What is "gyrinal"

n. (context organic compound English) A toxic unsaturated ketoaldehyde obtained from the water boatman

Gyrinal is an organic chemical compound - an unsaturated ketoaldehyde - with the formula C H O, obtained from the whirligig beetle (the water boatman, Gyrinus natator). It is a powerful antiseptic and fish and mammal toxin, and thus used as a defensive compound. Typically the beetles contain approx. 80 microgram of the compound. The LD of the compound is approx. 45 mg/kg in mice.