title: 5,6-de-epoxy-5-en-7-one-17-hydroxy withaferin A, a new cytotoxic steroid from Withania somnifera L. Dunal leaves.
abstract: From the leaves of Withania somnifera L. Dunal, a new withasteroid named as 5,6-de-epoxy-5-en-7-one-17-hydroxy withaferin A (6) was isolated along with several known compounds, namely 16β-acetoxy-6α,7α-epoxy-5α-hydroxy-1-oxowitha-2,17(20),24-trienolide (1), withanone (2), 16-en-27-deoxy withaferin A (3), 27-deoxy withaferin A (4), withaferin A (5), withanolide D (7) and 27-hydroxy withanone (8). Its structure was determined using spectroscopic methods, namely IR, (1)H NMR, (13)C NMR, COSY, HMBC and HRMS. Among the known compounds, 16β-acetoxy-6α,7α-epoxy-5α-hydroxy-1-oxowitha-2,17(20),24-trienolide (1) was previously reported from the roots of W. somnifera. Now, it has been isolated from the leaves, as well. The cytotoxic activity of the new steroid was carried out using the MTT assay against a panel of cancer cell lines, namely MCF-7 (breast), WRL-68 (liver), PC-3 (prostate) and CACO-2 (colon). The results showed that the new compound possesses strong cytotoxic activity against liver and breast cancer with an IC50 of 1.0 μg/mL and a moderate activity against colon (IC50 3.4 μg/mL) and prostate (IC50 7.4 μg/mL) cancer cells.
authors.affiliation: a Chemical Sciences Division, CSIR-Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP , Lucknow 226 015 , India.
authors.forename: Amreen A
authors.initials: AA
authors.lastname: Siddique
authors.forename: Pallavi
authors.initials: P
authors.lastname: Joshi
authors.forename: Laxminarain
authors.initials: L
authors.lastname: Misra
authors.forename: Neelam S
authors.initials: NS
authors.lastname: Sangwan
authors.forename: Mahendra P
authors.initials: MP
authors.lastname: Darokar
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018938:Caco-2 Cells; D004354:Drug Screening Assays, Antitumor; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D032341:Withania / Q000737:chemistry*; D054358:Withanolides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: C000592722:5,6-de-epoxy-5-en-7-one-17-hydroxy withaferin A; D000972:Antineoplastic Agents, Phytogenic; D054358:Withanolides; C010376:withanolide D