The stability and degradation mechanism of sulforaphene in solvents.

Sulforaphene, a natural compound, has been investigated as a potential anticancer agent. However, the stability of sulforaphene, in various solvents, and its degradation pathway have not been appropriately reported. This instability impairs the preparation process, the biological evaluation experiments, and the applications of sulforaphene. In this study, the stability of sulforaphene stored at 26°C was investigated in each of the following six solvents: two kinds of protic solvents (methanol and ethanol) and four kinds of aprotic solvents (acetonitrile, dichloromethane, ethyl acetate and acetone). Sulforaphene was found to be stable in aprotic solvents and unstable in the protic solvents. The degradation products of sulforaphene in protic solvents (methanol and ethanol) were purified by the preparative HPLC and identified by ESI/MS and NMR ((1)H NMR). The degradation pathways of sulforaphene in methanol and ethanol were proposed. It was found that sulforaphene was degraded into two kinds of structural isomer in alcohols.