>98% [HPLC]. Free 4MU < 100ppm.
Substrate for beta-glucosidase: D.H. Leaback, Biochem. J., 78, 22P (1961). Used to detect very low levels of beta-glucosidase activity in apple fruit: A.J. Dick et al., Physiol. Plant., 80, 250 (1990).
Enzymatic activities in traps of four aquatic species of the carnivorous genus Utricularia.