DETERMINATION OF URUSHIOL IN ALLERGENIC EXTRACTS--URUSHIOL STABILITY

毒藤等变应原提取物中的活性成分 毒柏属植物通常被指定为 “漆酚”，一种五或七十八烯基儿茶酚的混合物。提取物 目前可用于口服或注射的制剂为 植物油，如杏仁油、玉米油或橄榄油。漆酚化合物可能会被氧化 到能够进行Michael-加成反应的邻苯二酚 含有亲核化合物。其他漆酚分子上的烯基 可能起到亲核的作用，导致漆酚的齐聚 存在于溶液中。该项目的目标是：a)开发 漆酚的定量分析方法，包括漆酚的形态分析 单个化合物；b)开发样品制备技术以 从植物油基质中分离漆酚；c)开发方法学以 测定氧化和齐聚漆酚降解产物；d) 漆酚降解率与浓度、溶液类型等因素的相关性 和储存条件。漆酚样本已经形成形态， 三甲基硅基衍生物的气相色谱定量 极性固定相，OV-225。已对以下各项进行了验证研究 这种方法。采用硅胶色谱柱的正相高效液相色谱方法 以及一种毛细管气相色谱程序 将提供更好的个别化合物的分辨率。程序： 高纯度漆酚的分离(大于100微克/毫升) 从植物油中提取的浓缩物已经得到验证，开发了一种固体 相萃取法分离低浓度漆酚(<10 微克/毫升)浓度正在进行中。初步研究涉及 采用凝胶渗透色谱分离漆酚齐聚物的形态，建立了漆酚齐聚物形态分析的新方法 已执行。

The active constituents in allergenic extracts of Poison Ivy and other plants of the genus toxicodendron have been generically designated as "urushiol", a mixture of penta- or heptadecenyl catechols. Extracts currently available for oral administration or injection are formulated in plant oils, e.g. almond, corn or olive oil. Urushiol compounds may oxidize to orthoquinones which are capable of undergoing Michael-addition reactions with nucleophilic compounds. Olefinic sites on other urushiol molecules may function as nucleophiles, resulting in oligomerization of urushiols present in solution. Objectives of this project are: a) to develop methods for the quantitative analysis of urushiol, including speciation of individual compounds; b) to develop sample preparation techniques to isolate urushiol from plant oil matrices; c) to develop methodologies to determine oxidized and oligomerized urushiol degradation products; d) to correlate urushiol degradation with factors of concentration, solution type and storage conditions. Urushiol samples have been speciated and quantitated by gas chromatography of trimethylsilyl derivatives using a polar stationary phase, OV-225. Validation studies have been performed for this method. A normal phase HPLC method utilizing a silica column is to be investigated as well as a capillary gas chromatographic procedure that would provide better resolution of individual compounds. Procedures for the isolation of urushiol at high (greater than 100 microg/ml) concentrations from plant oils have been validated, development of a solid phase extraction procedure for isolation of urushiol at low (less than 10 microg/ml) concentrations is in progress. Initial studies involving speciation of urushiol oligomers by gel permeation chromatography have been performed.