Glucoraphanin is a glucosinolate found in broccoli, cauliflower, and mustard. Glucoraphanin is a glucosinolate found in broccoli, cauliflower, and mustard. Glucoraphanin is converted to sulforaphane by the enzyme myrosinase. In plants, sulforaphane deters insect predators and acts as a selective antibiotic. In humans, sulforaphane has been studied for its potential affects in neurodegenerative and cardiovascular diseases. Due to the potential health benefits, a variety of broccoli has been bred to contain two to three times more glucoraphanin than standard broccoli.