作者:Seoung-Soo Hong、Supriya A. Bavadekar、Sang-Il Lee、Popat. N. Patil、S.G. Lalchandani、Dennis R. Feller、Duane D. Miller
DOI:10.1016/j.bmcl.2005.07.083
日期:2005.11
The synthesis and biological evaluation of a new series of bioisosteric phentolamine analogs are described. Replacement of the carbon next to the imidazoline ring of phentolamine with a nitrogen atom provides compounds (2, 3) that are about 1.6 times and 4.1 times more potent functionally than phentolamine on rat alpha(1)-adrenergic receptors, respectively. In receptor binding assays, the affinities of phentolamine and its bioisosteric analogs were determined on the human embryonic kidney (HEK) and Chinese Hamster ovary (CHO) cell lines expressing the human alpha(1)- and alpha(2)-AR subtypes, respectively. Analogs 2 and 3, both, displayed higher binding affinities at the alpha(2)- versus the alpha(1)-ARs, affinities being the least at the alpha(1B)-AR. Binding affinities of the methoxy ether analog 2 were greater than those of the phenolic analog 3 at all six alpha-AR subtypes. One of the nitrogen atoms in the imidazoline ring of phentolamine was replaced with an oxygen atom to give compounds 4 and 5, resulting in a 2-substituted oxazoline ring. The low functional antagonist activity on rat aorta, and binding potencies of these two compounds on human alpha(1A)- and alpha(2A)-AR subtypes indicate that a basic functional group is important for optimum binding to the alpha(1)- and alpha(2A)-adrenergic receptors. (c) 2005 Elsevier Ltd. All rights reserved.