Discovery of quinolinequinones with N-phenylpiperazine by conversion of hydroxyquinoline as a new class of antimicrobial agents targeting resistant pathogenic microorganisms

Yıldız M., BAYRAK N., YILDIRIM H., Çakmak S. M., YILMAZ F. N., MATARACI KARA E., ...More

Bioorganic Chemistry, vol.128, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 128
  • Publication Date: 2022
  • Doi Number: 10.1016/j.bioorg.2022.106045
  • Journal Name: Bioorganic Chemistry
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Chimica, EMBASE, MEDLINE, Veterinary Science Database
  • Keywords: Antibiofilm activity, Antimicrobial activity, Bactericidal effect, Candida albicans, Quinolinequinones, Staphylococcus aureus
  • Istanbul University Affiliated: Yes


© 2022 Elsevier Inc.The development of new antimicrobial agents is necessary to overcome the emerging antimicrobial resistance among infectious microbial pathogens. Herein, we successfully designed and synthesized quinolinequinones (QQs) with N-phenylpiperazine (QQ1-7) containing strong or weak EDG in the amino moiety by converting hydroxyquinoline (HQ) to the dichloroquinolinequinone (QQ) via chlorooxidation. We performed an extensive antimicrobial activity assessment of the QQs with N-phenylpiperazine (QQ1-7). Among the seven quinolinequinones (QQs) with N-phenylpiperazine tested, QQ3 and QQ4 were the most active molecules against Staphylococcus aureus (ATCC® 29213) with a MIC value of 1.22 μg/mL. In addition to this, while QQ4 was more than six (6) times more effective towards Enterococcus faecalis (ATCC® 29212), QQ3 was twenty-six (26) times more effective against same strain. Furthermore, the evaluation of antimicrobial activity indicated that six of seven synthesized QQs (QQ1-4, QQ6, and QQ7) exhibited superior biological potency, eight (8) times for five of them (QQ1-4 and QQ6) and two (2) times for QQ7, against Staphylococcus epidermidis (ATCC® 12228). Besides, all QQs except QQ5 displayed excellent antifungal activity against the fungi Candida albicans (ATCC® 10231). Among these, the two QQs (QQ3 and QQ4), which showed the lowest values against gram-positive bacterial strains (Staphylococcus aureus (ATCC® 29213), Staphylococcus epidermidis (ATCC® 12228), and Enterococcus faecalis (ATCC® 29212)) as well as fungal strains (Candida albicans (ATCC® 10231) and Candida parapsilosis (ATCC® 22019)), were further evaluated for their biofilm inhibition properties and their mode of action with in vitro potential antimicrobial activity against each of 20 clinically obtained resistant strains of gram-positive bacteria, and bactericidal activity using time-kill curve assay. In this study, we investigated the bactericidal effects of QQ3 against methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans strains. The findings of this study suggest that a significant bactericidal effect was seen with all tested 1 × MIC and 4 × MIC concentrations used within 24 h. Our findings present significant implications for an antimicrobial drug candidate for treating infections, especially those caused by clinically resistant MRSA isolates.