Journal: Chemistry & Biodiversity Web
Ashwagandha (Withania somnifera) is a very well-known herbal medicine and it was well studied for its active metabolites throughout the World. Although, nearly 40 withanolides were isolated from W. somnifera root extract, still there is remaining unidenti?ed metabolites due to very low abundance and geographical variation. Advanced separation technology with online identi?cation by mass and nuclear magnetic resonance (NMR) are nowadays used to ?nd out the new compounds in the crude herbal extract. This article described the metabolite pro?ling of ashwagandha root hydroalcoholic extract using ultra-performance liquid chromatography coupled with a positive ion electrospray ionization tandem mass spectrometry through gas chromatography mass spectrometry (GC/MS) and NMR spectroscopy. A total of 43 possible withanolides was identi?ed and proposed their structures based on the mass of molecular and fragment ions. GC/MS and NMR analysis indicated the presence of several known withanolides including withaferin A, withanolide D, withanoside IV or VI, withanolide sulfoxide, etc. To the best of our knowledge, dihydrowithanolide D at m/z 473 (tR7.86 min) and ixocarpalactone A at m/z 505 (tR8.43 min) were ?rst time identi?ed in the ashwagandha root hydroalcoholic extract. The current study that described the identi?cation of withanolides with summarized literature review might be helpful for designing the experiment to identify of the new chemical constituents in Withania species.