Abstract: Objective To screen the effective antioxidant components in Trichosanthes extract based on the mean value of Deng's correlation degree and assess the antioxidant activity of the identified components. Method High-performance liquid chromatography (HPLC) was used to obtain the fingerprints of Trichosanthes extract, and the clearance rates of DPPH · and O2-· by 3, 9 and 27 mg/mL Trichosanthes extract were determined. The antioxidant spectrum effect of Trichosanthes extract was analyzed by calculating the mean value of Deng's correlation degree to screen the effective antioxidant component group. According to the contents of each known components in the antioxidant effective component group, mixed solutions of the components were prepared and tested for their clearance rates of DPPH · and O2-· . Results The 36 common peaks in HPLC fingerprints of Trichosanthes extract showed different degrees of correlation with DPPH · and O2-· clearance. The common peaks with a correlation degree greater than the median value included peaks 21, 36, 8, 31, 14, 5, 27, 2, 24, 15, 18, 33, 22, 34, 35, 19, 28 and 25. The 5 components, namely kaempferol (peak 36), isoquercitrin (peak 8), luteolin (peak 31), rutin (peak 5) and apigenin (peak 35), were tentatively identified to constitute the effective antioxidant component group with a mass ratio 3∶2∶2∶1∶1 in Trichosanthes extract. The prepared mixed solutions of antioxidant effective component group (6.12, 2.04, and 0.68 μg/mL) showed clearance rates of DPPH· of 65.4%, 64.0% and 61.0%, and clearance rates of O2-· of 12.9%, 9.5% and 8.3%, respectively. Conclusion We identified the material basis for the antioxidant activity of Trichosanthes and screened the antioxidant effective component group in Trichosanthes extract.

Key words: Trichosanthes extract; spectrum effect relationship; antioxidant effective components group; validation