DETERMINATION OF URUSHIOL IN ALLERGENIC EXTRACTS: URUSHIOL STABILITY STUDIES

毒藤和毒枝属的其它植物的过敏性提取物中的活性成分一般被指定为“漆酚”，一种五烯基或十七烯基儿茶酚的混合物。 用于口服或注射的提取物在植物油中配制，例如杏仁油、玉米油或橄榄油或乙醇。 漆酚化合物可以氧化成邻醌，邻醌能够与亲核化合物进行迈克尔加成反应。 其他漆酚分子上的烯烃位点可作为亲核试剂，导致溶液中存在的漆酚的低聚。 本项目的目标是：a）开发漆酚的定量分析方法，包括单个化合物的形态分析; B）开发样品制备技术，从植物油基质中分离漆酚; c）开发氧化和低聚漆酚降解产物的测定方法; d）将漆酚降解与浓度、溶液类型和储存条件等因素联系起来。 用三甲基硅衍生物气相色谱法对漆酚样品进行了形态分析和定量。 已对该方法进行了验证研究。 将研究使用硅胶柱的正相HPLC法。 毛细管气相色谱程序，提供更好的分辨率的个别化合物已经开发和部分验证。 从植物油中分离高浓度（大于100 ppm）漆酚的方法已经得到验证，分离低浓度（小于10 ppm）漆酚的固相萃取方法正在开发中。

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 for oral administration or injection are formulated in plant oils, e.g. almond, corn or olive oil or ethanol. 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. Validation studies have been performed for this method. A normal phase HPLC method utilizing a silica column is to be investigated. A capillary gas chromatographic procedure, providing better resolution of individual compounds has been developed and partially validated. Procedures for the isolation of urushiol at high (greater than 100 ppm) concentrations from plant oils have been validated, development of a solid phase extraction procedure for isolation of urushiol at low (less than 10 ppm) concentrations is in progress.