Isosinensetin is a polymethoxyflavone existing in various kinds of citrus. It has exhibited significant anti-proliferative activity and herb-drug interaction. To date, a specific determination method to quantify isosinensetin concentration in biological matrix has not been developed. In the present study, a highly specific, simple and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) approach was developed and validated for quantification of isosinensetin in rat plasma with subsequent application to a pharmacokinetic study. Isosinensetin and lysionotin (internal standard, IS) were extracted from rat plasma by a single step protein precipitation using acetonitrile as precipitation agent. The chromatographic separation was conducted using an Agilent C18 column with a gradient elution system (0.1 % formic acid aqueous solution and acetonitrile) within 3.5 min. An electrospray ionization (ESI) source operating in positive mode and multiple reaction monitoring (MRM) were used to monitor the transitions of m/z 373.1 → 343.1 for isosinensetin and m/z 345.1 → 315.1 for IS. The developed method was linear within the range of 1-1000 ng/mL and fully validated according to FDA guidelines. The accuracy values reported as relative errors were between 2.0 and 10.0 % for three quality control levels (2, 400 and 800 ng/mL) and lower limit of quantification (LLOQ). The precisions were ≤11.1 % for quality controls and ≤18.1 % for LLOQ. The recoveries and matrix effects of isosinensetin were in the range of 83.4-87.7 % and 105.6-108.8 %, respectively. Other parameters such as selectivity, carryover effect, dilution integrity and stability were also validated and met the acceptance criteria. The method was applied to a pharmacokinetic study in rats following oral and intravenous administration of isosinensetin. Isosinensetin was rapidly absorbed with a poor bioavailability of 2.19 % and quickly eliminated with mean half-life of 1.40 h and 1.76 h for oral and intravenous route, respectively.

中文翻译：

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用UHPLC-MS / MS测定大鼠血浆中的异信菌素：在健康大鼠的口服和静脉药代动力学研究中的应用。

异香豆素是存在于各种柑橘中的聚甲氧基黄酮。它表现出显着的抗增殖活性和草药-药物相互作用。迄今为止，尚未开发出定量测定生物基质中异香豆素浓度的特定测定方法。在本研究中，开发了一种高度特异性，简单且灵敏的超高效液相色谱-串联质谱（UHPLC-MS / MS）方法，并验证了该方法可定量测定大鼠血浆中异异游生物素的含量，并随后应用于药代动力学研究。使用乙腈作为沉淀剂，通过一步蛋白沉淀法从大鼠血浆中提取异信香素和溶菌素（内标，IS）。使用带有梯度洗脱系统的安捷伦C18色谱柱进行色谱分离（0。在3.5分钟内加入1％的甲酸水溶液和乙腈）。以正模式运行的电喷雾电离（ESI）源和多反应监测（MRM）用于监测异信使素的m / z 373.1→343.1和IS的m / z 345.1→315.1的跃迁。所开发的方法在1-1000 ng / mL范围内是线性的，并已根据FDA指南进行了充分验证。对于三个质量控制水平（2、400和800 ng / mL）和定量下限（LLOQ），报告为相对误差的准确度值在2.0和10.0％之间。质量控制的精度为≤11.1％，LLOQ的精度为≤18.1％。异麦皂苷的回收率和基质效应分别在83.4-87.7％和105.6-108.8％之间。其他参数，例如选择性，残留效应，稀释液的完整性和稳定性也得到了验证，并符合验收标准。将该方法应用于大鼠口服和静脉注射异麦角菌素后的药代动力学研究。异麦皂苷素被迅速吸收，不良生物利用度为2.19％，并迅速消除，口服和静脉内途径的平均半衰期分别为1.40 h和1.76 h。