Phytochemical Profiling and Preliminary in vitro Antibacterial Screening of an n-Hexane Extract of Zingiber officinale Roscoe Rhizomes Purchased in Jos North, Plateau State, Nigeria

Ginger (Zingiber officinale Roscoe) contains chemically diverse constituents that are sensitive to extraction conditions. Rhizomes purchased in Jos North, Plateau State, Nigeria, were macerated in n-hexane for 72 h, and the concentrated residue was examined by gas chromatography–mass spectrometry (GC–MS), Fourier-transform infrared (FT–IR) spectroscopy and preliminary antibacterial screening against Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli and Salmonella Typhi. Extraction of 370 g of rhizomes yielded 10.95 g of residue (apparent crude yield, 2.96% by mass). Thirteen provisionally assigned GC–MS peaks accounted for 41.9% of the stated total integrated area; zingerone (12%), β-sesquiphellandrene (10%), ar-curcumene (5%) and α-himachalene (5%) were the largest listed peaks. Fourteen FT–IR bands were consistent with hydroxyl-bearing, aliphatic, unsaturated and other oxygenated environments. Reported inhibition-zone diameters ranged from 15 to 18 mm, 13 to 15 mm and 8 to 11 mm at nominal extract concentrations of 100%, 50% and 25%, respectively. The lowest no-turbidity dilution steps were 12.5% or 25%, whereas the lowest no-regrowth subculture steps were 50% or 100%, depending on the organism. Because the percentages lack an established mass or volume basis and microbiological controls were incompletely documented, these visual endpoints cannot be considered standardized minimum inhibitory or bactericidal concentrations. The chemical assignments and observed inhibition patterns are preliminary, preparation-specific findings and do not establish antimicrobial potency or therapeutic efficacy.