𝔖 Bobbio Scriptorium
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PCILO study of the conformation of 20-oxopregnane hormones

✍ Scribed by Luci Martins Viana; Yuji Takahata

Book ID
104580678
Publisher
John Wiley and Sons
Year
1982
Tongue
English
Weight
438 KB
Volume
22
Category
Article
ISSN
0020-7608

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✦ Synopsis

Abstract

PCILO calculations on conformations of the C‐17 side chains of three 20‐oxopregnane hormones, progesterone, corticosterone, and cortisol, reveal that the calculated conformations are generally in close agreement with those observed crystallographically. Average deviation of the calculated rotation angle around the C(17)—C(20) bond from the experiment is 9°. The PCILO calculations also predict the intramolecular hydrogen bond between the 20‐carbonyl group and the 21‐hydroxyl for the three hormones. This is in accordance with experiment. It was concluded that the PCILO method is reliable in predicting conformations of the side chains of hormones whereas the extended Hückel theory (EHT) predicted wrong conformations. Based upon the PCILO calculations, biological activities of the hormones are discussed.

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