Natural inhibitors from polyalthia longifolia target NDM-1 and DNA gyrase B in multidrug-resistant Klebsiella pneumoniae and Acinetobacter baumannii: an integrated experimental and computational study

Olumide Oluyele, Ruth Loto, Gladys Egunjobi

Abstract



Background: Acinetobacter baumannii and Klebsiella pneumoniae are WHO critical-priority pathogens with widespread multidrug resistance, posing a significant threat to global health. This study evaluated the antibacterial activity of solvent fractions of Polyalthia longifolia leaves and examined the molecular docking, pharmacokinetic, and toxicity profiles of its phytochemicals against NDM-1 and DNA gyrase B.

Results: All fractions exhibited antibacterial activity, with zones of inhibition ranging from 18.33 ± 0.33 to 23.00 ± 0.58 mm. The aqueous fraction was most active (A. baumannii: 22.33 ± 0.33 mm; K. pneumoniae: 23.00 ± 0.58 mm) and showed the lowest minimum inhibitory concentration (6.25 mg/mL). High performance liquid chromatography identified quercetin, apigenin, and catechin as major bioactive constituents. Docking revealed that mangiferin (−9.263 kcal/mol), myricetin (−8.703 kcal/mol), and baicalin (−8.411 kcal/mol) bound NDM-1 more strongly than reference drugs, while quercetin (−7.400 kcal/mol), catechin (−7.262 kcal/mol), and apigenin (−7.216 kcal/mol) showed high affinity for DNA gyrase B. ADME profiling indicated good oral bioavailability, moderate lipophilicity, and minimal CYP450 interference. Toxicity predictions confirmed low hepatotoxicity, cardiotoxicity, and mutagenic risks.

Conclusion: P. longifolia leaves possess potent antibacterial metabolites. Mangiferin, quercetin, and myricetin showed strong inhibitory potential with favorable pharmacokinetic and safety profiles, supporting their promise as leads against multidrug-resistant K. pneumoniae and A. baumannii.

 

Received: 18 November 2025

Accepted: 10 February 2026

Published: 05 May 2026


Keywords


Polyalthia longifolia, antibiotics resistance, Klebsiella pneumoniae, Acinetobacter baumannii, NDM-1, DNA gyrase B, phytomedicine.

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References


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DOI: https://dx.doi.org/10.21622/AMPDR.2026.06.1.1808

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Copyright (c) 2026 Olumide Oluyele, Ruth Ayomipo Loto, Gladys Egunjobi

Advances in Medical, Pharmaceutical and Dental Research

E-ISSN: 2812-4898

P-ISSN: 2812-488X

 

Published by:

Academy Publishing Center (APC)

Arab Academy for Science, Technology and Maritime Transport (AASTMT)

Alexandria, Egypt

ampdr@aast.edu