Dietary organosulfur compounds from garlic and cruciferous vegetables as potent hypochlorite scavengers

• Organosulfides in garlic are strong hypochlorite scavengers.
• Sulfur containing amino acids are stronger HClO scavengers than polysulfides.
• Sulfur atoms of the sulfides are the acceptors of oxygen from hypochlorite.

Dietary organosulfur compounds commonly found in garlic and cruciferous vegetables are potent hypochlorite scavengers as measured using a novel fluorescence assay based on quantum dots (QDs) as the nanoprobe. By using hydrogen sulfide as a standard, we quantified the HClO scavenging capacity of organosulfides in the following order: cysteine > methionine > phenethylisothiocyanate > diallyldisulfide ~ dially trisulfide. The reaction products of these sulfides with hypochlorite were characterized by LC–MS spectra, which revealed that the sulfur atoms are the acceptor of oxygen from hypochlorite. Finally, the hypochlorite scavenging activity of garlic upon heat treatment reduced the ClO− scavenging activity significantly.