Chemical and antimicrobial analysis of husk fiber aqueous extract from <i>Cocos nucifera</i> L.

Abstract

Cocos nucifera L. (Arecaceae) is a widely distributed species around the tropical areas. Popular uses have been reported in the treatment of arthritis and diarrhea. This study evaluates the antimicrobial activity of husk fiber aqueous extract from C. nucifera and performed the identification of some biological active substances. The minimal inhibitory concentration (MIC) against human pathogen microorganisms was determined. Chromatographic and spectrometric procedures were also performed to isolate and identify the components present in the extract. In the MIC assay of crude aqueous extract, only the methicillin sensible and the resistant (MRSA) Staphylococcus aureus strains were susceptible at 156 μg/mL. The ethyl acetate partition taken from crude extract was more promising (MIC of 78 μg/mL). No fungal growth inhibition was observed. Catechin, epicatechin, two procyanidin dimers and condensed tannins were found in the organic phase. In addition, gallic and ellagic acids were detected for the first time in C. nucifera husk fiber. Gallic acid showed MIC of 39 μg/mL and minimal bactericidal concentration (MBC) at 78 μg/mL. Ellagic acid was not active against the tested strains, as well as catechin and epicatechin. Additionally catechin, epicatechin, two procyanidin dimers and condensed tannins were also detected. The antimicrobial activity observed was selective to S. aureus strains.

Keywords: Antimicrobial analyses, Cocos nucifera, arecaceae, ellagic acid, gallic acid, procyanidins, Staphylococcus aureus strains

African Journal of Biotechnology Vol. 12(18), pp. 2478-2483