Abstract: The reducing power and the scavenging activities against phenyl picryl hydrazine radical(DPPH·) and hydroxyl radical(·OH) of birch wood vinegar(BWV), miscellaneous wood vinegar(MWV), sawdust wood vinegar(SWV), and distillated sawdust wood vinegar(DWV) were determined. The results showed that four kinds of wood vinegar had strong reducing power and the reducing power of sawdust wood vinegar was the strongest with the half effective concentration(EC₅₀) of(1.73±0.06) g/L. Wood vinegar could effectively scavenge DPPH·, and DPPH·scavenging activity of sawdust wood vinegar was the highest with the median inhibitory concentration(IC₅₀) of(0.20±0.01) g/L. Wood vinegar showed relatively weak ·OH scavenging ability, except the IC₅₀ of sawdust wood vinegar was(9.69±0.20) g/L, the ·OH scavenging rates of the other three kinds of wood vinegar couldn't reach 50%.

Key words: wood vinegar, antioxidant, reducing power, radical scavenging