Fu I, Bowers L D
Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455.
Clin Chem. 1991 Jul;37(7):1185-90.
We report a micromethod for the analysis of cyclosporine (CsA), based on quantification of its constituent amino acids. The amino acids were released by gas-phase hydrolysis, derivatized with fluorenylmethyl chloroformate, and separated and analyzed in a reversed-phase HPLC system. The imprecision (CV) of the amino acid analysis was less than 4%, and several determinations of the amount of standard CsA were within 1% of the weighed material. The detection limits (signal-to-noise ratio = 2) were 500 fmol for ultraviolet detection and 100 fmol for fluorescence detection. We also used this method to determine the ultraviolet absorptivities of CsA and five metabolites at 210, 214, and 230 nm. The molar absorptivity of most metabolites was about 10% higher than that of CsA, although the metabolite that was oxidized to a carboxyl group on the terminal carbon of N-methyl-butenyl-methyl-threonine (AM1A) had a molar absorptivity about 40% higher than that of CsA.
我们报告了一种基于环孢素（CsA）组成氨基酸定量分析的微量方法。氨基酸通过气相水解释放，用芴甲氧羰酰氯衍生化，并在反相高效液相色谱系统中进行分离和分析。氨基酸分析的不精密度（CV）小于4%，标准CsA量的多次测定结果与称重物质相差在1%以内。紫外检测的检测限（信噪比 = 2）为500 fmol，荧光检测为100 fmol。我们还使用该方法测定了CsA及其五种代谢物在210、214和230 nm处的紫外吸光率。大多数代谢物的摩尔吸光率比CsA高约10%，尽管在N-甲基-丁烯基-甲基-苏氨酸（AM1A）末端碳上氧化为羧基的代谢物的摩尔吸光率比CsA高约40%。
