title: Quantification of conjugated metabolites of drugs in biological matrices after the hydrolysis with β-glucuronidase and sufatase: a review of bio-analytical methods.
abstract: Glucuronidation and sulfation represent two major pathways in phase II drug metabolism in humans and other mammalian species. The great majority of drugs, for example, polyphenols, flavonoids and anthraquinones, could be transformed into sulfated and glucuronidated conjugates simultaneously and extensively in vivo. The pharmacological activities of drug conjugations are normally decreased compared with those of their free forms. However, some drug conjugates may either bear biological activities themselves or serve as excellent sources of biologically active compounds. As the bioactivities of drugs are thought to be relevant to the kinetics of their conjugates, it is essential to study the pharmacokinetic behaviors of the conjugates in more detail. Unfortunately, the free forms of drugs cannot be detected directly in most cases if their glucuronides and sulfates are the predominant forms in biological samples. Nevertheless, an initial enzymatic hydrolysis step using β-glucuronidase and/or sulfatase is usually performed to convert the glucuronidated and/or sulfated conjugates to their free forms prior to the extraction, purification and other subsequent analysis steps in the literature. This review provides fundamental information on drug metabolism pathways, the bio-analytical strategies for the quantification of various drug conjugates, and the applications of the analytical methods to pharmacokinetic studies.
authors: Experiment Center for Teaching and Learning, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, People's Republic of China.
authors: Yue
authors: Y
authors: Ding
authors: Ming
authors: M
authors: Peng
authors: Tong
authors: T
authors: Zhang
authors: Jian-Sheng
authors: JS
authors: Tao
authors: Zhen-Zhen
authors: ZZ
authors: Cai
authors: Yong
authors: Y
authors: Zhang
mesh_terms: D000818:Animals; D005591:Chemical Fractionation; D002851:Chromatography, High Pressure Liquid; D008401:Gas Chromatography-Mass Spectrometry; D005966:Glucuronidase / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013429:Sulfatases / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D004364:Pharmaceutical Preparations; D013429:Sulfatases; D005966:Glucuronidase
keywords: conjugated metabolites; hydrolysis; pharmacokinetics; review; sulfatase; β-glucuronidase