(Bio)synthesis, extraction and purification of garlic derivatives showing therapeutic properties

peer reviewedGarlic has been used worldwide for centuries for its taste but also for its health benefits. Garlic's therapeutic compounds are mostly organosulfur compounds, recognized for their antioxidant, anticancer, anti-inflammatory and antimicrobial activity and their effect on cardiovascular diseases (reviewed by Block, 2010). When the cloves are crushed, allicin is synthesized as the vacuolar enzyme alliinase meets its substrate, the cytoplasmic alliin. Allicin is unstable and undergoes rearrangements to form three main groups of derivatives: allyl sulfides, ajoenes and vinyldithiins. The garlic processing method has a major influence on the products released both in terms of chemical composition and yields. For example, the type of medium (aqueous or oily) and the temperature can favour the formation of specific compounds. Our work aims at studying the influence of - the garlic origin, - the reaction conditions and - the extraction procedures (solvent, microwaves) on the organosulfur compounds formed. Particular attention is given to the stereochemistry and the stability of the compounds. Better understanding of the formation of high value natural molecules is important in order to lead further studies on the biological activity of the compounds or to use them as nutraceuticals