton buffering, metal ion chelation, scavenging of reactive oxygen and nitrogen species.Resveratrol (RSV) belongs to stilbene subgroup of antioxidants found in more than 70 plant species, including edible fruit and vegetable (grapes, cranberries, peanuts, cocoa). RSV is present in red wine, and it was involved playing a key role in the ?French paradox?, that relates an unhealthy diet, which includes cheese and red wine, with a low incidence of cardiovascular events. Under UVA or visible radiation in the presence of a suitable photosensitizer (PS), HIS undergoes oxidation starting with the loss of an electron to yield His radical cation (His?+). In the present work, pterin was used as PS. Aqueous solutions containing HIS, RSV and Ptr were exposed to UVA Radiation.All experimental evidence indicates that RSV reduces the rate of HIS consumption by acting as an electron donor allowing the recovery of the amino acid, after a PCET reaction with Ptr in its excited triplet state. These results are of a great relevance since His is a critical amino acid for the functionality of several enzymes and it is also extremely susceptible to oxidation in electron transfer reactions. Since the formation of HIS?+ often is the first step in HIS degradation, protection that RSV provides should be considered in food technology, medicinal and / or cosmetic products.