Cyanogenic glucosides are widely distributed natural products in the plant kingdom and are found in important crop plants like sorghum, barley, cassava, clover, flax, lotus and almonds. Plants also contain degradative enzymes that upon cellular disruption of the plant tissue are brought in contact with the cyanogenic glucosides causing hydrogen cyanide release. This binary system - two sets of components which separately are chemically inert – provides cyanogenic plants with an immediate chemical defense response to herbivores and pathogens causing tissue damage. The biosynthetic pathway is catalyzed by two membrane bound cytochrome P450s and a soluble UDPG-glucosyltransferase and is highly channelled. The channeling mechanism is studied by molecular modeling and by assembly of the metabolon into synthetic nano discs possessing the characteristics of a soluble protein. Biochemical knowledge of the pathway has enabled predicted metabolic engineering and transfer of the entire pathway to Arabidopsis thaliana. The trait of cyanogenesis is about 430 million years old enabling co-evolution of cyanogenic plants and their herbivores and pests. The burnet moth Zygaena filipendulae is able to sequester the two cyanogenic glucosides linamarin and lotaustralin present in its host plant Lotus corniculatus as well as to de novo synthesize the compounds. We have demonstrated that these cyanogenic glucosides play intimate roles in the life cycle of the burnet moth e.g. as pheromone attractants, mating determinants, as nuptial gifts as well as in defense. White clover is able to carry out nitrogen fixation and is used as a nitrogenous green manure especially in organic farming. White clover also contains the cyanogenic glucosides linamarin and lotaustralin. Recent studies using soil monoliths have demonstrated that cyanogenic glucosides present in green manure or wilted plant material left on the ground leach into surface and ground water in amounts exceeding the EU and WHO approved threshold values for drinking water.