Abstract: There are disclosed avermectin derivatives with a hydroxy and hydrocarbon substituents at the 5, 10, 13, 23, 4' and 4" positions which are prepared by the reaction of the 5, 10, 13, 23, 4' or 4" ketone compound with an organo-metallic Grignard reagent. The compounds are potent antiparasitic and anthelmintic agents in human and animal therapy and are potent pesticidical agents against agricultural pests. Compositions containing such compounds as the active agent are also disclosed.

Abstract: There are disclosed novel avermectin .DELTA. 23,24-derivatives (also referred to as 23,24-dehydro compounds). The compounds are prepared by selective dehydration of avermectin A2 or B2 compounds. The avermectin compounds have utility as anti-parasitic agents and compositions for that use are also disclosed. The compounds are also highly potent insecticides against agricultural pests. The .DELTA. 23,24-avermectin compounds have increased activity relative to the A2 or B2 compounds.

Abstract: The compound 4"-deoxy-4"-N-methylamino avermectin Bla/Blb has been discovered to have unexpected properties when used as an agricultural insecticide. Specifically, the compound is considerably more active against insects, particularly lepidoptera, than closely related compounds, and the compound exhibits significantly lower levels of mammalian toxicity and aquatic animal toxicity. Thus the compound presents a much wider margin of safety towards the human appliers of the compound and to other mammals that come in contact with treated areas as well as wider margins of safety to aquatic animals to which any spray drift or run-off containing the compound may be directed.

Abstract: There are disclosed novel avermectin compounds wherein the 4" or 4' hydroxy group is oxidized to an oxo group and replaced with a semicarbazone, carbonyl- or sulfonyl- hydrazone, hydrazone, or oxime, and optionally reduced to the corresponding semicarbazide, carbonyl- or sulfonyl-hydrazide or hydrazine. The semicarbozones and hydrazones are prepared from the 4" or 4' oxo compound using the corresponding semicarbazides or hydrazines. The compounds have utility as anti-parasitic agents and compounds for that use are also disclosed. The compounds are also highly potent insecticides against agricultural pests. Compositions for such uses are also disclosed.

Abstract: The marcfortines (marcfortines A, B, and C) are known fungal metabolites isolated from the known fungus Penicillium roqueforti. The compounds are useful antiparasitic agents for the treatment of diseases caused by endo and ecto parasites. Antiparasitic compositions which contain one or more of the marcfortines as the active ingredient are disclosed.

Abstract: There are disclosed novel avermectin reduction products. The compounds are prepared by selective catalytic hydrogenation of avermectin-like compounds or by reaction of selected double bonds with electrophylic reagents. The reduced avermectin compounds have utility as anti-parasitic agents and compositions for that use are also disclosed. The compounds are also highly potent insecticides against agricultural pests. The reduced avermectin compounds have increased stability towards light which prolongs their insecticidal activities when applied to field crops subject to irradiation by sunlight.

Abstract: There are disclosed derivatives of avermectin compounds with a .DELTA.26,27-alkyl chain of 4, 5 or 6 members at the 25-position. The compounds are prepared from the known .DELTA.26,27-compounds by the appropriate synthetic procedures at the 5-, 8-, 9-, 13- , 22- and 23-positions. The compounds are potent antiparasitic agents, in particular, the compounds are anthelmintic, insecticidal and acaricidal agents.

Abstract: Benzimidazole compounds are disclosed which are substituted at the 2-position with a loweralkoxy carbonylamino group and at the 5-position with a halogenated loweralkenyl group or a halogenated loweralkoxy, loweralkylthio, loweralkylsulfinyl or loweralkylsulfonyl. Processes for the preparation of such compounds are disclosed. The compounds are active anthelmintic agents and compositions for such use are also disclosed.