| 摘要 |
PURPOSE:To prepare the titled derivative either by culturing microorganisms belonging to Absidia genus, cunninghamella genus, Syncephalosporum genus, etc. in a medium containing ML-236B, or by contacting extract or microbial enzyme with ML-236B. CONSTITUTION:The titled derivative is prepared either by culturing microorganisms belonging to Absidia genus (e.g. Absidia coerulea IFO4423), Cunninghamella genus (e.g. Cunninghamella echinulata IFO4445), syncephalosporum genus (e.g. Syncephalosporum racemosum IFO4814), or Streptomyces genus in a medium containing ML-236B, or by contacting the extract of the enzyme of the above microorganisms with ML-236B. ML-236B is converted by the treatment to the objective ML-236B derivative of formula (I) (R1 is H, lower alkyl, etc.; R2 is group of formula II, etc.) or its ring-closed lactone. |
