A series of new 4-thiazolidinone derivatives were synthesized and evaluated against diverse DNA-and RNA-viruses in mammalian cell cultures. Some of the compounds were found to exhibit moderate antiviral activity. 3-Propyl-2-[((6-(4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl)acetyl)hydrazono]-5-methyl-4-thiazolidinone 13, displayed modest yet consistent activity against three strains of influenza A virus, including the 2009 pandemic virus A/H1N1 Virginia/ATCC3/2009 (cytotoxicity >100 µM). Compounds 6 and 11 displayed activity against vesicular stomatitis virus in HeLa cells (antiviral EC50 values of 9 (cytotoxicity 100 µM) and 2 µM (cytotoxicity 20 µM), respectively). Neither of the compounds was active against HIV.

The aim of this study was to determine the probable antibacterial, antitubercular, and antiviral activities of some N²-arylidene-(6-(4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl) acetic acid hydrazides (3a-j). Further structural optimization of the identified lead structures can lead us to new more active potential antibacterial, antitubercular, and antiviral agents. Antibacterial activities of the title compounds against Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853 and Escherichia coli ATCC 25922. These molecules were also evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv (ATCC 27294) using the BACTEC 460 radiometric system and BACTEC 12B medium. Moreover, all the compounds (3a-j) were also evaluated against some DNA and RNA viruses in Madin-Darby Canine Kidney, Crandell-Rees Feline Kidney (CRFK), Vero, human embryonic lung (HEL) and HeLa cells. Among the tested compounds, 3i displayed the highest efficacy against S. aureus and E. coli. Compound 3j, 5-nitro-2-furfurylidene derivative showed the highest antituberculosis activity (IC₅₀: 6.16 µg/mL and IC₉₀: 14.390 µg/mL). Compound 3i showed the most potent antiviral activity against feline corona virus in CRFK cell cultures (antiviral EC₅₀: 7.5 µM and SI>13). Furthermore, compounds 3c and 3g displayed activity against herpes simplex virus-1 and vaccinia virus in HEL cell cultures (antiviral EC₅₀ values of 9; 16 and 20; 14 µM, respectively). On the basis of aforementioned results, it can be conluded that imidazo[2,1-b]thiazole derivatives bearing hydrazone moieties serve as promising chemical probes to design therapeutic agents with antibacterial, antitubercular, and antiviral properties.

In this work, we reported the synthesis and evaluation of antibacterial and antifungal activities of three new compound series obtained from 6-(phenyl/4-chlorophenyl)imidazo[2,1-b]thiazole-3-acetic acid hydrazide: 2-{[6-(phenyl/4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl]acetyl}-N-alkyl/arylhydrazinecarbothioamides (2a–d), 4-alkyl/aryl-2,4-dihydro-5-{[6-(phenyl/4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl]methyl}-3H-1,2,4-triazole-3-thiones (3a–n), and 2-alkyl/arylamino-5-{[6-(phenyl/4-chlorophenyl)imidazo[2,1-b]thiazol-3-yl]methyl}-1,3,4-thiadiazoles (4a–g). The newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR (APT), mass and elemental analysis. Their antibacterial and antifungal activities were evaluated against Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Candida albicans ATCC 10231, C. parapsilosis ATCC 22019, C. krusei ATCC 6258, Trichophyton mentagrophytes var. erinacei NCPF 375, Microsporum gypseum NCPF 580, and T. tonsurans NCPF 245. 3c, 3f, 3m, 3n, and 4e showed the highest antibacterial activity. Particularly 3c, 3f, 3g, 3k, 3n, 4a, 4e, and 4g showed the highest antifungal activity against tested fungi.

Salvia species play a significant role in the pharmaceutical and nutraceutical industries due to their rich chemical profiles and notable biological activities. This study aimed, for the first time, to comprehensively investigate the phytochemical profile and antibacterial properties of eight selected Salvia species. Ethanol and water extracts were prepared from the dried aerial parts, and their chemical compositions were analyzed via LC-HRMS. Rosmarinic acid was the major compound in almost all the prepared extracts. Following rosmarinic acid, caffeic acid, fumaric acid, salvianolic acid B, and hispidulin-7-O-glucoside were also identified as principal constituents. The antibacterial potential of the relevant metabolites was evaluated in silico, and their receptor binding profiles targeting dihydrofolate reductase and dihydropteroate synthase were elucidated. Additionally, the in vitro antibacterial efficacy of all the extracts was determined against various bacterial strains using a modified microbroth dilution method. Among all tested extracts, both the infusion and decoction of Salvia albimaculata exhibited the strongest antibacterial activity against Staphylococcus aureus and MRSA. Additionally, the ethanol extracts of S. albimaculata, S. viridis, S. verticillata, and S. pilifera demonstrated moderate activity against MRSA. These findings contribute valuable insights into the development of natural-based antibacterial agents for the pharmaceutical and food industries.