Recurvataside, a new saponin from aerial parts of Mussaenda recurvata .

A new glycoside, recurvataside ( 1 ) and six known compounds, quinovic acid ( 2 ), quinovic acid 28- O - β -D-glucopyranosyl ester ( 3 ), 3- O - β -D-glucopyranosylquinovic acid ( 4 ), 3- O - β -D-glucopyranosylquinovic acid 28- O - β -D-glucopyranosyl ester ( 5 ), pomolic acid ( 6 ), and ursolic acid ( 7 ) were isolated from aerial parts of Mussaenda recurvata . The structure of compound 1 was identified from its spectroscopic data and by comparison with the literature. Recurvataside represents the first occurrence of δ -oleanolic acid saponin bearing two D-glucose units at C-3 and C-28 in nature. This is the first time δ -oleanane-type saponin reported in the genus Mussaenda . Compounds 1-7 were evaluated the cytotoxicity against two cancer cell lines MCF-7 and HepG2. Among them, only compound 7 exhibited moderate activity against MCF-7 and HepG2 cell lines with IC 50 value of 16.97 ± 1.55 and 20.28 ± 1.00 μM, respectively. Compounds 1 - 7 were also tested for their inhibitory NO production in LPS-stimulated RAW264.7 cells. Compounds 3 , 5 , and 7 showed significant reduction of nitrite accumulation in LPS-stimulated RAW 264.7 cells with the IC 50 values of 8.81 ± 0.48, 13.42 ± 0.84, and 18.37 ± 0.67 μM, respectively.