Products of Allicin Transformation: Ajoenes and Dithiins, Characterization and their Determination by HPLC*

Constituents of crushed garlic bulbs ( ALLIUM SATIVUM L.), such as allicin, ( E/Z)-ajoene, and the vinyldithiins, were synthesized and purified by an LC method. Purity was proved by TLC, HPLC, and GC systems. Identity was confirmed by comparison with spectral data from the literature. In order to establish external standards, silica gel adsorbates of the respective substances were prepared. For quantitative determination of allicin and its transformation products, an isocratic HPLC method was developed. Calibration was performed by the use of these external standards, and by comparison to an internal standard. The influence of different media on allicin transformation, including the ( E/Z)-ratio of the ajoenes, has been elaborated.