Course of Pharmaceutical Sciences, Graduate School of Biomedical Sciences , Nagasaki University , 1-14 Bunkyo-machi , Nagasaki 852-8521 , Japan.
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy , Mansoura University , Mansoura 35516 , Egypt.
Anal Chem. 2018 Dec 4;90(23):13867-13875. doi: 10.1021/acs.analchem.8b02458. Epub 2018 Nov 20.
Isotope-coded derivatization (ICD) is used as a promising alternative approach to isotope internal standards in order to overcome matrix effects caused by coexisting substances that often occur while analyzing metabolites by LC-MS/MS. ICD introduces two different mass tags to every analyte via the use of heavy and light forms of the derivatization reagents. Herein, we report the first ICD approach for aldehydes that uses commercially available reagents avoiding the need for expensive and tedious multisteps synthetic procedures. The method is based on the reaction of the safe and stable derivatizing agent, 9,10-phenanthrenequinone, and the cheap and commercially available ICD reagent, N/N-ammonium acetate, with aldehydes followed by LC/ESI-MS/MS. Multiple reaction monitoring is done at the transitions m/ z [M + H] → m/ z [Product ion A] and m/ z [M + 2 + H] → m/ z [Product ion A + 2] for N- and N-labeled analytes, respectively. Among lipid peroxidation products, 4-hydroxy-2-nonenal (HNE) and 4-hydroxy-2-hexenal (HHE) are considered the most toxic produced aldehydes as they contain additional two reactive functional groups, the unsaturated bond and the hydroxyl group, besides the aldehyde one. Thus, they were chosen as representative analytes in this study. The developed method was able to detect HHE and HNE in human serum with very high sensitivity down to LOQ of 0.2 and 0.05 nM, respectively, employing an expedient salting out liquid-liquid extraction method. The developed method was able to differentiate between the levels of HHE and HNE in serum samples of healthy subjects and diabetic, rheumatic, and cardiac disorder patients.
同位素编码衍生化（ICD）被用作一种有前途的替代方法，可以克服 LC-MS/MS 分析代谢物时经常出现的共存物质引起的基质效应。ICD 通过使用重质和轻质衍生试剂为每个分析物引入两种不同的质量标记。在此，我们报告了第一种用于醛的 ICD 方法，该方法使用市售试剂，避免了昂贵和繁琐的多步合成程序的需要。该方法基于安全稳定的衍生试剂 9,10-菲醌与醛的反应，以及廉价且市售的 ICD 试剂 N/N-乙酸铵，然后进行 LC/ESI-MS/MS。分别在 m/z [M+H] → m/z [产物离子 A]和 m/z [M+2+H] → m/z [产物离子 A+2]处进行多重反应监测，用于 N-和 N-标记的分析物。在脂质过氧化产物中，4-羟基-2-壬烯醛（HNE）和 4-羟基-2-己烯醛（HHE）被认为是产生的最有毒的醛，因为它们除了醛基外，还含有另外两个反应性官能团，即不饱和键和羟基。因此，它们被选为本研究的代表性分析物。开发的方法能够以非常高的灵敏度检测人血清中的 HHE 和 HNE，LOQ 分别低至 0.2 和 0.05 nM，采用简便的盐析液液萃取法。该方法能够区分健康受试者和糖尿病、风湿和心脏疾病患者血清样品中 HHE 和 HNE 的水平。
