Chromogenic lactate-leukocyte esterase substrates.

The first successful reported use of lactate-based chromogenic, colorimetric substrates for a serine protease-based enzyme is described. A series of hydroxy-protected 5-phenyl-3-hydroxypyrrolyl L-lactate substrates of the general formula RO-Lac-OPP were prepared and formulated into reagents for the determination of leukocytes in dry phase formats.