Stemodane skeletal rearrangement: chemistry and microbial transformation.
Solvolytic rearrangement of the C/D ring system of the tetracyclic diterpenoid stemodinone (2) afforded the compounds 15(13-->12)abeo-13beta-hydroxystemaran-2-one (5) and 15(8-->9)abeo-8beta(H)-12beta-hydroxystachan-2-one (10). Terpene 5 possesses a novel diterpene skeleton. Oxidation of these compounds yielded their respective diketones. Bioconversion of 5 by Rhizopus oryzae yielded 15(13-->12)abeo-7beta,13beta-dihydroxystemaran-2-one (18) while microbial transformation of 10 provided 15(8-->9)abeo-8beta(H)-6alpha,12beta-dihydroxystachan-2-one (19), 15(8-->9)abeo-8beta(H)-7beta,12beta-dihydroxystachan-2-one (20) and 15(8-->9)abeo-8beta(H)-6alpha,12beta,14beta-trihydroxystachan-2-one (21). A rationale for the formation of the rearranged compounds is proposed.
Martin
Glenroy D A
GD
Department of Chemistry, University of the West Indies, Mona, Kingston 7, Jamaica.
Reynolds
William F
WF
Reese
Paul B
PB
D001711:Biotransformation; D004224:Diterpenes / Q000737:chemistry* / Q000378:metabolism*; D015394:Molecular Structure; D012233:Rhizopus / Q000378:metabolism*; D028083:Scrophulariaceae / Q000737:chemistry*
D004224:Diterpenes