Aesculetin, a coumarin compound present in the sancho tree and chicory, exhibits excellent antioxidant and anti-inflammatory activities in the vascular and immune system. In this study, a rapid and sensitive ultra-high performance liquid chromatography electrospray ionization–tandem mass spectrometry (UHPLC–ESI–MS/MS) method was established and validated for the determination of aesculetin in rat plasma. Plasma samples were prepared by protein precipitation with acetonitrile. Chromatographic separation was performed on an Acquity UPLC HSS T3 C₁₈ column (2.1 × 100 mm, 1.8 μm) with gradient elution at a flow rate of 0.3 ml/min, using mobile phase consisting of 0.1% formic acid (A) and acetonitrile (B). Aesculetin and puerarin (internal standard) were detected by multiple reaction monitoring in negative ion mode. The method was fully validated according to the US Food and Drug Administration guidelines. The calibration curve was linear over the range of 2–1,000 ng/ml with correlation coefficient >0.9980. The carry-over, matrix effect, extraction recovery, dilution effect, intra- and inter-day precision and the accuracy were within acceptable limits. The method was then applied to a pharmacokinetic study of aesculetin in rats. After oral administration at doses of 5, 10 and 20 mg/kg, the plasma concentration reached peaks of 95.7, 219.9, 388.6 ng/ml at times of 1.22–1.78 h. The oral bioavailability was calculated as 15.6–20.3% in rat plasma. The result provided pre-clinical information for further application of aesculetin.

中文翻译：

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LC-MS/MS 测定大鼠血浆中七叶树苷及其在药代动力学研究中的应用

Aesculetin 是一种存在于桑乔树和菊苣中的香豆素化合物，在血管和免疫系统中表现出优异的抗氧化和抗炎活性。本研究建立了一种快速灵敏的超高效液相色谱电喷雾电离串联质谱 (UHPLC-ESI-MS/MS) 方法，用于测定大鼠血浆中七叶苷的含量。通过用乙腈沉淀蛋白质来制备血浆样品。_{在 Acquity UPLC HSS T3 C 18}上进行色谱分离色谱柱 (2.1 × 100 mm, 1.8 μm)，梯度洗脱，流速为 0.3 ml/min，流动相由 0.1% 甲酸 (A) 和乙腈 (B) 组成。采用负离子模式多反应监测检测七叶苷和葛根素（内标）。该方法已根据美国食品和药物管理局指南进行了充分验证。校准曲线在 2–1,000 ng/ml 范围内呈线性，相关系数 >0.9980。残留、基质效应、萃取回收率、稀释效应、日内和日间精密度和准确度均在可接受的范围内。然后将该方法应用于大鼠中七叶树苷的药代动力学研究。以5、10和20 mg/kg剂量口服给药后，血浆浓度在1.22-1.78 h达到峰值95.7、219.9、388.6 ng/ml。大鼠血浆中的口服生物利用度计算为 15.6-20.3%。该结果为七叶树苷的进一步应用提供了临床前信息。