Sensitive method for measuring tissue alpha-tocopherol and alpha-tocopheryloxybutyric acid by high-performance liquid chromatography with fluorometric detection.

The nonhydrolysable tocopherol ether analog, d-alpha-tocopheryloxybutyric acid (TSE), and its tocopherol ester counterpart, d-alpha-tocopheryl hemisuccinate (TS), have been shown to possess anti-tumor activity. In the present study, a sensitive high-performance liquid chromatography (HPLC) method using fluorometric detection is described for the simultaneous determination of TSE and alpha-T in biological specimens. Maximal sensitivity for the measurement of TSE and alpha-T was observed with the wavelengths, 210 nm excitation and 300 nm emission. Using an internal standard (I.S.) method, the amount of these tocopherol compounds was determined in standards, liver homogenates isolated from rats administered TSE-tris salt or vehicle (saline) and in HL-60 human leukaemia cells incubated with TSE-tris salt or saline. Treatment with TSE resulted in the significant accumulation of TSE, but not alpha-T, in the liver and HL-60 cells.