Thiazolotriazoles As Anti-infectives: Design, Synthesis, Biological Evaluation and In Silico Studies

The rational design of novel thiazolo[2,3-c][1,2,4]triazole derivatives was carried out based on previously identified antitubercular hit molecule H127 for discovering potent compounds showing antimicrobial activity. The designed compounds were screened for their binding efficacies against the antibacterial drug target enoyl-[acyl-carrier-protein] reductase, followed by prediction of drug-likeness and ADME properties. The designed analogues were chemically synthesized, characterized by spectroscopic techniques, followed by evaluation of antimicrobial activity against bacterial and fungal strains, as well as antitubercular activity against M. tuberculosis and M. bovis strains. Among the synthesized compounds, five compounds, 10, 11, 35, 37 and 38, revealed antimicrobial activity, albeit with differential potency against various microbial strains. Compounds 10 and 37 were the most active against S. mutans (MIC: 8 μg/mL), while compounds 11 and 37 showed the highest activity against B. subtillis (MIC: 16 μg/mL), whereas compounds 10, 11 and 37 displayed activities against E. coli (MIC: 16 μg/mL). Meanwhile, compounds 10 and 35 depicted activities against S. typhi (MIC: 16 μg/mL) and compound 10 showed antifungal activity against C. albicans (MIC: 32 μg/mL). The current study has identified two broad-spectrum antibacterial hit compounds (10 and 37). Further structural investigation on these molecules is underway to enhance their potency.

Synthesis, antimicrobial activity and modeling studies of thiazoles bearing pyridyl and triazolyl scaffolds

In this study, novel 4-(5-((2/3/4-substituted benzyl)thio)-4-(4-substituted phenyl)-4H-1,2,4-triazol-3-yl)-2-(pyridin-3/4-yl)thiazoles were synthesized following a multi-step synthetic procedure. All the compounds were screened with a panel of gram positive/negative bacteria, yeasts, and molds for antimicrobial activity using the disc diffusion method. Then, the minimum inhibitor concentration (MIC) and the minimum bactericidal concentration (MBC) values of active compounds were determined against Micrococcus luteus, Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus using the broth microdilution technique. These compounds were also screened for their inhibitory activities against S. aureus DNA gyrase by supercoiling assay. Furthermore, the crystal structure of S. aureus DNA gyrase B ATPase was subjected to a docking experiment to identify the possible interactions between the most active ligand and the active site. Lastly, the in silico technique was performed to analyze and predict the drug-likeness, molecular and ADME properties of the synthesized molecules.

Synthesis and antimicrobial activity of functional derivatives of thiazolo[2,3-c][1,2,4]triazoles

Background:

Condensed triazoles are a well-known class of heterocyclic compounds due to a wide range of biological activity. The study is dedicated to the evaluation of the antimicrobial potential of new functional derivatives of thiazolo[2,3-c][1,2,4]triazoles.

Methods:

Effective, easy-to-implement and low-cost routes to the production of title compounds via electrophilic intramolecular heterocyclization are reported. Bactericidal and fungicidal activities against Gram-positive and Gram-negative bacteria, and fungus were studied. The influence of functional groups on the biological activity of tested thiazolo[2,3-c][1,2,4]triazoles is discussed.

Results:

Microbiological evaluation shows that 6-[(trichlorotellanyl)methyl]-[1,3]thiazolo[2,3-c][1,2,4]triazol-3-amine hydrogen chloride 2a and 3-(2-hydroxyphenyl)-6-[(trichloro-λ4-tellanyl)methyl]-5,6-dihydro-[1,3]thiazolo[2,3-c][1,2,4]triazole 2g have a high bactericidal activity and Cu (I) salts of 3-(2-hydroxyphenyl)-6-iodomethyl/6-methylidene-5,6-dihydro-[1,3]thiazolo-[2,3-c][1,2,4]triazoles 5a,c have a high fungicidal activity.

Conclusion:

it must be concluded that these products or their derivatives may be of practical benefit as bactericidal and fungicidal agents.

Nucleobase sequence based building up of reliable QSAR models with the index of ideality correlation using Monte Carlo method

This study describes in silico designing of aptamers against the influenza virus using Monte Carlo method. Aptamers are short, single-stranded oligonucleotides and these bind to an ample range of biologically important proteins which are related to many disease conditions. The affinities and specificities of aptamers are comparable to antibodies. In the medicinal chemistry, quantitative structure-activity relationship (QSAR) is an important skill which is used for drug design and development. To study the inhibitory activity of aptamers, we have developed QSAR models based on Monte Carlo method. The nucleobase sequence descriptors B_k, BB_k and BBB_k are used to generate the QSAR models. A number of statistical benchmarks together with index of ideality of correlation (IIC) is considered to validate the build QSAR models. Data set of 98 aptamers is divided into four random splits. The statistical criteria R² = 0.8711 and CCC = 0.9207 of the validation set of split 3 are best, so the build QSAR model of split 3 is the paramount model. The aptamer fragment responsible for the promotors of endpoint increase and decrease are also determined. These fragments are applied to design new nine aptamers from the lead aptamer APT01.Communicated by Ramaswamy H. Sarma.