Department of Chemistry & Chemical Engineering, Xi'an University of Arts and Science, Xi'an, Shaanxi 710069, China.
Luminescence. 2013 Jul-Aug;28(4):523-9. doi: 10.1002/bio.2488. Epub 2013 Jan 31.
Rhaponticin (RH) demonstrates a variety of pharmacological activities, including antitumor, antithrombotic and antioxidant effects. It is essential to establish a simple, rapid and reliable analytical method for determining the pharmacokinetics of RH. A simple cerium ion (Ce(3+)) probe method was developed and validated to determine RH in rat plasma, feces and urine. The fluorescence intensities of the cerium ion (Ce(3+)) were quenched by addition of RH, along with a remarkable red shift. Spectral data revealed that fluorescence quenching of Ce(3+) by RH was due to the formation of a Ce(3+)-RH complex. Using to the Stern-Volmer equation, the binding parameters for interactions between Ce(3+) and RH were obtained. Based on these, a rapid and simple spectrofluorimetric method was developed to determine the metabolism and pharmacokinetics of RH using a Ce(3+) probe. The assay was linear over the concentration range of 0.11-9.52, 0.25-8.87 and 0.18-9.10 μM for plasma, feces and urine, respectively and RH recoveries were found to be 98.24 ± 0.8, 97.78 ± 1.2 and 97.54 ± 0.8% for plasma, feces and urine, respectively. The relative standard deviations were < 9.5%. The spectrofluorimetric method was simple and rapid for quantitative determination of RH and its metabolism, and was affordable for most laboratories because of the fluorescence spectroscopy and low equipment cost. These pharmacokinetic, bioavailability and metabolism studies of RH will provide helpful information for the development of suitable dosage forms and clinical references on rational administration.
瑞香素（RH）具有多种药理活性，包括抗肿瘤、抗血栓和抗氧化作用。建立一种简单、快速、可靠的分析方法来测定 RH 的药代动力学是至关重要的。本研究建立了一种简单的铈离子（Ce(3+))探针法，用于测定大鼠血浆、粪便和尿液中的 RH。随着 RH 的加入，铈离子（Ce(3+))的荧光强度被猝灭，并伴有明显的红移。光谱数据表明，RH 猝灭 Ce(3+)的荧光是由于形成了 Ce(3+)-RH 配合物。利用 Stern-Volmer 方程，获得了 Ce(3+)与 RH 相互作用的结合参数。基于这些参数，建立了一种快速简便的利用 Ce(3+)探针测定 RH 代谢和药代动力学的荧光分光光度法。该方法在血浆、粪便和尿液中的浓度范围分别为 0.11-9.52、0.25-8.87 和 0.18-9.10 μM 时呈线性，RH 在血浆、粪便和尿液中的回收率分别为 98.24 ± 0.8%、97.78 ± 1.2%和 97.54 ± 0.8%。相对标准偏差均小于 9.5%。该荧光分光光度法简单、快速，可用于 RH 及其代谢物的定量测定，由于荧光光谱和设备成本低，大多数实验室都能负担得起。这些 RH 的药代动力学、生物利用度和代谢研究将为开发合适的剂型和合理用药的临床参考提供有价值的信息。
