Abstract: There are disclosed novel ivermectin compounds and a process for preparing them, the novel ivermectin compounds containing straight chain or branched fatty acid residues of from about C.sub.2 to about C.sub.

Abstract: There are disclosed certain new derivatives of C-076 compounds which have been isolated from the livers of animals that had been administered ivermectin and the in vitro incubation of such compounds with animal liver preparations. The compounds retain the basic ivermectin structure, however, 24-methyl group has been oxidized to a hydroxy methyl group and, in some of the new compounds the disaccharide substituent of the starting materials has been cleaved to a monosaccharide moiety. The new compounds have been found to retain the biological activity of the parent C-076 compounds. The compounds are thus potent antiparasitic agents and compositions and methods for such uses are also disclosed.