Antioxidant activities of alliin and allicin

Due to the indeterminacy in chemical composition and antioxidant activities of garlic essential oil,this study aimed to synthesize alliin and allicin and evaluate their antioxidant activities by lipid oxidation assay and DPPH radical scavenging assay.The results showed that allicin exhibited strong scavenging capacity against DPPH free radicals.For instance,at the concentration of 10.0 μg/mL,allicin scavenged about 95% of the free radicals.In contrast,alliin displayed no antioxidant activity.At the concentration of 1 000.0 μg/mL,allicin significantly decreased the POV value of lipid.However,under the same concentration,allin only showed little effect on the lipid.Moreover,the acid-base environment was also found as a important factor affecting the antioxidant activity of allicin.