Synthesis of Stable Isotope-Labeled Steroids as Internal Standards

NCI最近开发的一种方法允许使用LC-MS-MS(LC-MS-MS)同时分析人类尿液小样本中的15种雌激素代谢物。流行病学研究表明，循环和尿液中雌激素水平高的女性患乳腺癌的风险增加。绝经后妇女在激素替代治疗中使用雌激素也与卵巢癌有关。对这些类固醇激素的准确测量可能有助于更好地了解和诊断癌症。这种分析方法的精密度要求使用这些代谢物的稳定重原子同分异构体作为内标。只有几种商业上可用的同种异构体是合适的。该研究计划概述了几种雌激素和雄烷的合成，这些雌激素和雄烷的分子量比天然化合物至少+3amu。对于分析中的使用至关重要，合成的设计是将重原子标记放置在在任何化学反应或分析条件下不会交换的位置，从而保持最终产品的同位素完整性。根据第二阶段RFP的建议，所描述的化学物质适合商业规模的生产，在这种情况下约为100毫克。此外，化学是非常好的先例，因此所描述的项目有非常高的成功几率。

A method recently developed at the NCI permits the simultaneous analysis of 15 estrogen metabolites from small samples of human urine using Liquid Chromatography-Mass Spectroscopy (LC-MS-MS). Epidemiological studies have suggested that an Increased risk of breast cancer has been found In women with high circulatory and urinary levels of estrogen. The use of estrogens In hormone replacement therapy in post-menopausal women has also been implicated In ovarian cancer. The accurate measurement of these steroid hormones may lead to better understanding and diagnoses of cancers. The precision of this analytical method requires the use of stable heavy atom isotopomers of these metabolites as Internal standards. Only a few of the commercially available isotopomers are suitable. The Research Plan outlines the synthesis of several estrogens and androstanes that would have molecular weights of at least +3 amu over the natural compounds. Of critical importance for use In the assay, the syntheses have been designed to place the heavy-atom labels in positions that will not exchange under any of the chemical reactions or the conditions of the assay, thus preserving the Isotopic integrity of the final products. The chemistry described is amenable to the commercial scale production, in this case approximately 100 mg, as suggested by the Phase II RFP. In addition, the chemistry Is very well precedented and the project as described therefore has a very high probability of success.