α-Glucosidase inhibitory phenolics from Echeveria subrigida (B. L. Rob & Seaton) leaves

Echeveria subrigida is native to Mexico and its methanol extract (ME) shows relevant biological activities for human health, including the α-glucosidase inhibitory (αGI) activity that suggests its antidiabetic potential. Fractionation of the ME based on the αGI activity (IC₅₀ in µg/mL) showed that quercetin-3-O-β-glucoside (131.1), isorhamnetin-3-O-β-glucoside (166.4), and dimers to heptamers proanthocyanidins (9.6) were among the main responsible of αGI activity in the ME. The purified compounds showed better activity than acarbose (IC₅₀ = 4426 µg/mL).

Keywords: Echeveria subrigida; alpha-glucosidase inhibition; flavonoids; proanthocyanidins; tannins.