Yan Z, Caldwell G W, Gauthier D, Leo G C, Mei J, Ho C Y, Jones W J, Masucci J A, Tuman R W, Galemmo R A, Johnson D L
Drug Discovery, R2013, Johnson & Johnson Pharmaceutical Research & Development, LLC, Welsh & McKean Roads, Spring House, PA 19477-0776, USA.
Drug Metab Dispos. 2006 May;34(5):748-55. doi: 10.1124/dmd.106.009274. Epub 2006 Feb 2.
The potential cancer therapeutic agent, 6,7-(dimethoxy-2, 4-dihydroindeno[1,2-c]pyrazol-3-yl)-(3-fluoro-phenyl)-amine (JNJ-10198409), formed three N-glucuronides that were positively identified by liquid chromatography-tandem mass spectrometry and NMR as N-amine-glucuronide (Glu-A), 1-N-pyrazole-glucuronide (Glu-B), and 2-N-pyrazole-glucuronide (Glu-C). All three N-glucuronides were detected in rat liver microsomes, whereas only Glu-A and -B were found in monkey and human liver microsomes. In contrast to common glucuronides, Glu-B was completely resistant to beta-glucuronidase. Kinetic analyses revealed that glucuronidation of JNJ-10198409 in human liver microsomes exhibited atypical kinetics that may be described by a two-site binding model. For the high affinity binding, K(m) values were 1.2 and 5.0 microM, and V(max) values were 2002 and 2,403 nmol min(-1) mg(-1) for Glu-A and Glu-B, respectively. Kinetic constants of low affinity binding were not determined due to low solubility of the drug. Among the human UDP-glucuronosyltransferases (UGTs) tested, UGT1A9, 1A8, 1A7, and 1A4 were the most active isozymes to produce Glu-A; for the formation of Glu-B, UGT1A9 was the most active enzyme, followed by UGT1A3, 1A7, and 1A4. Glucuronidation of JNJ-10198409 by those UGT1A enzymes followed classic Michaelis-Menten kinetics. In contrast, no glucuronides were formed by all UGT2B isozymes tested, including UGT2B4, 2B7, 2B15, and 2B17. Collectively, these results suggested that glucuronidation of JNJ-10198409 in human liver microsomes is catalyzed by multiple UGT1A enzymes. Since UGT1A enzymes are widely expressed in various tissues, it is anticipated that both hepatic and extrahepatic glucuronidation will likely contribute to the elimination of the drug in humans. Additionally, conjugation at the nitrogens of the pyrazole ring represents a new structural moiety for UGT1A-mediated reactions.
潜在的癌症治疗药物6,7 -（二甲氧基 - 2,4 - 二氢茚并[1,2 - c]吡唑 - 3 - 基） - （3 - 氟苯基） - 胺（JNJ - 10198409）形成了三种N - 葡萄糖醛酸苷，通过液相色谱 - 串联质谱法和核磁共振被确认为N - 胺 - 葡萄糖醛酸苷（Glu - A）、1 - N - 吡唑 - 葡萄糖醛酸苷（Glu - B）和2 - N - 吡唑 - 葡萄糖醛酸苷（Glu - C）。在大鼠肝微粒体中检测到了所有三种N - 葡萄糖醛酸苷，而在猴和人肝微粒体中仅发现了Glu - A和 - B。与常见的葡萄糖醛酸苷不同，Glu - B对β - 葡萄糖醛酸酶完全耐药。动力学分析表明，JNJ - 10198409在人肝微粒体中的葡萄糖醛酸化表现出非典型动力学，可用双位点结合模型描述。对于高亲和力结合，Glu - A和Glu - B的K(m)值分别为1.2和5.0 microM，V(max)值分别为2002和2403 nmol min(-1) mg(-1)。由于药物溶解度低，未测定低亲和力结合的动力学常数。在所测试的人尿苷二磷酸葡萄糖醛酸转移酶（UGT）中，UGT1A9、1A8、1A7和1A4是产生Glu - A最活跃的同工酶；对于Glu - B的形成，UGT1A9是最活跃的酶，其次是UGT1A3、1A7和1A4。这些UGT1A酶对JNJ - 10198409的葡萄糖醛酸化遵循经典的米氏动力学。相反，所测试的所有UGT2B同工酶，包括UGT2B4、2B7、2B15和2B17，均未形成葡萄糖醛酸苷。总体而言，这些结果表明，人肝微粒体中JNJ - 10198409的葡萄糖醛酸化由多种UGT1A酶催化。由于UGT1A酶在各种组织中广泛表达，预计肝脏和肝外的葡萄糖醛酸化都可能有助于人体中该药物的消除。此外，吡唑环氮原子处的缀合代表了UGT1A介导反应的一种新结构部分。
