New advanced glycation end-products inhibitors from Dichrostachys cinerea Wight & Arn

Free radical scavenging and advanced glycation end-product (AGE) inhibitory potential were evaluated in the crude methanol extract of Dichrostachys cinerea. Bioassay-guided isolation led to the identification of four flavan-3-ols, namely (−)-mesquitol (1), oritin (2), (−)-festidinol (3) and (−)-epicatechin (4). Analysis of structure–activity relationships revealed that the presence of 7,8-dihydroxyl groups in the A-ring of flavan-3-ols in conjunction with 3′,4′-dihydroxyls in the B-ring (1) is an important criterion for displaying potent AGE inhibitory activity along with free radical scavenging properties. (−)-Mesquitol (1), oritin (2), and (−)-festidinol (3) were found to be new natural AGE inhibitors. (−)-Mesquitol (1) displayed the most potent AGE inhibitory activity. Results suggest that (−)-mesquitol (1) may serve as an important natural organic lead compound for future development of antiglycating agents along with potent antioxidant activity.