An NMR study of the conformational mobility of steroid estrogen 7α-methyl-8α analogues

Autor:	Solov'ev AIu, A. G. Shavva, S. N. Morozkina, Stanislav I. Selivanov
Rok vydání:	2007
Předmět:	education.field_of_study Chemistry Stereochemistry medicine.medical_treatment Organic Chemistry Population Nuclear magnetic resonance spectroscopy Nuclear Overhauser effect Carbon-13 NMR Dihedral angle Ring (chemistry) Biochemistry Steroid Crystallography medicine education Conformational isomerism
Zdroj:	Russian Journal of Bioorganic Chemistry. 33:302-309
ISSN:	1573-9163 1068-1620
DOI:	10.1134/s1068162007030053
Popis:	All the signals in the 1H and 13C NMR spectra of some analogues of 7alpha-methyl-8alpha- and 6-oxa-8alpha-steroid estrogens were completely assigned. Considering the values of nuclear Overhauser effect and vicinal coupling constants, these steroids were shown to exhibit a fast, on the NMR time scale, conformational equilibrium arising due to the inversion of ring B. The conformer populations were obtained from a comparison of the experimental and theoretical values of the dihedral angles and the interproton distances. This conformational equilibrium was shown to depend on the nature of atom in position 6: for the 7alpha-methyl-6-oxa-8alpha analogues of the steroid estrogens, the population of the conformer with the pseudoaxial orientation of the 7alpha-methyl group was observed to be decreased compared with the 7alpha-methyl-8alpha analogue.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::29654d619d1a2928b98789e859f0ba64 https://doi.org/10.1134/s1068162007030053 Zobrazit plný text záznamu Full text from SpringerLink