Separation, identification, and quantification of selected withanolides in plant extracts of Withania somnifera by HPLC-UV(DAD)--positive ion electrospray ionisation-mass spectrometry.
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.
Khajuria
Ravi K
RK
Natural Product Chemistry Division, Regional Research Laboratory, Canal Road, Jammu-Tawi 180001, India. khajuriark@yahoo.com
Suri
Krishan A
KA
Gupta
Rajinder K
RK
Satti
Naresh K
NK
Amina
Musarat
M
Suri
Om P
OP
Qazi
Ghulam N
GN
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*
D004875:Ergosterol