Abstract
Bioactive compounds from plant foods are intensely investigated for effects on disease prevention. β-Glucuronidase/arylsulfatase from Helix pomatia (snail) is commonly used when quantifying exposure to metabolized dietary components. However, we describe here the contamination of multiple formulations of this enzyme preparation with 3,3'-diindolylmethane (DIM), 8-methoxypsoralen (8-MOP), and 5-methoxypsoralen (5-MOP), bioactives from cruciferous and apiaceous vegetables under investigation as putative cancer chemopreventive agents. We identified an Escherichia coli preparation of β-glucuronidase as free from contamination with any of the compounds tested. These results demonstrate the importance of selecting appropriate enzyme preparations when quantifying naturally occurring, trace level compounds in biological fluids.