Icaritin (ICT) has distinct bioactivities, especially known for its beneficial effects on bone‐related degenerative disorders; however, its pharmacokinetic properties remain unknown. A novel developed UPLC‐MS/MS method for the determination of ICT and its main metabolite glucuronidated icaritin (GICT) was firstly applied to pharmacokinetic and metabolism studies of ICT in female rats, which were intraperitoneally given 40 mg/kg ICT. Following the protein precipitation of plasma samples with acetonitrile, ICT and GICT were separated on a C18 column using gradient elution mode and quantified in the multiple reaction monitoring mode. The linearities were acceptable for ICT (r = 0.9960) and GICT (r = 0.9968), and the lower limit of quantification values was 0.5 and 5 ng/ml, respectively. The accuracy fell in the range of 92.0%–103.1% and precisions were within 9.5%. Good linearity, accuracy, precision, and recovery were achieved for the UPLC‐MS/MS method. ICT was predominantly and rapidly biotransformed to GICT which was slowly eliminated in vivo with a terminal half‐life value of 4.51 hr. Pharmacokinetics of pure ICT eliminated biotransformation interference of Epimedium extract and disclosed genuine pharmacokinetic manner of ICT, as well as firstly elucidated low concentration and bioavailability of ICT in rat plasma.

中文翻译：

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通过 UPLC-MS/MS 观察淫羊藿素在大鼠体内的药代动力学和代谢。

淫羊藿素 (ICT) 具有独特的生物活性，尤其以其对骨相关退行性疾病的有益作用而闻名；然而，其药代动力学特性仍然未知。一种新开发的 UPLC-MS/MS 方法用于测定 ICT 及其主要代谢物葡萄糖醛酸化淫羊藿素 (GICT)，该方法首次应用于雌性大鼠腹腔注射 40 mg/kg ICT 的药代动力学和代谢研究。用乙腈沉淀血浆样品的蛋白质后，使用梯度洗脱模式在 C18 柱上分离 IC​​T 和 GICT，并在多反应监测模式下进行定量。ICT ( r  = 0.9960) 和 GICT ( r = 0.9968)的线性可接受 ，定量值的下限分别为 0.5 和 5 ng/ml。准确度在 92.0%–103.1% 范围内，精密度在 9.5% 以内。UPLC-MS/MS 方法实现了良好的线性、准确度、精密度和回收率。ICT 主要且快速地生物转化为 GICT，后者在体内缓慢消除，终末半衰期值为 4.51 小时。纯ICT的药代动力学消除了淫羊藿提取物的生物转化干扰，揭示了ICT真正的药代动力学方式，并首次阐明了ICT在大鼠血浆中的低浓度和生物利用度。