Isolation and identification of flavonoidal constituents from the leaves of Lonicera japonica Thunb.

Objective To study the flavonoidal constituents from the 75% ethanol extract of the leaves of Lonicera japonica Thunb.Methods The compounds were isolated by chromatography on silica gel column,Sephadex LH-20 column,and identified on the basis of physico-chemical constant and spectral analysis.Results Seven compounds were isolated and identified as 5,7,4′-trihydroxy-8-methoxyflavone(1),luteolin(2),tricin(3),kaempferol-7-O-β-D-glucopyranoside(4),luteolin-7-O-β-D-glucopyranoside(5),apigenin-7-O-β-D-glucopyranoside(6) and diosmetin-7-O-β-D-glucopyranoside(7),respectively.Conclusions Compounds 1,4 are obtained from this genus for the first time,and compounds 3,6,7 are obtained from this plant for the first time.