Development of New Antimycobacterial Sulfonyl Hydrazones and 4-Methyl-1,2,3-thiadiazole-Based Hydrazone Derivatives

• Main Authors: Violina T. Angelova (Author), Tania Pencheva (Author), Nikolay Vassilev (Author), Elena K-Yovkova (Author), Rositsa Mihaylova (Author), Boris Petrov (Author), Violeta Valcheva (Author)
• Format: Book
• Published: MDPI AG, 2022-04-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antibiotics11050562; 2079-6382
• Keywords: antimycobacterial activity; ADME/Tox predictions; cytotoxicity; hydrazide-hydrazone derivatives; sulfonyl hydrazone derivatives; molecular docking; Therapeutics. Pharmacology; RM1-950
• Source: Antibiotics, Vol 11, Iss 5, p 562 (2022)

Fifteen 4-methyl-1,2,3-thiadiazole-based hydrazone derivatives <b>3a</b>-<b>d</b> and sulfonyl hydrazones <b>5a</b>-<b>k</b> were synthesized. They were characterized by ¹H-NMR, ¹³C NMR, and HRMS. <i>Mycobacterium tuberculosis</i> strain H37Rv was used to assess their antimycobacterial activity. All compounds demonstrated significant minimum inhibitory concentrations (MIC) from 0.07 to 0.32 µM, comparable to those of isoniazid. The cytotoxicity was evaluated using the standard MTT-dye reduction test against human embryonic kidney cells HEK-293T and mouse fibroblast cell line CCL-1. 4-Hydroxy-3-methoxyphenyl substituted 1,2,3-thiadiazole-based hydrazone derivative <b>3d</b> demonstrated the highest antimycobacterial activity (MIC = 0.0730 µM) and minimal associated cytotoxicity against two normal cell lines (selectivity index SI = 3516, HEK-293, and SI = 2979, CCL-1). The next in order were sulfonyl hydrazones <b>5g</b> and <b>5k</b> with MIC 0.0763 and 0.0716 µM, respectively, which demonstrated comparable minimal cytotoxicity. All compounds were subjected to ADME/Tox computational predictions, which showed that all compounds corresponded to Lipinski's Ro5, and none were at risk of toxicity. The suitable scores of molecular docking performed on two crystallographic structures of enoyl-ACP reductase (InhA) provide promising insight into possible interaction with the InhA receptor. The 4-methyl-1,2,3-thiadiazole-based hydrazone derivatives and sulfonyl hydrazones proved to be new classes of lead compounds having the potential of novel candidate antituberculosis drugs.