Flavonoids and a New Calamenene-type Sesquiterpene from Rhizomes of Alpinia oxymitra K. Schum. (Zingiberaceae)
Kusuma Jitsaeng, Wanchai De Eknamkul and Bernd Schneider
Max Planck Institute for Chemical Ecology, Beutenberg Campus, Hans-Knöll-Straße 8, D-07745 Jena, Germany
Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
Abstract: Chemical constituents of rhizomes of Alpinia oxymitra (Zingiberaceae) were investigated. Using chromatographic techniques, two known flavonoids, epicatechin and galloepicatechin, were isolated together with a new calamenene sesquiterpene, (–)-(1R,4S)-8-hydroxy-13-calamenenoic acid. Structure elucidation of the isolated compounds was accomplished by means of spectroscopic techniques, especially NMR spectroscopy and mass spectrometry.
Keywords: Alpinia oxymitra; Cenolophon oxymitrum; Zingiberaceae; flavonoids; calamenene sesquiterpene. |