title: 1H-indazole and 2H-indazole derivatives of androsta-5,16-dien-3beta-ol.
abstract: The title compounds, 17-(1H-indazol-1-yl)androsta-5,16-dien-3beta-ol, (I), and 17-(2H-indazol-2-yl)androsta-5,16-dien-3beta-ol, (II), both C(26)H(32)N(2)O, have an indazole substituent at the C17 position. The six-membered B ring of each compound assumes a half-chair conformation. A twist of the steroid skeleton is observed and reproduced in quantum-mechanical ab initio calculations of the isolated molecule using a molecular orbital Hartree-Fock method. In the 1H-indazole derivative, (I), the molecules are joined in a head-to-head fashion via O-H...O hydrogen bonds, forming chains along the a axis. In the 2H-indazole derivative, (II), the molecules are joined in a head-to-tail fashion with one of the N atoms of the indazole ring system acting as the acceptor. The hydrogen-bond pattern consists of zigzag chains running along the b axis. Substituted steroids have proven to be effective in inhibiting androgen biosynthesis through coordination of the Fe atoms of some enzymes, and this study shows that indazole-substituted steroids adopt twisted conformations that restrict their intermolecular interactions.
authors.affiliation: CEMDRX, Physics Department, University of Coimbra, P-3004-516 Coimbra, Portugal. manuela@pollux.fis.uc.pt
authors.forename: Manuela Ramos
authors.initials: MR
authors.lastname: Silva
authors.forename: Vânia M
authors.initials: VM
authors.lastname: Moreira
authors.forename: Cláudia
authors.initials: C
authors.lastname: Cardoso
authors.forename: Ana Matos
authors.initials: AM
authors.lastname: Beja
authors.forename: Jorge A R
authors.initials: JA
authors.lastname: Salvador
mesh_terms: D000737:Androstenols / Q000737:chemistry*; D006860:Hydrogen Bonding; D007191:Indazoles / Q000737:chemistry*; D015394:Molecular Structure; D014961:X-Ray Diffraction
chemical_list: D000737:Androstenols; D007191:Indazoles; C000152:androsta-5,16-dien-3 beta-ol