Udp - glucuronosyltransferases ( ugts ) are glycoproteins localized in the endoplasmic reticulum that catalyze the conjugation of a broad variety of endogenous and exogenous lipophilic aglycon substrates ( such as bilirubin , steroid hormone and drugs , insecticide , etc ) with glucuronic acid using udp - glucuronic acid ( udpga ) as the sugar donor . ugts are a gene superfamily of phase ii drug - metabolizing enzymes , they are responsible for the glucuronidation of a significant number of different functional groups ( e . g Ugts能催化各种各样外源和内源的亲脂性糖苷配基底物与葡醛酸的结合，该反应是机体清除外源性(如药物和杀虫剂)和内源性(如胆红素和甾体激素)亲脂性化合物的一个主要方式，也是药物相代谢的重要方式。
