Abstract
Phytotoxic substances were extracted from sawdust with boiling water. The ether soluble substances from the water extract were separated into acidic, neutral and basic fractions. Acidic fraction exhibited the highest phytotoxicity, followed by neutral fraction. Basic fraction showed only slight toxicity. The acidic materials in acidic fraction described above were fractionated into eight fractions on a alumina column using a solvent elution series. Six fractions of them showed inhibitory effect on the growth of wheat seedlings, of which the benzene, the methanol, the water and the sulfuric acid fractions had intensively inhibitory effect. The toxicity of the ethylacetate and the formic acid fractions were weak. Six fractions described above contained acidic substances and phenolic acid which gave a positive reaction with chlorophenolred or diazotized sulfanilic acid, respectively. The significant correlation was not recognized between phytotoxic activities and total amounts of phenolic acids in each fraction. It was found that the greater parts of phytotoxic activities are located at the Rf regions corresponding to non-phenolic acids by paperchromatography. The chromatographycally separated acids were not identified.
