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Updated: Jul 9, 2026

Enzymatic Synthesis of Epoxidized Metabolites of Docosahexaenoic, Eicosapentaenoic, and Arachidonic Acids
Published on: June 28, 2019
Selective reactivity of 2-mercaptoethanol with 5beta,6beta-epoxide in steroids from Withania somnifera
Laxminarain Misra1, Payare Lal, Narayan D Chaurasia
1Central Institute of Medicinal and Aromatic Plants, PO CIMAP, Lucknow, India. laxmisra@hotmail.com
Abstract:
2-Mercaptoethanol reacts selectively with the 5beta,6beta-epoxy steroids isolated from Withania somnifera substituting the epoxide by a six-membered oxyethylene-2'-thio ring whereas it failed to show such reactivity on 6alpha,7alpha-epoxy withasteroids. The structure of the product has been elucidated by spectroscopic methods, especially applying extensive 2D NMR methods. The anticancer activity of withaferin A was lost in the reaction product indicating that its activity is also linked to the free 5beta,6beta-epoxide functional group.
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