SallylLcysteine

S-allyl-L-cysteine (SAC) is a sulfur-containing amino acid derivative found in garlic and garlic-derived products. It is a non-volatile, water-soluble compound that accumulates during the aging or processing of garlic and is a major constituent of aged garlic extract (AGE).

Chemically, SAC is an S-alkyl analogue of cysteine, in which the thiol group is bound to an allyl group: (S)-2-amino-4-(prop-2-en-1-ylthio)butanoic acid.

Occurrence and sources: SAC is present in aged garlic preparations and certain processed garlic products. It is relatively stable compared with the volatile sulfur compounds released during crushing of fresh garlic, contributing to the profile of non-volatile sulfur compounds in AGE.

Biological properties: SAC exhibits antioxidant activity and may modulate inflammatory and immune responses. In animal studies and some human trials, SAC or AGE preparations containing SAC have been investigated for cardiovascular benefits, including modest reductions in blood pressure and improvements in endothelial function. Evidence is not conclusive for medical use, and SAC is not approved as a drug.

Safety and regulation: SAC is generally regarded as safe in the context of garlic supplements at typical doses; high doses may cause gastrointestinal discomfort in some individuals. Routine considerations include potential interactions with anticoagulants or antiplatelet medications, similar to other garlic-derived products.

Analytical and applications: SAC serves as a quality marker for AGE and is quantified by HPLC or LC-MS in quality control and research settings. Ongoing studies seek to clarify its specific mechanisms and therapeutic potential.