title: Recent advances in 4'-thionucleosides as potential antiviral and antitumor agents.
abstract: The classical 4'-oxonucleoside analogs exhibit interesting biological activities such as antibiotic, antiviral and antitumor, which are believed to be the result of inhibition of the viral or cellular DNA or RNA polymerase after being converted to their corresponding 5'-triphosphates. However, the activity of 4'-oxonucleosides were limited by their susceptibility to degradation by nucleoside phosphorylases or acid hydrolysis. This aspect called for the chemical modification of the carbohydrate portion. This compulsion led to two kinds of strategies; (1) replacement of the 4'-oxygen by the methylene group - carbocyclic nucleosides; (2) replacement of the 4' oxygen by sulphur-4'-thionucleosides. This group has also conferred the resistance to the nucleoside cleavage. Although, there were some pioneering work on 4'-thionucleosides in 1960s and 1970s, the interest in this group of compounds was rekindled by the antiviral activities of 2'-deoxy-4'-thionucleosides reported independently by Secrist et al. and Walker et al. Subsequent contributions by the other authors, enhanced its standing as an important class of antiviral agents. Following is a reasonably exhaustive account of this class of compounds reported after 1990.
authors.affiliation: Laboratory of Medicinal Chemistry, College of Pharmacy, Ewha Womans University, Seoul, 120-750, Korea.
authors.forename: Prashantha
authors.initials: P
authors.lastname: Gunaga
authors.forename: Hyung Ryong
authors.initials: HR
authors.lastname: Moon
authors.forename: Won Jun
authors.initials: WJ
authors.lastname: Choi
authors.forename: Dae Hong
authors.initials: DH
authors.lastname: Shin
authors.forename: Jae Gyu
authors.initials: JG
authors.lastname: Park
authors.forename: Lak Shin
authors.initials: LS
authors.lastname: Jeong
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000627:therapeutic use; D000998:Antiviral Agents / Q000737:chemistry* / Q000627:therapeutic use; D006801:Humans; D013872:Thionucleosides / Q000737:chemistry* / Q000627:therapeutic use
chemical_list: D000970:Antineoplastic Agents; D000998:Antiviral Agents; D013872:Thionucleosides