A Structure−Activity Relationship Study of Novel Phenylacetamides Which Are Sodium Channel Blockers
作者:Ioannis Roufos、Sheryl Hays、Roy D. Schwarz
DOI:10.1021/jm950467y
日期:1996.1.1
A structure-activity relationship study of a series of novel Na+ channel blockers, structurally related to N-[3-(2,6-dimethyl-1-piperidinyl)propyl]-alpha-phenylbenzeneacetamide (1, PD85639) is described. The diphenylacetic acid portion of the molecule was left unchanged throughout the study, while structural features in the amine portion and the amide alkyl linkage of the molecule were modified. The compounds were tested for inhibition of veratridine-stimulated Na+ influx in CHO cells expressing type IIA Na+ channels. Several derivatives show a trend toward more potent Na+ channel blockade activity with increasing lipophilicity of the amine portion of the molecule. The presence of a phenyl ring near the amine increases inhibitory potency. A three-carbon spacer between the amide and amine is optimal, and a secondary amide linkage is preferred.
Design and Synthesis of Novel α<sub>1a</sub> Adrenoceptor-Selective Dihydropyridine Antagonists for the Treatment of Benign Prostatic Hyperplasia
作者:Dhanapalan Nagarathnam、John M. Wetzel、Shou Wu Miao、Mohammad R. Marzabadi、George Chiu、Wai C. Wong、Xingfang Hong、James Fang、Carlos Forray、Theresa A. Branchek、William E. Heydorn、Raymond S. L. Chang、Theodore Broten、Terry W. Schorn、Charles Gluchowski
DOI:10.1021/jm980506g
日期:1998.12.1
We report the synthesis and evaluation of novel alpha(1a) adrenoceptor subtype-selective antagonists. Systematic modification of the lipophilic 4,4-diphenylpiperidinyl moiety of the dihydropyridine derivatives 1 and 2 provided several highly selective and potent alpha(1a), antagonists. From this series, we identified the 4-(methoxycarbonyl)-4-phenylpiperidine analogue SNAP 5540 (-) [(-)-63] for further characterization. When examined in an isolated human prostate tissue assay, this compound was found to have a K-i of 2.8 nM, in agreement with the cloned human receptor binding data (K-i = 2.42 nM). Further evaluation of the compound in isolated dog prostate tissue showed a K-i of 3.6 nM and confirmed it to be a potent antagonist (K-b = 1.6 nM). In vivo, this compound effectively blocked the phenylephrine-stimulated increase in intraurethral pressure (IUP) in mongrel dogs, at doses which did not significantly affect the arterial pressure (diastolic blood pressure, DBP), with a DBP K-b/IUP K-b ratio of 16. In addition, (-)-63 also showed greater than 40 000-fold selectivity over the rat L-type calcium channel and 200-fold selectivity over several G protein-coupled receptors, including histamine and serotonin subtypes. These findings prove that alpha(1a) adrenoceptor-subtype selective antagonists such as (-)-63 may be developed as uroselective agents for an improved treatment of BPH over nonselective alpha(1) antagonists such as prazosin and terazosin, with fewer side effects.