抄録
p-Hydroxybenzoic acid was newly isolated from Pinus densiflora pollen as a pollen growth inhibitor. The inhibitory effects of p-hydroxybenzoic acid on pollen germination and pollen tube elongation in four species were tested. Somephysiological properties of p-hydroxybenzoic acid and benzoic acid, the latter was isolated previously from P. densiflora pollen, were studied. The inhibitory activity of these acids increased progressively as the pHof the mediumwas lowered in the range of pH 4-7, in which pollen grains of Camellia japonica germinated well on the control medium. The inhibition by those compounds was reversed when the pollen grains were transferred to an inhibitor-free medium.
The structure-activity relationship of substituted benzoic acids was studied, and it was observed that the inhibitory activity was correlated to the substituent constant π(hydrophobic parameter).
