Biological activities of clinacanthus nutans (Burm .F) Lindau extracts

Abstract

The aim of this study is to evaluate the antibacterial activity and antioxidant activity of isolations from Clinacanthus nutans (burm.f) Lindau. Methanol extract was separated by column chromatography and purified by preparative thin-layer chromatography to isolate two pure compounds. Structure elucidation of the isolated compounds was carried out on the basic of spectra analyses, including 1H NMR, 13C-NMR, HMBC, HSQC and COSY. Two pure compounds Stigmasterol -β-D-glucoside (CN2) and 3-amino-4,5-dihydroxyfuran-2(3H)-one (CN6) were collected. This study used Well diffusion assay and Minimum inhibitory concentration (MIC) assay for antibacterial assay of CN2, CN6 and methanol extract on the two bacterial pathogens - Staphylococcus aureus ATCC 25213 and Salmonella typhimurium ATCC 14028. Moreover, DPPH Radical Scavening Assay was used for evaluation antioxidant activity on CN2, CN6 and methanol extract. For antibacterial evaluation, the compound CN6 and methanol extraction showed antibacterial ability. On Staphylococcus aureus, the MIC values of methanol extract is 62.5 mg/ mL while pure compound CN6 is 0.3125 mg/mL. On Salmonella typhimurium, methanol extract with MIC is 125 mg/mL and CN6 is 0.625 mg/mL. The compound CN2 insignificant antibacterial. In additon, the methanol extract with IC50 = 114.499 μg/mL and CN6 compound with IC50 = 102.949 μg/mL for antioxidant activity. This result showed that weak antioxidant ability of methanol extract and isolated compound CN6 from C. nutans in Vietnam when compared to standard vitamin C with IC50 =22.589 g/mL. The isolated compound CN2 no antioxidant activity. Keywords: Clinacanthus nutans (burm.f) Lindau, Stigmasterol -β-D-glucoside (CN2), 3-amino-4,5-dihydroxyfuran-2(3H)-one (CN6), Well diffusion assay, Minimum inhibitory concentration (MIC) assay, Staphylococcus aureus, Salmonella typhimurium, DPPH Radical Scavening Assay