DETERMINATION OF URUSHIOL IN ALLERGENIC EXTRACTS: URUSHIOL STABILITY STUDIES

毒藤和毒龙属其他植物的过敏原提取物中的活性成分通常被命名为漆酚，一种五或七十八烯基儿茶酚的混合物。口服或注射的提取物是用植物油配制的，例如杏仁、玉米或橄榄油或乙醇。漆酚化合物可以氧化成邻苯二酚，它能够与亲核化合物发生迈克尔加成反应。其他漆酚分子上的烯基可能起到亲核试剂的作用，导致漆酚在溶液中的齐聚。该项目的目标是：a)开发漆酚的定量分析方法，包括单个化合物的形态；b)开发从植物油基质中分离漆酚的样品制备技术；c)开发确定氧化和齐聚漆酚降解产物的方法；d)将漆酚降解与浓度、溶液类型和储存条件的因素相关联。采用三甲基硅基衍生物的气相色谱对漆酚样品进行了形态分析和定量。对该方法进行了验证研究。一种利用硅胶色谱柱的正相高效液相色谱方法将被研究。毛细管气相色谱程序，提供更好的个别化合物的分辨率已被开发和部分验证。从植物油中分离高浓度(大于100ppm)漆酚的程序已经得到验证，正在开发固相萃取程序以分离低浓度(低于10ppm)的漆酚。

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.