Chemical composition, antioxidant and antimicrobial activities, and molecular docking of Acacia gerrardii leaf extract

Abstract

This study aims to investigate the chemical composition, mineral content, antimicrobial and antioxidant activities, and pharmacokinetic properties of the methanolic extract of Acacia gerrardii leaves. Mineral analysis using ICP-AES revealed iron as the predominant element (6.67 mg/g), followed by aluminum (4.70 mg/g) and trace elements such as zinc (13.18 µg/g), silver (11.24 µg/g) and selenium (134.073 µg/g). Chemical profiling demonstrated the extract's richness in phenolic compounds (316.61 mg GAE/g) and flavonoids (11.17 ± 1.76 mg QE/g extract). LC-MS analysis identified major flavonoid constituents, while GC-MS revealed key components such as 4-O-methylmannose (73.83%) and linolenic acid (2.91%). The antimicrobial assays revealed concentration-dependent activity, with the highest inhibition zones (15.33 ± 0.57 mm) observed against Klebsiella pneumoniae at 3 mg/disc. The extract exhibited bacteriostatic effects against most bacterial strains and fungicidal properties against Candida species. Antioxidant evaluation showed significant activity, with IC₅₀ values of 0.28 mg/mL (DPPH) and 63.63 mg/mL (FRAP). Computational analyses affirmed the druglikeness of the phytochemicals, with most adhering to Lipinski's rule and exhibiting favorable bioavailability and pharmacokinetic profiles. Molecular docking highlighted strong binding affinities (- 10.4 kcal/mol) of specific compounds to microbial protein targets, suggesting their potential as antimicrobial agents. These findings underscore the pharmacological promise of A. gerrardii, particularly its antioxidant and antimicrobial properties linked to its phytochemical composition. Future research should explore the bioactivities of individual compounds in vivo and assess their therapeutic applications. This study enriches the understanding of A. gerrardii and highlights its potential as a resource for novel bioactive agents.