Stability of thiosulfinates from garlic (Allium sativum L.) supercritical extracts in polar and nonpolar solvents

For the first time a systematic investigation of the decomposition process of allicin and other thiosulfinates from garlic supercritical extracts (SCEs) in solvents of different polarity (water, ethanol, acetonitrile, dimethyl sulfoxide, dichloromethane, and hexane) was performed. Qualitative and quantitative analysis of the garlic thiosulfinate decomposition products was carried out. A new HPLC analytical procedure was developed; it allows simultaneous determination of both starting thiosulfinates and sulfur-containing products of their decomposition. It was shown that the decomposition of SCE thiosulfinates can be directed toward the formation of target substances (ajoenes, dithiins, trisulfides, etc.) by changing the solvent polarity. The results obtained and methodical developments can be used in biomedical research of garlic-based drugs, as well as in the processes of their preparation, storage, and analysis.