Oryzalexin D (3,7-Dihydroxy-(+)-sandaracopimaradiene), a New Phytoalexin Isolated from Blast-infected Rice Leaves

Abstract

A new phytoalexin, oryzalexin D, was isolated as a group of oryzalexins from blast-infected rice (Oryza sativa) leaves. The structure of oryzalexin D was confirmed as 3,7-dihydroxy-(+)-sandaracopimaradiene by UV, MS, 1H-NMR and optical rotation. Oryzalexin D significantly inhibited spore germination of Pyricularia oryzae at 100 ppm. © 1986, Pesticide Science Society of Japan. All rights reserved.