Screening of Brazilian plant extracts for antioxidant activity by the use of DPPH free radical method

Brazilian plant extracts belonging to 16 species of 5 different families (7 1 extracts) were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydr azyl-hydrate) free-radical. The ability to scavenge DPPH radical was measur ed in these experiments by the discoloration of the solution. Ginkgo biloba and rutin, commonly used as antioxidants for medical purposes, were used a s standards. Based on our results, we can say that as a general rule the et hanol extracts of plants belonging to the Verbenaceae family showed lower E C50 values than the other plant extracts. Among the partitions, the more po lar ones (ethyl acetate and n-butanol) are those that generally have higher antioxidant activity (AA), Copyright (C) 2001 John Wiley & Sons, Ltd.