Total phenolic, flavonoid content and antioxidant activity of Clinacanthus nutans leaves by water-based ultrasonic assisted extraction

Abstract

Clinacanthus nutans (C. nutans)is a prominent herb species that widely cultivated in Southeast Asia region. The effect of water-based ultrasonic assisted extraction at various temperature (30 to 60 °C) and time (5 to 30 minutes) on the total phenolic, flavonoid content and antioxidant activity in C. nutansleaves extract was investigated. Acquired extract was quantified for its total phenolic, flavonoid content and antioxidant activity by Folin-Ciocalteu, aluminium chloride test and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The result has revealed that the highest temperature led to the degradation of bioactive compound in C. nutansleaves. The highest phenolic content and antioxidant activity achieved at 55 °C and 25 minutes with 13.87 ± 0.15 mg gallic acid g-1dry sample and 52.88 ± 3.91% inhibition, respectively. Meanwhile, greatest flavonoid content was obtained for 12.25 ± 1.01 mg quercetin g-1of dry sample at 55 °C and 15 minutes of extraction. From this study, it was shown that C. nutansextraction has gained benefit from ultrasonic assisted extraction and has possibilities of being used for the herbs utilisation of beneficial food materials, nutraceuticals and pharmaceuticals at manufacturing industry.