Fumigation toxicity of volatile natural and synthetic cyanohydrins to stored-product pests and activity as soil fumigants

Abstract

secondary plant metabolites are useful for defense against herbivores.¹ Many food and feed plants have been shown to synthesize cyanogenic compounds which can decompose to produce hydrocyanic acid (HCN) as a main source of plant defense, which acts as a toxicant or feeding deterrent to herbivores. Cassava, lima beans, peas, almonds, white clover, bamboo and flax all produce cyanogenic compunds. Some cyanogenic plants are grown and used for starch, protein, oil aor fiber sources, and as spices or crude drugs.² The cyanogenic glycosides are biosynthesized by the plants from aromatic or branched-chain amino acids.³ The biochemical system for the formation of free HCN, cyanogensis, is associated with a cyanogenic glyscoside that is hydrolyzed by a B-glycosidase to produce a hydroxynitrile (cyanohydrin), which then decomposes to a carbonyl compound and HCN. As a non-selective respiratory inhibitor, hydrogen cyanide (hydrocyanic acid) has been used for many years as a fumigant for insects, inhibiting cytochrome a₃ in the mitochondrial electron-transport system.⁵

Citation

Park, Dong-Sik; Peterson, Chris; Zhao, Shaohan, Zhao; Coats, Joel R. 2004. Fumigation toxicity of volatile natural and synthetic cyanohydrins to stored-product pests and activity as soil fumigants. Pest Management Science 60:833-838