Sulforaphane (1-isothiocyanato-4-(methylsulfinyl)butane)

Sulforaphane (C6H11NOS2, MW 177.29 g/mol) is a bioactive isothiocyanate, not a macronutrient source. It is derived in vivo from its glucosinolate precursor glucoraphanin (4-methylsulfinylbutyl glucosinolate) via myrosinase-catalyzed hydrolysis. Key profile details: • Primary bioactive moiety: isothiocyanate group (–N=C=S) responsible for electrophilic signaling and Nrf2 pathway activation; secondary functional group: methylsulfinyl (CH3–S(O)–) contributing to redox chemistry. • Concentrations in food sources: broccoli sprouts (3-day-old) contain approximately 1,150–2,500 µmol glucoraphanin per 100 g dry weight, yielding roughly 50–200 mg sulforaphane equivalents per 100 g fresh weight depending on myrosinase activity; mature broccoli florets contain approximately 40–170 µmol glucoraphanin per 100 g fresh weight, yielding roughly 3–30 mg sulforaphane equivalents per 100 g fresh weight. • No meaningful contribution of macronutrients (protein, fat, carbohydrate), vitamins, or minerals from sulforaphane itself as it is consumed in microgram-to-milligram quantities. • Bioavailability: oral bioavailability in humans is estimated at 50–80% when derived from myrosinase-active sources (raw or lightly steamed cruciferous vegetables); bioavailability drops to approximately 10–40% from cooked vegetables where myrosinase is heat-inactivated, with partial rescue by gut microbiota thioglucosidases. Peak plasma concentration (Cmax) of approximately 1–2 µM achieved within 1–3 hours after ingestion of broccoli sprout preparations delivering ~150 µmol sulforaphane. Plasma half-life is approximately 2.2–2.6 hours. • Metabolic fate: rapidly conjugated with glutathione, then sequentially processed via the mercapturic acid pathway to cysteinylglycine, cysteine, and N-acetylcysteine (NAC) conjugates (dithiocarbamates), which are the predominant urinary metabolites. Approximately 60–80% of absorbed dose is excreted in urine within 24 hours as these conjugates. • Stability notes: sulforaphane is heat-sensitive and water-soluble; cooking at >60°C for extended periods degrades both myrosinase and sulforaphane itself. It is stable at acidic pH (stomach conditions) but degrades at neutral-to-alkaline pH over time. • Typical supplemental doses in clinical studies: 25–150 µmol/day (approximately 4.4–26.6 mg/day) as sulforaphane or glucoraphanin-standardized broccoli sprout extracts. • No known essential nutrient status; classified as a xenohormetic phytochemical rather than a vitamin or mineral.