Four Steroidal Saponins from the Trunks of Dracaena cambodiana with Inhibition of NO Production in LPS Activated RAW264.7 Cells

Dracaena cambodiana Pierre ex Gagnep. is well known as a medicinal plant and widely distributed in Vietnam. Phytochemical investigation on the trunks of D. cambodiana lead to the isolation of four undescribed compounds (1-4) together with seven known ones (5-11). Their structures were determined to be pennogenin-24-yl-O-beta-D-glucopyranoside (1), 17 alpha-hydroxycambodianoside C (2), (25R)-27-hydroxypenogenin 3-O-alpha-L-rhamnopyranosyl-(1 -> 3)-[alpha-L-rhamnopyranosyl-(1 -> 2)]-beta-D-glucopyranoside (3), (3 beta,25R)-17 alpha,22 alpha-dihydroxy-furost-5-en-3-yl-O-alpha-L-rhamnopyranosyl-(1 -> 3)-[alpha-L-rhamnopyranosyl-(1 -> 2)]-beta-D-glucopyranoside (4), dracagenin A (5), 1-O-beta-D-glucopyranosyl-2-hydroxy-4-allylbenzene (6), 1-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranosyl-2-hydroxy-allylbenzene (7), 2-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranosyl-1-hydroxy-allylbenzene (8), cinnamrutinoside A (9), icariside D1 (10), and seco-isolariciresinol 9-O-beta-glucopyranoside (11) by extensive spectroscopic investigation, HR-ESI-MS, 1D and 2D NMR spectra. The anti-inflammatory activity of the isolated compounds was evaluated on macrophages. Compounds 1-6 significantly inhibited nitric oxide production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Among them, compound 1 showed the best inhibitory activity with an IC50 value of 8.90 +/- 0.56 mu M.