Aino Lusi

Discovery of novel avermectins with unprecedented insecticidal activity

A new class of insecticidal and antiparasitic agents, 4″-amino-4′-deoxy avermectins, has been developed by chemical modification of avermectin B1. The most effective of these compounds are 1500-fold more potent than avermectin B1 (abamectin) against the beet armywormSpodoptera exigua and show similar potency against other lepidopteran larvae.

A new broad-spectrum anthelmintic: 2-(4-Thiazolyl)-5-isopropoxycarbonylamino-benzimidazole

Es werden die Synthese sowie die biologischen Eigenschaften des neuen Anthelminticums 2-(4-Thiazolyl)-5-isopropoxycarbonylaminobenzimidazols beschreiben.

4 -DEOXY-4 -AMINOAVERMECTINS WITH POTENT BROAD SPECTRUM ANTIPARASITIC ACTIVITIES

Abstract Reductive amination of 4″-oxo-5-O-tert-butyldimethylsilyl-avermectins with sodium cyanoborohydride and ammonium acetate gave an epimeric mixture of 4″-deoxy-4″-amino analogs with the epimeric, axial 4″-β-amino derivative as the major component. Acylation of the amino substituent gave highly active broad spectrum antiparasitic compounds, as determined in a sheep anthelmintic assay. 4″-Epi-acetylamino-4″-deoxyavermectin B 1 ( 12 ) was selected for further antiparasitic studies and is currently under development as a novel avermectin endectocide.

Coenzyme Q. XXXIX. Studies on the biosynthesis of coenzyme Q10

Tritium-labeled coenzyme Q0 has been previously used to study the alkylation step in the biosynthesis of coenzyme Q. The reaction of tritium and coenzyme Q0 by the Wilzbach technique does not give a uniformly labeled product as previously assumed; the reaction product has over 99% of the tritium in the 6-position. Since this tritium would be displaced on alkylation, the product is not useful for a study of this step in the biosynthesis. Coenzyme Q0 (I), fumigatin (II), and 2,3-dihydroxy-t-methyl-1,4-benzohydroquinone (III) were selectively labeled with tritium in the 5-methyl substituent and studied as potential precursors in the microbial biosynthesis of coenzyme Q. None of these products was utilized by Pseudomonas denitrificans in the biosynthesis of coenzyme Q10.

Coenzyme Q. XLIII. The new 5-chloromethyl-6-chromanyl acetate of vitamin K1(20)

Abstract A new and unexpected 6-chromanyl derivative of vitamin K 1(20) has been isolated from an acetylated enzymic reaction mixture obtained after incubating vitamin K 1(20) in a light-inactivated, cell-free extract of Mycobacterium phlei . The structure of the new compound was established as the 5-chloromethyl-6-chromanyl acetate derivative I of vitamin K 1(20) ; its non-enzymic origin was confirmed later by chemical transformations of vitamin K 1(20) .