Alicina

Alicina, commonly known in English as allicin, is a sulfur-containing organosulfur compound produced in garlic (Allium sativum) when the plant tissue is damaged. It is the primary defensive agent responsible for garlic's distinctive aroma and is the subject of extensive agricultural and pharmacological study.

Chemically, alicina is the diallyl thiosulfinate, formed from the amino acid derivative alliin through the action of the enzyme alliinase. This enzymatic reaction occurs rapidly when garlic cells are crushed, cut, or otherwise disrupted, releasing alicina from its precursor.

Alicina is unstable at room temperature and degrades into several sulfur-containing compounds, including ajoene and diallyl disulfide or trisulfide. Cooking, processing, and storage conditions markedly affect its formation and persistence in food products.

Biological activity attributed to alicina includes antimicrobial, antifungal, and certain antiviral effects in laboratory studies. It has also been investigated for anti-inflammatory and anticancer properties. However, clinical evidence of clear health benefits in humans remains inconclusive, and bioavailability from dietary sources is limited.

Because of its instability, products often aim to stabilize alicina’s precursors or generate it in situ. Public health and safety considerations focus on ordinary culinary use, while high-dose supplements may interact with medications such as anticoagulants and are not appropriate for everyone.