Fayin Ye, Qiang Liang, Hang Li, Guohua Zhao 

ABSTRACT

The common sunflower (Helianthus annuus L.) has been reported to be a rich source of phenolic compounds. The effects of solvent, of different polarities (distilled water (polarity P′ = 10.20), 50% (v/v) aqueous methanol (P′ = 8.40), 50% (v/v) aqueous ethanol (P′ = 7.25), 90% (v/v) aqueous methanol (P' = 6.69), 90% (v/v) aqueous ethanol (P′ = 4.89), and ethyl acetate (P′ = 4.30), on the extraction of phenolics from ray florets and disc florets of H. annuus L. were studied. Total phenolic contents, phenolic composition and antioxidant activity of the extracts were evaluated. Results indicated that the efficiency of solvents in the extraction of phenolics were in the following order: aqueous alcohols > water > ethyl acetate. The florets extracts with 90% (v/v) aqueous methanol presented the highest phenolic contents and the highest antioxidant activities. Nine and six phenolic compounds, 

 Chlorogenic acid, caffeicacid, ferulic acid, isoquercitrin, p-coumaric acid (>98.0%) were purchased from Chengdu Biopurify Phytochemicals (Sichuan, China).