6α,7α-epoxy-5α,17α,dihydroxy-1-oxo-22R-witha-2,24-dienolide in leaves of Withania somnifera: Isolation and its crystal structure
IR@IIIM: CSIR-Indian Institute of Integrative Medicine, Jammu
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| Title |
6α,7α-epoxy-5α,17α,dihydroxy-1-oxo-22R-witha-2,24-dienolide in leaves of Withania somnifera: Isolation and its crystal structure
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| Creator |
Bandhoria, Pankaj
Gupta, Vivek K. Amina, Musarat Satti, Naresh K. Dutt, Prabhu Suri, Krishan A. |
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| Subject |
Chemical Sciences
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| Description |
6α,7α-epoxy-5α,17α,dihydroxy-1-oxo-22R-witha-2,24-dienolide (C28H38O6) was isolated from Withania somnifera leaves. The structure of the withanolide was established by spectral analysis and X-ray diffraction studies as withanone. The compound crystallizes in the orthorhombic space group P212121 with unit cell parameters: a=9.191(10) A° ,
b=12.858(6) A° , c=21.400(16) A° , Z=4. The crystal structure was solved by direct methods and refined to R=0.0603 for 1742 observed reflections. There is positional disorder of the H atom in a hydroxy group (O5), resulting in two possible hydrogen-bond linkages. All the rings of the steroid skeleton are trans connected. Ring A exists in a half-chair conformation, ring B is intermediate between a half-chair and a sofa, ring C a distorted chair, and five-membered ring D is intermediate between a half-chair and an envelope. The δ-lactone ring E adopts a sofa conformation. The twist along the length of the steroid nucleus is negligible [C19–C10. . .C13–C18=1.8◦]. Both the hydroxy groups are involved
in hydrogen bonding.
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| Date |
2006
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://iiim.csircentral.net/181/1/10.1007s10870%2D005%2D9041%2D9.pdf
Bandhoria, Pankaj and Gupta, Vivek K. and Amina, Musarat and Satti, Naresh K. and Dutt, Prabhu and Suri, Krishan A. (2006) 6α,7α-epoxy-5α,17α,dihydroxy-1-oxo-22R-witha-2,24-dienolide in leaves of Withania somnifera: Isolation and its crystal structure. Journal of Chemical Crystallography, 36 (2). pp. 153-159. ISSN 1074-1542 |
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| Relation |
http://dx.doi.org/10.1007/s10870-005-9041-9
http://iiim.csircentral.net/181/ |
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