ANALYTICAL METHOD FOR QUANTITATION OF BREFELDIN A IN MOUSE PLASMA

Brefeldin A（NSC 89671），一种从青霉菌中分离的大环内酯 Brefeldianum作为一种抗肿瘤药物正在进行临床前评价 在国家癌症研究所。 布雷菲德菌素A的特异性测定是 从血浆中提取到乙醚中 随后在气体前用七氟丁酰咪唑衍生化， 色谱法与电子捕获检测。 仲羟基 快速和定量酯化布雷菲德菌素A组。 的 在可接受的条件下测定的布雷菲德菌素A的最低浓度 在50 μ l血浆中的再现性为0.1fg/ml。 该分析已被 用于研究布雷菲德菌素A在小鼠中的血浆药代动力学。 布雷菲德菌素A血浆水平在治疗期间以明显的双相方式下降。 静脉推注后60分钟。 由于初始时间极短， 处置阶段，终末期是主要决定因素， 布雷菲德菌素A处置，占血浆下面积的74% profile. 中央室（0.71 l/kg）和全身（1.5 l/kg） 表观分布容积较低，但表明药物 分布到外周组织中。 布雷菲德菌素A无生物利用度 在PO之后局 因此，长期暴露于 治疗浓度的布雷菲德菌素A（> 0.1fg/ml）可能需要 连续输注时间表。 此外，对布雷菲德菌素A的兴趣也在增长， 到这样的比例，连续供应的化合物， 需求 布雷菲德菌素A的结构复杂性阻碍了 合成，因此从布雷菲尔德青霉菌中大规模分离， 研究了 产率优化和纯度评估 因此，来自发酵液的布雷菲德菌素A通过应用 开发的检测。

Brefeldin A (NSC 89671), a macrolide isolated from Penicillium brefeldianum, is undergoing preclinical evaluation as an antitumor agent at the National Caner Institute. A specific assay for Brefeldin A was developed involving its extraction from plasma into diethyl ether followed by derivatization with heptafluorobutyrylimidazole prior to gas chromatography with electron capture detection. Both secondary hydroxyl groups of Brefeldin A were rapidly and quantitatively esterified. The lowest concentration of Brefeldin A determined with acceptable reproducibility in 50 fl of plasma was 0.1 fg/ml. This assay has been utilized to investigate Brefeldin A plasma pharmacokinetics in mice. Brefeldin A plasma levels declined in an apparent biphasic manner during 60 min after bolus i.v. injection. Due to the extremely short initial disposition phase, the terminal phase was the primary determinant of Brefeldin A disposition, accounting for 74% of the area under the plasma profile. The central compartment (0.71 l/kg) and total body (1.5 l/kg) apparent volumes of distribution were low, but indicative of drug distribution into peripheral tissues. Brefeldin A was not bioavailable following p.o. administration. Therefore, long term exposure to therapeutic concentrations of Brefeldin A (> 0.1 fg/ml) may require a continuous infusion schedule. Further, interest in Brefeldin A has grown to such proportions that a continuous supply of the compound is now in demand. The structural complexity of Brefeldin A precludes facile synthesis, thus large scale isolation from Penicillium brefeldianum was investigated. Optimization of yield and assessment of purity of Brefeldin A from fermentation broths were thus guided by application of the developed assay.