title: N-[2-(1-cyclohexenyl)ethyl]-N'-[2-(5-bromopyridyl)]-thiourea and N'-[2-(1-cyclohexenyl)ethyl]-N'-[2-(5-chloropyridyl)]-thiourea as potent inhibitors of multidrug-resistant human immunodeficiency virus-1.
abstract: We have replaced the pyridyl ring of trovirdine with an alicyclic cyclohexenyl, adamantyl or cis-myrtanyl ring. Only the cyclohexenyl-containing thiourea compound N-[2-(1-cyclohexenyl)ethyl]-N'-[2-(5-bromopyridyl)]- thiourea (HI-346) (as well as its chlorine-substituted derivative N-[2-(1-cyclohexenyl)ethyl]-N'-[2-(5-chloropyridyl)]- thiourea/HI-445) showed RT inhibitory activity. HI-346 and HI-445 effectively inhibited recombinant RT with better IC50 values than other anti-HIV agents tested. The ranking order of efficacy in cell-free RT inhibition assays was: HI-346 (IC50 = 0.4 microM) > HI-445 (IC50 = 0.5 microM) > trovirdine (IC50 = 0.8 microM) > MKC-442 (IC5 = 0.8 microM) = delavirdine (IC50 = 1.5 microM) > nevirapine (IC50 = 23 microM). In accord with this data, both compounds inhibited the replication of the drug-sensitive HIV-1 strain HTLV(IIIB) with better IC50 values than other anti-HIV agents tested. The ranking order of efficacy in cellular HIV-1 inhibition assays was: HI-445 = HI-346 (IC50 = 3 nM) > MKC-442 (IC50 = 4 nM) = AZT (IC50 = 4 nM) > trovirdine (IC50 = 7 nM) > delavirdine (IC50 = 9 nM) > nevirapine (IC50 = 34 nM). Surprisingly, the lead compounds HI-346 and HI-445 were 3-times more effective against the multidrug resistant HIV-1 strain RT-MDR with a V106A mutation (as well as additional mutations involving the RT residues 74V,41L, and 215Y) than they were against HTLV(IIIB) with wild-type RT. HI-346 and HI-445 were 20-times more potent than trovirdine, 200-times more potent than AZT, 300-times more potent than MKC-442, 400-times more potent than delavirdine, and 5000-times more potent than nevirapine against the multidrug resistant HIV-1 strain RT-MDR. HI-445 was also tested against the RT Y181C mutant A17 strain of HIV-1 and found to be >7-fold more effective than trovirdine and >1,400-fold more effective than nevirapine or delavirdine. Similarly, both HI-346 and HI-445 were more effective than trovirdine, nevirapine, and delavirdine against the problematic NNI-resistant HIV-1 strain A17-variant with both Y181C and K103N mutations in RT, although their activity was markedly reduced against this strain. Neither compound exhibited significant cytotoxicity at effective concentrations (CC50 >100 microM). These findings establish the lead compounds HI-346 and HI-445 as potent inhibitors of drug-sensitive as well as multidrug-resistant stains of HIV-1.
authors.affiliation: Drug Discovery Program, Department of Chemistry, Hughes Institute, St. Paul, MN 55113, USA.
authors.forename: F M
authors.initials: FM
authors.lastname: Uckun
authors.forename: C
authors.initials: C
authors.lastname: Mao
authors.forename: S
authors.initials: S
authors.lastname: Pendergrass
authors.forename: D
authors.initials: D
authors.lastname: Maher
authors.forename: D
authors.initials: D
authors.lastname: Zhu
authors.forename: L
authors.initials: L
authors.lastname: Tuel-Ahlgren
authors.forename: T K
authors.initials: TK
authors.lastname: Venkatachalam
mesh_terms: D000631:Aminopyridines / Q000737:chemistry / Q000494:pharmacology*; D019380:Anti-HIV Agents / Q000737:chemistry / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D018432:Drug Resistance, Multiple; D054303:HIV Reverse Transcriptase / Q000737:chemistry / Q000187:drug effects; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D008958:Models, Molecular; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D013890:Thiourea / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000631:Aminopyridines; D019380:Anti-HIV Agents; C122094:N-(2-(1-cyclohexenyl)ethyl)-N'-(2-(5-bromopyridyl))thiourea; C122095:N-(2-(1-cyclohexenyl)ethyl)-N'-(2-(5-chloropyridyl))thiourea; D018894:Reverse Transcriptase Inhibitors; D054303:HIV Reverse Transcriptase; D013890:Thiourea