The biological function of steroidal estrogens is related to their electronic properties. An experimental charge density study has been carried out on 17alpha-estradiol and compared to similar studies on more potent estrogens. High accuracy X-ray data were measured with a Rigaku rotating anode diffractometer equipped with an R-Axis Rapid curved image plate detector at 20 K. The total electron density in the 17alpha-estradiol x 1/2 H(2)O crystal was modeled using the Hansen-Coppens multipole model. Topological analysis of the electron density based on Bader's QTAIM theory was performed. The crystal structure, chemical bonding, and molecular properties, including the electrostatic potential (ESP), are reported and discussed. Observed disordering of hydroxyl and water hydrogen atom positions are interpreted as a superstructural ordering in a lower symmetry space group. The ESP's for the resulting four conformers are compared with each other and with that of 17beta-estradiol. The relative binding affinities are discussed in terms of the observed potentials.

Download full-text PDF

Source
http://dx.doi.org/10.1021/ja906057zDOI Listing

Publication Analysis

Top Keywords

17alpha-estradiol 1/2
8
1/2 h2o
8
electronic properties
8
chemical bonding
8
electron density
8
h2o super-structural
4
super-structural ordering
4
ordering electronic
4
properties chemical
4
bonding biological
4

Similar Publications

Neuroestrogens are synthesized within the brain and regulate social behavior, learning and memory, and cognition. In song sparrows, , 17β-estradiol (17β-E) promotes aggressive behavior, including during the nonbreeding season when circulating steroid levels are low. Estrogens are challenging to measure because they are present at very low levels, and current techniques often lack the sensitivity required.

View Article and Find Full Text PDF

Application of animal manure on agricultural lands is one of the main sources of estrogen contamination in the environment. Poultry and cow manure contain free and conjugated forms of the natural estrogens (e.g.

View Article and Find Full Text PDF

Solid-state {(1)H}(13)C cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopy has been applied to 17β-estradiol (E2) and 17α-estradiol (E2α), to analyze the steroidal ring conformations of the two isomers in the absence and presence of lipids at the atomic level. In the absence of lipid, the high-resolution (13)C NMR signals of E2 in a powdered form show only singlet patterns, suggesting a single ring conformation. In contrast, the (13)C signals of E2α reveal multiplet patterns with splittings of 20-300Hz, implying multiple ring conformations.

View Article and Find Full Text PDF

Impact of estradiol structural modifications (18-methyl and/or 17-hydroxy inversion of configuration) on the in vitro and in vivo estrogenic activity.

J Steroid Biochem Mol Biol

November 2011

Laboratory of Medicinal Chemistry, CHUQ, CHUL-Research Center, Endocrinology and Genomic Unit, and Laval University, Faculty of Medicine, Quebec, Quebec G1V 4G2, Canada.

It is well recognized that the majority of breast cancers are initially hormone-dependent and that 17β-estradiol (17β-E2) plays a crucial role in their development and progression. For this reason, using a compound able to block a specific enzyme involved in the last steps of the biosynthesis of 17β-E2 remains a rational way to treat estrogen-dependent diseases such as breast cancer. The present study describes the biological in vitro and in vivo evaluation of a structural modification (inversion of C18-methyl group at position 13 from β to α face) of 17β-E2 (1) and 17α-estradiol (17α-E2; 2).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!