Synthesis of anthraquinone-connected coumarin derivatives via grindstone method and their evaluation of antibacterial, antioxidant, tyrosinase inhibitory activities with molecular docking, and DFT calculation studies

• Published in: Heliyon 2024-02, Vol.10 (3), p.e25168-e25168, Article e25168
• Main Authors: Loganathan, Velmurugan, Ahamed, Anis, Radhakrishnan, Surendrakumar, Z. Gaafar, Abdel-Rhman, Gurusamy, Raman, Akbar, Idhayadhulla
• Format: Article
• Language: English
• Subjects: Anthraquinone; Antibacterial activity; Antioxidant activity; Coumarin; DFT calculation; Molecular docking; Tyrosinase inhibitory
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2024.e25168

Anthraquinones and coumarins have excellent pharmacological activities and are an important class of natural plant metabolites with various biological activities. In this study, anthraquinone-9,10-dione and coumarin derivatives were combined to develop a novel anthraquinone-connected coumarin-derivative sequence. The synthesised novel anthraquinone-connected coumarin derivatives (1a-t) were screened for in vitro antibacterial, antioxidant, and tyrosinase inhibitory activities. The antibacterial activities of the synthesised compounds (1a–t) were tested against both gram-positive and gram-negative bacteria. Specifically, compound 1t was more active against E. aerogenes than ciprofloxacin. With regard to antioxidant activity, compound 1o (50.68 % at 100 μg/mL) was highly active compared to the other compounds, whereas it was less active than the standard BHT (76.74 % at 100 μg/mL). In terms of compound 1r (9.31 ± 0.45 μg/mL) was highly active against tyrosinase inhibitory activity compared with kojic acid (10.42 ± 0.98 μg/mL). In the molecular docking study, compound 1r had a higher docking score (−8.8 kcal mol−1) than kojic acid (−1.7 kcal mol−1). DFT calculations were performed to determine the energy gap of highly active compound 1r (ΔE = 0.11) and weakly active compound 1a (ΔE = 0.12). In this study, we found that every molecule displayed significant antibacterial, antioxidant, and tyrosinase inhibitory properties. Based on these reports, compounds 1r and 1t may act as multi-target agents.