Chemical constituents from Sonneratia ovata Backer and their in vitro cytotoxicity and acetylcholinesterase inhibitory activities.

Sonneratia ovata Backer, Sonneratiaceae, is a widespread plant in mangrove forests in Vietnam, Cambodia, Thailand, Indonesia. Sonneratia ovata's chemical composition remains mostly unknown. Therefore, we now report on the structural elucidation of three new phenolics, sonnerphenolic A (1), sonnerphenolic B (2), and sonnerphenolic C (23), a new cerebroside, sonnercerebroside (3) together with nineteen known compounds, including nine lignans (5-13), two steroids (14, 15), two triterpenoids (16, 17), three gallic acid derivatives (18-20), two phenolic derivatives (4, 22) and a 1-O-benzyl-β-d-glucopyranose (21) isolated from the leaves of Sonneratia ovata. Their chemical structures were established by spectroscopic data, as well as high resolution mass spectra and comparison with literature data. The in vitro acetylcholinesterase (AChE) inhibition and cytotoxic activities against HeLa (human epithelial carcinoma), NCI-H460 (human lung cancer), MCF-7 (human breast cancer) cancer cell lines and PHF (primary human fibroblast) cell were evaluated on some extracts and purified compounds at a concentration of 100 μg/mL. Compounds (5, 6, 23) exhibited cytotoxicity against the MCF-7 cell line with the IC50 values of 146.9±9.0, 114.5±7.2, and 112.8±9.4 μM, respectively, while they showed nontoxic with the normal cell (PHF) with IC50s >277 μM. Among 15 tested compounds, (S)-rhodolatouchol (22) showed inhibition against AChE with an IC50 value of 96.1±14.5 μM.