| Summary: | The human gastrointestinal (GI) tract plays an important role in disease and health. The overexpression of <i>β</i>-glucuronidase, an enzyme produced in the gastrointestinal tract, has been found to cause the retoxification of potentially damaging substances already detoxified by liver glucuronidation. Thus, <i>β</i>-glucuronidase has been implicated in a number of diseases including colon cancer, liver disease and Crohn's disease. This study investigated <i>β</i>-glucuronidase inhibitory activity of a bromophenol purified from the red alga <i>Grateloupia lancifolia</i>. Using an assay-guided fractionation technique, a bromophenol, bis(2, 3-dibromo-4, 5-dihydroxybenzyl) ether, a bromophenol, was isolated from the red alga <i>G. lancifolia</i>. Its structure was elucidated on the basis of extensive 1D- and 2D-NMR studies, high resolution EI-MS analysis and comparisons with literature data. Bis(2, 3-dibromo-4, 5-dihydroxybenzyl) ether showed potent <i>β</i>-glucuronidase inhibitory activity. The IC<sub>50</sub> and <i>K<sub>I</sub></i> values of bromophenol against <i>E. coli</i> <i>β</i>-glucuronidase were 0.54 and 0.53 mM, respectively. This bromophenol inhibited <i>β</i>-glucuronidase competitively and was stable at pH 2 up to 40 min at 37 ℃.
|
|---|
