Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
Department of Pharmacy, Huashan Hospital, Fudan University, Shanghai 200040, China.
Int J Biol Macromol. 2021 Jun 1;180:252-261. doi: 10.1016/j.ijbiomac.2021.03.073. Epub 2021 Mar 16.
Strong inhibition of the human UDP-glucuronosyltransferase enzymes (UGTs) may lead to undesirable effects, including hyperbilirubinaemia and drug/herb-drug interactions. Currently, there is no good way to examine the inhibitory effects and specificities of compounds toward all the important human UGTs, side-by-side and under identical conditions. Herein, we report a new, broad-spectrum substrate for human UGTs and its uses in screening and characterizing of UGT inhibitors. Following screening a variety of phenolic compound(s), we have found that methylophiopogonanone A (MOA) can be readily O-glucuronidated by all tested human UGTs, including the typical N-glucuronidating enzymes UGT1A4 and UGT2B10. MOA-O-glucuronidation yielded a single mono-O-glucuronide that was biosynthesized and purified for structural characterization and for constructing an LC-UV based MOA-O-glucuronidation activity assay, which was then used for investigating MOA-O-glucuronidation kinetics in recombinant human UGTs. The derived K values were crucial for selecting the most suitable assay conditions for assessing inhibitory potentials and specificity of test compound(s). Furthermore, the inhibitory effects and specificities of four known UGT inhibitors were reinvestigated by using MOA as the substrate for all tested UGTs. Collectively, MOA is a broad-spectrum substrate for the human UGTs, which offers a new and practical tool for assessing inhibitory effects and specificities of UGT inhibitors.
强效抑制人尿苷二磷酸葡萄糖醛酸转移酶（UGTs）可能导致不良影响，包括高胆红素血症和药物/草药-药物相互作用。目前，尚无很好的方法在相同条件下并排检测化合物对所有重要的人 UGTs 的抑制作用和特异性。本文报道了一种新的广谱人 UGT 底物及其在筛选和表征 UGT 抑制剂中的应用。在筛选了多种酚类化合物后，我们发现甲基胡椒酚酮 A（MOA）可被所有测试的人 UGT 迅速 O-葡糖醛酸化，包括典型的 N-葡糖醛酸化酶 UGT1A4 和 UGT2B10。MOA-O-葡糖醛酸化生成了一种单-O-葡糖苷，可用于生物合成和纯化进行结构表征，并构建基于 LC-UV 的 MOA-O-葡糖醛酸化活性测定法，然后用于研究重组人 UGT 中的 MOA-O-葡糖醛酸化动力学。所得 K 值对于选择最适合评估测试化合物抑制潜力和特异性的测定条件至关重要。此外，还使用 MOA 作为所有测试 UGT 的底物重新研究了四种已知 UGT 抑制剂的抑制作用和特异性。总之，MOA 是人 UGT 的广谱底物，为评估 UGT 抑制剂的抑制作用和特异性提供了一种新的实用工具。
