Luteolin, isolated from the seeds of Perilla frutescens (perilla seeds), inhibited the peroxidation of linoleic acid catalyzed by soybean lipoxygenase-1 (EC 1.13.11.12, Type 1) with an IC(50) of 5.0 M (1.43 ìg/mL) noncompetitively. The progress curves for an enzyme reaction indicate that luteolin shows slow binding kinetics. Both the initial velocity and steady-state rate in the progress curve were decreased with increasing the concentration of luteolin. The kinetic parameters, which described the inhibition by luteolin, were evaluated by nonlinear regression fits.
Chromatography, High Pressure Liquid Kinetics