3-(allyltrisulfanyl)-2-aminopropanoic acid, a novel nonvolatile water-soluble antimicrobial sulfur compound in heated garlic.

A nonvolatile and slightly water-soluble antimicrobial sulfur compound newly isolated from heated garlic extract was characterized. The compound was generated most when heated at 120°C for 30 minutes and completely disappeared after 90 minutes of heating. It has a molecular mass of 225 daltons with an elemental ratio of C₆H₁₁N₁O₂S₃, and the interpretation of ¹H- and ¹³C-nuclear magnetic resonance and Fourier transform-infrared data showed that the compound was CH₂=CH-CH₂-S-S-S-CH₂-CH(NH₂)COOH, 3-(allyltrisulfanyl)-2-aminopropanoic acid, a derivative of cysteine, presumably derived from alliin (S-allyl-L-cysteine sulfoxide).