The effect of ethanol concentrations as the extraction solvent on antioxidant activity of Katuk (Sauropus androgynus (L.) Merr.) leaves extracts

Abstract

Katuk is widely popular with its benefits for breastfeeding mothers. Katuk is also known as a plant with a high antioxidant content. This study aims to determine the effect of using variations in the ethanol concentration as an extracting solvent in producing Total Phenolics Content (TPC) and Total Flavonoids Content (TFC) and their activities in reducing DPPH free radicals. The dried katuk leaves were extracted by cold maceration method. The solvent used for extraction is ethanol with 3 variations in concentration: 50%, 70%, and 96% (absolute ethanol). TPC and TFC were determined by colorimetric method using a UV-Vis spectrophotometer. TPC was stated to be equivalent to gallic acid, while TFC was stated to be equivalent to quercetin. DPPH free radical scavenging activity was measured based on the IC50 value. The results showed that Katuk leaf extract produced from 50% ethanol solvent was able to produce TPC (42.18 ± 0.30 mgGAE / g), TFC (11.18 ± 0.38 mgQE / g) and reduction activity against DPPH radicals (IC50 = 88.33 ± 3.53 ppm). These were higher than ethanol with other concentrations. However, various things need to be considered when using this solvent given the high water content in the solvent.