藤茶中杨梅素、二氢杨梅素及其乙酰化衍生物在SD大鼠体内药动学研究

目的：建立LC-MS/MS法测定SD大鼠血浆中杨梅素（myricetin，MY）和二氢杨梅素（dihydromyricetin，DMY）的浓度，将其运用到药动学研究，并评价DMY乙酰化衍生物是否改善生物利用度。方法：SD大鼠随机分为4组，分别灌胃DMY （100 mg·kg^-1，相当于9 375.0 μmo·L^-1）的0.5%羧甲基纤维素钠生理盐水溶液，以及等摩尔剂量的DMY-1、DMY-2、MY。于给药前0.0 h和给药后0.08，0.17，0.25，0.33，0.50，0.75，1.0，2.0，4.0，6.0，8.0，12.0 h尾静脉断尾采血200 μL，血浆样品经0.1%甲酸-乙腈沉淀蛋白，内标法定量，DAS3.0和SPSS统计分析得到药动学参数和曲线。结果：低、中、高的质控样品日内、日间精密度RSD均小于10.2%；DMY和MY的基质效应分别为98.3%~105.5%、98.0%~108.1%；萃取回收率分别为99.4%~103.0%、95.0%~99.7%，均符合生物样品分析检测的要求；DMY-2和DMY-1组相比于DMY组，相对生物利用度分别为47.22%，10.70%，表明口服灌胃给药DMY相对生物利用度要高出乙酰化衍生物组。结论：本研究建立测定大鼠血浆中DMY和MY的LC-MS/MS法，具有灵敏度高、准确性高、重复性好等优点，能够满足生物样品分析检测的要求，可应用于MY、DMY及其衍生物的药动学研究，也可为DMY结构修饰和新药开发提供参考依据。

Pharmacokinetics of myricetin,dihydromyricetin from ampelopsis grossedentata and its acetylated derivatives in SD rats

OBJECTIVE To establish an LC-MS/MS method for the determination of myricetin (MY) and dihydromyricetin (DMY) in SD rat plasma and to evaluate whether DMY acetylated derivatives improve the bioavailability.METHODS SD rats were randomly divided into four groups and received intragastric administration of DMY (100 mg·kg^-1, equivalent to 9 375.0 μmo·L^-1) in normal saline containing 0.5% sodium carboxymethyl cellulose, and equimolar doses of DMY-1, DMY-2, MY. 200 μL blood samples were collected from the tail vein at 0.0 h before administration and 0.08, 0.17, 0.25, 0.33, 0.50, 0.75, 1.0, 2.0, 4.0, 6.0, 8.0 and 12.0 h after administration. The plasma samples were precipitated with 0.1% formic acid-acetonitrile and quantified by internal standard method. The pharmacokinetic parameters and curves were obtained by DAS3.0 and SPSS statistical analysis.RESULTS The intra-day and inter-day precision of quality control samples of DMY and MY for low, middle and high concentrations were less than 10.2%, and the extraction recovery and matrix effects of DMY (or MY) was 99.4%-103.0% (or 95.0%-99.7%) and 98.3%-105.5% (or 98.0%-108.1%), respectively. Compared with the DMY group, the relative bioavailability of the DMY-2 group and the DMY-1 group were 47.22% and 10.70%, respectively. The relative bioavailability of DMY was higher than that of the acetylated derivative groups.CONCLUSION This study established the LC-MS/MS method for the determination of DMY and MY in rat plasma, which has the advantages of high sensitivity, high accuracy and good repeatability, and can meet the requirements of biological sample analysis. It not only can be applied to the pharmacokinetic study of MY, DMY and its derivatives, but also provide reference for the structural modification and the development of new drugs of DMY.