Germination Inhibitor from Eucalyptus pulverulenta

Abstract

A potent germination inhibitor was found in the n-hexane soluble fraction of the methanolic extract of Eucalyptus pulverulenta. This inhibitor was identified as grandinol (1) which had been isolated from E. grandis. On the cress germination test, 1 showed I₅₀ at 10 ppm. The other eight compounds in the fraction containing 1 on silica gel chromatography were also identified. Compounds(2) and (3) are regarded as phloroglucinol metabolites characteristic of the Eucalyptus species. The knowncompound (4) may be a good taxonomical marker for E. pulverulenta, and (5)-(9) are possibly commonmetabolites of Eucalyptus.