Artania Adnin Tri Suma, Norman Yoshi Haryono, Navista Sri Octa Ujiantari, Adhetya Kurnia Wicaksana, Anastacia Verena Salim, Cintya Nurul Apsari, Siti Nurul Hidayah, Syazwani Itri Amran, Badra Sanditya Rattyananda
Bacterial resistance remains a persistent challenge to most antibiotics, urging the need to develop novel antibacterial agents. Styrylpyrazoline derivatives, previously reported to possess diverse bioactivities, were synthesized, and the antibacterial potential was studied. Styrypyrazolines 2a-2b were tested on five bacterial strains, namely Gram-positive Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, as well as Gram-negative Escherichia coli and Pseudomonas aeruginosa. The in vitro evaluation was performed using disk diffusion and microdilution methods. The results revealed that compounds 2a and 2b had the highest inhibitory activity toward S. aureus. Compound 2b showed significantly lower MIC50 values due to the phenyl substituent existence at the N-1 position of the pyrazoline ring. In contrast, both compounds were inactive against B. subtilis and S. epidermidis. Molecular docking targeting DNA gyrase subunit B was performed to further investigate their antibacterial mechanism. It was revealed that the two compounds were found to interact with the receptor within the ATP-binding pocket. Similar to ciprofloxacin, compound 2a formed hydrogen bonds with the Asp81 residue, showing the potential as a DNA gyrase inhibitor. Compound 2b formed an aromatic-hydrogen bridge interaction with the Pro87 residue. This study suggests that styrypyrazolines 2a and 2b possess promising antibacterial activity. However, the potency is lower compared with the reference antibiotics. Further optimization is therefore necessary to enhance their potency as antibacterial agents. Copyright © 2026 by Indonesian Journal of Pharmacy (IJP).
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Universitas Gadjah Mada, Sekip Utara, Bulaksumur, Yogyakarta, 55281, Indonesia; Biotechnology Study Program, Department of Applied Science, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jl. Semarang No.5, Malang, 65145, Indonesia; Health and Food Centre, Institute of Research and Community Services, Universitas Negeri Malang, Jl. Semarang No.5, Malang, 65145, Indonesia; Department of Biosciences, Faculty of Science, Universiti Teknologi Malaysia, Johor, Johor Bahru, 81310, Malaysia; Research Centre for Computation, Research Organization for Electronics and Informatics, National Research and Innovation Agency (BRIN), Jl. Tamansari 71, Bandung City, 40132, Indonesia; Doctoral Program of Computational Science, Division of Mathematical & Physical Sciences, Graduate School of Science & Technology, Kanazawa University, Kakuma, Ishikawa, Kanazawa, 920-1192, Japan
