Microwave-assisted Extraction of Bioactive Substance from Clinacanthus nutans

Polyphenols, flavonoids, triterpenoid and VitaminC from Clinacanthus nutans were extracted by microwave-assisted extraction (MAE) technology. The optimal extracting conditions were established as distilled water as solvent, solid-liquid ratio 1: 45 (g/ml), irradiation power 160W, and every extraction cycle of 50s. Results revealed that microwave time exert a significant effect on triterpenoid and VitaminC, whereas irradiation power plays a key role in the extraction of flavonoids. Furthermore, the effect of solid-liquid ratio on polyphenols is obvious. Under these conditions the extraction yield of each component were: polyphenols 8.382 mg/g, flavonoids 24.928 mg/g, triterpenoid 14.058 mg/g, vitaminC 0.129 mg/g. This study shows that MAE is an efficient technology to extract bioactive substances from leaves and Clinacanthus nutans could potentially be a resource for natural antioxidants.