Abstract: 1,1-Dipheny-2-picrylhydrazine free radical(DPPH·)-microplate assay was used to determine the free radical scavenging activity of methanolic extracts from 50 kinds of woods. Results revealed that these woods had very different radical scavenging activity. The maximum activity was 15.48 times of the minimum. Among the 50 kinds of woods, Robinia pseudoacacia, Morus alba, Prunus salicina, Amygdalus persica and Cunninghamia lanceolata had strong radical scavenging activity. Their half-inhibitory-concentrations(IC₅₀) of dry samples were 0.52, 0.64, 0.66, 0.67 and 1.00 g/L respectively. Among the tested woods, Ginkgo biloba, Celtis sinensis, Magnolia grandiflora and Populus canadensis had the lowest radical scavenging activity. Results of variance analysis showed that the difference of radical scavenging activity between the woods possessing strong and weak decay resistance was significant.

Key words: wood extracts, 1-dipheny-2-picrylhydrazine free radical, free radical scavenging activity