Collect. Czech. Chem. Commun. 1996, 61, 1396-1404

Crystal Structures of Ergot Alkaloid Derivatives. Ergometrine Maleate and Methylergometrine Maleate

Jan Čejkaa, Michal Hušáka, Bohumil Kratochvíla, Alexandr Jegorovb and Ladislav Cvakc

a Department of Solid State Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6, Czech Republic
b Galena Co., Research Unit, Branišovská 31, 370 05 České Budějovice, Czech Republic
c Galena Co., R.& D., 747 70 Opava-Komárov, Czech Republic


Two ergot alkaloid derivatives were examined by X-ray diffraction techniques. The crystal and molecular structure of ergometrine maleate (1) was evaluated from single-crystal data and the molecular structure of related methylergometrine maleate (2) was obtained by molecular modelling. The measured and calculated X-ray powder patterns of 1 and 2 were compared. Derivative 1 crystallizes in the orthorhombic space group P212121 with a = 5.7112(7) Å, b = 12.337(2) Å, c = 33.276(6) Å, Z = 4, V = 2 344.5(6) Å3. Derivative 2 is nearly isostructural with 1, it has slightly expanded unit cell, a = 5.724(2) Å, b = 12.762(6) Å, c = 33.25(2) Å, Z = 4, V = 2 428(1) Å3. No effect of an additional methyl group on the molecular packing of 2 was found.

Keywords: Ergot alkaloids; Ergometrine; Methylergometrine; X-Ray crystal structure.