Sinigrin or allyl glucosinolate is a glucosinolate that belongs to the family of glucosides found in some plants of the family Brassicaceae such as Brussels sprouts, broccoli, and the seeds of black mustard (Brassica nigra).

[3]: Section 2  Sinigrin is now known to occur widely in other brassica families including Brassicaceae and Capparaceae.

The enzyme myrosinase removes the glucose group in sinigrin to give an intermediate which spontaneously rearranges to allyl isothiocyanate, the compound responsible for the pungent taste of Dijon mustard.

This is a reactive material which is toxic to many insect predators and its production is triggered when the plant is damaged.

[10] At concentrations typically found in foods, the glucosinolates are not toxic to humans and can be useful flavor components.