Glucosinolates are a large class of anionic sulfur-rich secondary metabolites characteristic of plants in the Brassicaceae family and related families. They consist of a β-D-thioglucose group linked to a sulfonated oxime moiety and a variable side chain derived from amino acids. Upon tissue damage, they are hydrolyzed by the enzyme myrosinase to form isothiocyanates, nitriles, or other bioactive products. These compounds contribute to the pungent flavor of mustard, horseradish, and cruciferous vegetables and exhibit chemopreventive, antimicrobial, and anti-inflammatory activities in scientific studies. They function primarily in plant defense against herbivores and pathogens.