Phenolic compounds and antioxidant activity of Taraxacum gracilens Dahlst. aerial parts

Abstract

The genus Taraxacum is a member of the family Asteraceae, subfamily Cichorioideae, tribe Lactuceae. The name is derived from the Greek words 'taraxis', for inflammation, and 'akeomai' for curative (1 – 2). The total number of Taraxacum in Turkey at present is 43 species (3). In folk medicine, this genus has been utilized for the treatment of various diseases such as dyspepsia, heartburn, spleen and liver complaints, hepatitis and anorexia (1). Previous phytochemical investigations have shown that Taraxacum species contain sesquiterpene lactones, triterpenes, phytosterols, flavonoids, lignans, coumarins, phenolic acids, beta-carboline alkaloids, indole alkaloids, carotenoids (1 – 2). Taraxacum gracilens Dahlst. is a perennial herb growing in the European part of Turkey (3). In this work, we report the isolation of flavonoids, coumarins, phenolic acids from the aerial parts of T. gracilens by repeated column chromatography and prep. TLC, and structure determination by spectral analyses. The polyphenolic content and antioxidant activities of the petroleum ether, CH2Cl2, EtOAc and BuOH fractions of the MeOH extract from the aerial parts of T. gracilens were investigated. EtOAc and CH2Cl2 fractions showed the highest antioxidant activity, respectively. This is the first report on the isolation of phytochemical constituents and the antioxidant activity of the aerial parts of T. gracilens.