Structure-activity relationship of procyanidins on advanced glycation end products formation and corresponding mechanisms

•This study reported a systematic study of different structures of procyanidins on the mechanism of AGEs inhibition for the first time.•CC was found to be more efficient than EC as inhibitor of RO, OH and CHO radicals, which may be the primary reason that CC was more effective than EC on AGEs inhibition.•This study illustrates the mechanism of CC and EC inhibition of AGEs by comprehensive applications of LC-MS/MS, ESR and molecular docking. Nonenzymatic glycosylation (NEG) can generate advanced glycation end products (AGEs) and its intermediates α-dicarbonyl compounds, which contribute to the risk of diabetes. This study investigated the anti-glycation mechanisms and structure–activity relationship of (+)-catechin (CC) and (−)-epicatechin (EC). The results showed that the effect of CC on inhibiting AGEs was significantly better than that of EC (p