Isolation and antioxidant activity of chemical constituents from Vitex gardneriana Schauer

Abstract

Vitex gardneriana Schauer (Verbenaceae) popularly known as “jaramataia”, is a shrub commonly found in caatinga biome located in Northeast Brazil. In folk medicine, its leaves have been used as analgesic and anti-inflammatory agents. Chromatographic analysis of leaf extracts, stem bark, wood and roots of V. gardneriana allowed isolation of the mixture ursolic and oleanolic acids (1 and 2), 4-hydroxy-3-methoxybenzoic (3) and 4-hydroxybenzoic acid (4) and four more compounds: 4-carboxyphenyl 4-hydroxy-3-methoxybenzoate (5), acid 2I±, 3I±, 19I±-trihydroxyursan-12-en-oic (6), 3,4-dihydroxybenzoic acid (7) and 5-Hydroxy-3,7,4’-trimethoxyflavone (8)all compounds are being reported for the first time in the genus Vitex. Structural elucidation was done on the basis of spectral data, mainly by high field NMR. For the antioxidant assays, 4-carboxyphenyl 4-hydroxy-3-methoxybenzoate was able to reduce DPPH free radicals, as well as inhibit AŸ-carotene oxidation on a level of 95 and 50%, respectively, demonstrating high and moderate antioxidant ability when compared with controls quercetinand BHA.