RESUMO
The synthesis of new 2,6-disubstituted purine 2',3'-dideoxy-2',3'-difluoro-D-arabino nucleosides is reported. Their ability to block HIV and HCV replication along with their cytotoxicity toward Huh-7 cells, human lymphocyte, CEM and Vero cells was also assessed. Among them, ß-2,6-diaminopurine nucleoside 25 and guanosine derivative 27 demonstrate potent anti-HIV-1 activity (EC50 = 0.56 and 0.65 µM; EC90 = 4.2 and 3.1 µM) while displaying only moderate cytotoxicity in primary human lymphocytes.
RESUMO
The synthesis of 9-(ß-d-1,3-dioxolan-4-yl)2,6-diaminopurine nucleoside phosphoramidate prodrugs as well as various 2-amino-6-carbamoylpurine dioxolane derivatives and their phosphoramidates prodrugs is reported. Their ability to block HIV and HBV replication along with their cytotoxicity toward HepG2, human lymphocyte, CEM and Vero cells was also assessed.
Assuntos
Adenosina/análogos & derivados , Amidas/farmacologia , Antivirais/farmacologia , Dioxolanos/farmacologia , HIV-1/efeitos dos fármacos , Vírus da Hepatite B/efeitos dos fármacos , Nucleosídeos/farmacologia , Ácidos Fosfóricos/farmacologia , Pró-Fármacos/farmacologia , Adenosina/síntese química , Adenosina/química , Adenosina/farmacologia , Amidas/síntese química , Amidas/química , Antivirais/síntese química , Antivirais/química , Dioxolanos/síntese química , Dioxolanos/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Nucleosídeos/síntese química , Nucleosídeos/química , Ácidos Fosfóricos/síntese química , Ácidos Fosfóricos/química , Pró-Fármacos/síntese química , Pró-Fármacos/química , Relação Estrutura-AtividadeRESUMO
Understanding the cellular pharmacology of antiretroviral agents in macrophages and subsequent correlation with antiviral potency provides a sentinel foundation for definition of the dynamics between antiretroviral agents and viral reservoirs across multiple cell types, with the goal of eradication of HIV-1 from these cells. Various clinically relevant nucleoside antiviral agents, and the integrase inhibitor raltegravir, were selected for this study. The intracellular concentrations of the active metabolites of the nucleoside analogs were found to be 5- to 140-fold lower in macrophages than in lymphocytes, and their antiviral potency was significantly lower in macrophages constitutively activated with macrophage colony-stimulating factor (M-CSF) during acute infection than in resting macrophages (EC(50), 0.4 to 9.42 µM versus 0.03 to 0.4 µM, respectively). Although tenofovir-treated cells displayed significantly lower intracellular drug levels than cells treated with its prodrug, tenofovir disoproxil fumarate, the levels of tenofovir-diphosphate for tenofovir-treated cells were similar in lymphocytes and macrophages. Raltegravir also displayed significantly lower intracellular concentrations in macrophages than in lymphocytes, independent of the activation state, but had similar potencies in resting and activated macrophages. These data underscore the importance of delivering adequate levels of drug to macrophages to reduce and eradicate HIV-1 infection.
Assuntos
Adenina/análogos & derivados , Adenina/farmacologia , Fármacos Anti-HIV/farmacologia , HIV-1/efeitos dos fármacos , Linfócitos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Organofosfonatos/farmacologia , Pirrolidinonas/farmacologia , Transporte Biológico , Inibidores de Integrase de HIV/farmacologia , HIV-1/enzimologia , HIV-1/crescimento & desenvolvimento , Humanos , Linfócitos/virologia , Ativação de Macrófagos/efeitos dos fármacos , Fator Estimulador de Colônias de Macrófagos/farmacologia , Macrófagos/virologia , Especificidade de Órgãos , Cultura Primária de Células , Raltegravir Potássico , Inibidores da Transcriptase Reversa/farmacologia , TenofovirRESUMO
The synthesis of new ribo and 2'-ß-C-methyl ribo Janus type nucleosides J-AA, J-AG and J-AU is reported along with their ability to block HCV and HIV replication. Their toxicity was also assessed in Huh7, human lymphocytes, CEM and Vero cells.
Assuntos
Inibidores Enzimáticos/síntese química , Hepacivirus/enzimologia , Nucleosídeos/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Linhagem Celular , Chlorocebus aethiops , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Nucleosídeos/síntese química , Nucleosídeos/farmacologia , Relação Estrutura-Atividade , Células Vero , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
A series of 2',3'-dideoxy-2',2'-difluoro-4'-azanucleosides of both pyrimidine and purine nucleobases were synthesized in an efficient manner starting from commercially available L-pyroglutamic acid via glycosylation of difluorinated pyrrolidine derivative 15. Several 4'-azanucleosides were prepared as a separable mixture of α- and ß-anomers. The 6-chloropurine analogue was obtained as a mixture of N(7) and N(9) regioisomers and their structures were identified based on NOESY and HMBC spectral data. Among the 4'-azanucleosides tested as HIV-1 inhibitors in primary human lymphocytes, four compounds showed modest activity and the 5-fluorouracil analogue (18d) was found to be the most active compound (EC(50)=36.9µM) in this series. None of the compounds synthesized in this study demonstrated anti-HCV activity.
Assuntos
Antivirais/química , Antivirais/farmacologia , HIV-1/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Nucleosídeos/química , Nucleosídeos/farmacologia , Antivirais/síntese química , Antivirais/toxicidade , Compostos Aza/síntese química , Compostos Aza/química , Compostos Aza/farmacologia , Compostos Aza/toxicidade , Infecções por HIV/tratamento farmacológico , Halogenação , Hepatite C/tratamento farmacológico , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/virologia , Nucleosídeos/síntese química , Nucleosídeos/toxicidadeRESUMO
BACKGROUND: Use of dietary supplements is common among people living with HIV/AIDS. Because dietary supplements are used in the context of other health behaviors, they may have direct and indirect health benefits. However, supplements may also be associated with vulnerability to medical misinformation and unfounded health claims. We examined use of dietary supplements among people living with HIV/AIDS (PLWH) and the association between use of dietary supplements and believing medical misinformation. METHODS: A convenience sample of 268 men and 76 women living with HIV was recruited from AIDS services and clinics in Atlanta, GA. Participants completed measures of demographic and health characteristics, dietary supplement use, beliefs about dietary supplements, internet use, and an internet evaluation task designed to assess vulnerability to medical misinformation. RESULTS: One out of four PLWH currently used at least one dietary supplement product excluding vitamins. Dietary supplement use was associated with higher education and greater use of the internet for health-related information. Dietary supplement users also endorsed greater believability and trust in unfounded claims for HIV cures. CONCLUSIONS: Dietary supplement use is common among PLWH and is associated with a broad array of health information seeking behaviors. Interventions are needed to reduce the vulnerability of PLWH, particularly dietary supplement users, to medical misinformation propagated on the internet.
RESUMO
Resistance to human immunodeficiency virus type 1 (HIV-1) represents a significant problem in the design of novel therapeutics and the management of treatment regimens in infected persons. Resistance profiles can be elucidated by defining modifications to the viral genome conferred upon exposure to novel nucleoside reverse transcriptase (RT) inhibitors (NRTI). In vitro testing of HIV-1LAI-infected primary human lymphocytes treated with ß-D-2',3'-dideoxy-2',3'-didehydro-5-fluorocytidine (DFC; Dexelvucitabine; Reverset) produced a novel deletion of AGT at codon 68 (S68Δ) alone and in combination with K65R that differentially affects drug response. Dual-approach clone techniques utilizing TOPO cloning and pyrosequencing confirmed the novel S68Δ in the HIV-1 genome. The S68Δ HIV-1 RT was phenotyped against various antiviral agents in a heteropolymeric DNA polymerase assay and in human lymphocytes. Drug susceptibility results indicate that the S68Δ displayed a 10- to 30-fold increase in resistance to DFC, lamivudine, emtricitabine, tenofovir, abacavir, and amdoxovir and modest resistance to stavudine, ß-d-2',3'-oxa-5-fluorocytidine, or 9-(ß-D-1,3-dioxolan-4-yl)guanine and remained susceptible to 3'-azido-3'-deoxythymidine, 2',3'-dideoxyinosine (ddI), 1-(ß-D-dioxolane)thymine (DOT) and lopinavir. Modeling revealed a central role for S68 in affecting conformation of the ß3-ß4 finger region and provides a rational for the selective resistance. These data indicate that the novel S68Δ is a previously unrecognized deletion that may represent an important factor in NRTI multidrug resistance treatment strategies.
Assuntos
Transcriptase Reversa do HIV/genética , HIV-1/efeitos dos fármacos , HIV-1/enzimologia , Inibidores da Transcriptase Reversa/farmacologia , Células Cultivadas , Farmacorresistência Viral/genética , Transcriptase Reversa do HIV/química , Transcriptase Reversa do HIV/metabolismo , HIV-1/genética , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Ligação Proteica , Estrutura Secundária de ProteínaRESUMO
Thirty novel α- and ß-d-2'-deoxy-2'-fluoro-2'-C-methyl-7-deazapurine nucleoside analogs were synthesized and evaluated for in vitro antiviral activity. Several α- and ß-7-deazapurine nucleoside analogs exhibited modest anti-HCV activity and cytotoxicity. Four synthesized 7-deazapurine nucleoside phosphoramidate prodrugs (18-21) showed no anti-HCV activity, whereas the nucleoside triphosphates (22-24) demonstrated potent inhibitory effects against both wild-type and S282T mutant HCV polymerases. Cellular pharmacology studies in Huh-7 cells revealed that the 5'-triphosphates were not formed at significant levels from either the nucleoside or the phosphoramidate prodrugs, indicating that insufficient phosphorylation was responsible for the lack of anti-HCV activity. Evaluation of anti-HIV-1 activity revealed that an unusual α-form of 7-carbomethoxyvinyl substituted nucleoside (10) had good anti-HIV-1 activity (EC(50)=0.71±0.25 µM; EC(90)=9.5±3.3 µM) with no observed cytotoxicity up to 100 µM in four different cell lines.
Assuntos
Antivirais , Hepacivirus/efeitos dos fármacos , Nucleosídeos , Pró-Fármacos , Amidas/síntese química , Amidas/farmacologia , Antivirais/síntese química , Antivirais/farmacologia , Linhagem Celular , Flúor/química , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Nucleosídeos/síntese química , Nucleosídeos/farmacologia , Ácidos Fosfóricos/síntese química , Ácidos Fosfóricos/farmacologia , Pró-Fármacos/síntese química , Pró-Fármacos/farmacologia , Purinas/síntese química , Purinas/química , Purinas/farmacologia , Replicação Viral/efeitos dos fármacosRESUMO
BACKGROUND: Human HBV and HIV integrate their retro-transcribed DNA proviruses into the human host genome. Existing antiretroviral drug regimens fail to directly target these intrachromosomal xenogenomes, leading to persistence of viral genetic information. Retinazone (RTZ) constitutes a novel vitamin A-derived (retinoid) thiosemicarbazone derivative with broad-spectrum antiviral activity versus HIV, HCV, varicella-zoster virus and cytomegalovirus. METHODS: The in vitro inhibitory action of RTZ on HIV-1 strain LAI, human HBV strain ayw, HCV-1b strain Con1, enhanced green fluorescent protein-expressing Ebola virus Zaire 1976 strain Mayinga, wild-type Ebola virus Zaire 1976 strain Mayinga, human herpesvirus 6B and Kaposi's sarcoma-associated herpesvirus replication was investigated. The binding of RTZ to human glucocorticoid receptor was determined. RESULTS: RTZ inhibits blood-borne human HBV multiplication in vitro by covalent inactivation of intragenic and intraexonic viral glucocorticoid response elements, and, in close analogy, RTZ suppresses HIV-1 multiplication in vitro. RTZ disrupts the multiplication of blood-borne human HCV and Ebola Zaire virus at nanomolar concentrations in vitro. RTZ has the capacity to bind to human glucocorticoid receptor, to selectively and covalently bind to intraexonic viral glucocorticoid response elements, and thereby to inactivate human genome-integrated proviral DNA of human HBV and HIV. CONCLUSIONS: RTZ represents the first reported antiviral agent capable of eradicating HIV and HBV proviruses from their human host. Furthermore, RTZ represents a potent and efficacious small-molecule in vitro inhibitor of Ebola virus Zaire 1976 strain Mayinga replication.
Assuntos
Antivirais/farmacologia , Ebolavirus/efeitos dos fármacos , HIV-1/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Vírus da Hepatite B/efeitos dos fármacos , Tiossemicarbazonas/farmacologia , Vitamina A/análogos & derivados , Antivirais/química , Ebolavirus/classificação , Humanos , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Tiossemicarbazonas/química , Vitamina A/química , Vitamina A/farmacologiaRESUMO
BACKGROUND: Limited health literacy is a known barrier to medication adherence among people living with HIV. Adherence improvement interventions are urgently needed for this vulnerable population. PURPOSE: This study tested the efficacy of a pictograph-guided adherence skills-building counseling intervention for limited literacy adults living with HIV. METHODS: Men and women living with HIV and receiving antiretroviral therapy (N = 446) who scored <90% correct on a test of functional health literacy were partitioned into marginal and lower literacy groups and randomly allocated to 1 of 3 adherence-counseling conditions: (1) pictograph-guided adherence counseling, (2) standard adherence counseling, or (3) general health improvement counseling. Participants were followed for 9 months postintervention with unannounced pill count adherence and blood plasma viral load as primary end points. RESULTS: Preliminary analyses demonstrated the integrity of the trial and >90% of participants were retained. Generalized estimating equations showed significant interactions between counseling conditions and levels of participant health literacy across outcomes. Participants with marginal health literacy in the pictograph-guided and standard-counseling conditions demonstrated greater adherence and undetectable HIV viral loads compared with general health counseling. In contrast and contrary to hypotheses, participants with lower health literacy skills in the general health improvement counseling demonstrated greater adherence compared with the 2 adherence counseling conditions. CONCLUSIONS: Patients with marginal literacy skills benefit from adherence counseling regardless of pictographic tailoring, and patients with lower literacy skills may require more intensive or provider-directed interventions.
Assuntos
Aconselhamento , Infecções por HIV/tratamento farmacológico , Letramento em Saúde , Adesão à Medicação , Adulto , Terapia Antirretroviral de Alta Atividade , Feminino , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Resultado do TratamentoRESUMO
BACKGROUND: Amantadine constitutes an interesting, diamond crystal lattice-shaped, antivirally active amine with an inhibitory effect on influenza A viruses causing common 'flu' in humans. Unfortunately, amantadine forfeited most of its therapeutic potential because of resistance development in recent influenza A virus isolates. The antiviral efficacy of amantadine congeners can be chemically modified, resulting in re-constitution, improvement and/or extension of antiviral activities mediated by amino-adamantyls. METHODS: Newly synthesized compounds were evaluated towards HIV type-1 (HIV-1) replication in primary human lymphocytes. One N-phenacyl amantadine derivative was investigated for inhibiting the in vitro replication of respiratory viruses (influenza A viruses, influenza B virus, human parainfluenza virus type 3 and severe acute respiratory syndrome coronavirus). RESULTS: Two ketone-stabilized 1-adamantyl singlet nitrenes were discovered serendipitously. To our best knowledge these are the first persistently stable nitrenes to be reported. Their structure was proved by determining the X-ray single crystal structure of one hydrolytic elaboration product. This salt adduct revealed an incommensurately modulated crystal structure, which was solved by extensive computational refinement. We could show that ketone-stabilized 1-adamantyl singlet nitrenes are versatile synthons for the synthesis of antiviral drug candidates. An amantadine-folate conjugate was inhibitory on HIV-1 replication in primary human lymphocytes, and one N-phenacyl amantadine derivative was inhibitory towards low pathogenic avian influenza A virus (H5N1) replication in vitro. CONCLUSIONS: These results indicate that the aromatic-aliphatic ketone-stabilized 1-adamantyl singlet nitrenes, beyond being of fundamental interest in organic chemistry, represent versatile synthons for the synthesis of new amantadine-related potentially antiviral drugs.
Assuntos
Amantadina/farmacologia , Antivirais/farmacologia , HIV-1/efeitos dos fármacos , Iminas/farmacologia , Vírus da Influenza A/efeitos dos fármacos , Vírus da Influenza B/efeitos dos fármacos , Vírus da Parainfluenza 3 Humana/efeitos dos fármacos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacos , Amantadina/análogos & derivados , Antivirais/química , Células Cultivadas , Cristalografia por Raios X , Humanos , Iminas/química , Influenza Humana/tratamento farmacológico , Modelos Moleculares , Infecções por Respirovirus/tratamento farmacológico , Síndrome Respiratória Aguda Grave/tratamento farmacológicoRESUMO
9-(2',3'-Dideoxy-2',3'-difluoro-beta-D-arabinofuranosyl)adenine (20), 2-chloro-9-(2',3'-dideoxy-2,3-difluoro-beta-D-arabinofuranosyl)adenine (22), as well as their respective alpha-anomers 21 and 23, were synthesized by the nucleobase anion glycosylation of intermediate 5-O-benzoyl-2,3-dideoxy-2,3-difluoro-alpha-D-arabinofuranosyl bromide (13) starting from methyl 5-O-benzyl-3-deoxy-3-fluoro-alpha-D-ribofuranoside (3) and methyl 5-O-benzoyl-alpha-D-xylofuranoside (10). These compounds were evaluated as potential inhibitors of HIV-1 and hepatitis C virus in human PBM and Huh-7 Replicon cells, respectively. The adenosine analog 20 demonstrated potent activity against HIV-1 in primary human lymphocytes with no apparent cytotoxicity. Conformation of pentofuranose ring of nucleoside 20 in solution was studied by PSEUROT calculations.
Assuntos
Antivirais/química , Antivirais/farmacologia , Compostos de Flúor/química , HIV-1/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Nucleosídeos de Purina/química , Nucleosídeos de Purina/farmacologia , Antivirais/síntese química , Técnicas de Cultura de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Hepatite C/tratamento farmacológico , Humanos , Linfócitos/efeitos dos fármacos , Conformação Molecular , Nucleosídeos de Purina/síntese químicaRESUMO
Nucleoside reverse transcriptase inhibitors (NRTIs), such as zidovudine (AZT) and stavudine (d4T), cause toxicities to numerous tissues, including the liver and vasculature. While much is known about hepatic NRTI toxicity, the mechanism of toxicity in endothelial cells is incompletely understood. Human aortic endothelial and HepG2 liver cells were exposed to 1 muM AZT or d4T for up to 5 weeks. Markers of oxidative stress, mitochondrial function, NRTI phosphorylation, mitochondrial DNA (mtDNA) levels, and cytotoxicity were monitored over time. In endothelial cells, AZT significantly oxidized glutathione redox potential, increased total cellular and mitochondrial-specific superoxide, decreased mitochondrial membrane potential, increased lactate release, and caused cell death from weeks 3 through 5. Toxicity occurred in the absence of di- and tri-phosphorylated AZT and mtDNA depletion. These data show that oxidative stress and mitochondrial dysfunction in endothelial cells occur with a physiologically relevant concentration of AZT, and require long-term exposure to develop. In contrast, d4T did not induce endothelial oxidative stress, mitochondrial dysfunction, or cytotoxicity despite the presence of d4T-triphosphate. Both drugs depleted mtDNA in HepG2 cells without causing cell death. Endothelial cells are more susceptible to AZT-induced toxicity than HepG2 cells, and AZT caused greater endothelial dysfunction than d4T because of its pro-oxidative effects.