Molecular Pharmacology, Vol 7, 406-412, Copyright © 1971 by the American Society for Pharmacology and Experimental Therapeutics

The Stereochemical Basis of Anticonvulsant Drug Action

III. The Structure of Procyclidine Hydrochloride

¹ Department of Biochemistry, University of Toronto, Toronto 5, Ontario, Canada, and Department of Biological Structure, University of Washington, Seattle, Washington 98105

The crystal and molecular structure of procyclidine (-cyclohexyhl--phenyl-1-pyrrolidinepropanol) has been determined in order to investigate structural bases for its biological activity as an aniticonvulsant drug. Crystals of procyclidine hydrochloride are monoclinic, space group P2₁/c, with cell dimensions a = 5.891 ± 0.006, b = 28.603 ± 0.018, c = 11.314 ± 0.004 A, = 106.0 degrees ± 15', Z = 4 molecules/cell. The structure was determined by the symbolic addition procedure, utilizing data collected on an automated diffractometer (CuK radiation). Refinement was accomplished by an anisotropic full-matrix least-squares procedure, resulting in a final R value of 0.081.

Stereochemical features which the molecule has in common with other anticonvulsants, diphenylhydantoin and diazepam, and which may account for its anticonvulsant activity are analyzed and discussed.

Note:
ACKNOWLEDGMENTS The authors thank Dr. H. Kalant for supplying the procyclidine hydrochloride.