Design and synthesis of novel Imidazo[2,1-b]thiazole derivatives as potent antiviral and antimycobacterial agents

Abstract

A B S T R A C TA series of novel acyl-hydrazone (4a-d) and spirothiazolidinone (5a-d, 6a-d) derivatives of imidazo[2,1-b] thiazole were synthesized and evaluated for their antiviral and antimycobacterial activity. The antituberculosis activity was evaluated by using the Microplate Alamar Blue Assay and the antiviral activity was evaluated against diverse viruses in mammalian cell cultures. According to the biological activity studies of the compounds, 5a-c displayed hope promising antitubercular activity, 6d was found as potent for Coxsackie B4 virus, 5d was found as effective against Feline corona and Feline herpes viruses. Consequently, the obtained results displayed that, 5a-d and 6d present a leading structure for future drug development due to its straightforward synthesis and relevant bioactivity.

Thiazole Ring—A Biologically Active Scaffold

“…Gürsoy et al [149] synthesized a series of novel acyl-hydrazone and spirothiazolidinone ( 97a-d, 98a-d) derivatives of imidazo[2,1-b] thiazole and evaluated their antiviral activity (Figure 38). The study revealed that among all compounds tested, only compound 98d exhibited very good activity against Feline corona virus in CRFK cells, with an EC 50 value of 4.8 µM and SI more than 20, being much more potent than ganciclovir, used as reference drug (EC 50 value of >100 µM).…”

“…The best activity among all mentioned compounds was achieved for compound 150 with 96% inhibition followed by 153 and 154b with 94% and 92% of edema inhibition, respectively. For 4,7dihydrothiazolo [4,5-b]pyridine derivatives as well as pyridazine derivatives, the beneficial for activity was the presence of 4-chlorophenyl moiety (148), while for the thieno [3,2d]thiazole derivatives, the presence of the 3-cyano group (149) was more favorable than the presence of the COOEt moiety (149). For the thiazolo [4 ,5 :4,5]thieno [2,3-d]pyrimidine derivatives, a positive effect was observed with the presence of the hydroxyl group (150), while for arylhydrazone derivatives, the unsubstituted derivatives showed the best activity.…”

Updated Information on Antimicrobial Activity of Hydrazide–Hydrazones

“…Hydrazide-hydrazone 39 was found to be most active against M. tuberculosis H37Rv (MIC = 16.252 µg/mL) and had no cytotoxicity towards CRFK (Crandell Rees feline kidney) cells (CC 50 > 100 µg/mL). However, its activity was lower than for rifampicin, which was used as a reference substance (MIC = 0.125 µg/mL) (Figure 31) [41]. New 1,3-oxazole-isoniazid hybrids synthesized by Shah et al were evaluated for their antitubercular activity against M. tuberculosis H37Rv strain.…”

“…The authors discovered that compounds bearing methoxy groups in the phenyl ring attached to the 1,3-oxazole scaffold displayed better activity compared to the other compounds (Figure 32). Synthesized substances (40,41) were tested in vitro for cytotoxicity in human embryonic kidney (HEK-293T) cells and did not display changes in cytotoxicity as compared with vehicle (DMSO) [42].…”

Synthesis of New Thiazole and Pyrazole Clubbed 1,2,3-Triazol Derivatives as Potential Antimycobacterial and Antibacterial Agents

“…5 It is known that thiazole derivatives many compounds have exhibited remarkable antimycobacterial activity. [19][20][21][22][23][24][25][26] Moreover, thiazole derivatives have also exhibited a wide range of other pharmacological activity such as antimicrobial, 27,28 anti-inflammatory, 29 CNS active agents, 30 antimalarial 31 and anticancer 32 activities. Additionally, compounds bearing the pyrazole skeleton have been exhibited to exhibit significant antimycobacterial activity, [33][34][35] as well as antimicrobial, 36 anti-inflammatory 37 anticancer 38 and antimalarial 39 activities.…”