1,2,3-Triazol-carboxanilides and 1,2,3-triazol-(N-benzyl)-carboxamides as BK-potassium channel activators. XII.

The chemical structures of many synthetic activators of large-conductance calcium-activated potassium channels (BK channels) satisfy a simple pharmacophore model, consisting of two appropriately substituted phenyl rings connected by a linker of a heterogeneous nature. In this paper, a series of new compounds with modifications of the linker portion of the above pharmacophore are described. In particular, in these new derivatives, the linker portion is represented by a 1,2,3-triazole-carboxamide group, which can be viewed as a combination of two different kinds of linker, independently used in previous series of BK-openers: the amide function and the 1,2,3-triazole ring.

N6-1,3-diphenylurea derivatives of 2-phenyl-9-benzyladenines and 8-azaadenines: synthesis and biological evaluation as allosteric modulators of A2A adenosine receptors.

Some 1-[4-(9-benzyl-2-phenyl-9H-purin-6-ylamino)-phenyl]-3-phenyl-urea derivatives and some 1-[4-(9-benzyl-2-phenyl-9H-8-azapurin-6-ylamino)-phenyl]-3-phenyl-urea derivatives were synthesised and evaluated for their interaction with adenosine receptors. It was found that some of these compounds can act as positive enhancers of agonist and antagonist radioligands for the A(2A) adenosine receptors. This evidence was also strengthened by functional data.

New amido derivatives as potential BKCa potassium channel activators. XI.

The vasorelaxing effects of exogenous activators of large-conductance calcium-activated potassium channels (BK channels) can furnish the pharmacological rational basis for the treatment of hypertension and/or other diseases related with an impaired contractility of vessels. Since in previous works some benzanilide derivatives showed BK channel-induced vasorelaxing activity, in this paper we have taken into consideration the introduction of methylene spacer(s) between the amide linker and one or both the aromatic substituents, to evaluate the pharmacological effect caused by these lengthenings and to obtain possible useful information about structure-activity relationships. Overall, the main findings of this work suggest that the introduction of one or two methylene group(s) in the amide linker exerts a negative influence on the BK-opening properties, which can be due to an excessive lengthening of the spacer between the two aromatic rings and/or to further degrees of conformational freedom.

Synthesis of new 2-phenyladenines and 2-phenylpteridines and biological evaluation as adenosine receptor ligands.

Synthesis and biological assays of a series of 2-phenylpteridine derivatives are described to compare their affinities to adenosine receptors with those of the corresponding adenines, purposely prepared, and 8-azaadenines previously described. This study demonstrates that the enlargement of the five-membered ring of the adenine nucleus to a six-membered one is a modification that does not allow the molecules to maintain high activity towards adenosine receptors; in fact, pteridine derivatives did not show themselves to be good adenosine receptor ligands. On the contrary, N(6)-cycloalkyl- or N(6)-alkyl-2-phenyladenines showed a very high affinity and selectivity for A(1) adenosine receptors.