Alliin

Alliin (al'-ee-in) is a sulfoxide that is a natural constituent of fresh garlic. It is a derivative of the amino acid cysteine. When fresh garlic is chopped or crushed, the enzyme aliinase converts alliin into allicin which is primarily responsible for the aroma of fresh garlic. Garlic has been used since antiquity as a therapeutic remedy for oxygen toxicity, and when this was investigated, garlic did indeed show strong antioxidant and hydroxyl radical scavenging properties, possibly owing to the alliin contained within.

When the effect of alliin is observed on blood cells in vitro, a noted increase in the engulfing capacity of phagocyting cells is seen.