Antielastase and free radical scavenging activities of compounds from the stems of Cornus kousa.

Bioassay-guided investigation of the stems of Cornus kousa led to the isolation of 12 compounds such as four triterpenoids: betulinic acid (1), maslinic acid (2), arjunolic acid (3), 3-isoarjunolic acid (4), four flavanoids; catechin (5), epi-catechin (6), 2-hydroxynaringenin (7), 2-hydroxynaringenin-7-O-beta-D-glucopyranoside (8), two ellagic acid derivatives; 3,4,3'-tri-O-methylellagic acid (9), 3,4-di-O-methylellagic acid (10), a daucosterol (11) and a sucrose derivative; (3'-O-p-coumaroyl)-beta-D-fructofuranosy-(2?1)-(6-O-p-coumaroyl)-alpha-D-glucopyranoside (12). Their structures were elucidated on the basis of spectroscopic studies as well as by comparison with available data in the literature. The free radical scavenging activity and elastase inhibition activity were investigated for the development of antiaging ingredients as a raw material for use in cosmetics. Among these compounds, compounds 1, 2 and 8 showed significant elastase inhibition activity and IC(50) was 10.81 microg/mL, 21.21 microg/mL and 44.63 microg/mL, respectively, on porcine pancreatic elastase, whereas compounds 5, 6, 7 and 8 showed significant free radical scavenging activity and SC(50) was 8.37 microg/mL, 9.31 microg/mL, 9.23 microg/mL and 17.45 microg/mL, respectively.