Chemical constituents in root tuber of Tetrastigma hemsleyanum and their anti-oxidative activities / 中草药

ABSTRACT

Objective: To study the chemical compositions from the root tuber of Tetrastigma hemsleyanum and their anti-oxidative activities. Methods: The compounds were isolated by various column chromatography. Their structures were identified by spectroscopic methods including 1H-NMR, 13C-NMR, MS, HR-MS, etc. The anti-oxidative activities were evaluated by DPPH radical scavenging assay. Results: Fourteen compounds were isolated from the root tuber of T. hemsleyanum, they were identified as kaempferol (1), quercetin (2), salicylic acid (3), benzoic acid (4), oxyresveratrol (5), catechin (6), L-epicatechin (7), epigallocatechin (8), procyanidin B2 (9), procyanidin B1 (10), 3-O-caffeoylquinic acid (11), protocatechualdehyde (12), p-hydroxybenzoic acid (13), and protocatechuic acid (14). The anti-oxidative IC50 values of compounds 2, 8, 9, 10, and 12 were 14.15, 14.19, 15.99, 12.4, and 15.98 μmol/L, respectively, better than the positive control Vit C (IC50 value was 23.0 μmol/L). Conclusion: Compounds 4-12 are isolated from T. hemsleyanum for the first time. It has been demonstrated that the root tuber contain flavonoids and also is rich in organic acids. Moreover, compounds 2, 8, 9, 10, and 12 have the certain prospects in the development of natural anti-oxidative agents.