7,8-Dihydroxy-4-propyl-1,2,3,4,4a,5,6,10b-octahydrobenzo[f]quinolinium bromide monohydrate, a dopamine agonist.
In the crystal structure of the title dopaminergic compound, C16H24NO2+.Br-.H2O, protonation occurs at the piperidine N atom. The piperidine ring adopts a chair conformation and the cyclohexene ring adopts a half-chair conformation; together with the planar benzene ring, this results in a relatively planar shape for the whole molecule. Classical hydrogen bonds (N-H...Br, O-H...Br and O-H...O) produce an infinite three-dimensional network. Hydrogen bonds between water molecules and Br- anions create centrosymmetric rings throughout the crystal structure. Structural comparison of the molecule with the ergoline dopamine agonist pergolide shows that it is the hydrogen-bond-forming hydroxy or imino group that is necessary for dopaminergic activity, rather than the presence of a phenyl or a pyrrole ring per se.
Hempel
Andrew
A
Department of Biochemistry, University of Toronto, Medical Sciences Building, Toronto, Canada M5S 1A8.
Ma
Lilian Y Y
LY
Camerman
Arthur
A
Mastropaolo
Donald
D
Camerman
Norman
N
D018360:Crystallography, X-Ray; D018491:Dopamine Agonists / Q000737:chemistry* / Q000494:pharmacology; D006860:Hydrogen Bonding; D008958:Models, Molecular; D011806:Quinolinium Compounds / Q000737:chemistry* / Q000494:pharmacology
D018491:Dopamine Agonists; D011806:Quinolinium Compounds