title: Design, synthesis, and antiviral evaluation of 2-deoxy-D-ribosides of substituted benzimidazoles as potential agents for human cytomegalovirus infections.
abstract: Stereoselective glycosylation of 2,5,6-trichlorobenzimidazole (1b), 2-bromo-5,6-dichlorobenzimidazole (1c), 5,6-dichlorobenzimidazole (1d), 5,6-dichlorobenzimidazole-2-thione (1e), 5,6-dichloro-2-(methylthio)benzimidazole (1f), 2-(benzylthio)-5,6-dichlorobenzimidazole (1g), and 2-chloro-5,6-dimethylbenzimidazole (1h) with 2-deoxy-3,5-di-O-p-toluoyl-alpha-D-erythro-pentofuranosyl chloride was achieved to give the desired beta nucleosides 2b-h. Subsequent deprotection afforded the corresponding free beta-D-2-deoxyribosides 3b-h. The 2-methoxy derivative 3i was synthesized by the treatment of 2b with methanolic sodium methoxide. Displacement of the 2-chloro group of 2b with lithium azide followed by a removal of the protective groups gave the 2-azido-5,6-dichlorobenzimidazole derivative (5). The 2-amino derivative (6) was obtained by hydrogenolysis of 5 over Raney nickel. 5,6-Dichloro-2-isopropylamino-1-(2-deoxy-beta-D-erythro- pentofuranosyl)benzimidazole (10) was prepared using 2'-deoxyuridine (7), N-deoxyribofuranosyl transferase and 1d followed by functionalization of the C2 position. Antiviral evaluation of target compounds established that compounds 3b and 3c were active against human cytomegalovirus (HCMV) at non-cytotoxic concentrations. The activity of these 2-deoxy ribosides, however, was less than the activity of the parent riboside, 2,5,6-trichloro-1-beta-D-ribofuranosylbenzimidazole (TCRB). Compared to TCRB, 3b and 3c were somewhat more cytotoxic and active against herpes simplex virus type 1. Compounds 3d-i with other substituents in the 2-position were inactive against both viruses and non-cytotoxic. In contrast, compounds with amine substituents in the 2-position (5, 6, 10) were active against HCMV albeit less so than TCRB. These results establish that 2-deoxy-D-ribosyl benzimidazoles are less active against the DNA virus HCMV than are the corresponding D-ribosides.
authors.affiliation: Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor 48109-1065, USA.
authors.forename: R
authors.initials: R
authors.lastname: Zou
authors.forename: E
authors.initials: E
authors.lastname: Kawashima
authors.forename: G A
authors.initials: GA
authors.lastname: Freeman
authors.forename: G W
authors.initials: GW
authors.lastname: Koszalka
authors.forename: J C
authors.initials: JC
authors.lastname: Drach
authors.forename: L B
authors.initials: LB
authors.lastname: Townsend
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D001562:Benzimidazoles / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D003587:Cytomegalovirus / Q000187:drug effects* / Q000254:growth & development; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D018139:Simplexvirus / Q000187:drug effects*; D013329:Structure-Activity Relationship; D010948:Viral Plaque Assay
chemical_list: D000998:Antiviral Agents; D001562:Benzimidazoles; D009705:Nucleosides