Synthesis and Biological Activity Evaluation of Pyrazole–1,2,4–triazole Hybrids: A Computer-aided Docking Studies

Background: In the present study, a new series of 1,2,4-triazole linked to pyrazole derivatives (8a-j) of 4-(((7-amino-7H-[1,2,4]triazolo[4,3-b][1,2,4]triazol-6-yl)methyl)amino)-1,5-dimethyl- 2-phenyl-1H-pyrazol-3(2H)-one were synthesized and assessed for their antibacterial and anticancer activity. Objective: Encouraged by these results, these analogues 4-(((7-amino-7H-[1,2,4]triazolo[4,3- b][1,2,4]triazol-6-yl)methyl)amino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-ones 8 have been synthesized and their inhibitory potential activity against different bacterial microorganisms and cancer cell lines was discussed. Methods: All the synthesized final scaffolds were characterized by ¹H NMR, ¹³C NMR, IR, mass and elemental analysis. All the synthesized 1,2,4–triazole linked to pyrazole compounds were evaluated for their antimicrobial sensitivity by using the agar dilution technique. The anticancer activity of these compounds has been assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay and docking results are described by Autodock 4.2. Results: In vitro analysis suggests that compounds 8h, 8f, and 8b demonstrated excellent antibacterial activity against S. aureus, P. aeruginosa, S. epidermidis with MICs of 8, 8, 11 μg/mL respectively, while the remaining compounds showed moderate to good inhibitory potential. Some of them exhibited potent cytotoxicity against MCF-7 and P388 cancer cell lines and compounds 8c, 8f, and 8d reveal the highest potency against MCF-7 with IC50 values 2.8 ± 0.4, 3.1 ± 0.4, 3.5 ± 0.2 μM, respectively. Especially 8c, 8i and 8f showed better interaction patterns with amino acids Ala197 (N–N), Lys168 (N–N), Asn163 (O–N) at 3.13, 3.09, 3.00 A° as reported in DNA (Topo II) complex (1ZXM). Conclusion: New findings have established the fact that fused 1,2,4-triazoles linked to pyrazole contributed great significance in the field of medicinal chemistry due to their various biological properties.