title: The analysis and crystallographic characterization of 20-hydroxyecdysone.
abstract: 20-Hydroxyecdysone (20E) is an insect molting hormone that is also widely spread in various plants. Many chromatographic methods can be used to identify and/or determine 20E content in samples of biological origin and various spectroscopic methods serve to identify its structural elements. We have utilized X-ray crystallography to reveal the stereostructures of 20E. Our data demonstrates that 20E exists in two different crystalline forms that are both orthorhombic modifications. One form is homo-molecular, with a limited freedom of internal rotation of the side chain around the C23-C24 bond and the other, which is a clathrate formed with methanol and water, which minimize the conformational freedom of the side chain.
authors.affiliation: Department of Pharmacology and Pharmacotherapy, Semmelweis University, Nagyvarad ter 4, P.O. Box 370, Budapest, H-1445, Hungary.
authors.forename: M
authors.initials: M
authors.lastname: Báthori
authors.forename: A
authors.initials: A
authors.lastname: Kálmán
authors.forename: G
authors.initials: G
authors.lastname: Argay
authors.forename: H
authors.initials: H
authors.lastname: Kalász
mesh_terms: D000818:Animals; D018360:Crystallography, X-Ray; D004441:Ecdysterone / Q000737:chemistry* / Q000494:pharmacology; D015394:Molecular Structure
chemical_list: D004441:Ecdysterone