Some Benzyl-Substituted Imidazoles, Triazoles, Tetrazoles, Pyridinethiones, and Structural Relatives as Multisubstrate Inhibitors of Dopamine β-Hydroxylase. 4. Structure-Activity Relationships at the Copper Binding Site

Article abstract of DOI:10.1021/jm00164a051

Structure-activity relationships (SAR) were determined for novel multisubstrate inhibitors of dopamine β-hydroxylase (DBH; EC 1.14.17.1) by examining the effects upon in vitro inhibitory potencies resulting from structural changes at the copper-binding region of inhibitor.Attempts were made to determine replacement groups for the thione sulfur atom of the prototypical inhibitor 1-(4-hydroxybenzyl)imidazole-2-thione described previously.The synthesis and evaluation of oxygen and nitrogen analogues of the soft thione group demonstrated the sulfur atom to be necessary for optimal activity.An additional series of imidazole-2-thione relatives was prepared in an effort to probe the relationship between the pK_a of the ligand group and inhibitor potency.In vitro inhibitory potency was shown not to correlate with ligand pK_a over a range of approximately 10 pK_a units, and a rationale for this is advanced.Additional ligand modifications were prepared in order to explore bulk tolerance at the enzyme oxygen binding site and to determine the effects of substituting a six-membered ligand group for the five-membered imidazole-2-thione ligand.