Institute of Chemistry-Analytical Chemistry, University Graz, Universitaetsplatz 1, 8010 Graz, Austria.
Talanta. 2013 Nov 15;116:876-81. doi: 10.1016/j.talanta.2013.07.066. Epub 2013 Aug 7.
Although melarsoprol, an organoarsenic compound, is widely used for the treatment of trypanosomiasis (human African sleeping sickness), very little is known about its fate in the human body, its active metabolites passing the blood-brain barrier and the mode of action. Previous pharmacological studies based on the determination of melarsoprol by HPLC-UV or by a bioassay method produced different results. We report a HPLC-ICPMS method suitable for determining melarsoprol and its metabolites in biological fluids. The arsenic selective capability of the method allowed the quantitative measurement of melarsoprol and two arsenic-containing conversion products produced when melarsoprol was incubated with human serum and blood. The major product was identified as melarsen [4-[(4,6-diamino-1,3,5-triazin-2-yl)amino]phenyl]arsonic acid by HPLC/electrospray MS, and by accurate mass measurements. Investigations about the stability of melarsoprol in serum showed that within 30 h about 10% of melarsoprol is converted to melarsen. In blood, however, most of the melarsoprol was bound to proteins and only 1% was converted to melarsen after 30 hours. The limit of detection for melarsoprol and its conversion products were in the range of 1 µg AsL(-1) (13 nmol As L(-1)) based on signal to noise ratio of 3 with a 10 µL injection volume allowing direct determination of the compounds in blood and serum (after protein precipitation) at therapeutically realistic concentrations.
虽然有机砷化合物美拉胂醇被广泛用于治疗锥虫病（非洲人类昏睡病），但对于它在人体中的命运、其活性代谢物通过血脑屏障的方式和作用模式知之甚少。以前基于 HPLC-UV 或生物测定法测定美拉胂醇的药理学研究产生了不同的结果。我们报告了一种适合于在生物流体中测定美拉胂醇及其代谢物的 HPLC-ICPMS 方法。该方法对砷的选择性使能够定量测量美拉胂醇及其与人体血清和血液孵育时产生的两种含砷转化产物。主要产物通过 HPLC/电喷雾 MS 和精确质量测量被鉴定为美拉胂 [4-[(4,6-二氨基-1,3,5-三嗪-2-基)氨基]苯基]砷酸。关于美拉胂醇在血清中的稳定性的研究表明，在 30 小时内，约有 10%的美拉胂醇转化为美拉胂。然而，在血液中，大部分美拉胂醇与蛋白质结合，在 30 小时后只有 1%转化为美拉胂。美拉胂醇及其转化产物的检测限范围为 1µg AsL(-1)（13 nmol As L(-1)），基于信噪比为 3，用 10µL 进样量允许直接在治疗现实浓度下测定血液和血清中的化合物（在蛋白质沉淀后）。
