Antiretroviral and cytotoxic activities of Tityus obscurus synthetic peptide.

New drugs are constantly in demand, and nature's biodiversity is a rich source of new compounds for therapeutic applications. Synthetic peptides based on the transcriptome analysis of scorpion venoms of Tityus obscurus, Opisthacanthus cayaporum, and Hadrurus gertschi were assayed for their cytotoxic and antiretroviral activity. The Tityus obscurus scorpion-derived synthetic peptide (FFGTLFKLGSKLIPGVMKLFSKKKER), in concentrations ranging from 6.24 to 0.39 µM, proved to be the most active one against simian immunodeficiency virus (SIV) replication in the HUT-78 cell line and in primary human leukocytes, with the lowest toxicity for these cells. The immune cellular response evaluated in primary human leukocytes treated with the most promising peptide and challenged with SIV infection exhibited production of cytokines such as interleukin (IL)-4, IL-6, IL-8, IL-10, and interferon-γ, which could be involved in cell defense mechanisms to overcome viral infection through proinflammatory and anti-inflammatory pathways, similar to those evoked for triggering the mechanisms exerted by antiviral restriction factors.

Synthesis of a long acting nanoformulated emtricitabine ProTide.

While antiretroviral therapy (ART) has revolutionized treatment and prevention of human immunodeficiency virus type one (HIV-1) infection, regimen adherence, viral mutations, drug toxicities and access stigma and fatigue are treatment limitations. These have led to new opportunities for the development of long acting (LA) ART including implantable devices and chemical drug modifications. Herein, medicinal and formulation chemistry were used to develop LA prodrug nanoformulations of emtricitabine (FTC). A potent lipophilic FTC phosphoramidate prodrug (M2FTC) was synthesized then encapsulated into a poloxamer surfactant (NM2FTC). These modifications extended the biology, apparent drug half-life and antiretroviral activities of the formulations. NM2FTC demonstrated a >30-fold increase in macrophage and CD4+ T cell drug uptake with efficient conversion to triphosphates (FTC-TP). Intracellular FTC-TP protected macrophages against an HIV-1 challenge for 30 days. A single intramuscular injection of NM2FTC, at 45 mg/kg native drug equivalents, into Sprague Dawley rats resulted in sustained prodrug levels in blood, liver, spleen and lymph nodes and FTC-TP in lymph node and spleen cells at one month. In contrast, native FTC-TPs was present for one day. These results are an advance in the transformation of FTC into a LA agent.

Pyrrolopyrimidines: An update on recent advancements in their medicinal attributes.

Fused heterocycles are reported to demonstrate variety of biological activities such as anticancer, antibacterial, antifungal and anti-inflammatory, and are thus exhaustively utilized in the field of medicinal chemistry. Pyrrolopyrimidines is one of the major classes of fused heterocycles which are extensively reported throughout the literature. Several reports suggest that pyrrolopyrimidine as fused scaffold possess more diverse and potent pharmacological profile than individual pyrrole and pyrimidine nucleus. Different pathological targets require different structural attributes reflected via varied substitutions, thus in recent years, researchers have employed various synthetic strategies to achieve desired substitutions on the pyrrolopyrimidine nucleus. In this review, authors highlight the recent advancement in this area, special focus was laid on the pharmacological profile and structure-activity relationship studies (SAR) of various synthesized pyrrolopyrimidine derivatives.

Recent updates for designing CCR5 antagonists as anti-retroviral agents.

The healthcare system faces various challenges in human immunodeficiency virus (HIV) therapy due to resistance to Anti-Retroviral Therapy (ART) as a consequence of the evolutionary process. Despite the success of antiretroviral drugs like Zidovudine, Zalcitabine, Raltegravir WHO ranks HIV as one of the deadliest diseases with a mortality of one million lives in 2016. Thus, there emerges an urgency of developing a novel anti-retroviral agent that combat resistant HIV strains. The clinical development of ART from a single drug regimen to current triple drug combination is very slow. The progression in the structural biology of the viral envelope prompted the discovery of novel targets, which can be demonstrated a proficient approach for drug design of anti-retroviral agents. The current review enlightens the recent updates in the structural biology of the viral envelope and focuses on CCR5 as a validated target as well as ways to overcome CCR5 resistance. The article also throws light on the SAR studies and most prevalent mutations in the receptor for designing CCR5 antagonists that can combat HIV-1 infection. To conclude, the paper lists diversified scaffolds that are in pipeline by various pharmaceutical companies that could provide an aid for developing novel CCR5 antagonists.

Enantioselective and Regiodivergent Addition of Purines to Terminal Allenes: Synthesis of Abacavir.

The rhodium-catalyzed atom-economic asymmetric N-selective intermolecular addition of purine derivatives to terminal allenes is reported. Branched allylic purines were obtained in high yields, regioselectivity and outstanding enantioselectivity utilizing a Rh/Josiphos catalyst. Conversely, linear selective allylation of purines could be realized in good to excellent regio- and E/Z-selectivity with a Pd/dppf catalyst system. Furthermore, the new methodology was applied to a straightforward asymmetric synthesis of carbocyclic nucleoside abacavir.

Continuous flow synthesis of α-halo ketones: essential building blocks of antiretroviral agents.

The development of a continuous flow process for the multistep synthesis of α-halo ketones starting from N-protected amino acids is described. The obtained α-halo ketones are chiral building blocks for the synthesis of HIV protease inhibitors, such as atazanavir and darunavir. The synthesis starts with the formation of a mixed anhydride in a first tubular reactor. The anhydride is subsequently combined with anhydrous diazomethane in a tube-in-tube reactor. The tube-in-tube reactor consists of an inner tube, made from a gas-permeable, hydrophobic material, enclosed in a thick-walled, impermeable outer tube. Diazomethane is generated in the inner tube in an aqueous medium, and anhydrous diazomethane subsequently diffuses through the permeable membrane into the outer chamber. The α-diazo ketone is produced from the mixed anhydride and diazomethane in the outer chamber, and the resulting diazo ketone is finally converted to the halo ketone with anhydrous ethereal hydrogen halide. This method eliminates the need to store, transport, or handle diazomethane and produces α-halo ketone building blocks in a multistep system without racemization in excellent yields. A fully continuous process allowed the synthesis of 1.84 g of α-chloro ketone from the respective N-protected amino acid within ~4.5 h (87% yield).

In vitro inhibition of feline leukaemia virus infection by synthetic peptides derived from the transmembrane domain.

BACKGROUND: The feline leukaemia virus (FeLV) is a gammaretrovirus commonly affecting cats. Infection with this virus often leads to fatal outcomes and, so far, no cure is available for this disease. Synthetic peptides with structures mimicking the transmembrane protein of the viral surface proteins hold the potential to effectively interfere with viral entry by hampering the fusion of viral and host cell membranes and constitute a novel approach for the treatment of infections with retroviruses. We identified and synthetically produced 11 FeLV peptides and evaluated their potential to block FeLV infection in vitro. METHODS: Cell cultures were exposed to FeLV subgroup A prior to the addition of the peptides. The inhibitory effect of the peptides was assessed by measuring FeLV gag protein in the supernatant of peptide versus mock-treated cell cultures using an ELISA. RESULTS: A peptide (EPK364) of 37 amino acids in length, with sequence homology to the HIV fusion inhibitor T-20, significantly suppressed viral replication by 88%, whereas no effects were found for shorter peptides. Two structurally modified variants of EPK364 also inhibited viral replication by up to 58% (EPK397) and 27% (EPK398). CONCLUSIONS: Our data support the identification of synthetic FeLV peptides that have the potential for a curative short-term therapy of viraemic cats. In addition, these peptides might become an important tool in xenotransplantation, where endogenous gammaretroviruses of the donor species might be able to infect the host.

Synthesis and in vitro anti-HIV activity of N-1,3-benzo[d]thiazol-2-yl-2-(2-oxo-2H-chromen-4-yl)acetamide derivatives using MTT method.

A series of novel N-1,3-benzo[d]thiazol-2-yl-2-(2-oxo-2H-chromen-4-yl)acetamide derivatives has been synthesized. All the newly synthesized compounds were evaluated for their anti-HIV activity using MTT method. Most of these compounds showed moderate to potent activity against wild-type HIV-1 with an EC(50) ranging from >7 EC(50) [µg/ml] to <100 EC(50) [µg/ml]. Among them, N-1,3-benzo[d]thiazol-2-yl-2-(2-oxo-2H-chromen-4-yl)acetamide 6v was identified as the most promising compound (EC(50)=<7 µg/ml). Among all the compounds, three compounds 6m, 6v and 6u have been exhibits potent anti-HIV activity against MT-4 cells.

Antiretroviral activity of thiosemicarbazone metal complexes.

Thiosemicarbazones display a wide antimicrobial activity by targeting bacteria, fungi, and viruses. Here, we report our studies on the antiviral activity of two thiosemicarbazone metal complexes, [bis(citronellalthiosemicarbazonato)nickel(II)] and [aqua(pyridoxalthiosemicarbazonato)copper(II)] chloride monohydrate, against the retroviruses HIV-1 and HTLV-1/-2. Both compounds exhibit antiviral properties against HIV but not against HTLVs . In particular, the copper complex shows the most potent anti-HIV activity by acting at the post-entry steps of the viral cycle.

Comprimidos de liberación inmediata de Valsartán y Efavirenz: el papel de la concentración de superdisgregantes / Immediate release tablets of Valsartan and Efavirenz: role of concentration of superdisintegrants

El objetivo de este estudio fue formular comprimidos de rápida disgregación, obtenidos mediante compresión directa,de fármacos con baja solubilidad en agua y diferentes grados de solubilidad, tomando como modelo Valsartány Efavirenz. Se estudió el efecto de diversas concentraciones de diferentes superdisgregantes como crospovidona,croscarmelosa sódica y glicolato sódico de almidón sobre el tiempo de disgregación y la disolución del fármaco invitro. Se observó que el tiempo de disgregación del comprimido con mejor liberación inmediata, de entre todaslas formulaciones probadas, fue de 21,5 ± 1,26 s y 20,16 ± 0,85 s para los comprimidos de Valsartán y Efavirenz,respectivamente que contenían, en ambos casos, un 20% de crospovidona. La liberación del fármaco (tanto en loscomprimidos de Valsartán como Efavirenz) fue más rápida en el caso de las formulaciones con crospovidona encomparación con la otra formulación. El efecto fue más evidente en el caso de Efavirenz, cuya solubilidad en aguaes menor que la de Valsartán. Se observó que era necesario un 20% de crospovidona para obtener una liberacióndel fármaco del 80% en comprimidos de Efavirenz. Los estudios por calorimetría diferencial de barrido no indicaronninguna incompatibilidad fármaco-excipiente. En conclusión, se obtuvieron por compresión directa comprimidosde rápida disgregación de Valsartán y Efavirenz con tiempos de disgregación más cortos y una alta velocidad dedisolución. Además, la crospovidona resultó ser un mejor disgregante tanto para Valsartán como para Efavirenz,de acuerdo con el tiempo de disgregación y los valores T80% obtenidos

The objective of this study was to formulate directly compressible fast disintegrating tablets of poorly water solubledrugs with different extent of drug solubilities, like valsartan and efavirenz, as model drugs. Effect of varying concentrationsof different superdisintegrants such as crospovidone, croscarmellose sodium, and sodium starch glycolate ondisintegration time and in vitro drug dissolution was studied. The disintegration time of the best immediate release tabletformulation among those tested was observed to be 21.5±1.26 sec and 20.16±0.85 sec for valsartan and efavirenz tabletscontaining 20% of Crospovidone, respectively. Drug release (from both valsartan and Efavirenz tablets) was faster fromformulations containing crospovidone compared to the other formulation. The effect was more apparent in Efavirenz,which has lesser aqueous solubility than valsartan. It was observed that 20% crospovidone was required to achieve80% drug release from efavirenz tablets. Differential scanning calorimetric studies did not indicate any drug-excipientincompatibility. In conclusion, directly compressible fast disintegrating tablets of valsartan and efavirenz with shorterdisintegration times and high dissolution rate were obtained and crospovidone seemed to be a better disintegrant forboth valsartan and efavirenz, based on disintegration time and T80% values obtained (AU)

Facilitating compound progression of antiretroviral agents via modeling and simulation.

Pharmacotherapy in human immunodeficiency virus (HIV)-infected patients and the development of safe and effective antiretroviral dosing regimens has been hindered by numerous issues, including the rapid development of viral resistance to drug therapy, the narrow therapeutic window of the drug compounds, and lack of fundamental knowledge concerning the sources of variation in exposure and response to antiretroviral agents. Sources of variation may include factors such as interpatient differences in genetic expression, immunological response, pathogenesis, epidemiologic and socioeconomic factors, and demographics. Modeling and simulation (M&S) techniques have become valuable tools to identify and quantify variability in exposure and response to antiretroviral agents throughout the drug development process. Before actual entry into human safety and pharmacokinetic (PK) trials, in vitro screening and in vivo pharmacology studies conducted to assess compound potency and compatibility with agents included in acceptable antiretroviral therapy (ART) regimens can be characterized via quantitative relationships. In addition, physiochemical data is initially used to screen drug candidates based on favorable PK and biopharmaceutic properties. Compound progression can likewise be supported with M&S exercises to ensure the traceability of key assumptions and decisions. The underlying techniques utilize nonlinear mixed effect modeling, Monte Carlo simulation, Neural networks, several regression-based approaches, and less computationally intensive techniques. The application of such an approach promises to be an essential component in the development of new agents to treat HIV-1 and is being implemented in the context of evaluating Nk1r antagonists as potential candidates to treat NeuroAIDS.

The role of cohort studies in drug development: clinical evidence of antiviral activity of serotonin reuptake inhibitors and HMG-CoA reductase inhibitors in the central nervous system.

BACKGROUND: Effective antiretroviral therapy (ART) has reduced the incidence of HIV-associated neurocognitive impairment (HNCI) but its prevalence remains high. Clinical trials have yet to identify a consistently effective treatment for HNCI, other than ART, but in vitro data support that some drugs approved by the Food and Drug Administration (FDA) for other indications might benefit individuals with HNCI. Some of these drugs, such as serotonin reuptake inhibitors (SRIs) and HMG-CoA reductase inhibitors (statins), may do so by reducing HIV replication in the CNS and are already widely used by HIV-infected individuals. METHODS: Six-hundred fifty-eight HIV-infected participants of the CHARTER cohort had a baseline assessment, which included comprehensive neuropsychological (NP) testing and HIV RNA measurements in plasma and cerebrospinal fluid (CSF). Four-hundred sixty-seven (71%) subjects used ART, 195 (30%) used SRIs, and 63 (10%) used statins. RESULTS: SRI users were less likely to have HIV RNA levels in CSF above 50 copies (c)/mL (29 vs. 37% in non-SRI users, OR 0.69, p = 0.05). This association was most evident for three of the seven SRIs (citalopram, sertraline, and trazodone, or "antiviral" SRIs, combined 25 vs. 38% in non-SRI users, OR 0.56, p = 0.01) and was strongest in those not taking concomitant ART (61 vs. 83%, OR 0.31, p = 0.01). "Antiviral" SRI users also performed better on NP tests (median global deficit score 0.37 vs. 0.47, p = 0.04). Statin users were also less likely to have HIV RNA levels in CSF above 50 c/mL (16 vs. 37%, p < 0.001) but, in contrast to SRIs, the association was strongest in those taking ART (2 vs. 18%, p < 0.001). Statin use was not associated with better NP performance. Multivariate analyses indicated that the use of "antiviral" SRIs-but not statins-was associated with undetectable HIV RNA levels in CSF and better NP performance. CONCLUSIONS: SRIs may reduce HIV replication in CSF and improve NP performance. This was particularly true for three SRIs-supporting differences in antiviral efficacy between drugs-in individuals who were not taking ART. In contrast, statins were not associated with lower HIV replication in CSF in multivariate analyses and were not associated with better NP performance. These analyses support the value of large observational cohort studies in identifying FDA-approved drugs that may be worth further investigation.

Phosphonated carbocyclic 2'-oxa-3'-azanucleosides as new antiretroviral agents.

Phosphonated carbocyclic 2'-oxa-3'-azanucleosides have been synthesized and tested for their antiretroviral activity. The obtained results have shown that some of the compounds were as powerful as azydothymidine in inhibiting the reverse transcriptase activity of the human retrovirus T-cell leukemia/lymphotropic virus type 1 and in protecting human peripheral blood mononuclear cells against human retrovirus T-cell leukemia/lymphotropic virus type 1 transmission in vitro. These data indicate that phosphonated carbocyclic 2'-oxa-3'-azanucleosides possess the necessary requirements to efficiently counteract infections caused by human retroviruses.

Structure-activity relationships in platelet-activating factor. Part 13: synthesis and biological evaluation of piperazine derivatives with dual anti-PAF and anti-HIV-1 or pure antiretroviral activity.

HIV-1 infection of the brain and PAF neurotoxicity are implicated in AIDS dementia complex. We previously reported that a trisubstituted piperazine derivative is able to diminish both HIV-1 replication in monocyte-derived macrophages and PAF-induced platelet aggregation. We report in this work new compounds obtained by modifying its piperazine substituents. The structure-activity relationship study shows that a better dual activity or even pure antiretroviral compounds can be obtained in this series.

Structure-activity relationship studies of a series of antiviral and antibacterial aglycon derivatives of the glycopeptide antibiotics vancomycin, eremomycin, and dechloroeremomycin.

N-(adamantyl-1)methyl, N-(adamantyl-2), and N-(omega-aminodecyl) amides of vancomycin, eremomycin, and dechloroeremomycin aglycons and their des-(N-Me-D-Leu) derivatives were synthesized and their antibacterial and anti-HIV activities were investigated. Carboxamides with an intact peptide core demonstrated activity against glycopeptide-susceptible and -resistant bacteria (1-32 microM). N-(adamantyl-1)methylcarboxamide of eremomycin aglycons had good antiretroviral activity (1.6 microM against HIV-1). Compounds with destroyed peptide core [des-(N-Me-D-Leu)-aglycon amides] were inactive against both glycopeptide-sensitive and -resistant bacteria. (Adamantyl-1)methylamide of des-(N-Me-D-Leu)-eremomycin aglycon had good antiretroviral activity (EC50 of 5.5 microM for HIV-1 and 3.5 microM for HIV-2). (Adamantyl-1)methylamides of eremomycin aglycon and its des-(N-Me-d-Leu)-derivative are the most promising and selective antiretroviral agents. Their ability to induce bacterial resistance to glycopeptide antibiotics during prolonged administration may be expected to be very low or absent. This might make the use of these derivatives feasible in the prolonged therapy or prophylaxis of HIV infections.

Design, synthesis and biological evaluation of heteroaryl diketohexenoic and diketobutanoic acids as HIV-1 integrase inhibitors endowed with antiretroviral activity.

Highly active anti-retroviral therapy (HAART) using reverse transcriptase (RT) and protease (PR) inhibitors and, more recently, inhibitors of the fusion is currently the best clinical approach in combating acquired immunodeficiency syndrome (AIDS), caused by infection from human immunodeficiency virus type 1 (HIV-1). However, this therapy does not completely eradicate the virus, so that resistant strains easily emerge. The above problem calls urgently for research on inhibitors of further viral targets such as integrase (IN), the third enzyme produced by HIV. Recently, our research group was engaged in studies on conformationally restrained cinnamoyl compounds related to curcumin as anti-IN agents. Compounds containing both a 3,4,5-trihydroxyphenyl group and a carboxylic acid function were potent IN inhibitors active against viral replication. More recently, a promising new class of inhibitors synthesized by Merck Company has emerged, which contain aryldiketoacid (ADK) functionality. The ADKs selectively inhibited the stand transfer (ST) step of integration and were proven to be effective IN inhibitors in vivo. Our interest in the field of IN inhibitors led us to design pyrrole and indole derivatives containing both a cinnamoyl moiety and a diketoacid group. A number of the cited derivatives were proven potent IN inhibitors, which selectively inhibited the ST step at submicromolar concentrations and were effective against virus replication in HIV-1 infected cells.

Análisis coste-eficacia de tenofovir versus zidovudina en terapia combinada con efavirenz y lamivudina para el tratamiento de VIH en pacientes no pretratados / Cost-effectiveness analysis of tenofovir versus zidovudine in combination therapy with efavirenz and lamivudine for the treatment of HIV in naive patients

Objetivos: Evaluar los regímenes en pacientes no pretratados de tenofovir + lamivudina + efavirenz versus zidovudina + lamivudina + efavirenz mediante un estudio coste-eficacia. Métodos: Se diseñó un árbol de decisiones. Se estimó la eficaciaa través de ensayos clínicos. Para valorar la medida sobre los resultados de la salud se consideró la carga viral y los CD4. Se consideraron costes asistenciales y de tratamiento, y se realizó un análisis de sensibilidad univariante. Resultados: El régimen con tenofovir tendría un coste anual, en caso de ser efectivo, de 10.116,61 €, mientras que si existefallo terapéutico el coste sería de 12.140,40 €. El régimen que incluye zidovudina tendría un coste anual de 7.470,36 € en caso de ser efectivo, y un coste de 8.964,90 €, en caso de fallo terapéutico.El coste de pasar al régimen que incluye tenofovir supone 14.765,86 € al año por paciente adicional con carga viral indetectable. En 3 años, el coste anual esperado es de 8.765,83 € para el régimen que incluye tenofovir frente a 8.894,36 € del régimen que incluye zidovudina. Conclusión: El régimen que incluye zidovudina es menos costoso a corto plazo que el que incluye tenofovir. Si ampliamos el horizonte del estudio, los dos regímenes se equiparan económicamente

Objectives: To assess tenofovir + lamivudine + efavirenz versus zidovudine + lamivudine + efavirenz in treatment-naive patients using a cost-effectiveness analysis. Methods: A decision tree was designed. Effectiveness was estimated from clinical trials. Viral load and CD4 cells count were chosen as end points for health outcome. Both healthcare and treatment costs were considered, and univariate sensitivity tests were performed. Results: The regimen including tenofovir would have a yearly cost of € 10,116.61 when effective, and of € 12,140.40 in case of therapeutic failure. The regimen including zidovudine would have a yearly cost of € 7,470.36 when effective, and of € 8,964.90 incase of therapeutic failure. The cost of switching to the regimen with tenofovir represents € 14,765.86 per year per additional patient with non-detectable viral load. After 3 years, the expected yearly cost is € 8,765.83 for the regimen including tenofovir versus € 8,894.36 for the regimen including zidovudine. Conclusion: The regimen including zidovudine is less costly in the short run when compared to the regimen including tenofovir. Both regimens become financially similar when extending the study horizon