Determination of curdione in rabbit plasma by liquid chromatography mass spectrometry

A sensitive and selective liquid chromatography mass spectrometry method for determination of curdione in rabbit plasma was developed. After addition of tramadol as internal standard (IS), protein precipitation by acetonitrile was used for sample preparation. Chromatographic separation was achieved on a Zorbax SB‐C₁₈ (2.1 × 50 mm, 3.5 µm) column with acetonitrile–0.1% formic acid as mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive‐ion mode; selective ion monitoring was used for quantification using target fragment ions m/z 237 for curdione and m/z 264 for the IS. Calibration plots were linear over the range of 20–4000 ng/mL for curdione in plasma. The lower limit of quantification for curdione was 20 ng/mL. Mean recovery of curdione from plasma was in the range 94.3–98.4%. The RSD of intra‐day and inter‐day precision were both less than 9%. This method is simple and sensitive enough to be used in pharmacokinetic research for the determination of curdione in rabbit plasma. Copyright © 2011 John Wiley & Sons, Ltd.     

A New Sesquiterpene from Transformation of Curdione by Cell Suspension Culture of Platycodon Grandiflorum

Curcuma aromatica (Family Zingiberaceae) is an important medicinal plant and its rhizome has been used as a traditional Chinese medicine possessing activities of anticancer, antioxidation and bile secretion promotion. Curdione, compound 1, with a germacrane skeleton is one of its major active constituents. Recently, curdione was reported to exhibit hepatoprotective activity 1, 2. In an endeavor to find new chemical entities, we examined the plant cell suspension cultures of Platycodon grandi…     

A validated LC‐MS/MS assay for the quantitative determination of curdione in rabbit plasma and its application to a pharmacokinetic study after administration of zedoary turmeric oil and bioavailability of the oil

A selective and sensitive liquid chromatography tandem mass spectrometry method was developed for the first time for the identification and quantification of curdione in rabbit plasma after vaginal drug administration and intravenous administration of zedoary turmeric oil (ZTO) solution (10 mg/kg). The analysis was performed on a triple‐quadrupole tandem mass spectrometer with multiple reaction monitoring mode via electrospray ionization source in positive ionization mode. After mixing with internal standard diazepam, plasma samples were extracted with ethyl ether–acetic ether (1:1, v/v). Chromatographic separation was carried out on a C₁₈ column with gradient elution using a mixture of water and acetonitrile (both containing 0.1% formic acid) as mobile phases. Linearity ranged over 1.06–106 and 10.6–530 ng/mL (r ≥ 0.995) with the lower limit of quantfication 1.06 ng/mL. The intra‐ and inter‐day precision relative standard deviation values were <12% and the accuracy relative error was from ?10.6 to ?6.1% at all quality control sample levels. The method was applied to a study of the pharmacokinetics of curdione after vaginal drug administration and intravenous administration of ZTO. Copyright © 2014 John Wiley & Sons, Ltd.     

Development and application of an analytical method for curdione quantification in pregnant sprague–dawley rats by LC‐MS/MS

The vaginal administration route suffers from relatively low absorption efficiency, which may hinder the identification of the toxicokinetics of curdione in pregnant women. A sensitive analytical method for determining the plasma concentration of curdione was developed and applied in the determination of curdione in pregnant Sprague–Dawley rats as a simulated model. Glimepiride was used as an internal standard and chromatographic separation was achieved on a Capcell Pak C₁₈ MGIII column. A gradient elution profile with 0.5% formic acid (A)–0.5% formic acid–acetonitrile (B) was selected as mobile phase. The selected reaction monitoring mode was used for quantification based on the target fragment ions m/z 237.2 to m/z 135.1 for curdione and m/z 491.3 to m/z 352.1 for the glimepiride. The standard curve was linear over the range of 0.5–500 ng/mL for curdione in rat plasma and yielded a consistent peak pattern, even at the lower limit of quantitation of 0.5 ng/mL. The retention times of curdione and IS were 6.55 and 6.59 min, respectively. The mean recovery of curdione in rat plasma was 95.5–101.1%. The intra‐day and inter‐day precisions were between 2.35 and 9.08%. This LC‐MS/MS method provides a simple and sensitive means for determining the plasma concentration. Copyright © 2015 John Wiley & Sons, Ltd.     

Simultaneous quantification of curdione,furanodiene and germacrone in rabbit plasma using liquid chromatography–tandem mass spectrometry and its application to a pharmacokinetic study

A simple, rapid and sensitive method was developed for the simultaneous quantification of curdione, furanodiene and germacrone in rabbit plasma using a LC‐MS/MS analysis. The plasma sample preparation was a simple deproteinization by the addition of 3 vols of acetonitrile followed by centrifugation. The analytes and internal standard (IS) costunolide were separated on a Zorbax SB‐C₁₈ column (3.5 µm, 2.1 × 100 mm) with mobile phase of methanol–water (90:10, v/v) containing 0.1% formic acid at a flow rate of 0.3 mL/min with an operating temperature of 25°C. Detection was carried out by atmospheric pressure chemical ionization in positive ion selected reaction monitoring mode. Linear detection responses were obtained for the three test compounds ranging from 5 to 5000 ng/mL and the lower limits of quantitation were 5‐10ng/mL. The intra‐ and inter‐day precisions (relative standard deviations) were within 9.4% for all analytes, while the deviation of assay accuracies was within ±10.0%. The average recoveries of analytes were >80.0%. All analytes were proved to be stable during all sample storage, preparation and analytical procedures. The method was successfully applied to the pharmacokinetic study of the three compounds after vaginal drug delivery of Baofukang suppository to rabbit. Copyright © 2015 John Wiley & Sons, Ltd.     

Structural determination of three new germacrane-type sesquiterpene alcohols from curdione by microbial transformation

Five germacrane-type sesquiterpene alcohols obtained from curdione (1) by microbial biotransformation were isolated. Their structures were characterized as (2R)-2beta-hydroxycurdione (2), 1alpha, 10beta-epoxy-11-hydroxycurdione (3), (2S)-2alpha, 11-dihydroxycurdione (4), 11,15-dihydroxycurdione (5) and (3R)-3alpha-hydroxycurdione (6) based on the extensive NMR studies. Among them, 4, 5 and 6 are new compounds.