GC–MS Analysis and Antimicrobial Activity of the Hydroethanolic Leaf Extract of Achyranthes aspera L. (Amaranthaceae)

Abstract

Background: Achyranthes aspera is a traditionally important medicinal plant with documented antimicrobial properties, whose hydroethanolic leaf extract warrants phytochemical and antimicrobial evaluation to identify bioactive compounds and support its therapeutic applications. Aims: This study aimed to identify the phytochemical constituents of the hydroethanolic leaf extract of Achyranthes aspera L. by Gas Chromatography–Mass Spectrometry (GC–MS) and to evaluate its in vitro antimicrobial activity against selected clinical pathogens. Methodology: Fresh leaves of A. aspera were collected, shade-dried, and extracted using a hydroethanolic solvent system. GC–MS analysis was performed on a GCMS5975 instrument using an Agilent DB-5 capillary column, and compound identification was carried out by library matching against the NIST11 mass spectral database. Antimicrobial activity was assessed by the agar well-diffusion method against Klebsiella sp., Proteus sp., Staphylococcus aureus, Escherichia coli, and Candida albicans. Minimum Inhibitory Concentrations (MIC) were determined by the broth dilution method. Results: GC–MS analysis revealed 20 phytoconstituents, dominated by 11-Octadecynoic acid, methyl ester (74.78%), followed by falcarinol (5.71%) and 7,10-hexadecadienoic acid, methyl ester (4.65%). Other pharmacologically relevant compounds included myricetin (0.78%), α-tocopheryl acetate (1.37%), phytol (0.69%), stearic acid (0.95%), and myristic acid (0.62%). The extract exhibited broad-spectrum, concentration-dependent antimicrobial activity. At 500 mg/mL, inhibition zones ranged from 27.7 mm (Klebsiella sp.) to 38.0 mm (C. albicans), surpassing the chloramphenicol control (28.0 mm) against several organisms. MIC values ranged from 25 mg/mL (E. coli) to 100 mg/mL (Klebsiella sp.). Conclusion: The hydroethanolic leaf extract of A. aspera is rich in bioactive phytoconstituents, particularly fatty acid methyl esters, polyacetylenes, flavonoids, and vitamins. Its strong broad-spectrum antimicrobial activity, including exceptional antifungal potency against C. albicans, supports its ethnopharmacological use in treating infectious diseases and validates the plant as a candidate for further pharmacological investigation.