Synthesis and antileishmanial activity of new 1-(pyridin-2-yl)imidazolidin-2-ones derived from 2-amino-4,6-dimethylpyridine.

Derivatives of 2-amino-4,6-dimethylpyridine resulting from the integration of the amino function into a 2-imidazolidinone were synthetized via the corresponding 2-chloroethylurea. N3-benzylation, acylation or sulfonylation afforded the target compounds 6-14 which were evaluated for their in vitro and in vivo antileishmanial activity. Two compounds, the N3-benzyl derivative 7 and the N3-tolylsulfonyl derivative 14, exhibited potent inhibition against cultured extracellular promastigotes of Leishmania mexicana with IC50 comparable to that of the previously studied N-(4,6-dimethylpyridin-2-yl) furan-2-carboxamide 2: 32.4, 46 and 69 mumol/l, respectively. Experimentation of their activity against mice macrophage amastigotes pointed out that IC50 of imidazolidones 7 and 14 were 7 and 13-fold lower than that of amide 2: 13.7 and 89 mumol/l. In vivo evaluation in Balb/c mice, intradermally infested with Leishmania mexicana, confirmed that, in the lesion site, compound 14 was able to significantly reduce the parasite burden at a daily i.p. dose of 10 mg/kg. It was demonstrated that these N-pyridinylimidazolidinones could act by interference with the parasite PLA2 activity.

[Synthesis and pharmacologic evaluation of 3-(2- and 4-pyridinyl)indane-1,3-diones and structural analogues with potential anti-inflammatory and antineoplastic activity]. / Synthèse et évaluation pharmacologique de 2-(2 et-4-pyridinyl)indane-1,3-diones et d'analogues structuraux à potentialités anti-inflammatoire et antitumorale.

Our on going work in the series of enamido-diketones issued from 2-azaarylindane-1,3-diones led us to synthesize and experiment N and C2-substituted derivatives of 2-(2 and 4-pyridinyl)indane-1,3-diones as well as of structurally related compounds resulting from the replacement of pyridine by quinoline and benzimidazole. Pharmacological evaluation of their anti-inflammatory activity (by inhibition of carrageenan foot edema) and their anticoagulant activity (by prothombin assay) led to the conclusion of the possibility of achieving a selective anti-inflammatory effect. It has been previously established that anticoagulants are liable to exert a protective effect in the development of cancer metastasis. Nevertheless none of the six experimented 2-(pyridin-2-yl)indane-1,3-diones extended survival time of mice treated by P388 lymphocytic leukemia.

Synthesis and anti-inflammatory activity of polyazaheterocyclic derivatives of 6-amino-2,4-lutidine and their precursors.

Derivatives of N-(4,6-pyridin-2-yl)arylcarboxamides resulting from the integration of the amidic function into 4H-1,2,4-triazole, triazol-3(2H)-one and 1H-tetrazole rings were evaluated as potential anti-inflammatory compounds. The level of activity decreased as compared to carboxamides, nevertheless their precursors and notably the corresponding amidrazones exhibited potent activity; amidrazone 21, whose ID50 was 34.4 mg.kg-1 in the rat paw edema test, was selected for further investigation. These heteroarylcarboxamide derivatives could represent an interesting alternative to classical non-steroidal anti-inflammatories in so far as they partly act by inhibition of tumor necrosis factor-alpha production.

Cholinesterase inhibition by derivatives of 2-amino-4,6-dimethylpyridine.

Derivatives of 2-amino-4,6-dimethylpyridine, aryl(alkyl)carboxamides, thiocarbamides and amidrazones, already known for their anti-inflammatory properties, were found to be moderately active inhibitors of acetyl and butyrylcholinesterase. Quantitative structure-activity relationships showed that the binding affinity was enhanced by the following structural modifications: (1) increase in molecular volume, (2) decrease in the energy of the lowest unoccupied molecular orbital, (3) insertion of a methylene group between the amide carbonyl and the aromatic ring, (4) replacement of the amide oxygen by sulfur. The affinity remained, however, weaker than that of the specific inhibitor 9-amino-1,2,3,4-tetrahydroacridine (tacrine). The association of anti-inflammatory and cholinesterase inhibiting activities within the same compound may prove useful for the treatment of Alzheimer's disease.