The racemic trimeric quinone and polycyclic quinones isolated from the aerial parts of Morinda umbellata L

Four undescribed racemic quinones, umbellatas Q−T, were isolated from the aerial parts of Morinda umbellata L. All enantiomers were separated on a chiral HPLC column, and their structures were elucidated by UV spectroscopy, IR spectroscopy, HR-ESI-MS, 1D and 2D NMR spectroscopy, DP4+ NMR calculations, ECD spectroscopy, and X-ray diffraction. Three of the racemes are polycyclic anthraquinones, and one is a rare racemic trimer of naphthoquinone-bisnaphthohydroquinones. (+)-Umbellata S exhibited potent cytotoxicity (IC50: 6.2–9.3 μM) against the A2780, HeLa, H7420, Ketr3 and SW 1990 human cancer cell lines. Four pairs of previously undescribed quinones were isolated from Morinda umbellata L. (+)-Umbellata S exhibited potent cytotoxicity against several human cancer cell lines. [Display omitted] •The rare racemic trimeric quinones were obtained from Morinda umbellata.•All enantiomers were obtained by chiral HPLC separation.•(+)-Umbellata S exhibited potent cytotoxicity against human cancer cell lines.