ABSTRACT
Liquid chromatography/mass spectrometry and liquid chromatography/nuclear magnetic resonance techniques with ultraviolet/diode array detection were used as complementary analytical tools for the reliable identification of polymethoxylated flavones in residues from molecular distillation of cold-pressed peel oils of Citrus sinensis. After development of a liquid chromatographic separation procedure, the presence of several polymethoxy flavones such as sinensetin, nobiletin, tangeretin, quercetogetin, heptamethoxyflavone, and other derivatives was unambiguously confirmed. In addition, proceranone, an acetylated tetranortriterpenoid with limonoid structure, was identified for the first time in citrus.
Subject(s)
Chromatography, High Pressure Liquid/methods , Citrus sinensis/chemistry , Flavones/analysis , Magnetic Resonance Spectroscopy , Mass Spectrometry , Plant Oils/chemistry , Flavones/chemistry , Fruit/chemistry , Gas Chromatography-Mass SpectrometryABSTRACT
Two different enantioselective sesquiterpene synthases catalyze the biosynthesis of the enantiomers (+)- and (-)-germacrene D (1 a and 1 b, respectively) in the plant Solidago canadensis, from which they were isolated and characterized for the first time.