Microbial infections remain a grave threat to global health security due to an increase in antibiotic resistance. The ongoing coronavirus pandemic has increased the risk of microbial and fungal infections....

A new series of 3,5-bis(2-arylthiazol-4-yl)-1,2,4-oxadiazole (8a-o) has been synthesized by modified reaction conditions. The reaction of ester 7a with N 0hydroxy-2-phenylthiazole-4-carboximidamide 6a using NaOH in DMSO gave the formation of product 8a up to 40% yield. In the second method, the reaction with K 2 CO 3 in toluene at reflux conditions gave a 50% yield. In the third method, the reaction condition was modified. The ester 7a was hydrolyzed to acid 9a. The reactions of acid 9a using N,N-dimethyl amino pyridine (DMAP) in N,N-dimethylformamide (DMF), followed by the addition of N-(3-dimethylaminopropyl)-N 0 -ethylcarbodiimide hydrochloride (EDCÁHCl), and then N 0hydroxy-2-phenylthiazole-4-carboximidamide 6a, furnished a 65% yield of 8a.The compounds 8b-o were synthesized using DMAP and EDCÁHCl as coupling reagents and gave 60%-72% yields. The structure of newly synthesized compounds was confirmed by spectral analysis. The synthesized compounds were screened for in vitro antimicrobial activity against Escherichia coli (NCIM 2574), Proteus mirabilis (NCIM 2388), Bacillus subtilis (NCIM2063), Staphylococcus albus (NCIM 2178), Candida albicans (NCIM 3100), and Aspergillus niger (ATCC 504). Among the 8a-o derivatives, eight compounds 8c, 8e, 8f, 8g, 8i, 8j, 8k, and 8l showed good activity S. albus with a MIC 31.25-62.5 μg/mL.

Resistance to antibiotic drugs has directed global health security to a life-threatening situation due to mycobacterial infections. In search of a new potent antimycobacterial, a series of (±) 2-(6-substituted quinolin-4-yl)-1-alkoxypropan-2-ol ( 8a–p ) have been synthesized. The structures of the newly synthesized derivatives were characterized by spectrometric analysis. Derivatives 8a–p were evaluated for antitubercular activity against Mycobacterium tuberculosis H37Rv (ATCC 25177), antibacterial activity against Proteus mirabilis (NCIM2388), Escherichia coli (NCIM 2065), Bacillus subtilis (NCIM2063) Staphylococcus albus (NCIM 2178) and antifungal activity against Candida albicans (NCIM 3100), Aspergillus niger (ATCC 504). Thirteen 2-(6-substituted quinolin-4-yl)-1-alkoxypropan-2-ol ( 8a–m) derivatives reported moderate to good antitubercular activity against M. tuberculosis H37Rv with MIC 9.2–106.4 μM. Compounds 8a and 8h showed comparable activity with respect to the standard drug pyrazinamide. The active compounds screened for cytotoxicity activity against L929 mouse fibroblast cells showed no significant cytotoxic activity. Compounds 8c , 8d , 8e , 8g , 8k , and 8o displayed good activity against S. albus . Compounds 8c and 8n showed good activity against P. mirabilis and E. coli , respectively. The potential antimycobacterial activities imposed that the 2-(6-substituted quinolin-4-yl)-1-alkoxypropan-2-ol derivatives could lead to compounds that could treat tuberculosis. Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s11696-023-02741-3.

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A 59-year-old married male, a known case of line probe assay-confirmed multidrug-resistant pulmonary tuberculosis was treated with kanamycin, levofloxacin, ethionamide, ethambutol, pyrazinamide and cycloserine for seven months [...]