title: Gas chromatography-mass spectrometry characterisation of the anti-Listeria components of Garcinia kola seeds.
abstract: Adsorption chromatography was used to separate the bioactive constituents of the crude n-hexane extract of Garcinia kola seeds. The silica gel 60 column fractions were eluted using the solvent combination of benzene: ethanol : ammonium hydroxide (BEA) in the ratio combination of 36 : 4 : 0.4 v/v. The fractions were tested for anti-Listeria activities by determining their MIC50, MIC90 or MIC against 4 Listeria isolates. The fractions were labelled BEA1 to BEA5 and 3 out of the 5 fractions eluted were active against the test Listeria species with MIC's ranging from MIC 0.57 mg/mL to MIC50 0.625 mg/mL. The most active fractions, BEA2 and BEA3, were subjected to gas chromatography coupled to mass spectrometry (GC-MS) to identify their composition. Fraction BEA2 constituted of 18 compounds mostly sterols and the BEA3 fraction contained 27 compounds with the most abundant compounds being fatty acids derivatives. The BEA2 fraction's interactions with antibiotics proved to be 100% synergistic with ciprofloxacin and ampicillin whilst it exhibited 50% additivity and 50% synergism with penicillin G. However, all the interactions of the BEA2 fraction with each of the conventional antibiotics used were synergistic against the human listeriosis causative bacteria Listeria monocytogenes.
authors.forename: D
authors.initials: D
authors.lastname: Penduka
authors.forename: K A
authors.initials: KA
authors.lastname: Basson
authors.forename: B
authors.initials: B
authors.lastname: Mayekiso
authors.forename: L
authors.initials: L
authors.lastname: Buwa
authors.forename: I A
authors.initials: IA
authors.lastname: Okoh
mesh_terms: D064753:Ammonium Hydroxide; D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D001554:Benzene; D005591:Chemical Fractionation; D002939:Ciprofloxacin / Q000494:pharmacology; D004357:Drug Synergism; D000431:Ethanol; D005227:Fatty Acids / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D029763:Garcinia kola / Q000737:chemistry*; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D010400:Penicillin G / Q000494:pharmacology; D012639:Seeds / Q000737:chemistry*; D012997:Solvents; D013261:Sterols / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D005227:Fatty Acids; D012997:Solvents; D013261:Sterols; D000431:Ethanol; D064753:Ammonium Hydroxide; D002939:Ciprofloxacin; D000667:Ampicillin; D001554:Benzene; D010400:Penicillin G