雄诺龙 、 糖质酸-1,4-内酯 在
recombinant human uridinne diphosphate-glucuronosyltransferase 1A4 from HEK293 cells 、 uridine 5'-diphosphoglucuronic acid triammonium salt 、 magnesium chloride 、 alamethicin 作用下,
以
二甲基亚砜 为溶剂,
生成 5α-androstan-17β-ol-3-one-17-glucuronide
参考文献:
名称:
Glucuronidation of Dihydrotestosterone and trans-Androsterone by Recombinant UDP-Glucuronosyltransferase (UGT) 1A4: Evidence for Multiple UGT1A4 Aglycone Binding Sites
摘要:
UDP-葡萄糖醛酸基转移酶(UGT)1A4催化的葡萄糖醛酸化作用是一种重要的药物消除途径。虽然 UGT1A4 催化葡萄糖醛酸化的非典型动力学特征(非双曲、非迈克尔斯-门顿)偶有报道,但尚未开展系统的动力学研究来探索 UGT1A4 中是否存在多个苷元结合位点。为此,我们使用了两种位置异构体--双氢睾酮(DHT)和反式-雄甾酮(t -AND)--作为探针底物,评估了它们与 HEK293 表达的 UGT1A4 单独和在 UGT1A4 底物[他莫昔芬(TAM)或拉莫三嗪(LTG)]存在时的葡萄糖醛酸化动力学。与高亲和力 UGT1A4 底物 TAM 共同作用会对 DHT 和 t -AND 的葡萄糖醛酸化产生浓度依赖性激活/抑制作用,而低亲和力 UGT1A4 底物 LTG 则对这两个过程产生非竞争性抑制作用。然后评估了 TAM 单独和在不同浓度的 DHT 或 t -AND 存在下的葡萄糖醛酸化动力学。TAM 显示出底物抑制动力学,表明 TAM 在 UGT1A4 中可能有两个结合位点。然而,随着 DHT 或 t -AND 浓度的增加,TAM 的底物抑制动力学曲线变得更加双曲线。各种双位点动力学模型充分解释了 TAM 与 DHT 或 TAM 与 t -AND 之间的相互作用。此外,还评估了 TAM 对 LTG 葡萄糖醛酸化的影响。与 TAM 对 DHT 和 t -AND 葡萄糖醛酸化的混合效应不同,TAM 可抑制 LTG 葡萄糖醛酸化。我们的研究结果表明,UGT1A4 中存在多个苷元结合位点,这可能会以底物依赖的方式导致非典型动力学(同向和异向)。
CORROSION INHIBITOR COMPOSITIONS AND METHODS OF USING SAME
申请人:Ecolab USA Inc.
公开号:US20170306504A1
公开(公告)日:2017-10-26
Disclosed are methods for inhibiting the corrosion of metal containments such as carbon-steel pipes used in oil recovery processes, the methods comprising adding urine and/or compositions comprising urine to water sources to form corrosion inhibitor compositions, and contacting metal containments with the corrosion inhibitor compositions. The water sources are for example aqueous solutions that are corrosive to metal containments such as carbon-steel pipes. Compositions comprising urine that provide reduced corrosion or corrosion inhibition are also described. Metal containment assemblages comprising corrosion inhibitor compositions and a metal containment are also described.
[EN] CORROSION INHIBITOR COMPOSITIONS AND METHODS OF USING SAME<br/>[FR] COMPOSITIONS INHIBITRICES DE LA CORROSION ET LEURS PROCÉDÉS D'UTILISATION
申请人:ECOLAB USA INC
公开号:WO2017189528A1
公开(公告)日:2017-11-02
Disclosed are methods for inhibiting the corrosion of metal containments such as carbon-steel pipes used in oil recovery processes, the methods comprising adding urine and/or compositions comprising urine to water sources to form corrosion inhibitor compositions, and contacting metal containments with the corrosion inhibitor compositions. The water sources are for example aqueous solutions that are corrosive to metal containments such as carbon-steel pipes. Compositions comprising urine that provide reduced corrosion or corrosion inhibition are also described. Metal containment assemblages comprising corrosion inhibitor compositions and a metal containment are also described.