Zhu Yuanyuan, Wang Lina, Guo Guoxian, Tang Jing, Yu Jia
School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, China.
Department of Animal Products and Fishery products, Liaoning Institute for Agro-Product Veterinary Drugs and Feed Control, Liaoning Inspection, Examination and Certification Center, Shenyang, China.
Chirality. 2022 Jun;34(6):901-912. doi: 10.1002/chir.23442. Epub 2022 Mar 23.
Isoconazole with an asymmetrical carbon is a broad-spectrum antimicrobial imidazole, but there is still lack of relevant report about the potential enantioselectivity in biological samples. The object of this research was to develop and validate a sensitive and effective high performance liquid chromatography-electrospray ionization coupled with tandem mass spectrometry (HPLC-ESI-MS/MS) method for stereoselective separation and determination of isoconazole enantiomers in Sprague-Dawley (SD) rat plasma and tissues. The greater enantioseparation of isoconazole enantiomers was obtained on a Chiralpak IC column with a mobile phase consisted of acetonitrile-10 mM aqueous ammonium acetate (90:10, v/v) under the reversed-phase mode. Subsequently, the studied compounds and internal standard (IS) were detected on a multiple reaction monitoring (MRM) mode with positive electrospray ionization source. The experimental and theoretical Electronic Circular Dichroism (ECD) spectra were employed to confirm the absolute configuration of isoconazole enantiomers. Eventually, after full method validation, the newly developed method was successfully applied to the study of enantioselectivity in plasma and tissues in SD rats. Results illustrated that the enantioselective differences in plasma were observed for the evidence that the concentrations of S-(-)-isoconazole were always higher than R-(+)-isomer. In terms of tissue distribution, liver, kidney, lung, spleen, and small intestine were the mainly distributed tissues and then followed by heart and muscle. This is the first study to reveal the stereoselective behavior of isoconazole enantiomers in vivo, which also provides reliable and valuable reference for further elucidating the enantioselective metabolisms of isoconazole enantiomers.
具有不对称碳原子的异康唑是一种广谱抗菌咪唑类药物，但关于其在生物样品中潜在对映体选择性的相关报道仍然较少。本研究的目的是建立并验证一种灵敏有效的高效液相色谱 - 电喷雾电离串联质谱法（HPLC - ESI - MS/MS），用于立体选择性分离和测定Sprague - Dawley（SD）大鼠血浆和组织中的异康唑对映体。在反相模式下，采用Chiralpak IC色谱柱，以乙腈 - 10 mM乙酸铵水溶液（90:10，v/v）为流动相，可实现异康唑对映体的较大对映体分离。随后，在正电喷雾电离源的多反应监测（MRM）模式下检测所研究的化合物和内标（IS）。利用实验和理论电子圆二色光谱（ECD）确定异康唑对映体的绝对构型。最终，经过全面的方法验证后，新建立的方法成功应用于SD大鼠血浆和组织中的对映体选择性研究。结果表明，血浆中存在对映体选择性差异，证据是S - (-)-异康唑的浓度始终高于R - (+)-异构体。在组织分布方面，肝脏、肾脏、肺、脾脏和小肠是主要分布组织，其次是心脏和肌肉。这是首次揭示异康唑对映体在体内立体选择性行为的研究，也为进一步阐明异康唑对映体的对映体选择性代谢提供了可靠且有价值的参考。
