MRSA infection is one of the alarming diseases in the current scenario. Identifying newer molecules to treat MRSA infection is of urgent need. In the present study, we have designed fluorinated thiazolidinone derivatives with various aryl/heteroaryl units at 5 th position of the thiazolidinone core as promising anti-MRSA agents. All the compounds were screened for antibacterial activity against four bacterial strains. Among the tested compounds, the halogenated compounds with simple arylidene ring, (5Z 4f) and (5Z)-5-[(3,5-difluorophenyl)methylidene]-2-[(1,3-thiazol-2-yl)amino]-1,3thiazol-4(5H)-one (4g) showed excellent activity with MIC 3.125 -6.25 μg/mL against S. aureus and P. aeruginosa organism. Furthermore, these potent compounds were screened against MRSA strains, ESKAPE panel organism, and H37Rv mycobacterium strain. Compounds 4c (MIC 0.39 μg/mL), and 4f (MIC 0.39 and 0.79 μg/mL) displayed promising activity against MRSA strains (ATCC and clinical isolates, respectively). The most potent compounds, 4c and 4f eradicated the growth of bacterial colonies in a time-kill assay indicated that these are bactericidal in nature. The preliminary toxicity study of the potent molecules revealed that these compounds are non-hemolytic in nature as they did not induce lysis in human RBCs. In addition, the molecular docking and dynamics studies of compounds 4b, 4c, 4f and 4g were carried out on MurB protein of S. aureus (PDB code: 1HSK). Docking results demonstrated remarkable hydrogen bonding interaction with key amino acids ARG310, ASN83, GLY79 and π-π interactions with TYR149 which confirm the mode of action of the molecules.

Objective: To evaluate the chemical composition, antibacterial and antioxidant properties of stem bark essential oil of Litsea glutinosa C. B. Rob. Methods:The essential oil isolated from stem bark of L. glutinosa and their chemical composition was analyzed by gas chromatography coupled with mass spectrometry detector. The in vitro antibacterial activity of the stem bark essential oil was investigated against eight human pathogenic bacterial clinical isolates using agar disc diffusion method and MIC value was determined by modified resazurin microtitre-plate assay. The antioxidant activity of essential oil was measured by 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH), 2, 2-azinobis-3-ethylbenzothiazoline-6-sulphonate radical cation (ABTS) and β-carotene bleaching assay.Results: GC-MS analysis of stem bark essential oil resulted in the identification of 37 compounds, off which 9,12-octadecadienoic acid (62.57%), hexadecanoic acid (12.68%), stigmast-5-en-3-ol (6.87%) and vitamin E (2.51%) were the main constituents representing 84.63% of the oil. The determination of in vitro antibacterial activity of stem bark essential oil resulted in significant inhibition zone (15.00±0.57 mm) and MIC value (0.15±0.15×10 -2 Conclusion: L. glutinosa stem bark essential oil showed potential antibacterial activity against the Vibrio cholera. The results of this investigation supported the ethnomedical claim of essential oil as a demulcent, antidiarrheal and antioxidant drug. mg/ml) against the pathogenic bacteria Vibrio cholera followed by Pseudomonas aeruginosa and Salmonella typhi. The results of DPPH radical scavenging (IC50:4.540±0.06 µg/ml), ABTS (IC50:256.02±0.06 µg/ml) and β-carotene bleaching assay (%I: 78.51±0.42 %) showed significant in vitro antioxidant property.