Isolation of antioxidants from Alchemilla xanthochlora

Abstract

The aim of this study was to find conditions for isolation of antioxidants from Alchemilla xanthochlora. The solid-liquid extraction of plant material with different solvents (n-hexane, chloroform, ethylacetate, methanol, and water) was used for preparation of crude extracts of antioxidants. For additional purification of crude extract, liquid-liquid extraction in different organic solvents (chloroform, ethylacetate, methanol) and water, and column chromatography with silica gel as stationary phase and mixture of chloroform : methanol as mobile phase were used. The content of active compounds was monitored by photometric method and special TLC analysis using DPPH as basic reagent. TLC-DPPH analysis of herbal extracts showed that antioxidants from Alchemilla xanthochlora were separated into two groups with different polarity. Finally, for the isolation of antioxidants from Alchemilla xanthochlora were successfully used the following procedures: extraction of dried grounded plant material with methanol at 50°C during 1 hour, subsequent liquid-liquid extraction in isopropanol and water and fractionation of isopropanol extract by column chromatography. Fraction with isolated antioxidants showed antioxidant activity 535.2 mg to g of fraction residue.