In the course of our screening program for inhibitors of soybean lipoxygenase, we isolated two new phenolic sesquiterpene ketones named turmeronol A and turmeronol B from the spice turmeric (dried rhizome of Curucuma longa L.). Their structures were determined to be 2-methyl-6-(3-hydroxy4-methyIphenyl)-2-hepten-4-one and 2-methyl-6-(2-hydroxy-4-methylphenyl)-2-hepten-4-one, respectively. Turmeronol A and turmeronol B inhibited soybean lipoxygenase at the IC50 values of 16μM and 9 μM, respectively. These compounds prevented the autoxidation of h'noleic acid at a concentration of ca. 200 ppm.