title: Separation, identification, and quantification of selected withanolides in plant extracts of Withania somnifera by HPLC-UV(DAD)--positive ion electrospray ionisation-mass spectrometry.
abstract: This paper describes a method for separation, identification, and quantification of selected withanolides in Withania somnifera plant extracts by HPLC-UV(DAD)-Mass Spectrometry (HPLC-MS). Withaferin-A (WS-3), 12-deoxywithastramonolide (WS-12DS), Withanolide A (WS-1), and Withanone (WS-2) were used as external standards. The compounds were isolated from Withania somnifera by repeated column chromatography of the root extract and their identity was established by 1H- and 13C-NMR and mass spectral data. The compounds were chromatographed on a Merck (250 x 4.6 mm ID, 5 microm) column and analyzed by Electrospray Ionization on a mass spectrometer in Selected Ion Mode (SIM). For quantification, [M + Na]+ ions were monitored. Linear calibration curves were obtained in the concentration range of 1.50 microg/mL to 6.5 microg/mL. The method was applied successfully to the detection and quantification of the said withanolides in a number of samples.
authors.affiliation: Natural Product Chemistry Division, Regional Research Laboratory, Canal Road, Jammu-Tawi 180001, India. khajuriark@yahoo.com
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Khajuria
authors.forename: Krishan A
authors.initials: KA
authors.lastname: Suri
authors.forename: Rajinder K
authors.initials: RK
authors.lastname: Gupta
authors.forename: Naresh K
authors.initials: NK
authors.lastname: Satti
authors.forename: Musarat
authors.initials: M
authors.lastname: Amina
authors.forename: Om P
authors.initials: OP
authors.lastname: Suri
authors.forename: Ghulam N
authors.initials: GN
authors.lastname: Qazi
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004875:Ergosterol / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000302:isolation & purification; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D032341:Withania / Q000737:chemistry*
chemical_list: D004875:Ergosterol