2-Triazole-Substituted Adenosines: A New Class of Selective A<sub>3</sub> Adenosine Receptor Agonists, Partial Agonists, and Antagonists
作者:Liesbet Cosyn、Krishnan K. Palaniappan、Soo-Kyung Kim、Heng T. Duong、Zhan-Guo Gao、Kenneth A. Jacobson、Serge Van Calenbergh
DOI:10.1021/jm0608208
日期:2006.12.1
''Click chemistry" was explored to synthesize two series of 2-(1,2,3-triazolyl) adenosine derivatives (1-14). Binding affinity at the human A(1), A(2A), and A(3)ARs (adenosine receptors) and relative efficacy at the A(3)AR were determined. Some triazol-1-yl analogues showed A(3)AR affinity in the low nanomolar range, a high ratio of A(3)/A(2A) selectivity, and a moderate-to-high A(3)/A(1) ratio. The 1,2,3-triazol-4-yl regiomers typically showed decreased A(3)AR affinity. Sterically demanding groups at the adenine C2 position tended to reduce relative A(3)AR efficacy. Thus, several 5'-OH derivatives appeared to be selective A(3)AR antagonists, i.e., 10, with 260-fold binding selectivity in comparison to the A(1)AR and displaying a characteristic docking mode in an A(3)AR model. The corresponding 5'-ethyluronamide analogues generally showed increased A(3)AR affinity and behaved as full antagonists, i.e., 17, with 910-fold A(3)/A(1) selectivity. Thus, N-6-substituted 2-( 1,2,3-triazolyl)-adenosine analogues constitute a novel class of highly potent and selective nucleoside-based A(3)AR antagonists, partial agonists, and agonists.
“点击化学”被用来合成两类2-(1,2,3-三氮唑基)腺苷衍生物(1-14)。测定其在人A1、A2A和A3腺苷受体上的结合亲和力及其在A3腺苷受体上的相对效能。一些三氮唑-1-基衍生物显示出低纳摩尔级的A3受体亲和力、高水平的A3/A2A选择性比值以及中等到高的A3/A1比值。1,2,3-三氮唑-4-基衍生物的A3受体亲和力通常较低。在腺嘌呤C2位的位阻较大基团往往降低相对A3受体效能。因此,几个5'-OH衍生物似乎成为选择性A3受体拮抗剂,即化合物10,与A1受体相比具有260倍的结合选择性,并在A3受体模型中显示出特征的结合模式。相应的5'-乙基脲酰胺衍生物通常显示出较高的A3受体亲和力,并表现为空气满拮抗剂,即化合物17,具有910倍的A3/A1选择性。因此,N6-取代的2-(1,2,3-三氮唑基)-腺苷衍生物构成了一类基于核苷的高效且高选择性的A3受体拮抗剂、部分激动剂和激动剂的新颖化合物。