[Chemical constituents from stems of Lonicera japonica].

OBJECTIVE: To investigate the chemical constituents from the ethanol extract of the stems of Lonicera japonica. METHOD: The constituents were isolated and purified by repeated column chromatography on silica gel, Sephadex LH-20 and MCI HP-20. Their structures were identified by phsicochemical properties and spectroscopic analysis. RESULT: Thirteen compounds were isolated and identified as protocatechuic acid (1), caffeic acid (2), macranthoin G (3), esculetin (4), luteolin (5), quercetin (6), apigenin (7), luteolin-7-O-beta-D-glucopyranoside (8), isorhamnetin-7-O-beta-D-glucopyranoside (9), diosmetin-7-O-beta-D-glucopyranoside (10), rhoifolin (11), lonicerin (12), hydnocarpin D (13). CONCLUSION: Compound 4, 7, 9-11 were isolated from this plant for the first time, while compound 13 was first reported flavanolignan from this genus Lonicera.