Flavonoid glucosides from the leaves of Croton tonkinensis Gagnep., Euphorbiaceae

Abstract

Two flavone C-glucosides vitexin (1) and isovitexin (2) were isolated as the major constituents with the total content of 59.5% of the methanol extract of the Croton tonkinensis leaves along with an minor acylated flavonol O-glucoside kaempferol 3-O-β- D-(6’’-O-coumaroyl)glucopyranoside (tiliroside, 3) (0.9%). The structures of 1, 2 and 3 were determined on the basis of ESIMS, 1D and 2D NMR spectroscopic data. Although the flavonoid glucosides found exclusively in the ethyl acetate and n-butanol soluble fractions are reported for antioxidative and antiinflammatory activities their contribution to the medicinal properties of C. tonkinensis is demonstrated to be less than the lipid soluble entkaurene diterpenoid constituents of this plant. Journal of Chemistry, Vol. 42 (1), P. 125 - 128, 2004