Isolation of abikoviromycin and dihydroabikoviromycin as inhibitors of polyketide synthase involved in melanin biosynthesis by Colletotrichum lagenarium.

pathogens such as Colletotrichum lagenarium and Magnaporthe grisea, melanization of appressoria is essential for penetration into the host plant.1) Fungal conidia germinate and the tips of germ tubes differentiate into appressoria, which synthesize melanin. The melanin mediates the buildup of pressure in the appressorium and this high pressure provides the essential driving force for mechanical penetration into the host plant.2) Blocking of the melanin biosynthesis renders the fungus unable to