Plant-derived natural products remain crucial in drug development. However, the identification of undescribed natural products is becoming increasingly challenging. A comprehensive strategy combining LC-MS with diagnostic ions was proposed for the discovery of undescribed 5-methylcoumarin meroterpenoids.
View Article and Find Full Text PDFH-NMR guided fractionation led to the isolation of twenty-two coumarin monoterpenes from the whole plant of Gerbera piloselloides, among which fourteen were undescribed. All coumarin monoterpenes were initially found to be racemates without optical activity. Subsequently, eleven pairs of optically pure enantiomers were successfully separated by chiral phase HPLC.
View Article and Find Full Text PDFA phytochemical investigation of the 95% ethanol extract from Gerbera piloselloides obtained fourteen compounds, including three undescribed phenone-monoterpenes (1a/1b and 2), seven undescribed chromone-monoterpenes (3a/3b-5a/5b and 6), and one undescribed coumarin-monoterpene (8). Among them, four pairs of enantiomers (1a/1b and 3a/3b-5a/5b) were successfully isolated by the chiral-phase HPLC resolution. The structures and absolute configurations were unambiguously determined based on comprehensive spectroscopic data, electronic circular dichroism (ECD) data, and X-ray diffraction analysis.
View Article and Find Full Text PDF