A new and useful substance, the aktivitaet and disease kon troll of the activated vita differential in the case of some plant diseases, and process for their preparation

摘要

A new antibiotic, ascochytin is a slightly acidic, light yellow needle crystalline substance having the composition C, 65.66%, H 5.91%, 028.43%, melting at 200-201 DEG C. with decomposition, having a degree of optical rotation [a ]25D of -85.99 degrees (C = 1% in chloroform), exhibiting maxima in the ultra-violet absorption spectrum at 415 to 286 mm and in the infra-red in potassium bromide pellet at 3100, 2950, 1640, 1590, 1530, 1460, 1410, 1340, 1250, 1200, 1160, 1120, 1070, 1050, 1005, 960, 935 and 835 reciprocal centimetres. Ascochytin may be produced by cultivating Ascochyta fabae Spegazyini under aerobic conditions at a temperature in the range of from 20 DEG to 32 DEG C. in an aqueous nutrient medium having a pH between 5 and 10 and containing an assimilable carbon source, a source of nitrogen and mineral salts, and recovering ascochytin from the medium, e.g. by extraction with a solvent such as chloroform or ethyl acetate.