RESUMEN
Objective To study the chemical constituents from the flower buds of Lonicera macranthoides and their antitumor activities. Methods The constituents were separated by chromatography of silica gel, ODS, Sephadex LH20, and semi-pre HPLC. Their structures were elucidated by spectral means. The in vitro cytotoxic activities of the isolated compounds were studied by MTT method. Results Seven compounds were isolated and identified as 3-O-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl- hederagenin 28-O-β-D-glucopyranosyl ester (1), 3-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-oleanolic acid 28-O-α- L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (2), 3-O-α-L-rhamnopyranosyl-(1→2)-α-L- arabinopyranosyl-hederagenin 28-O-β-D-glucopyranosyl ester (3), 3-O-α-L-rhamnnopyranosyl-(1→2)-α-L-arabinopyranosyl- hederagenin 28-O-α-L-rhamnopyransyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (4), 3-O-α-L-arabinopyranosyl- hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (5), 3-O-β-D-glucopyra- nosyl-(1→4)-α-L-arabinopyranosyl-hederagenin 28-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside ester (6), and 3-O-β-D-glucopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-hederagenin 28-O-α-L-rhamno- pyranosyl-(1→4)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (7). Conclusion Compound 1 is a new compound named macranthoidin C, and compounds 2-7 are isolated from L. macranthoides for the first time. Compounds 1, 4, and 5 show cytotoxicities against HeLa cells with IC50 of 54.3, 43.9 and 61.2 μmol/L, respectively.