Pesthetoxin, a New Phytotoxin Produced by the Gray Blight Fungus,Pestalotiopsis theae

Pestalotiopsis theae is known to be a causal fungus for tea gray blight disease. Pesthetoxin was isolated from P. theae as a potent leaf-necrosis substance against tea. The structure of pesthetoxin was established principally by NMR studies to be of four different enolic forms, viz the pairs of internal tautomers (1a)/(1b) and (1c)/(1d) with external tautomerism between them.