Mass spectrometry guided isolation of chlorinated aromatic glycosides from the tubers of Hypoxis aurea.

Twelve chlorinated aromatic glycosides were isolated from Hypoxis aurea by mass spectrometry guided isolation. [Display omitted] • Twelve chlorinated aromatic glycosides were isolated from Hypoxis aurea tubers. • The chlorine containing fractions were detected by using HR-ESI-TOF mass spectrometry. • This study added the typical profile of the secondary metabolites to the genus Hypoxis. High resolution electrospray time-of-flight mass spectrometric analysis was applied as a guiding tool for selection of the chlorine containing fractions by their characteristic clusters of isotopic molecular ion peaks in mass spectra. Twelve target-compounds, chlorinated aromatic glycosides were carried out and identified from the methanolic extract of Hypoxis aurea tubers by chromatographic methods. Hypoxichlorosides A–F (3 , 6 , 9−12) were found to be undescribed compounds. Curculigine A (1), curculigine B (2), curculigine E (4), curculigine J (5), 2,4,6-trichloro-3-methoxy-5-methylphenyl 1- O -β- d -glucopyranosyl-(1→6)-β- d -glucopyranoside (7) and curculigine C (8) were isolated for the first time from this species. The structure determinations were considered based on the spectroscopic evidence including 1D and 2D NMR experiments. [ABSTRACT FROM AUTHOR]