Parasiticidal milbemycin derivatives, a process for their production, and compositions containing the same.

摘要

Compounds of formula (I): wherein R<1> is hydrogen or methyl, R<2> is hydrogen or E 2-methyl 2-butenoyloxy, and R<3> is hydrogen or hydroxy, with the proviso that when R<3> is hydrogen, R<1> and R<2> are both hydrogen, and when R<2> is E 2-methyl 2-butenoyloxy, R<1> is methyl; the compound of formula (II): and the compound of formula (III): are obtainable by the fermentation of Streptomyces E225 NC1B 12310 or Streptomyces E225B NC1B 12509. The compounds have anthelmintic utility.