WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14627/6

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  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Synthesis of Novel Thiazole/Thiadiazole Conjugates of Fluoroquinolones as Potent Antibacterial and Antimycobacterial Agents
    (John Wiley and Sons Inc, 2025) Poyraz Yılmaz, P.; Kulabaş, N.; Bozdeveci, A.; Vagolu, S.K.; Imran, M.; Tatar, E.; Küçükgüzel, İ.; Yilmaz, Pinar Poyraz
    Twenty azole-fluoroquinolone hybrids were designed and synthesized by conjugating thiazole and thiadiazole structures to ciprofloxacin and norfloxacin via a 2-oxoethyl bridge. The structures and purities of the synthesized compounds were proven by spectral techniques. The antimycobacterial effects of target compounds 21–40 were tested against Mycobacterium tuberculosis H37Rv strain. Among the 20 synthesized compounds, 12 exhibited minimal inhibition concentration (MIC) values in the range of 1.56–25 μg/mL. Among the molecules screened for antimycobacterial effects, the most effective was compound 35, a thiadiazole-ciprofloxacin hybrid. The cytotoxic effect of this molecule was found to be lower than the reference drugs, and it was also determined to be a more effective inhibitor than ciprofloxacin and norfloxacin in the DNA-gyrase supercoiling test. The antimicrobial effects of compounds 21–40 were screened by agar-well diffusion and microdilution tests against Gram-positive/negative bacteria, a fast-growing mycobacterium, and two yeast strains. While most of the compounds tested showed antibacterial effects, the most effective fluoroquinolone derivative appeared to be compound 31 with an MIC value of < 0.63 μg/mL against all Gram-negative bacteria tested. Azole-fluoroquinolone hybrids 21–40 did not show any activity against non-pathogenic Lactobacillus species and yeast-like fungi, indicating that they have selective antibacterial and antimycobacterial activity, particularly against Gram-negative bacteria. In silico molecular docking studies were conducted to uncover the interactions between lead compound 35 and the DNA gyrase proteins of M. tuberculosis and S. aureus. Additionally, a 100 ns molecular dynamics simulation was carried out to assess the stability of the complexes formed between compound 35 and both proteins. © 2025 The Author(s). Chemical Biology & Drug Design published by John Wiley & Sons Ltd.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 14
    Synthesis, Antimicrobial Evaluation and Molecular Modeling Studies of Novel Thiosemicarbazides/Semicarbazides Derived From <i>p</I>-aminobenzoic Acid
    (Elsevier, 2022) Han, M. Ihsan; Ince, Ufuk; Gunduz, Miyase Gozde; Coskun, G. Pelin; Birgul, Kaan; Dogan, Senguel Dilem; Kucukguzel, S. Guniz; İhsan Han, M.
    The development of novel antimicrobial agents is critical to combat life-threatening drug-resistant bacterial and fungal pathogens. In the present study, a new series of p-aminobenzoic acid (PABA) derivatives carrying thiosemicarbazide/semicarbazide moiety were designed, synthesized, and studied for their antimicrobial activity. The target molecules (3a-f, 4a-f) were achieved by the reaction of 4aminobenzohydrazide, obtained from PABA, and various phenyl isothiocyanates/isocyanates. Following structural characterization by spectroscopic methods (H-1 NMR, C-13 NMR, FT-IR, and LC-MS analyses), the synthesized compounds were tested for their antimicrobial activity against Staphylococcus aureus, Escherichia coli, Candida albicans, and their clinical isolates. Thiosemicarbazides with lipophilic substituents on the phenyl ring were identified as the most active compounds in this series. Among the studied molecules, compound 3e, thiosemicarbazide derivative with trifluoromethyl groups on the phenyl moiety, showed the best antimicrobial activity. Physicochemical parameters of the compounds were computed to predict the drug-likeness of the title compounds. Finally, molecular docking studies were performed in the allosteric binding pocket of ?-alanine: ?-alanine ligase (Ddl) to explain the potential antibacterial activity mechanism of 3e against S. aureus strains . (C) 2022 Elsevier B.V. All rights reserved.