Antioxidant Activity of Tetraterpene Glycosides from the Fruits of Lycium Chinense Miller

Lycium chinense, a famous Chinese medicinal herb, has long history of use as a traditional remedy for many disease. Two compounds 6-(1,1,5-trimethyl-5 a -hydroxycyclohexanyl)-6'-(1', 1', 5'-trimethyl-2' b -hydroxycyclohexanyl)-9,13,9', 13'-tetramethyloctadec7,9,11,13,15,7', 9', 11', 13'-nonene-5 a -D-arabinopyranosyl (2a -> 1b)-beta-D-arabinopyranosyl-(2b -> 1c)-beta-D-arabinopyranosyl-2'-b -Darabinopyranosyl-( 2d -> 1e)-alpha-D-arabinopyranosyl-(2e -> 1f)-alpha-D-arabinopyranoside (1) and 1(6), 11(12), 13(14), 1'(6'), 11'(12'), 13'(14')dodecahydro- b -caroten-4 b, 4' beta-diol-4 b -L-arabinopyranosyl-(2a -> 1b)-beta-L-arabinopyranosyl-(2b -> 1c)-beta-D-arabinopyranosido-4' beta-Larabinopyranosyl-( 2d -> 1e)-beta-L-arabinopyranosyl-(2e -> 1f)-beta-D-arabinopyranoside (2) were isolated from the butanol fraction of methanol extract of fruits of L. chinense. The compounds (1 and 2) were investigated for scavenging of the diphenylpicrylhydrazyl (DPPH) radical scavenging activity, reducing power and the phosphomolybdenum activity and the results demonstrate that the compound 1 has potential as a natural antioxidant whereas the compound 2 exhibited moderate antioxidant activity.