Inhibitory effect of methyl methanethiosulfinate on ß-glucuronidase activity.

Minced or cut-up leaves of Chinese chive (Allium tuberosum Rottler) contain thiosulfinates and their disproportionate reaction products. Among these organosulfur compounds, methyl methanethiosulfinate was found to be an uncompetitive inhibitor of ß-glucuronidase. Approximately 80% of the enzyme activity was inhibited by methyl methanethiosulfinate at 50 µM, the IC50 value being comparable to 3.6 µM.