Two new glycosides, farnesyl pentaglycoside and oleanane triglycoside from Lepisanthes rubiginosa, a mangrove plant collected from Thua Thien-Hue province, Vietnam

Phytochemical investigation of the leaves of Lepisanthes rubiginosa led to the isolation of two new glycosides, lepisantheside A (1) and lepisantheside B (2), together with two known compounds acutoside A (3) and 3-O-[β-D-xylopyranosyl-(1→3)-β-D-glucopyranosyl-]-oleanolic acid (4). Their structures were elucidated by means of spectroscopic methods (HR-ESI-MS, 1D and 2D NMR), and by comparison with the reported data. The cytotoxicity of compounds 1-4 against four human cancer cell lines (KB, HepG2, SK-LU-1 and MCF7) was evaluated. Compound 4 exhibited significant activity with IC₅₀ values of 9.57, 6.66, 6.97 and 18.32 µM, respectively, in comparison with the postive control ellipticine.

Keywords: Lepisanthes rubiginosa; Lepisantheside A; Lepisantheside B; cytotoxic activity; farnesyl glycoside; mangrove plant; oleanane glycoside.