Primofiore G, Da Settimo F, Marini AM, Taliani S, La Motta C, Simorini F, Novellino E, Greco G, Cosimelli B, Ehlardo M, Sala A, Besnard F, Montali M, Martini C. Refinement of the benzodiazepine receptor site topology by structure-activity relationships of new N-(heteroarylmethyl)indol-3-ylglyoxylamides.
J Med Chem 2006;
49:2489-95. [PMID:
16610792 DOI:
10.1021/jm0511841]
[Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-(heteroarylmethyl)indol-3-ylglyoxylamides (1-26) were synthesized and evaluated as ligands of the benzodiazepine receptor (BzR) to probe the hydrogen bonding properties of the so-called S(1) site of the BzR by means of suitable heterocyclic side chains. SARs were developed in light of our hypothesis of binding modes A and B. Pyrrole and furan derivatives adopting mode A (2, 8, 10, 20, 22) turned out to be more potent (K(i) values < 35 nM) than their analogues lacking hydrogen bonding heterocyclic side chains. These data suggest that the most potent indoles interact with a hydrogen bond acceptor/donor (HBA/D) group located within the S(1) site of the BzR. Compounds 1, 2, 8, 19, 20, and 22, tested at recombinant rat alpha(1)beta(2)gamma(2), alpha(2)beta(2)gamma(2), and alpha(5)beta(3)gamma(2) BzRs, elicited selectivity for the alpha(1)beta(2)gamma(2) isoform. On the basis of published mutagenesis studies and the present SARs, we speculate that the S(1) HBA/D group might be identified as the hydroxyl of alpha(1)-Tyr209 or of other neighboring amino acids.
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