Formation of Ent-isophleichrome by Cladosporium herbarum Isolated from Sugar Beet.

An isolate of Cladosporium herbarum obtained from leaves of sugar beet produced a phytotoxic red pigment which was identified as ent-isophleichrome (1). Production of the pigment was dependent on composition of the culture medium. The toxicity of ent-isophleichrome to sugar beet was strongly influenced by light. The polyketide biosynthetic origin of ent-isophleichrome in C. herbarum was demonstrated by (13)C acetate labelling/(13)C NMR studies.