Determination of Total Polyphenols in Different Extraction Fractions of Pholidota chinensis Lindl.and Their Antioxidant Activity

[Objectives]This study was conducted to study the total polyphenol content and antioxidant capacity of different extraction fractions of Pholidota chinensis.[Methods]Different polar fractions of P.chinensis were obtained by ultrasonic extraction method,and determined for polyphenol contents by UV spectrophotometry,and their antioxidant activity was evaluated by DPPH free radical scavenging and ferric ion reducing antioxidant power(FRAP).SPSS analysis software was used to analyze the correlation between total polyphenol contents and antioxidant activity of different extracts.[Results]The contents of total polyphenols in different polar fractions ranged from 1.52 to 6.41 mg/g,and the order from low to high was:water<petroleum ether<ethyl acetate<95%ethanol.The reduction capacity of the total antioxidant capacity method ranged from 12.54 to 22.45μmol/L,and the order was 95%ethanol>ethyl acetate>petroleum ether>water.The DPPH median inhibition concentration ranged from 0.35 to 2.65 mg/ml,and the order was water>petroleum ether>ethyl acetate>95%ethanol.The total polyphenol content of P.chinensis was best in the 95%ethanol extraction fraction,which showed the strongest total antioxidant capacity,so the total polyphenol content of the 95%ethanol fraction was positively correlated with its antioxidant capacity,while the DPPH free radical-scavenging capacity was better in the water fraction,indicating that the free radical-scavenging capacity of the water fraction was better.[Conclusions]This study provides a theoretical basis for the further study of the chemical components of P.chinensis and the development and utilization of natural antioxidants.

Antioxidant and antibacterial activities of the ethyl acetate extracts of endophytic fungi isolated from Ageratum conyzoides L.

Accumulating evidence has demonstrated that endophytic fungi metabolites possess important biological activities.Ageratum conyzoides L.(Asteraceae)is an invasive aromatic herb with immense therapeutic importance.In the present study,we aimed to isolate and identify endophytic fungi in the roots,stems,leaves and flowers of Ageratum conyzoides L.and evaluate its antioxidant activity(DPPH,ABTS^(+) and FRAP assays),the contents of flavonoids and phenolic and antibacterial activity of their ethyl acetate extracts.Accordingly,a total of 25 endophytic fungi were isolated from Ageratum conyzoides L.and classified into 14 genera based on the Internal transcribed spacer sequence,among which Fusarium sp.(20%)were found to be the dominant groups.All fungal extracts exhibited antioxidant activity,and the extracts of fungi WZ07 exhibited antioxidant activities as well as higher flavonoids and phenolic content in all tests.Moreover,the extracts of fungi WL01 had good antibacterial activity against both Gram-positive and Gram-negative bacteria.We,for the first time,reported the antioxidant and antibacterial activity of endophytic fungi from Ageratum conyzoides L.,which may help lay the foundation for developing other medicinal components.