Isolation of non-ionic lipophilic materials on macroreticular polymeric absorbents

A process for isolating or separating avermectin compounds from the aqueous fermentation broth that produced such compounds, which comprises:

• preparing a mycelial extract by adding acetone to the fermentation broth to from 40 to 60% by volume of the original broth to form a mycelial extract:
• treating the aqueous-acetone mycelial extract with an insoluble synthetic resin which is an addition copolymer having a cross linked structure to selectively absorb the avermectin compounds into the resin:
• and
• eluting the resin with an aqueous acetone mixture in excess of 60% acetone to remove the avermectin compounds from the resin.