Horseradish peroxidase was used to synthesize diferulates by a procedure in which ethyl ferulate was used as substrate. Four different forms were obtained, of which two dominant were the 5-5' and 8-5' diferulate. Fluorescence emission spectra of the diferulates (excited at 284 nm) indicate that they contain two chromophores, as opposed to the substrate molecule. Fluorescence excitation spectra with emission at 417 nm further demonstrate the difference between the synthesized diferulates and starting substrates.