Collect. Czech. Chem. Commun.
2002, 67, 479-489
https://doi.org/10.1135/cccc20020479
Crystal Forms of Semisynthetic Ergot Alkaloid Terguride
Michal Hušáka, Bohumil Kratochvíla, Ivana Císařováb, Ladislav Cvakc, Alexandr Jegorovd,* and Stanislav Böhme
a Department of Solid State Chemistry, Institute of Chemical Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
b Department of Inorganic Chemistry, Charles University, 128 43 Prague 2, Czech Republic
c IVAX CR, R&D, Ostravská 29, 747 70 Opava-Komárov, Czech Republic
d IVAX CR, Research Unit, Branišovská 31, 370 05 České Budějovice, Czech Republic
e Computing Service Centre, Institute of Chemical Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
Abstract
Two new structures of semisynthetic ergot alkaloid terguride created by unusual number of symmetry-independent molecules were determined by X-ray diffraction methods at 150 K. Form A (monoclinic, P212121, Z = 12) contains three symmetry-independent terguride molecules and two molecules of water in the asymmetric part of the unit cell. The form CA (monoclinic, P21, Z = 8) is an anhydrate remarkable by the presence of four symmetry-independent molecules in the crystal structure. Conformations of twelve symmetry-independent molecules that were found in four already described terguride structures are compared with torsion angles obtained by ab initio quantum-mechanical calculations for the simplified model of N-cyclohexyl-N'-diethylurea.
Keywords: Indole alkaloids; Ergot alkaloids; Terguride; Crystal forms; X-Ray crystal structure; Conformation analysis; Polymorphism; Ab initio calculations.
References: 15 live references.
