Macrocyclic lactones, their production and parasiticidal uses, compositions containing them, and a biological culture suitable for producing them.

摘要

Novel parasiticidal compounds have the formula <CHEM> where the variables R1 and R2 have the following meanings for the compounds identified as A1, A2 and B1: <CHEM> They are made into compositions for the treatment of agricultural pests and parasitic infections, especially tapeworms. The compounds are made by fermenting a culture of the novel microorganism Streptomyces sp. MA-5038 having the identifying characteristics of ATCC 31587 in an aqueous nutrient medium containing assimilable sources of carbon, nitrogen and inorganic salts.