Integrated analysis of <i>Zehneria scabra</i> leaf extract: phytochemical screening, GC–MS, FT-IR spectroscopy, and antibacterial activity evaluation

<i>Zehneria scabra</i> is a perennial climbing herb used by Ethiopian traditional medicine practitioners. The study aimed to detect phytochemicals, assess antibacterial activities, and analyse the chemical constituents of its leaf extract using GC-MS and FTIR techniques. Phytochemical analysis revealed terpenoids, alkaloids, flavonoids, phenols, tannins, and saponins. Significant antibacterial activity was observed against <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> at low concentrations (0.05 mg), particularly inhibiting <i>E. coli</i>. Quantitative phytochemical analysis showed that eight compounds make up almost ¾ part of the GC-MS chromatogram. These main constituents were 13-Octadecenal (17.77%), Valerenic acid (16.19%), 7-Acetyl-6-ethyl-1,1,4,4-tetramethyltetralin (8.96%), (Z, Z, Z)-9,12,15-Octadecatrienoic acid, methyl ester (7.35%), Neophytadiene (7.11%), 9,12-Octadecadienoic acid (Z, Z)-, methyl ester (5.45%), Hexadecanoic acid, methyl ester (5.08%), and 2-Isopropylidene-3-methylhexa-3,5-dienal (5.06%). FT-IR analysis also confirmed the presence of alkanes, alcohols, phenols, aldehydes, ketones, esters, and aromatic functional groups. Overall, these identified compounds from <i>Z. scabra</i> hold promise for developing innovative antibacterial drugs.