Glucoraphanin is a glucosinolate found in broccoli, mustard and other cruciferous vegetables.
Glucoraphanin is converted to sulforaphane by the enzyme myrosinase. In plants, sulforaphane deters insect predators and acts as a selective antibiotic.
Synthesis
Glucoraphanin is derived from dihomomethionine, which is methionine chain-elongated twice. The sulfinyl group is chiral, and has R absolute configuration. The stereochemistry is set when an oxygen atom added to 4-methylthiobutylglucosinolate by a flavin monooxygenase.
Research
Sulforaphane and other isothiocyanates have been studied for their potential biological effects.
Plant breeding
Cultivars of broccoli have been bred to contain two to three times more glucoraphanin than standard broccoli. Romanesco broccoli may contain up to ten times more glucoraphanin than typical broccoli varieties. Frostara, Black Tuscany, and red cabbage also contain higher levels of glucoraphanin than broccoli.