title: Steroid structure and function:I. Conformational transmission in 17alpha-acetoxy progesterone.
abstract: The molecular conformation of 17alpha-acetoxy progesterone has been determined crystallographically and is compared with that of progesterone. The 17alpha-acetate substituent restricts the flexibility of the progesterone side chain, strains bond lengths in the C- and D-rings, and has long range effects on the A-ring conformation. The A-ring adopts a perfect sofa conformation similar to that observed in one conformational isomer of progesterone. Consequently this progesterone isomer is proposed to be that best suited to binding in the rabbit and human uterus.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003461:Crystallography; D006908:Hydroxyprogesterones; D008958:Models, Molecular; D008968:Molecular Conformation; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
chemical_list: D006908:Hydroxyprogesterones