In Vitro Antimycobacterial Activity and Physicochemical Characterization of Diaryl Ether Triclosan Analogues as Potential InhA Reductase Inhibitors.

Two sets of diphenyl ether derivatives incorporating five-membered 1,3,4-oxadiazoles, and their open-chain aryl hydrazone analogs were synthesized in good yields. Most of the synthesized compounds showed promising in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv. Three diphenyl ether derivatives, namely hydrazide 3, oxadiazole 4 and naphthylarylidene 8g exhibited pronounced activity with minimum inhibitory concentrations (MICs) of 0.61, 0.86 and 0.99 µg/mL, respectively compared to triclosan (10 µg/mL) and isoniazid (INH) (0.2 µg/mL). Compounds 3, 4, and 8g showed the InhA reductase enzyme inhibition with higher IC50 values (3.28-4.23 µM) in comparison to triclosan (1.10 µM). Correlation between calculated physicochemical parameters and biological activity has been discussed which justifies a strong correlation with respect to the inhibition of InhA reductase enzyme. Molecular modeling and drug-likeness studies showed good agreement with the obtained biological evaluation. The structural and experimental information concerning these three InhA inhibitors will likely contribute to the lead optimization of new antibiotics for M. tuberculosis.

Synthesis and Characterization of New Series of 1,3-5-Triazine Hydrazone Derivatives with Promising Antiproliferative Activity.

A new series of s-triazine hydrazone derivatives was prepared based on the reaction of 6-hydrazino-2,4-disubstituted-s-triazine with p-substituted benzaldehyde derivatives using a straightforward synthetic pathway. The antiproliferative activity of all synthesized compounds was evaluated against two human cancer cell lines; breast cancer MCF-7 and colon carcinoma HCT-116 using MTT assay. Among all, 11 compounds have shown strong to moderate antiproliferative activity with IC50 values in the range 1.01-18.20 µM in MCF-7 and 0.97-19.51 µM in HCT-116. The best results were obtained with 4,4'-(6-(2-(pyridin-2-ylmethylene)hydrazinyl)-1,3,5-triazine-2,4-diyl) dimorpholine 11 (IC50 = 1.0 µM and 0.98 µM in MCF-7 and HCT-116 cell lines, respectively). The substituents on the s-triazine core as well as the substituent at the benzylidene moiety have a great effect on the antiproliferative activity. Whereas compounds containing dimorpholino-s-triazine derivatives 8a-e showed more potent antiproliferative in MCF-7 compared to their analogs 7a-f (compounds containing two-piperidine rings), compounds containing one piperidine and one morpholine ring 9a-f showed better IC50 values in the range 10.4-22.2 µM. On the other hand, compounds containing two-piperidine rings 7a-f showed more potent antiproliferative in HCT-116 (IC50 values in the range 8.8-19.5 µM) than their analogs 8a-e and 9a-f.