Kinetics and Mechanism for Reduction of the Anticancer Prodrug <i>trans,trans,trans</i>-[PtCl<sub>2</sub>(OH)<sub>2</sub>(<i>c</i>-C<sub>6</sub>H<sub>11</sub>NH<sub>2</sub>)(NH<sub>3</sub>)] (JM335) by Thiols
作者:Kelemu Lemma、Tiesheng Shi、Lars I. Elding
DOI:10.1021/ic991351l
日期:2000.4.1
of the platinum(IV) prodrug trans,trans,trans-[PtCl2(OH)2(c-C6H11NH2)(NH3)] (JM335) by L-cysteine, DL-penicillamine, DL-homocysteine, N-acetyl-L-cysteine, 2-mercaptopropanoic acid, 2-mercaptosuccinic acid, and glutathione has been investigated at 25 degrees C in a 1.0 M aqueous perchlorate medium with 6.8 < or = pH < or = 11.2 using stopped-flow spectrophotometry. The stoichiometry of Pt(IV):thiol
L-半胱氨酸,DL-青霉胺,DL-高半胱氨酸,N-乙酰基-N-还原还原铂(IV)前药的反式,反式,反式-[PtCl2(OH)2(c-C6H11NH2)(NH3)](JM335) L-半胱氨酸,2-巯基丙酸,2-巯基琥珀酸和谷胱甘肽已在25°C下于1.0 M高氯酸盐水溶液中于6.8 <或= pH <或= 11.2的条件下使用停止流光度法进行了研究。Pt(IV):硫醇的化学计量比为1:2,氧化还原反应遵循二级速率定律-d [Pt(IV)] / dt = k [Pt(IV)] [RSH] tot,其中k表示pH依赖的二级速率常数,[RSH]总硫醇浓度。k的pH依赖性归因于巯基各种蛋白水解物种对JM335的平行还原,其相对贡献随pH的变化而变化。从硫醇(RSH)或硫醇盐(RS-)到JM335的电子转移被认为是一种还原性消除过程,通过硫在相互转移的氯化物配体之一处的进攻,产生了反-[Pt(OH)2(c