New erythritol derivatives from the fertile form of Roccella montagnei. (May 2017) - Duong, Thuc Huy
Abstract: Chemical investigation of the methanol extract of the fertile form of Roccella montagnei collected in Vietnam afforded twelve secondary metabolites, including five new montagnetol derivatives, orsellinylmontagnetols A−D and a furanyl derivative together with seven known compounds. Their chemical structures were elucidated by analysis of 1D and 2D NMR and high resolution mass spectroscopic data. The relative stereochemistry of two chiral centers (C-2 and C-3) of orsellinylmontagnetols A and B was elucidated by comparison of their coupling constants and the specific rotation with those reported in the literature while the absolute stereochemistry was determined by the application of a modified Mosher method for the hydroxy group at C-3. The absolute configuration (2 R, 3 S ) of the butanetetraol moiety of these compounds is in accordance with that of erythrin, a recognized chemotaxonomic marker of the genus Roccella . Five of these compounds were evaluated for their cytotoxic activities against four cancer cell lines. Only orsellinylmontagnetol A exerted a moderate activity against MCF-7 cell line with an IC50 value of 68.39 ± 3.46 μM. Graphical abstract: Chemical investigation of the methanol extract of the fertile form of Roccella montagnei collected in Vietnam afforded twelve secondary metabolites, including five new montagnetol derivatives, orsellinylmontagnetols A−D and a furanyl derivative. Highlights: Five montagnetol derivatives were isolated from the fertile form of Roccella montagnei collected in Vietnam. Chemical structures were elucidated by 1D and 2D NMR, HR-ESI-MS analysis and the application of a modified Mosher method. The cytotoxic activities of some isolated compounds against HepG2, NCI-H460, MCF-7, and HeLa cell lines were evaluated.