Isolation of Mangiferin fromBombax malabaricumand Structure Revision of Shamimin

Abstract
Repeated column chromatography of the n-BuOH fraction of the 70 % EtOH of the dried leaves of Bombax malabaricum led to the isolation of mangiferin, a xanthone. Mangiferin was identified by UV, 1H- and 13C-NMR spectroscopy and electrospray mass spectrometry. It was found to be identical to shamimin, a compound for which originally a flavonol structure was proposed, and the structure of which has to be revised.