Identification of benzenesulfonamide quinoline derivatives as potent HIV-1 replication inhibitors targeting Rev protein

Exploring the HIV-1 Rev Recognition Element (RRE)-Rev Inhibitory Capacity and Antiretroviral Action of Benfluron Analogs

Human immunodeficiency virus-type 1 (HIV-1) remains one of the leading contributors to the global burden of disease, and novel antiretroviral agents with alternative mechanisms are needed to cure this infection. Here, we describe an exploratory attempt to optimize the antiretroviral properties of benfluron, a cytostatic agent previously reported to exhibit strong anti-HIV activity likely based on inhibitory actions on virus transcription and Rev-mediated viral RNA export. After obtaining six analogs designed to modify the benzo[c]fluorenone system of the parent molecule, we examined their antiretroviral and toxicity properties together with their capacity to recognize the Rev Recognition Element (RRE) of the virus RNA and inhibit the RRE-Rev interaction. The results indicated that both the benzo[c] and cyclopentanone components of benfluron are required for strong RRE-Rev target engagement and antiretroviral activity and revealed the relative impact of these moieties on RRE affinity, RRE-Rev inhibition, antiviral action and cellular toxicity. These data provide insights into the biological properties of the benzo[c]fluorenone scaffold and contribute to facilitating the design of new anti-HIV agents based on the inhibition of Rev function.

Urine-derived stem cells-extracellular vesicles ameliorate diabetic osteoporosis through HDAC4/HIF-1α/VEGFA axis by delivering microRNA-26a-5p

Critical roles of stem cell-extracellular vesicles (EVs) in the management of osteoporosis have been documented. Here, this study was designed to enlarge the research of the specific effects and underlying mechanism of urine-derived stem cells-EVs (USCs-EVs) on osteoporosis in diabetes rats. Firstly, miR-26a-5p and histone deacetylase 4 (HDAC4) expression in USCs of rats after diabetic osteoporosis (DOP) modeling induced by streptozotocin injection was determined, followed by study of their interaction. Then, USCs-EVs were co-cultured with osteogenic precursor cells, the effects of miRNA-26a-5p (miR-26a-5p) on osteoblasts, osteoclasts, bone mineralization deposition rate were evaluated. Meanwhile, the effect of USCs-EVs carrying miR-26a-5p on DOP rats was assessed. Elevated miR-26a-5p was seen in USCs-EVs which limited HDAC4 expression. Moreover, USCs-EVs delivered miR-26a-5p to osteogenic precursor cells, thereby promoting their differentiation, enhancing the activity of osteoblasts, and inhibiting the activity of osteoclasts, thereby preventing DOP through the activation of hypoxia inducible factor 1 subunit alpha (HIF-1α)/vascular endothelial growth factor A (VEGFA) pathway by repressing HDAC4. In a word, USCs-EVs-miR-26a-5p is a promising therapy for DOP by activating HIF-1α/VEGFA pathway through HDAC4 inhibition. 1. USCs-EVs-miR-26a-5p targeted HDAC4 and limited HDAC4 expression. 2. miR-26a-5p was delivered by USCs-EVs into osteoblast precursor cells. 3. USCs-EVs-miR-26a-5p promoted the differentiation of osteoblast precursor cells into osteoblasts. 4. miR-26a-5p delivered by USCs-EVs could inhibit HDAC4. 5. USCs-EVs-miR-26a-5p could prevent the pathogenesis of DOP via HIF-1α/VEGFA aix.

Novel HIV-1 RNA biogenesis inhibitors identified by virtual pharmacophore-based screening

The complex between the Rev protein of HIV-1 and the Rev Recognition Element (RRE) within the virus RNA promotes nuclear export of unspliced or incompletely spliced viral transcripts and is required for virus transmission. Here, we have screened a virtual collection of compounds using a pharmacophore based on the chemical similarity of previously characterized inhibitors to identify new chemical scaffolds blocking the RRE-Rev interaction. The best molecules discovered with this strategy inhibited the complex by binding to the RRE and exhibited substantial antiretroviral activity (between 0.582 and 11.3 μM EC50 values) likely associated to inhibitory actions on viral transcription and Rev function. These results have allowed us to identify structural features required for RRE-Rev inhibition as well as to add new compounds to the pool of possible candidates for developing antiretroviral agents based on blockage of HIV-1 RNA biogenesis.

Synthesis, description, and application of novel corrosion inhibitors for CS AISI1095 in 1.0 M HCl based on benzoquinoline derivatives

This study aims to synthesize and evaluate the corrosion inhibition properties of three newly prepared organic compounds based on benzo[h]quinoline hydrazone derivatives. The compounds structure were characterised using FTIR, 1H-NMR, 13C-NMR and Mass spectroscopy. Electrochemical methods, including Potentiodynamic Polarization (PP), Electrochemical Frequency Modulation (EFM), and Electrochemical Impedance Spectroscopy (EIS) were employed to evaluate the compounds as corrosion inhibitors in HCl (1.0 M) for carbon steel (CS). Additionally, surface examination techniques such as scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used to investigate the surface morphology and elemental composition of the CS before and after exposure to the synthesized compounds. The electrochemical measurements showed that compound VII achieved corrosion inhibition efficiency. SEM and EDX analysis further confirmed the creation of a passive film on the CS surface. These findings demonstrated the potential of benzo[h]quinoline hydrazone derivatives as effective organic corrosion inhibitors for CS in aggressive solution.

Quinolines and isoquinolines as HIV-1 inhibitors: Chemical structures, action targets, and biological activities

Human immunodeficiency virus type 1 (HIV-1), a lentivirus that causes acquired immunodeficiency syndrome (AIDS), poses a serious threat to global public health. Since the advent of the first drug zidovudine, a number of anti-HIV agents acting on different targets have been approved to combat HIV/AIDS. Among the abundant heterocyclic families, quinoline and isoquinoline moieties are recognized as promising scaffolds for HIV inhibition. This review intends to highlight the advances in diverse chemical structures and abundant biological activity of quinolines and isoquinolines as anti-HIV agents acting on different targets, which aims to provide useful references and inspirations to design and develop novel HIV inhibitors for medicinal chemists.

Advances in polymer based Friedlander quinoline synthesis

Nitrogen containing heterocyclic compounds has acquired their remarkable and distinct place in the wide area of organic synthesis due to the broad range of applications. Among them, quinoline motifs have attracted researchers in the synthetic chemistry because of its presence in the large number of pharmacologically active compounds. Different methods for synthesis of quinoline derivatives are reported, among them the Friedlander synthesis have provided comparatively more efficient approach. Many of the reported conventional Friedlander methodologies have some problems such as difficult product isolation procedures, poor yields and use of expensive catalysts, etc. Recently, polymer or solid supported synthetic approaches have attracted the attention of researchers because of their easy execution, greater selectivity, increased product yields, simple work-up procedures, recoverability and reusability of the catalysts. In consideration with the advantages of polymer supported synthetic strategies, the proposed review covers the role of polymers in the Friedlander synthesis; which may use polymers of organic, inorganic or hybrid in nature and of nanolevel as well.

Benzoquinoline Derivatives: A Straightforward and Efficient Route to Antibacterial and Antifungal Agents

We report here the design, synthesis, experimental and in silico evaluation of the antibacterial and antifungal activity of some new benzo[f]quinoline derivatives. Two classes of benzo[f]quinolinium derivatives—(benzo[f]quinolinium salts (BQS) and pyrrolobenzo[f]quinolinium cycloadducts (PBQC)—were designed and obtained in two steps via a direct and facile procedure: quaternization followed by a cycloaddition reaction. The synthesized compounds were characterized by elemental and spectral analysis (FT-IR, ¹H-NMR, ¹³C-NMR). The antimicrobial assay reveals that the BQS salts have an excellent quasi-nonselective antifungal activity against the fungus Candida albicans (some of them higher that the control drug nystatin) and very good antibacterial activity against the Gram positive bacterium Staphylococcus aureus. The PBQC compounds are inactive. Analysis of the biological data reveals interesting SAR correlations in the benzo[f]quinolinium series of compounds. The in silico studies furnished important data concerning the pharmacodynamics, pharmacokinetics and ADMET parameters of the BQS salts. Studies of the interaction of each BQS salt 3a–o with ATP synthase in the formed complex, reveal that salts 3j, 3i, and 3n have the best fit in a complex with ATP synthase. Study of the interaction of each BQS salt 3a-o with TOPO II in the formed complex reveals that salts 3j and 3n have the best-fit in complex with TOPO II. The in silico ADMET studies reveal that the BQS salts have excellent drug-like properties, including a low toxicity profile. Overall, the experimental and in silico studies indicate that compounds 3e and 3f (from the aliphatic series), respectively, and 3i, 3j and 3n (from the aromatic series), are promising leading drug candidates.

Metal-free regioselective C5-cyanoalkylation of the 8-aminoquinolineamides/sulfonamides via oxidative cross-dehydrogenative coupling with alkylnitriles

A practical, versatile and Metal-free regioselective C5-cyanoalkylation of the 8-aminoquinolineamides/sulfonamides with acetonitrile has been described.

Hybrid Quinoline-Sulfonamide Complexes (M2+) Derivatives with Antimicrobial Activity

Two new series of hybrid quinoline-sulfonamide complexes (M²⁺: Zn²⁺, Cu²⁺, Co²⁺ and Cd²⁺) derivatives (QSC) were designed, synthesized and tested for their antimicrobial activity. The synthesis is straightforward and efficient, involving two steps: acylation of aminoquinoline followed by complexation with metal acetate (Cu²⁺, Co²⁺ and Cd²⁺) or chloride (Zn²⁺). The synthesized QSC compounds were characterized by FTIR and NMR spectroscopy and by X-ray diffraction on single crystal. The QSC compounds were preliminary screened for their antibacterial and antifungal activity and the obtained results are very promising. In this respect, the hybrid N-(quinolin-8-yl)-4-chloro-benzenesulfonamide cadmium (II), considered as leading structure for further studies, has an excellent antibacterial activity against Staphylococcus aureus ATCC25923 (with a diameters of inhibition zones of 21 mm and a minimum inhibitory concentration (MIC) of 19.04 × 10⁻⁵ mg/mL), a very good antibacterial activity against Escherichia coli ATCC25922 (with a diameters of inhibition zones of 19 mm and a MIC of 609 × 10⁻⁵ mg/mL), and again an excellent antifungal activity against Candida albicans ATCC10231 (with a diameters of inhibition zones of 25 mm and a MIC of 19.04 × 10⁻⁵ mg/mL).

Visible Light-Promoted Photocatalytic C-5 Carboxylation of 8-Aminoquinoline Amides and Sulfonamides via a Single Electron Transfer Pathway

An efficient photocatalytic method was developed for the remote C5-H bond carboxylation of 8-aminoquinoline amide and sulfonamide derivatives. This methodology uses in situ generated ^•CBr₃ radical as a carboxylation agent with alcohol and is further extended to a variety of arenes and heteroarenes to synthesize the desired carboxylated product in moderate-to-good yields. The reaction proceeding through a single electron transfer pathway was established by a control experiment, and a butylated hydroxytoluene-trapped aryl radical cation intermediate in high-resolution mass spectrometry was identified.

Oxazole-Benzenesulfonamide Derivatives Inhibit HIV-1 Reverse Transcriptase Interaction with Cellular eEF1A and Reduce Viral Replication

HIV-1 replication requires direct interaction between HIV-1 reverse transcriptase (RT) and cellular eukaryotic translation elongation factor 1A (eEF1A). Our previous work showed that disrupting this interaction inhibited HIV-1 uncoating, reverse transcription, and replication, indicating its potential as an anti-HIV-1 target. In this study, we developed a sensitive, live-cell split-luciferase complementation assay (NanoBiT) to quantitatively measure inhibition of HIV-1 RT interaction with eEF1A. We used this to screen a small molecule library and discovered small-molecule oxazole-benzenesulfonamides (C7, C8, and C9), which dose dependently and specifically inhibited the HIV-1 RT interaction with eEF1A. These compounds directly bound to HIV-1 RT in a dose-dependent manner, as assessed by a biolayer interferometry (BLI) assay, but did not bind to eEF1A. These oxazole-benzenesulfonamides did not inhibit enzymatic activity of recombinant HIV-1 RT in a homopolymer assay but did inhibit reverse transcription and infection of both wild-type (WT) and nonnucleoside reverse transcriptase inhibitor (NNRTI)-resistant HIV-1 in a dose-dependent manner in HEK293T cells. Infection of HeLa cells was significantly inhibited by the oxazole-benzenesulfonamides, and the antiviral activity was most potent against replication stages before 8 h postinfection. In human primary activated CD4+ T cells, C7 inhibited HIV-1 infectivity and replication up to 6 days postinfection. The data suggest a novel mechanism of HIV-1 inhibition and further elucidate how the RT-eEF1A interaction is important for HIV-1 replication. These compounds provide potential to develop a new class of anti-HIV-1 drugs to treat WT and NNRTI-resistant strains in people infected with HIV.IMPORTANCE Antiretroviral drugs protect many HIV-positive people, but their success can be compromised by drug-resistant strains. To combat these strains, the development of new classes of HIV-1 inhibitors is essential and a priority in the field. In this study, we identified small molecules that bind directly to HIV-1 reverse transcriptase (RT) and inhibit its interaction with cellular eEF1A, an interaction which we have previously identified as crucial for HIV-1 replication. These compounds inhibit intracellular HIV-1 reverse transcription and replication of WT HIV-1, as well as HIV-1 mutants that are resistant to current RT inhibitors. A novel mechanism of action involving inhibition of the HIV-1 RT-eEF1A interaction is an important finding and a potential new way to combat drug-resistant HIV-1 strains in infected people.

A Review on Quinoline Derived Scaffolds as Anti-HIV Agents

After restricting the proliferation of CD4+T cells, Human Immunodeficiency Virus (HIV), infection persists at a very fast rate causing Acquired Immunodeficiency Syndrome (AIDS). This demands the vigorous need of suitable anti-HIV agents, as existing medicines do not provide a complete cure and exhibit drawbacks like toxicities, drug resistance, side-effects, etc. Even the introduction of Highly Active Antiretroviral Therapy (HAART) failed to combat HIV/AIDS completely. The major breakthrough in anti-HIV discovery was marked with the discovery of raltegravir in 2007, the first integrase (IN) inhibitor. Thereafter, the discovery of elvitegravir, a quinolone derivative emerged as the potent HIV-IN inhibitor. Though many more classes of different drugs that act as anti-HIV have been identified, some of which are under clinical trials, but the recent serious focus is still laid on quinoline and its analogues. In this review, we have covered all the quinoline-based derivatives that inhibit various targets and are potential anti-HIV agents in various phases of the drug discovery.

Green recipes to quinoline: A review

The quinoline core possesses a vast number of biological activities such as anticancer, antimalarial, antimicrobial, antifungal, antitubercular and antileishmanial. The conventional classical synthetic methods require the use of expensive and harsh conditions such as high temperature. Currently the scientific communities are searching new methodology to eliminate the use of chemicals, solvents and catalysts, which are hazardous to human health as well as to environment. This review provides a concise overview of new dimensions of green chemistry approaches in designing quinoline scaffold that would encourage the researchers towards green chemistry as well as future application of these greener, non-toxic, environment friendly methods in designing quinoline scaffold.

A small-molecule inhibitor of HIV-1 Rev function detected by a diversity screen based on RRE-Rev interference

The Rev protein of HIV-1 binds to the Rev Recognition Element (RRE) in the virus RNA to promote nuclear export of unspliced and partially spliced transcripts, an essential step in the virus transmission cycle. Here, we describe the screening of a library of chemically diverse compounds with an assay based on monitoring the interaction between the RNA-binding α-helix of Rev and its high-affinity binding site in the RRE. This screen allowed the identification of a benzofluorenone compound that inhibited the formation of the full-length RRE-Rev ribonucleoprotein by associating to the RRE, and blocked HIV-1 transcription and Rev action in cells. This molecule, previously studied as a cytostatic agent, had substantial antiretroviral activity. Together with other screening hits, it provides a new chemical scaffold for the development of antiretroviral agents based on blockage of HIV-1 RNA biogenesis.

Synthesis of C-2 and C-3 substituted quinolines and their evaluation as anti-HIV-1 agents

A plenty of natural products and synthetic derivatives containing quinoline moiety have been reported to possess various pharmacological activities. Quinolines such as 2-styrylquinolines and 8-hydroxyquinolines are extensively studied for their anti-HIV-1 activity and found to act mainly through HIV-1 integrase enzyme inhibition. In continuation of our efforts to search for newer anti-HIV-1 molecules, thirty-one quinoline derivatives with different linkers to ancillary phenyl ring were synthesized and evaluated for in vitro anti-HIV-1 activity using TZM-bl assays. Compound 31 showed higher activity in TZM-bl cell line against HIV-1_VB59 and HIV-1_UG070 cell associated virus (IC₅₀ 3.35 ± 0.87 and 2.57 ± 0.71 μM) as compared to other derivatives. Compound 31 was further tested against cell free virus HIV-1_VB59 and HIV-1_UG070 (IC₅₀ 1.27 ± 0.31 and 2.88 ± 1.79 μM, TI 42.20 and 18.61, respectively). This lead molecule also showed good activity in viral entry inhibition assay and cell fusion assay defining its mode of action. The activity of compound 31 was confirmed by testing against HIV-1_VB51 in activated peripheral blood mononuclear cells (PBMCs). Binding interactions of 31 were compared with known entry inhibitors.

A general method for the metal-free, regioselective, remote C-H halogenation of 8-substituted quinolines

An operationally simple, metal-free protocol for regioselective halogenation of a range of 8-substituted quinolines has been established using recyclable trihaloisocyanuric acids.

An operationally simple and metal-free protocol for geometrically inaccessible C5–H halogenation of a range of 8-substituted quinoline derivatives has been established. The reaction proceeds under air, with inexpensive and atom economical trihaloisocyanuric acid as a halogen source (only 0.36 equiv.), at room temperature. Exceptionally high generality with respect to quinoline is observed, and in most instances, the reaction proceeded with complete regioselectivity. Quinoline with a variety of substituents at the 8-position gave, exclusively, the C5-halogenated product in good to excellent yields. Phosphoramidates, tertiary amides, N-alkyl/N,N-dialkyl, and urea derivatives of quinolin-8-amine as well as alkoxy quinolines were halogenated at the C5-position via remote functionalization for the first time. This methodology provides a highly economical route to halogenated quinolines with excellent functional group tolerance, thus providing a good complement to existing remote functionalization methods of quinolin-8-amide derivatives and broadening the field of remote functionalization. The utility of the method is further showcased through the synthesis of several compounds of biological and pharmaceutical interest.

Synthesis of 3-acylquinolines through Cu-catalyzed double C(sp3)–H bond functionalization of saturated ketones

A novel synthesis of 3-acylquinolines through Cu-catalyzed one-pot reactions of 2-aminoaryl aldehydes/ketones with inactivated ketones featured with double C(sp³)–H bond functionalization is presented.

Identification of Tetraazacyclic Compounds as Novel Potent Inhibitors Antagonizing RORγt Activity and Suppressing Th17 Cell Differentiation

CD4⁺ T-helper cells that produce interleukin-17 (Th17 cells) are characterized as pathological T-helper cells in autoimmune diseases. Differentiation of human and mouse Th17 cells requires a key transcription regulator, retinoic acid receptor-related orphan receptor γt (RORγt), which is a potential therapeutic target for autoimmune diseases. To develop a therapeutic agent for Th17-mediated autoimmune diseases, we have established a high-throughput screening (HTS) assay for candidate screening, in which the luciferase activity in RORγt-LBD positive and negative Jurkat cells were analyzed to evaluate induction of RORγt activity by compounds. This technique was applied to screen a commercially-available drug-like chemical compound library (Enamine) which contains 20155 compounds. The screening identified 17 compounds that can inhibit RORγt function in the HTS screen system. Of these, three tetraazacyclic compounds can potently inhibit RORγt activity, and suppress Th17 differentiation and IL-17 production. These three candidate compounds could significantly attenuate the expression of the Il17a by 65%- 90%, and inhibit IL-17A secretion by 47%, 63%, and 74%, respectively. These compounds also exhibited a potent anti-RORγt activity, with EC₅₀ values of 0.25 μM, 0.67 μM and 2.6 μM, respectively. Our data demonstrated the feasibility of targeting the RORγt to inhibit Th17 cell differentiation and function with these tetraazacyclic compounds, and the potential to improve the structure of these compounds for autoimmune diseases therapeutics.