A new iridoid glycoside from Vitex negundo Linn (Verbenacea)

Five compounds have been isolated from the leaves of Vitex negundo Linn (Verbenacea) and their structures established by spectral analysis. Compound 1 has been identified and characterised as a new iridoid with a novel structure which has never before been reported in literature from Vitex or any other source. Its structure has been established as 1,4a,5,7a-tetrahydro-1-beta-D-glucosyl-7-(3',4'-dihydroxybenzoyloxymethyl)-5-ketocyclopenta[c]pyran-4-carboxylic acid. Other compounds, 2, 3, 4 and 5, have been identified as luteolin-7-O-beta-D glucoside, nishindaside, negundoside, and agnuside, respectively. Compound 2, a flavone-O-glycoside, is being reported from this plant for the first time, and compounds 3, 4 and 5 are structurally known iridoids.