Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, China.
Hainan Key Laboratory for Research and Development of Tropical Herbs, School of Pharmacy, Hainan Medical University, Haikou, China.
Biomed Chromatogr. 2021 Dec;35(12):e5197. doi: 10.1002/bmc.5197. Epub 2021 Jul 23.
This study aimed to develop a rapid, sensitive, and specific LC-tandem mass spectrometry method for the determination of nootkatone in rat plasma. α-Cyperone was chosen as the internal standard (IS). The plasma was processed using a one-step acetonitrile protein precipitation method. Chromatographic separation of nootkatone was achieved on a Phenomenex Kinetex XB-C18 column (2.10 × 50 mm, 2.6 μm) at 35°C with a mobile phase consisting of acetonitrile and water under a gradient elution at a flow rate of 0.35 mL/min. An electrospray ionization source was applied and operated in positive ion and multiple reaction monitoring modes. Nootkatone and IS were quantified using the transitions of m/z 219.200 → 163.110 and m/z 219.200 → 111.000, respectively. The calibration curves were linear over the range of 10-2000 ng/mL (r = 0.9943). The lower limit of quantification was 10 ng/mL. The intra- and inter-day precision (relative standard deviation) ranged from 2.56% to 8.41%, with the accuracy values ranging from 98.9% to 99.17% for four different concentration levels. The matrix effect and extraction recovery were within acceptable limits. The validated method was successfully applied to the pharmacokinetic study of nootkatone in rats after oral and intravenous administration at three dosages. The main pharmacokinetic parameters were calculated, showing low bioavailability of nootkatone.
本研究旨在开发一种快速、灵敏、特异的 LC-串联质谱法，用于测定大鼠血浆中的诺卡酮。α-环酮被选为内标（IS）。采用一步法乙腈蛋白沉淀法处理血浆。采用 Phenomenex Kinetex XB-C18 柱（2.10×50mm，2.6μm），在 35℃下，以乙腈和水为流动相，在梯度洗脱下，流速为 0.35mL/min，实现诺卡酮的色谱分离。采用电喷雾电离源，在正离子模式和多反应监测模式下进行操作。诺卡酮和 IS 分别通过 m/z 219.200→163.110 和 m/z 219.200→111.000 的跃迁进行定量。校准曲线在 10-2000ng/mL 范围内呈线性（r=0.9943）。定量下限为 10ng/mL。四个不同浓度水平的日内和日间精密度（相对标准偏差）范围为 2.56%至 8.41%，准确度值范围为 98.9%至 99.17%。基质效应和提取回收率在可接受范围内。该验证方法成功应用于大鼠口服和静脉注射三种剂量后诺卡酮的药代动力学研究。计算了主要药代动力学参数，表明诺卡酮的生物利用度较低。
