Keywords: Coffea arabica green seeds, RP-HPLC-PDA, Antioxidant activity, Antibacterial activity
This study concerns the evaluation of the antioxidant and antibacterial activities of Coffea arabica green seed extract. The chemical compositions were analyzed by RP-HPLC-PDA spectroscopy. Antioxidant activities were assessed using 2,2-diphenyl-1-picrylhydrazyl scavenging, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), reducing power and phenanthroline assays. The antibacterial activity was tested against 14 bacterial strains as per CLSI recommendation. The RP-HPLC-PDA revealed the presence of resorcinol, ferulic acid, rutin, catechin, gallic acid, caffeic acid, quercetin, chlorogenic acid and p-coumaric acid. The n-butanolic extract has the highest activity with 2,2-diphenyl-1-picryl-hydrazyl-hydrate (20.09 ± 0.40 µg/ml) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (5.27 ± 0.19 μg/ml) assays. The A0.5 of the methanolic crude extract was 8.18 ± 0.63 μg/J ml for reducing power and 2.54 ± 0.06 μg/ml for phesnanthroline assay. The n-butanol extract showed an interesting antibacterial activity against Citrobacter freundii ATCC 8090 and Staphylococcus aureus ATCC 6538 with minimal inhibitory concentration of 13.02 µg/ml. Our finding provides an effective and specific natural approach to search for classes of antioxidant and antibacterial compounds for different uses.
The authors are grateful to Pr Atik-Bekkara F., head of the Laboratory of Natural Product. Tlemcen University-Algeria.