Phytoconstitution and Antimicrobial Activity of Costus Lucanusianus Floral Volatile Extract

Abstract

Authors: Akens Hamilton-Amachree and Ngozi M. Uzoekwe

Received: 12 December 2022/Accepted 30 March 2023

Information on volatile constituents of plant extracts have a significant backing to theseveral biological activities and applications of plants. Consequently, in this work, phyto content and the antimicrobial activity of the volatile floral extract of Costus lucanusianus are investigated in this work to complement the information database on plant volatile components. The volatile constituents of the floral part were extracted using the conventional hydrodistillation technique and its phyto-constitution was determined via Gas Chromatography-Mass Spectrometry (GCMS) instrumentation. The antimicrobial pharmacological activity was established using the pour method against eight (8) strains of microbes. The volatile extract has a total of twenty-three (23) phytochemicals comprising eight (8) sesquiterpenes, four (4) sesquiterpenoids and eleven (11) non-terpenoids. The major identified constituents are  4-(3-hydroxy-2-methoxyphenyl)-but-2-one (38.29%), 1-(4-Hydroxymethoxy-phenyl)dec-4-en-3-one (13.83%),[S-(R*,S*)] 5-(1,5-dimethyl-4-hexenyl)-2-methyl-1,3-cyclohexad- iene  (7.66%), 1-(1,5-dimethyl-4-hexenyl)-4-methyl- benzene (6.13%), decanal (4.35%),[S-(R*,S*)]-3-(1,5-dimethyl-4-hexenyl)-6-methy- lene- cyclohexene (3.47%) and β-bisabolene (2.76%). The antimicrobial activity witnessed a dose-dependent gradient extract–inhibitory relationship. The highest inhibitory activity was observed at 100 mg/ml for all the strains. There was no inhibition observed below 12.5 mg/ml for Escherichia coli and Fusarium spp.while Staphylococcus aureus, Bacillus subtillis, Pseudomonas aeruginosa, Salmonella typhi, Candida albicanandKlebsiela pneumonia showed no inhibition below 6.25 mg/ml. The present study has established that the floral part of Costus lucanusianus has volatile constituents with antimicrobial potency.