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Two new guaiane sesquiterpenoids, (1 β,5 β)-1-hydroxyguaia-4(15),11(13)-dieno-12,5-lactone ( 1) and 1,5-epoxy-4-hydroxyguai-11(13)-en-12-oic acid ( 2), together with five known compounds, rupestonic acid ( 3), strobilactone A ( 4), antiquorin ( 5), isosclerone ( 6), and 5-hydroxy-2′,3′,4′,7,8-pentamethoxyflavone ( 7), were isolated from a 95% EtOH extract of Artemisia rupestris. Compounds 1 and 2 are rare examples of guaiane sesquiterpenoids, incorporating a 12,5-lactone group or featuring a 1,5-epoxy ring, respectively. The structures of 1 and 2 were identified by various spectroscopic methods. Compounds 1, 4, and 5 exhibited moderate cytotoxic activities against the human lung cancer 95-D cell line with IC50 values of 11.3, 19.8, and 34.5 μ M, respectively. [ABSTRACT FROM AUTHOR]

ABSTRACT A novel, simple and rapid ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) assay was established for quantification of saxagliptin in rat plasma. Plasma samples were processed by liquid-liquid extraction with ethyl acetate and chromatographed on a C18 column (2.1 × 50 mm i.d., 1.7 µm). The mobile phase consisted of methanol and 0.1% formic acid (40:60, v/v). Multiple reaction monitoring transitions were performed for detection in positive-ion mode with an electrospray ionization source. The calibration curve was linear over the concentration range of 0.5-100 ng/mL ( R2 > 0.99). All accuracy values were between 90.62 and 105.60% relative error and the intra- and inter-day precisions were less than 9.66% relative standard deviation. Extraction recovery was more than 81.01% and the matrix effect ranged from 90.27 to 109.15%. After validation, the method was applied to a pharmacokinetic study where healthy rats were orally given 0.5 mg/kg saxagliptin. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]