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Herein, we report an efficient strategy towards the synthesis of amino acid substituted isoquinoline derivatives via reaction of unprotected amino acid/amino acid ester/amino acid based drugs with 2‐(2‐oxo‐2‐aryl/alkylethyl)benzonitrile under metal‐free conditions. The developed protocol is highly simple and shows functional group tolerance to provide corresponding novel amino acid substituted isoquinolines in aqueous medium. The applicability of the reaction is an easier modification of well‐known drugs and successfully extended to gram‐scale synthesis. [ABSTRACT FROM AUTHOR]

The HIV capsid (CA) protein is a promising target for anti‐AIDS treatment due to its critical involvement in viral replication. Herein, we utilized the well‐documented CA inhibitor PF74 as our lead compound and designed a series of low‐molecular‐weight phenylalanine derivatives. Among them, compound 7t exhibited remarkable antiviral activity with a high selection index (EC50 = 0.040 µM, SI = 2815), surpassing that of PF74 (EC50 = 0.50 µM, SI = 258). Furthermore, when evaluated against the HIV‐2 strain, 7t (EC50 = 0.13 µM) demonstrated approximately 14‐fold higher potency than that of PF74 (EC50 = 1.76 µM). Insights obtained from surface plasmon resonance (SPR) revealed that 7t exhibited stronger target affinity to the CA hexamer and monomer in comparison to PF74. The potential interactions between 7t and the HIV‐1 CA were further elucidated using molecular docking and molecular dynamics simulations, providing a plausible explanation for the enhanced target affinity with 7t over PF74. Moreover, the metabolic stability assay demonstrated that 7t (T1/2 = 77.0 min) significantly outperforms PF74 (T1/2 = 0.7 min) in human liver microsome, exhibiting an improvement factor of 110‐fold. In conclusion, 7t emerges as a promising drug candidate warranting further investigation. [ABSTRACT FROM AUTHOR]

Pharmacophores such as hydroxyethylamine (HEA) and phthalimide (PHT) have been identified as potential synthons for the development of compounds against various parasitic infections. In order to further advance our progress, we conducted an experiment utilising a collection of PHT and HEA derivatives through phenotypic screening against a diverse set of protist parasites. This approach led to the identification of a number of compounds that exhibited significant effects on the survival of Entamoeba histolytica, Trypanosoma brucei, and multiple life-cycle stages of Leishmania spp. The Leishmania hits were pursued due to the pressing necessity to expand our repertoire of reliable, cost-effective, and efficient medications for the treatment of leishmaniases. Antileishmanials must possess the essential capability to efficiently penetrate the host cells and their compartments in the disease context, to effectively eliminate the intracellular parasite. Hence, we performed a study to assess the effectiveness of eradicating L. infantum intracellular amastigotes in a model of macrophage infection. Among eleven L. infantum growth inhibitors with low-micromolar potency, PHT-39, which carries a trifluoromethyl substitution, demonstrated the highest efficacy in the intramacrophage assay, with an EC50 of 1.2 +/- 3.2 μM. Cytotoxicity testing of PHT-39 in HepG2 cells indicated a promising selectivity of over 90-fold. A chemogenomic profiling approach was conducted using an orthology-based method to elucidate the mode of action of PHT-39. This genome-wide RNA interference library of T. brucei identified sensitivity determinants for PHT-39, which included a P-type ATPase that is crucial for the uptake of miltefosine and amphotericin, strongly indicating a shared route for cellular entry. Notwithstanding the favourable properties and demonstrated efficacy in the Plasmodium berghei infection model, PHT-39 was unable to eradicate L. major infection in a murine infection model of cutaneous leishmaniasis. Currently, PHT-39 is undergoing derivatization to optimize its pharmacological characteristics. Author summary: Two novel compound series, based on hydroxyethylamine (HEA) and phthalimide (PHT) pharmacophores, previously led to the discovery of antiplasmodial lead compounds, both with therapeutic efficacy in a murine Plasmodium infection model. Here we employed these compound libraries, supplemented with newly designed HEA derivatives, for phenotypic screening against a wide range of protist parasites associated with unmet medical needs. We report potent hit compounds for Entamoeba histolytica, Trypanosoma brucei and Leishmania spp., with limited overlap in their structure–activity relation. PHT-39 efficiently penetrated host macrophages to effectively eliminate Leishmania intracellular amastigotes, while displaying high selectivity. Leveraging an orthology-based genome-wide RNAi library screen, we propose an uptake route for the PHT-39 that relies on a transmembrane flippase, known as crucial uptake transporter for the two frontline antileishmanials miltefosine and amphotericin. Despite favourable drug properties of PHT-39, experimental PHT-39 treatment failed to eliminate the Leishmania infection in a cutaneous leishmaniasis animal model. Considering PHT-39 high selectivity and the ability of the drug to effectively reach the intracellular stage of the parasite, we suggest PHT-39 for further optimization. [ABSTRACT FROM AUTHOR]

Benzo‐fused five‐membered N/O/S heterocyclic compounds, such as indole, benzofuran, and benzothiophene, possessing a single heteroatom, have important applications in medicinal chemistry, agrochemistry, and material chemistry. Metal‐catalysed reactions are well‐established synthetic pathways for the formation of C−X bonds, enabling the direct synthesis of heterocycles. This approach offers advantages over traditional methods, such as fewer steps, increased atom economy, low catalyst loading, regioselectivity, and stereoselectivity. Due to their widespread use in the pharmaceutical industry, the formation of C−N, C−O, and C−S bonds has gained significant attention. This article focusses on the metal‐catalysed synthesis and corresponding mechanistic approaches for N/O/S‐heterocycles, particularly indole, benzofuran, and benzothiophene, reviewing the progress of the past five years and discussing unexplored future opportunities. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic has resulted in global shortages in supplies for diagnostic tests, especially in the developing world. Risk factors for COVID-19 severity include pre-existing comorbidities, older age and male sex, but other variables are likely play a role in disease outcome. There is indeed increasing evidence that supports the role of host genetics in the predisposition to COVID-19 outcomes. The identification of genetic factors associated with the course of SARS-CoV-2 infections relies on DNA extraction methods. This study compared three DNA extraction methods (Chelex®100 resin, phenol-chloroform and the QIAamp DNA extraction kit) for COVID-19 host genetic studies using nasopharyngeal samples from patients. The methods were compared regarding number of required steps for execution, sample handling time, quality and quantity of the extracted material and application in genetic studies. The Chelex®100 method was found to be cheapest (33 and 13 times cheaper than the commercial kit and phenol-chloroform, respectively), give the highest DNA yield (306 and 69 times higher than the commercial kit and phenol-chloroform, respectively), with the least handling steps while providing adequate DNA quality for downstream applications. Together, our results show that the Chelex®100 resin is an inexpensive, safe, simple, fast, and suitable method for DNA extraction of nasopharyngeal samples from COVID-19 patients for genetics studies. This is particularly relevant in developing countries where cost and handling are critical steps in material processing. [ABSTRACT FROM AUTHOR]

Junin virus consists of ribonucleic acid as the genome and is responsible for a rapidly changing tendency of the virus. The virus is accountable for ailments in the human body and causes Argentine Haemorrhagic Fever (AHF). The infection is may be transmitted through contact between an infected animal/host and a person, and later between person to person. Prevention of outbreaks of AHF in humans can be a tough practice, as their occurrence is infrequent and unpredictable. In this review, recent information from the past 5 years available on the Junin virus including the risk of its emergence, infectious agents, its pathogenesis in humans, available diagnostic and therapeutic approaches, and disease management has been summarised. Altogether, this article would be highly significant in understanding the mechanistic basis behind virus interaction and other processes during the life cycle. Currently, no specific therapeutic options are available to treat the Junin virus infection. The information covered in this review could be important for finding possible treatment options for Junin virus infections. [ABSTRACT FROM AUTHOR]

Herein, we report a metal/additive-free protocol for the activation of nitrile towards nucleophilic addition and subsequent annulation under an aqueous medium for the first time. The protocol divulges an efficient and atom economical route for the construction of diverse aminated isoquinolines. Differently substituted primary as well as secondary amines underwent the reaction in a highly regioselective manner. The reaction is operationally simple, shows high functional group tolerance and easier modification of well-known drugs, and can be successfully extended to gram-scale synthesis. [ABSTRACT FROM AUTHOR]

Diagnosis and treatment of lung diseases pose serious challenges. Currently, diagnostic as well as therapeutic methods show poor efficacy toward drug-resistant bacterial infections, while chemotherapy causes toxicity and nonspecific delivery of drugs. Advanced treatment methods that cure lung-related diseases, by enabling drug bioavailability via nasal passages during mucosal formation, which interferes with drug penetration to targeted sites, are in demand. Nanotechnology confers several advantages. Currently, different nanoparticles, or their combinations, are being used to enhance targeted drug delivery. Nanomedicine, a combination of nanoparticles and therapeutic agents, that delivers drugs to targeted sites increases the bioavailability of drugs at these sites. Thus, nanotechnology is superior to conventional chemotherapeutic strategies. Here, the authors review the latest advancements in nanomedicine-based drug-delivery methods for managing acute and chronic inflammatory lung diseases. [ABSTRACT FROM AUTHOR]

Human immunodeficiency virus (HIV) capsid (CA) protein is a promising target for developing novel anti‐HIV drugs. Starting from highly anticipated CA inhibitors PF‐74, we used scaffold hopping strategy to design a series of novel 1,2,4‐triazole phenylalanine derivatives by targeting an unexplored region composed of residues 106–109 in HIV‐1 CA hexamer. Compound d19 displayed excellent antiretroviral potency against HIV‐1 and HIV‐2 strains with EC50 values of 0.59 and 2.69 µM, respectively. Additionally, we show via surface plasmon resonance (SPR) spectrometry that d19 preferentially interacts with the hexameric form of CA, with a significantly improved hexamer/monomer specificity ratio (ratio = 59) than PF‐74 (ratio = 21). Moreover, we show via SPR that d19 competes with CPSF‐6 for binding to CA hexamers with IC50 value of 33.4 nM. Like PF‐74, d19 inhibits the replication of HIV‐1 NL4.3 pseudo typed virus in both early and late stages. In addition, molecular docking and molecular dynamics simulations provide binding mode information of d19 to HIV‐1 CA and rationale for improved affinity and potency over PF‐74. Overall, the lead compound d19 displays a distinct chemotype form PF‐74, improved CA affinity, and anti‐HIV potency. [ABSTRACT FROM AUTHOR]

The lack of licensed vaccines and effective drugs against Zika virus (ZIKV) disease creates alarming situations for public health and therefore warrants the discovery of therapeutics. Hydroxyethylamine (HEA) analogs have entered clinical trials for their antiviral properties, presenting a validated pharmacophore for the design of novel antiviral treatments. We thus synthesized HEA compounds (VI and VII) and tested them against ZIKV in culture. Compound VI showed 72-fold higher efficacy to block the infectivity of ZIKV infection over the positive control, 6-methylmercaptopurine riboside. Hit compound VI displayed a 50% inhibitory concentration of 0.34 μM with a selectivity index of 22.47. Biodistribution and bioimaging studies suggested a major uptake of VI in the liver and kidneys of the experimental animals. Slightly lower uptake was also noted in the brain, which showed 6-fold higher accumulation than in the blood. Rhodamine B labeled VI (Rho-VI) was treated with a 5-HT1A receptor that showed a binding affinity of 7.54 nM. Next, compound VI indicated negligible acute and subacute cytotoxicity evaluated in mice. This study supports compound VI as a prime antiviral contender for preclinical and clinical trials against ZIKV disease. [ABSTRACT FROM AUTHOR]

As a key structural protein, HIV capsid (CA) protein plays multiple roles in the HIV life cycle, and is considered a promising target for anti-HIV treatment. Based on the structural information of CA modulator PF-74 bound to HIV-1 CA hexamer, 18 novel phenylalanine derivatives were synthesized via the Ugi four-component reaction. In vitro anti-HIV activity assays showed that most compounds exhibited low-micromolar-inhibitory potency against HIV. Among them, compound I-19 exhibited the best anti-HIV-1 activity (EC50 = 2.53 ± 0.84 μM, CC50 = 107.61 ± 27.43 μM). In addition, I-14 displayed excellent HIV-2 inhibitory activity (EC50 = 2.30 ± 0.11 μM, CC50 > 189.32 μM) with relatively low cytotoxicity, being more potent than that of the approved drug nevirapine (EC50 > 15.02 μM, CC50 > 15.2 μM). Additionally, surface plasmon resonance (SPR) binding assays demonstrated direct binding to the HIV CA protein. Moreover, molecular docking and molecular dynamics simulations provided additional information on the binding mode of I-19 to HIV-1 CA. In summary, we further explored the structure—activity relationships (SARs) and selectivity of anti-HIV-1/HIV-2 of PF-74 derivatives, which is conducive to discovering efficient anti-HIV drugs. [ABSTRACT FROM AUTHOR]

Malaria elimination urgently needs novel antimalarial therapies that transcend resistance, toxicity, and high costs. Our multicentric international collaborative team focuses on developing multistage antimalarials that exhibit novel mechanisms of action. Here, we describe the design, synthesis, and evaluation of a novel multistage antimalarial compound, 'Calxinin'. A compound that consists of hydroxyethylamine (HEA) and trifluoromethyl-benzyl-piperazine. Calxinin exhibits potent inhibitory activity in the nanomolar range against the asexual blood stages of drug-sensitive (3D7), multidrug-resistant (Dd2), artemisinin-resistant (IPC4912), and fresh Kenyan field isolated Plasmodium falciparum strains. Calxinin treatment resulted in diminished maturation of parasite sexual precursor cells (gametocytes) accompanied by distorted parasite morphology. Further, in vitro liver-stage testing with a mouse model showed reduced parasite load at an IC50 of 79 nM. A single dose (10 mg/kg) of Calxinin resulted in a 30% reduction in parasitemia in mice infected with a chloroquine-resistant strain of the rodent parasite P. berghei. The ex vivo ookinete inhibitory concentration within mosquito gut IC50 was 150 nM. Cellular in vitro toxicity assays in the primary and immortalized human cell lines did not show cytotoxicity. A computational protein target identification pipeline identified a putative P. falciparum membrane protein (Pf3D7_1313500) involved in parasite calcium (Ca2+) homeostasis as a potential Calxinin target. This highly conserved protein is related to the family of transient receptor potential cation channels (TRP-ML). Target validation experiments showed that exposure of parasitized RBCs (pRBCs) to Calxinin induces a rapid release of intracellular Ca2+ from pRBCs; leaving de-calcinated parasites trapped in RBCs. Overall, we demonstrated that Calxinin is a promising antimalarial lead compound with a novel mechanism of action and with potential therapeutic, prophylactic, and transmission-blocking properties against parasites resistant to current antimalarials. [ABSTRACT FROM AUTHOR]