2,9-Disubstituted-N6-(arylcarbamoyl)-8-azaadenines as new selective A3 adenosine receptor antagonists: Synthesis, biochemical and molecular modelling studies
摘要:
A number of N-6-(N-arylcarbamoyl)-2-substituted-9-benzyl-8-azaadenines, obtained by a modification of the synthetic scheme used to prepare selective A(1) ligands, by only three or two steps, are described. At first we prepared a series of 2-phenyl-9-benzyl-8-azaadenines having as N-6 substituent a variously substituted N-phenylcarbamoyl group. Some of these derivatives demonstrated good affinity towards the A(3) subtype but low selectivity. Compounds having p-CF3, p-F and p-OCH3, as substituents on the phenylcarbamoyl group were selected as lead compounds for the second part of this study. Without modifying the N-6 substituent, which would assure A(3) affinity, we varied the 9 and 2 positions on these molecules to enhance selectivity. Some compounds having a p-methyl group on the 2-phenyl substituent showed a very good affinity and selectivity for the A(3) subtype, revealing the first class of A(3) adenosine receptor selective antagonists with a bicyclic structure strictly correlated to the adenine nucleus. The molecular modelling work, carried out using the DOCK program, supplied two models which may be useful for a better understanding of the binding modes. Both models highlighted the preferred interacting tautomeric forms of the antagonists for human A(1) and A(3) receptors. (c) 2005 Elsevier Ltd. All rights reserved.
2,9-Disubstituted-N6-(arylcarbamoyl)-8-azaadenines as new selective A3 adenosine receptor antagonists: Synthesis, biochemical and molecular modelling studies
摘要:
A number of N-6-(N-arylcarbamoyl)-2-substituted-9-benzyl-8-azaadenines, obtained by a modification of the synthetic scheme used to prepare selective A(1) ligands, by only three or two steps, are described. At first we prepared a series of 2-phenyl-9-benzyl-8-azaadenines having as N-6 substituent a variously substituted N-phenylcarbamoyl group. Some of these derivatives demonstrated good affinity towards the A(3) subtype but low selectivity. Compounds having p-CF3, p-F and p-OCH3, as substituents on the phenylcarbamoyl group were selected as lead compounds for the second part of this study. Without modifying the N-6 substituent, which would assure A(3) affinity, we varied the 9 and 2 positions on these molecules to enhance selectivity. Some compounds having a p-methyl group on the 2-phenyl substituent showed a very good affinity and selectivity for the A(3) subtype, revealing the first class of A(3) adenosine receptor selective antagonists with a bicyclic structure strictly correlated to the adenine nucleus. The molecular modelling work, carried out using the DOCK program, supplied two models which may be useful for a better understanding of the binding modes. Both models highlighted the preferred interacting tautomeric forms of the antagonists for human A(1) and A(3) receptors. (c) 2005 Elsevier Ltd. All rights reserved.