NMR and X-ray studies of isomeric 22,23-dihydroxy stigmastanes

Autor:	Galina V. Ivanova, Dmitrii V. Tsavlovskii, Alexander Yu. Misharin, Vladimir A. Khripach, Alexander S. Lyakhov, Vladimir N. Zhabinskii, Galina P. Fando, Natalya B. Khripach
Rok vydání:	2010
Předmět:	Steric effects Chemistry Stereochemistry medicine.medical_treatment Organic Chemistry X-ray Nuclear magnetic resonance spectroscopy Analytical Chemistry Steroid Inorganic Chemistry Crystal Crystallography X-ray crystallography Side chain medicine Single crystal Spectroscopy
Zdroj:	Journal of Molecular Structure. 975:242-246
ISSN:	0022-2860
DOI:	10.1016/j.molstruc.2010.04.030
Popis:	A comparative conformational study of steroidal side chain of (22R,23R)- and (22S,23S)-dihydroxy stigmastane derivatives was performed using single crystal X-ray diffraction and NMR spectroscopy. The preferred conformation in solution was shown to be close to that in the crystal. (22R,23R)-Isomers typical for natural plant steroid hormones brassinosteroids adopt a conformation in which both hydroxyl groups are pointed toward unhindered α-side of the steroidal plane and can thus participate in biochemical processes. Unnatural (22S,23S)-counterparts exhibit a conformation with the two hydroxyl groups oriented in the opposite direction and sterically hindered by 21-methyl group and terminal side chain fragment.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::fc006b2bddd2370ecdc34f4d749ec9e7 https://doi.org/10.1016/j.molstruc.2010.04.030 Zobrazit plný text záznamu Full Text from ScienceDirect