The structure elucidation of three related pregnane glycosides, sarcovimiside A, B, and C from Sarcostemma viminale, is based on a detailed study of their highfield 1H and 13C NMR spectra. The results show that all the sugars are (1→4)-linked and both (β-D- and α-L-cymarose residues are present in each glycoside chain. The aglycone of sarcovimiside A was identified as 12β-benzoyloxy-3β,8β,14.17-tetrahydroxy-14β,17α-pregn-5-en-20-one whereas in the case of both sarcovimiside B and C, oxidative cleavage of the C(8)–C(14) bond occurred and the aglycone is the 12,20-O,O-dibenzoyl derivative of (20S)-3β,5,12β,17,20-pentahydroxy-8,14-seco-5β,17α-pregn-6-ene-8,14-dione. Sarcovimiside C is the β-(1→4)-glucopyranosyl derivative of sarcovimiside B.
Publication DOI: 10.1039/P19930000483Journal NLM ID: 7505598Publisher: Chemical Society
Institutions: Department of Chemistry, University of Pretoria, Pretoria, South Africa, Department of Chemistry and Biochemistry, Rand Afrikaans University, Auckland Park, South Africa, Department of Toxicology, Onderstepoort, Veterinary Institute, Onderstepoort, South Africa
Methods: 13C NMR, 1H NMR, FAB-MS, acid hydrolysis, enzymatic digestion, PLC, CC
Found