5+1-Heterocyclization as preparative approach for carboxy-containing triazolo[1,5-c]quinazolines with anti-inflammatory activity.

Present article is devoted to the purposeful search of novel anti-inflammatory agents among carboxyl-containing partially hydrogenated [1,2,4]triazolo[1,5-с]quinazolines and products of their tandem cyclization. It has been shown that target compound's could be obtained via interaction between [2-(3-R-1H-1,2,4-triazol-5-yl)phenyl]amines and oxo-containing carboxylic acids and their esters of various structure. The structures of synthesized compounds were verified by appropriate methods, the features of NMR-spectra patterns were discussed as well. The low predicted toxicity of obtained compounds has been estimated using in silico methods. In vivo study on the model of acute aseptic inflammation (carrageenan test) have been revealed that synthesized compounds expose anti-inflammatory activity in the range of 0.94-52.66%. 4-(2-(Ethoxycarbonyl)-5,6-dihydro-[1,2,4]triazolo[1,5-c]quinazolin-5-yl)benzoic acid has been identified as most active compound. Additionally, the effects of some (2-R-5,6-dihydro[1,2,4]triazolo[1,5-c]quinazolin-5-yl)benzoic acids (compounds 3) on the levels of key inflammatory markers have been estimated. It has been shown that studied compounds decrease the level of neutrophils, COX-2, nitrotyrosine, IL-1b, C-reactive protein and increase level of eNOS. 4-(2-(Ethoxycarbonyl)-5,6-dihydro-[1,2,4]triazolo[1,5-c]quinazolin-5-yl)benzoic acid (3.2) has been identified as compound with most expressed anti-inflammatory activity and significant effect on the levels of marker of inflammatory processes. Molecular docking study towards СОХ-1 and СОХ-2 has been conducted to substantiate possible mechanism of obtained compounds anti-inflammatory activity. It has been found that fixation of 4-(2-(ethoxycarbonyl)-5,6-dihydro-[1,2,4]triazolo[1,5-c]quinazolin-5-yl)benzoic acid (3.2) molecule in active site of enzyme is outstandingly similar to the reference ligands. The essential value of carboxylic group for presence of anti-inflammatory activity has been estimated as result of SAR-analysis. It has been found that studied class of compounds is perspective for further structural modification aimed to the creation of novel anti-inflammatory agents.

Тhio-containing pteridines: Synthesis, modification, and biological activity.

The present article is devoted to searching for biologically active agents among novel thio-containing pteridines. Synthetic protocols based on the condensation of 5,6-diamino-2-thioxo-2,3-dihydropyrimidin-4(1H)-ones with dicarbonyl compounds were elaborated and used for the synthesis of target products. The directions for further modification of the obtained thio-containing pteridines were substantiated and realized. The spectral properties of the obtained compounds were studied and described. The results of the in silico study revealed that the predicted affinity of the obtained compounds to the dihydrofolate reductase (DHFR) active site is comparable with the affinity of methotrexate, despite the differences in the nature of the ligand-enzyme interactions. The in vitro study of DHFR-inhibiting activity revealed that the most active compounds 3.9 and 4.2 have lg IC50 values of -5.889 and -5.233, respectively, significantly inferior to methotrexate (lg IC50 = -7.605). Additionally, the synthesized compounds were studied for their antiradical activity as a possible mechanism of pharmacological effects. Among the obtained pteridines, compounds 5.1 (lg EC50 = -4.82) and 5.3 (lg EC50 = -4.92) have antiradical activity higher than the reference compound ascorbic acid (lg EC50 = -4.81). The conducted structure-activity relationship analysis provided valuable data for the further search for biologically active agents among thio-containing pteridines and related compounds.

Quinazoline-containing Hydrazydes of Dicarboxylic Acids and Products of Their Structural Modification: A Novel Class of Anti-inflammatory Agents.

The synthesis of hydrazides formed by quinazolin-4(3H)-ylidenehydrazine and dicarboxylic acids, as well as their further modification are described in the present manuscript. It was shown that above-mentioned hydrazides may be obtained via acylation of initial quinazolin-4(3H)-ylidenehydrazine by corresponding acylhalides, cyclic anhydrides and imidazolides of dicarboxylic acids monoesters. Obtained hydrazides were converted into [1,2,4]triazolo[1,5-c]quinazolines that were used as initial compounds for chemical modification aimed to the introduction of amide fragment to the molecule. The IR, 1H NMR and chromato-mass spectral data of obtained compounds were studied and discussed. Obtained substances were studied for anti-inflammatory activity using carrageenan-induced paw inflammation model. Amides of ([1,2,4]triazolo[1,5-c]quinazoline-2-yl)alkyl carboxylic acids were detected as promising class of anti-inflammatory agents for further purposeful synthesis and profound study of anti-inflammatory activity.