Abstract

Leaves from two Chilean Phaseolus vulgaris landraces cultivated in a growth chamber were assessed for total phenolic (TP), total flavonoid (TF) content and composition, as well as inhibition of alpha-glucosidase at three different development stages and three sampling times to determine the optimum production of bioactive constituents. The chemical profiles were obtained by HPLC-DAD and UHPLC-MS. We observed qualitative and quantitative differences in the phenolic profile in the Tortola and Negro landraces, with a more complex profile in Tortola. Leaf development and collection time significantly affected (P 0.05) the phenolic composition and alpha-gluco-sidase inhibitory activity. Higher enzyme inhibition was found in mature leaves of the Negro landrace with an IC50 value of 0.55-0.89 mu g/mL, regardless of collection time. A significant correlation (P 0.05) was observed between alpha-glucosidase inhibition (r = 0.572) and caffeoyl malic acid concentration in the extracts. Our results provide a first approach to the accumulative dynamics of alpha-glucosidase inhibitors in the leaves of Chilean bean landraces, supporting their possible use as a source of bioactive compounds.