Title: Withaferin A
CAS Registry Number: 5119-48-2
CAS Name: (4b,5b,6b,22R)-5,6-Epoxy-4,22,27-trihydroxy-1-oxoergosta-2,24-dien-26-oic acid d-lactone
Additional Names: 4b,27-dihydroxy-1-oxo-5b,6b-epoxywitha-2,24-dienolide
Molecular Formula: C28H38O6
Molecular Weight: 470.60
Percent Composition: C 71.46%, H 8.14%, O 20.40%
Literature References: Isolated from the leaves of Withania somnifera Dun., Solanaceae: Lavie, Yarden, J. Chem. Soc. 1962, 2925; Kirson et al., Tetrahedron 26, 2209 (1970); Subramanian, Sethi, Indian J. Pharm. 32, 16 (1970); from roots of Withania coagulans: eidem, Curr. Sci. 38, 267 (1969); from Acnistus arborescens (L.): Kupchan et al., J. Org. Chem. 34, 3858 (1969). Structure: Lavie et al., J. Chem. Soc. 1965, 7517; Kupchan, loc. cit. Crystal structure: McPhail, Sim, J. Chem. Soc. C 1968, 962. Antitumor activity studies: B. Shohat et al., Cancer Chemother. Rep. 51, 271 (1967); B. Shohat, H. Joshua, Int. J. Cancer 8, 487 (1971). Synthetic studies: M. Hirayama et al., J. Chem. Soc. Perkin Trans. 1 1981, 88. Stereoselective synthesis: eidem, Tetrahedron Lett. 23, 4725 (1982).
Properties: White prisms from acetone-petroleum ether, mp 252-253° (Kupchan). Also reported as mp 243-245° (ethyl acetate). [a]D28 +125° (c = 1.30 in CHCl3). uv max (ethanol): 214, 335 nm (e 17300, 165).
Melting point: mp 252-253° (Kupchan); mp 243-245° (ethyl acetate)
Optical Rotation: [a]D28 +125° (c = 1.30 in CHCl3)
Absorption maximum: uv max (ethanol): 214, 335 nm (e 17300, 165) |