Comparison of radical scavenging activities between extracts from 20 strains entomogenous fungi of the genus Paecilomyces

A DPPH-microplate assay and DPPH-TLC assay were used to test the free radical scavenging activities of methanol extracts from 20 strains belonging to 5 species of Paecilomyces.The results revealed that the free radical scavenging activities of the methanol extracts were different.The highest free radical scavenging rate is 71.9%,while the lowest is 15.9% at the concentration of 5.0 mg·mL~(-1) after incubated at 37 ℃ for 10 min.We also found that the free radical scavenging rates of all the tested fungi are positively related to their concentrations and reaction time.Meanwhile,the DPPH-TLC assays showed that the components of extracts from different strains were different,and all the strains contain more than one free radical scavenger.