title: Phase II drug metabolizing enzymes.
abstract: BACKGROUND
  Phase II biotransformation reactions (also 'conjugation reactions') generally serve as a detoxifying step in drug metabolism. Phase II drug metabolising enzymes are mainly transferases. This review covers the major phase II enzymes: UDP-glucuronosyltransferases, sulfotransferases, N-acetyltransferases, glutathione S-transferases and methyltransferases (mainly thiopurine S-methyl transferase and catechol O-methyl transferase). The focus is on the presence of various forms, on tissue and cellular distribution, on the respective substrates, on genetic polymorphism and finally on the interspecies differences in these enzymes.
  
  
  RESULTS
  A literature search using the following databases PubMed, Science Direct and EBSCO for the years, 1969-2010.
  
  
  CONCLUSIONS
  Phase II drug metabolizing enzymes play an important role in biotransformation of endogenous compounds and xenobiotics to more easily excretable forms as well as in the metabolic inactivation of pharmacologically active compounds. Reduced metabolising capacity of Phase II enzymes can lead to toxic effects of clinically used drugs. Gene polymorphism/ lack of these enzymes may often play a role in several forms of cancer.
authors.affiliation: Department of Medical Chemistry and Biochemistry, Palacky University, Olomouc, Czech Republic. jancovapetra@seznam.cz
authors.forename: Petra
authors.initials: P
authors.lastname: Jancova
authors.forename: Pavel
authors.initials: P
authors.lastname: Anzenbacher
authors.forename: Eva
authors.initials: E
authors.lastname: Anzenbacherova
mesh_terms: D000818:Animals; D001711:Biotransformation; D006801:Humans; D050217:Metabolic Detoxication, Phase II; D011110:Polymorphism, Genetic; D014166:Transferases / Q000235:genetics / Q000378:metabolism*; D015262:Xenobiotics / Q000493:pharmacokinetics*
chemical_list: D015262:Xenobiotics; D014166:Transferases