title: 6-[1-(4-Fluorophenyl)methyl-1H-pyrrol-2-yl)]-2,4-dioxo-5-hexenoic acid ethyl ester a novel diketo acid derivative which selectively inhibits the HIV-1 viral replication in cell culture and the ribonuclease H activity in vitro.
abstract: The human immunodeficiency virus-type 1 (HIV-1) reverse transcriptase (RT) is a multifunctional enzyme which displays DNA polymerase activity, which recognizes RNA and DNA templates, and a degradative ribonuclease H (RNase H) activity. While both RT functions are required for retroviral replication, until now only the polymerase function has been widely explored as drug target. We have identified a novel diketo acid derivative, 6-[1-(4-fluorophenyl)methyl-1H-pyrrol-2-yl)]-2,4-dioxo-5-hexenoic acid ethyl ester (RDS 1643), which inhibits in enzyme assays the HIV-1 RT-associated polymerase-independent RNase H activity but has no effect on the HIV-1 RT-associated RNA-dependent DNA polymerase (RDDP) activity and on the RNase H activities displayed by the Avian Myeloblastosis Virus and E. coli. Time-dependence studies revealed that the compound is active independently on the order of its addition to the reaction mixture, and inhibition kinetics studies demonstrated that RDS 1643 inhibits the RNase H activity noncompetitively, with a K(I) value of 17 microM. When RDS 1643 was combined with non-nucleoside RT inhibitors (NNRTI), such as efavirenz and nevirapine, results indicated that RDS 1643 does not affect the NNRTIs anti-RDDP activity and that, vice versa, the NNRTIs do not alter the RNase H inhibition by RDS 1643. When assayed on the viral replication in cell-based assays, RDS 1643 inhibited the HIV-1(IIIB) strain with an EC(50) of 14 microM. Similar results were obtained against the Y181C and Y181C/K103N HIV-1 NNRTI resistant mutant strains. RDS 1643 may be the first HIV-1 inhibitor selectively targeted to the viral RT-associated RNase-H function.
authors.affiliation: Department of Sciences and Biomedical Technologies, University of Cagliari, Cittadella Universitaria SS554, 09142 Monserrato (Cagliari), Italy. tramon@unica.it
authors.forename: Enzo
authors.initials: E
authors.lastname: Tramontano
authors.forename: Francesca
authors.initials: F
authors.lastname: Esposito
authors.forename: Roberta
authors.initials: R
authors.lastname: Badas
authors.forename: Roberto
authors.initials: R
authors.lastname: Di Santo
authors.forename: Roberta
authors.initials: R
authors.lastname: Costi
authors.forename: Paolo
authors.initials: P
authors.lastname: La Colla
mesh_terms: D019380:Anti-HIV Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D002208:Caproates / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D004952:Esters / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D015497:HIV-1 / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D011758:Pyrroles / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry / Q000494:pharmacology; D016914:Ribonuclease H / Q000037:antagonists & inhibitors; D014779:Virus Replication / Q000187:drug effects
chemical_list: C500206:6-(1-(4-fluorophenyl)methyl-1H-pyrrol-2-yl)-2,4-dioxo-5-hexenoic acid ethyl ester; D019380:Anti-HIV Agents; D002208:Caproates; D004791:Enzyme Inhibitors; D004952:Esters; D011758:Pyrroles; D018894:Reverse Transcriptase Inhibitors; D016914:Ribonuclease H; D008274:Magnesium