Isolation of angiotensin converting enzyme (ACE) inhibitory flavonoids from Sedum sarmentosum

Abstract

Bioassay-guided fractionation of the EtOAc-soluble extract of Sedum sarmentosum afforded a new flavonoid, quercetin-3-O-α-(6?- caffeoylglucosyl-β-1,2-rhamnoside) (1), along with four known flavonoids, quercetin 3-O-α-(6?-p-coumaroylglucosyl-β-1,2-rhamnoside) (2), isorhamnetin-3-β-glucopyranoside (3), quercetin-3-β-glucopyranoside (4), and kaempferol-3-α-arabinopyranoside (5). Purification of these compounds was conducted with the application of various chromatographic methods. Compounds 1-5 inhibited angiotensin I converting enzyme (ACE) activity in a concentration-dependent manner. Compounds 1-5 had 50% inhibitory concentration values of 158.9±11.1 μM, 351.6±3.9 μM, 408.9±4.6 μM, 708.8±23.1 μM, and 392.8±13.4 μM.