allisiini

Allisiini is a naturally occurring organosulfur compound found in garlic and other Allium species, such as onions and leeks. It is a precursor to allicin, the compound responsible for the characteristic pungent odor and many of the purported health benefits associated with garlic. Allisiini itself is not stable and rapidly converts to allicin when the plant tissue is damaged, such as through cutting or crushing.

The conversion of allisiini to allicin is an enzymatic process. The enzyme alliinase, also present in garlic, catalyzes the reaction when the cellular compartments of the plant are broken. Allicin is known for its antimicrobial, antioxidant, and anti-inflammatory properties. While allisiini is the initial compound, it is the subsequent formation of allicin that is largely attributed to the biological activity. Research into allisiini often focuses on its role as a precursor and the stability of its conversion products. The precise physiological effects of allisiini on its own, separate from its conversion to allicin, are less extensively studied.