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This article is focused on the seasonal variation in the contents of 5-methoxycanthin-6-one from the leaves of Zanthoxylum chiloperone (Rutaceae). Based on the pharmacological interest presented by 5-methoxycanthin-6-one, its seasonal variation in Z. chiloperone leaves was analysed in order to determine the best time for harvesting, optimising the 5-methoxycanthin-6-one content. The seasonal dynamics of canthinone alkaloids can be the key to improve the isolation from natural sustainable sources, such as leaves. Complementarily, this study describes the phytochemistry of leaf from this Ruraceae species. [ABSTRACT FROM AUTHOR]

The Michaelis-Arbuzov reaction of ethyl α -bromo-α -fluoro- and α, α -difluoro-acetates with dialkyl phenylphosphonites leads to the formation of unusual products including a fluorophosphinate. The reaction of ethyl bromofluoracetate with diisopropyl- and dimethyl-phenylphosphonites furnishes a complex mixture of eight and five compounds respectively. Five different compounds are obtained when ethyl bromodifluoroacetate is reacted with diisopropyl phenylphosphonite. Dimethyl phenylphosphonite yields three compounds when heated with bromochloromethane. The probable mechanism of formation of the compounds and their mass spectral characterization using GC-MS, tandem MS-MS and DART™ techniques are presented in this paper. [ABSTRACT FROM AUTHOR]

A rapid static headspace-gas chromatography–mass spectrometry (GC–MS) method was used to determine and to identify the volatile compounds in the rhizomes of Rhodiola sachalinensis and Rhodiola sacra. The total ion chromatograms (TIC) of the rhizomes powders of the R. sachalinensis and R. sacra showed their differences in the volatiles compositions. Thirty two volatile compounds in the rhizome of R. sachalinensis were identified; the main volatile compounds are butanal, 2,6,6-trimethyl-2-ethenyltetrahydro-2-pyran, limonene, linalool, geranial, 2-butanal, and 3-butanal. Twenty five volatile compounds in the rhizome of R. sacra were identified with butanal, 3-butanal, 2-butanal, β-pinene, limonene, terpinolene, and linalool. 2,6,6-Trimethyl-2-ethenyltetrahydro-2-pyran was further identified by the MS–MS technique. The applied method not only effectively differentiates the two species of Rhodiolas but also offers a prospective method for the quality control of aromatic medicine plants. [ABSTRACT FROM AUTHOR]