New nitrogen containing substituents at the indole-2-carboxamide yield high potent and broad spectrum indolylarylsulfone HIV-1 non-nucleoside reverse transcriptase inhibitors

Recent Advances in Nitrogen-Containing Heterocyclic Scaffolds as Antiviral Agents

This study aims to provide a thorough analysis of nitrogen-containing heterocycles, focusing on their therapeutic implications for the development of targeted and effective antiviral drugs. To better understand how nitrogen-containing heterocycles can be used to create antiviral drugs, this review adopts a systematic literature review strategy to compile and analyze pertinent research studies. It combines information from various fields to understand better the compounds' mode of action and their therapeutic potential. This review paper summarizes data from multiple sources to highlight the promising potential of heterocycles containing nitrogen as promising possibilities for future antiviral treatments. The capacity to engage selectively and modulate critical pathways bodes well for their use in developing new viral therapies. In conclusion, nitrogen-containing heterocycles are shown to be of utmost importance in the field of medicinal chemistry, as emphasized by the review paper. It emphasizes the central importance of chemical insights and pharmacological potential in developing novel and effective antiviral medicines by bringing them together.

Metal-free hydrosulfonylation of α,β-unsaturated ketones: synthesis and application of γ-keto sulfones

γ-Keto sulfones are versatile building blocks and valuable intermediates in organic synthesis and pharmaceutical chemistry. Motivated by their excellent properties, we herein report a green, convenient, metal-free hydrosulfonylation method for a variety of ynones, vinyl ketones, and sodium sulfinates in the absence of stoichiometric oxidants. This operationally simple protocol provides straightforward and practical access to a wide range of γ-keto sulfones with broad functional group tolerance from easily available starting materials. Moreover, the β,γ-unsaturated keto sulfones could further react with 2,3-butadienoate to generate cyclopentenes in phosphine-mediated [3 + 2] cycloaddition.

Design, Synthesis and In Vitro Evaluation of Spirooxindole-Based Phenylsulfonyl Moiety as a Candidate Anti-SAR-CoV-2 and MERS-CoV-2 with the Implementation of Combination Studies

The search for an effective anti-viral to inhibit COVID-19 is a challenge for the specialized scientific research community. This work investigated the anti-coronavirus activity for spirooxindole-based phenylsulfone cycloadducts in a single and combination protocols. The newly designed anti-SARS-CoV-2 therapeutics spirooxindoles synthesized by [3 + 2] cycloaddition reactions represent an efficient approach. One-pot multicomponent reactions between phenyl vinyl sulfone, substituted isatins, and amines afforded highly stereoselective anti-SARS-CoV-2 therapeutics spirooxindoles with three stereogenic centers. Herein, the newly synthesized spirooxindoles were assessed individually against the highly pathogenic human coronaviruses and proved to be highly potent and safer. Interestingly, the synergistic effect by combining the potent, tested spirooxindoles resulted in an improved antiviral activity as well as better host-cell safety. Compounds 4i and 4d represented the most potent activity against MERS-CoV with IC₅₀ values of 11 and 23 µM, respectively. Both compounds 4c and 4e showed equipotent activity with the best IC₅₀ against SARS-CoV-2 with values of 17 and 18 µM, respectively, then compounds 4d and 4k with IC₅₀ values of 24 and 27 µM, respectively. Then, our attention oriented to perform a combination protocol as anti-SARS-CoV-2 for the best compounds with a different binding mode and accompanied with different pharmacophores. Combination of compound 4k with 4c and combination of compounds 4k with 4i proved to be more active and safer. Compounds 4k with 4i displayed IC₅₀ = 3.275 µM and half maximal cytotoxic-concentration CC₅₀ = 11832 µM. MD simulation of the most potential compounds as well as in silico ADMET properties were investigated. This study highlights the potential drug-like properties of spirooxindoles as a cocktail anti-coronavirus protocol.

Spectroscopic, electronic structure, molecular docking, and molecular dynamics simulation study of 7-Trifluoromethyl-1H-indole-2-carboxylic acid as an aromatase inhibitor

The present work encompasses a combined experimental and theoretical investigation of the molecular structure, vibrational wavenumbers, electronic structure at the ground and electronic excited states, molecular electrostatic potential surface of 7-(Trifluoromethyl)-1H-indole-2-carboxylic acid (TICA) and possibility of the title molecule as an aromatase inhibitor using molecular docking and molecular dynamic simulations. A stable conformer has been obtained using potential energy scans by varying appropriate dihedral angles. The obtained minimum energy conformer was further optimized at the 6-311++G (d, p) basis set by applying the most accepted B3LYP functional. A good agreement between experimental and calculated normal modes of vibration has been observed. The hydrogen-bonded interaction between two monomeric units of TICA has been investigated using NBO,QTAIM, and NCI (noncovalent interactions) analysis. Molecular docking of TICA with human placental aromatase (PDB ID: 3S79) reveals the formation of polar hydrogen bonds as well as hydrophobic interactions between the ligand and the protein, right in the binding cavity. TICA satisfies all pharmacokinetic filters (Lipinski rule of five, the Veber rule, Ghose rule, Egan rule, as well as the Muegge rule) and has a high bioavailability score of 0.85. Dynamic stability of the ligand within the binding pocket of the target protein has been confirmed by 100 ns molecular dynamics simulation results. The present study provides an excellent starting point for additional in vivo research, and TICA may eventually serve as a significant therapeutic candidate for the treatment of breast cancer.

Indolylarylsulfones bearing phenylboronic acid and phenylboronate ester functionalities as potent HIV‑1 non-nucleoside reverse transcriptase inhibitors

To explore the chemical space around the entrance channel of the HIV-1 reverse transcriptase (RT) binding pocket, we innovatively designed and synthesized a series of novel indolylarylsulfones (IASs) bearing phenylboronic acid and phenylboronate ester functionalities at the indole-2-carboxamide as new HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) through structure-based drug design. All the newly synthesized compounds exhibited excellent to moderate potency against wild-type (WT) HIV-1 with EC₅₀ values ranging from 6.7 to 42.6 nM. Among all, (3-ethylphenyl)boronic acid substituted indole-2-carboxamide and (4-ethylphenyl) boronate ester substituted indole-2-carboxamide were found to be the most potent inhibitors (EC₅₀ = 8.5 nM, SI = 3310; EC₅₀ = 6.7 nM, SI = 3549, respectively). Notably, (3-ethylphenyl)boronic acid substituted indole-2-carboxamide maintained excellent activities against the single HIV-1 mutants L100I (EC₅₀ = 7.3 nM), K103N (EC₅₀ = 9.2 nM), as well as the double mutant V106A/F227L (EC₅₀ = 21.1 nM). Preliminary SARs and molecular modelling studies are also discussed in detail.

Therapeutic potential of indole derivatives as anti-HIV agents: A mini-review

Acquired immunodeficiency syndrome (AIDS), caused by human immunodeficiency virus (HIV), is one of the leading causes of human deaths. The advent of different anti-HIV drugs over different disease progress has made AIDS/HIV from a deadly infection to chronic and manageable disease. However, the development of multidrug-resistant viruses, together with the severe side effects of anti-HIV agents, compromised their efficacy and limited the treatment options. Indoles, the most common frameworks in the bioactive molecules, represent attractive scaffolds for the design and development of novel drugs. Indole derivatives are potential inhibitors of HIV enzymes such as reverse transcriptase, integrase and protease, and some indole-based agents like Delavirdine have already been applied in clinics or under clinical evaluations for the treatment of AIDS/HIV, revealing that indole moiety is a useful template for the development of anti-HIV agents. This review focuses on the recent advancement of indole derivatives including indole alkaloids, hybrids, and dimers with anti-HIV potential, covering articles published between 2010 and 2020. The chemical structures, structure-activity relationship and mechanisms of action are also discussed.

Copper-catalyzed sulfonylation of N-tosylhydrazones followed by a one-pot C-N bond formation

A new methodology to synthesize sulfonyl-N-phenylaniline derivatives via the trapping of bromo-sulfone derivatives generated from N-tosylhydrazones (NTHs) with amines is described. The reaction proved successful for a wide range of NTHs and amines and tolerated various functional groups on either coupling partner (35 examples). The mechanism was studied, and we showed that the sulfone formation does not follow a radical pathway.

Synthetic strategies, SAR studies, and computer modeling of indole 2 and 3-carboxamides as the strong enzyme inhibitors: a review

Abstract

Indole derivatives have been the focus of many researchers in the study of pharmaceutical compounds for many years. Researchers have investigated the effect of carboxamide moiety at positions 2 and 3, giving unique inhibitory properties to these compounds. The presence of carboxamide moiety in indole derivatives causes hydrogen bonds with a variety of enzymes and proteins, which in many cases, inhibits their activity. In this review, synthetic strategies of indole 2 and 3-carboxamide derivatives, the type, and mode of interaction of these derivatives against HLGP, HIV-1, renin enzyme, and structure–activity studies of these compounds were investigated. It is hoped that indole scaffolds will be tested in the future for maximum activity in pharmacological compounds.

Graphic abstract

Novel Thiazolidin-4-ones as Potential Non-nucleoside Inhibitors of HIV-1 Reverse Transcriptase

BACKGROUND

HIV is the causative agent of Acquired Immunodeficiency Syndrome (AIDS), an infectious disease with increasing incidence worldwide. Non-nucleoside reverse transcriptase inhibitors (NNRTIs) play an important role in the treatment of AIDS. Although, many compounds are already being used as anti-HIV drugs, research for the development of new inhibitors continues as the virus develops resistant strains.

METHODS

The best features of available NNRTIs were taken into account for the design of novel inhibitors. PASS (Prediction of activity spectra for substances) prediction program and molecular docking studies for the selection of designed compounds were used for the synthesis. Compounds were synthesized using conventional and microwave irradiation methods and HIV RT inhibitory action was evaluated by colorimetric photometric immunoassay.

RESULTS

The evaluation of HIV-1 RT inhibitory activity revealed that seven compounds have significantly lower ΙC50 values than nevirapine (0.3 μΜ). It was observed that the activity of compounds depends not only on the nature of substituent and it position in benzothiazole ring but also on the nature and position of substituents in benzene ring.

CONCLUSION

Twenty four of the tested compounds exhibited inhibitory action lower than 4 μΜ. Seven of them showed better activity than nevirapine, while three of the compounds exhibited IC50 values lower than 5 nM. Two compounds 9 and 10 exhibited very good inhibitory activity with IC50 1 nM.

Discovery of novel indolylarylsulfones as potent HIV-1 NNRTIs via structure-guided scaffold morphing

For more in-depth exploration of the chemical space around the entrance channel of HIV-1 reverse transcriptase (RT), a series of novel indolylarylsulfones (IASs) bearing different chiral N-substituted pyrrolidine, azetidine or substituted sulfonamide groups at indole-2-carboxamide were designed and synthesized as potent HIV NNRTIs by structure-guided scaffold morphing approach. All the IASs exhibited moderate to excellent potency against wild-type HIV-1 with EC₅₀ values ranging from 0.0043 μM to 4.42 μM. Notably, compound 27 (EC₅₀ = 4.7 nM, SI = 5183) and 33 (EC₅₀ = 4.3 nM, SI = 7083) were identified as the most potent compounds, which were more active than nevirapine, lamivudine and efavirenz, and also reached the same order of etravirine. Furthermore, some compounds maintained excellent activity against various single HIV-1 mutants (L100I, K103 N, E138K, Y181C) as well as one double mutant (F227L/V106A) with EC₅₀ values in low-micromolar concentration ranges. Notably, 34 displayed outstanding potency against F227L/V106A (EC₅₀ = 0.094 μM), and also showed exceptional activity against E138K (EC₅₀ = 0.014 μM), L100I (EC₅₀ = 0.011 μM) and K103 N (EC₅₀ = 0.025 μM). Additionally, most compounds showed markedly reduced cytotoxicity (CC₅₀) compared to lead compounds, especially 36 (CC₅₀ > 234.91 μM, SI > 18727) and 37 (CC₅₀ > 252.49 μM, SI > 15152). Preliminary SARs and molecular modeling studies were also discussed in detail, which may provide valuable insights for further optimization.

Synthetic routes and structure-activity relationships (SAR) of anti-HIV agents: A key review

The worldwide increase of AIDS, an epidemic infection in constant development has an essential and still requires potent antiretroviral chemotherapeutic agents for reducing the integer of deaths caused by HIV. Thus, there is an urgent need for new anti-HIV drug candidates with increased strength, new targets, superior pharmacokinetic properties, and compact side effects. From this viewpoint, we first review present strategies of anti-HIV drug innovation and the synthesis of heterocyclic or natural compound as anti-HIV agents for facilitating the development of more influential and successful anti-HIV agents.

Synthetic approaches and pharmaceutical applications of chloro-containing molecules for drug discovery: A critical review

At present more than 250 FDA approved chlorine containing drugs were available in the market and many pharmaceutically important drug candidates in pre-clinical trials. Thus, it is quite obvious to expect that in coming decades there will be an even greater number of new chlorine-containing pharmaceuticals in market. Chlorinated compounds represent the family of compounds promising for use in medicinal chemistry. This review describes the recent advances in the synthesis of chlorine containing heterocyclic compounds as diverse biological agents and drugs in the pharmaceutical industries for the inspiration of the discovery and development of more potent and effective chlorinated drugs against numerous death-causing diseases.

Indolylarylsulfones, a fascinating story of highly potent human immunodeficiency virus type 1 non-nucleoside reverse transcriptase inhibitors

Indolylarylsulfones are a potent class of human immunodeficiency virus type 1 non-nucleoside reverse transcriptase inhibitors. In this review, the structure activity relationship (SAR) studies to improve the profile of sulfone L-737,126 discovered by Merck AG have been analysed with focus on introduction of the 3′,5′-dimethyl groups at the 3-phenylsulfonyl moiety, the 2-hydroxyethyl tail at the indole-2-carboxamide nitrogen, coupling of the carboxamide nitrogen with one or two glycinamide and alaninamide units, a fluorine atom at position 4 of the indole ring and correlation between configuration of the asymmetric centre and linker length. IAS derivatives look like promising drug candidates for the treatment of AIDS and related infections in combination with other antiretroviral agents.

Medicinal chemistry of indole derivatives: Current to future therapeutic prospectives

Indole is a versatile pharmacophore, a privileged scaffold and an outstanding heterocyclic compound with wide ranges of pharmacological activities due to different mechanisms of action. It is an superlative moiety in drug discovery with the sole property of resembling different structures of the protein. Plenty of research has been taking place in recent years to synthesize and explore the various therapeutic prospectives of this moiety. This review summarizes some of the recent effective chemical synthesis (2014-2018) for indole ring. This review also emphasized on the structure-activity relationship (SAR) to reveal the active pharmacophores of various indole analogues accountable for anticancer, anticonvulsant, antimicrobial, antitubercular, antimalarial, antiviral, antidiabetic and other miscellaneous activities which have been investigated in the last five years. The precise features with motives and framework of each research topic is introduced for helping the medicinal chemists to understand the perspective of the context in a better way. This review will definitely offer the platform for researchers to strategically design diverse novel indole derivatives having different promising pharmacological activities with reduced toxicity and side effects.

Recent Advances in the Design and Development of Non-nucleoside Reverse Transcriptase Inhibitor Scaffolds

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) have always been an important part of the anti-HIV-1 combination therapy known as combination antiretroviral therapy (cART) since 1996. The use of NNRTIs for about 22 years has led to some mutations in the residues that compose the reverse transcriptase active site, resulting in the emergence of drug-resistant viruses. Thus, the search for new potent NNRTIs with an improved safety profile and activity against drug-resistant HIV strains is indispensable, and many hit and lead NNRTIs have been discovered in the last decade. This review provides an overview of the development in this field from 2013 to August 2018.

Quantitative structure-activity relationship of anti-HIV integrase and reverse transcriptase inhibitors using norm indexes

The development of new and safe anti-human immunodeficiency virus (anti-HIV) drugs has been an urgent task for medical research recently. Herein, based on the norm-index descriptors proposed in this work and previous works, a couple of models were developed for investigating the quantitative structure-activity/toxicity relationship (QSAR/QSTR) of dual-target anti-HIV integrase (IN) and reverse transcriptase (RT) inhibitors. The validation results proved that the developed models were stable and reliable, both in statistical quality and predictive capacity. Moreover, potential dual-target inhibitors with high activity and low toxicity were deduced from the developed models; molecular docking results indicated that these inhibitors could interact with some important residues of HIV IN and RT through H-bonding. Accordingly, the norm indexes descriptors proposed by this work might be helpful for the research and development of dual-target anti-HIV drugs.

Discovery of novel piperidine-substituted indolylarylsulfones as potent HIV NNRTIs via structure-guided scaffold morphing and fragment rearrangement

To further explore the chemical space around the entrance channel of HIV-1 reverse transcriptase (RT), a series of novel indolylarylsulfones (IASs) bearing N-substituted piperidine at indole-2-carboxamide were identified as potent HIV NNRTIs by structure-guided scaffold morphing and fragment rearrangement. All the IASs exhibited moderate to excellent potency against wild-type HIV-1 with EC₅₀ values ranging from 0.62 μM to 0.006 μM 8 (EC₅₀ = 6 nM) and 18 (EC₅₀ = 9 nM) were identified as the most potent compounds, which were more active than NVP and DLV, and reached the same order of EFV and ETV. Furthermore, most compounds maintained high activity agaist various single HIV-1 mutants (L100I, K103N, E138K, Y181C) as well as one double mutant (F227L/V106A) with EC₅₀ values in low-micromolar to double-digit nanomolar concentration ranges. Especially, 8 displayed outstanding potency against L100I (EC₅₀ = 17 nM with a 2.8-fold resistance ratio) and 18 was relatively more potent to E138K mutant (EC₅₀ = 43 nM with a 4.7-fold resistance ratio). Preliminary SARs and molecular modeling studies were also discussed in detail, which may provide valuable insights for further optimization.

Structural optimization of pyridine-type DAPY derivatives to exploit the tolerant regions of the NNRTI binding pocket

Based on the crystallographic studies of diarylpyrimidines (DAPYs), we embarked on incorporating the hydrophilic piperidyl or morpholinyl group into the known DAPY derivatives bearing the pyridine moiety as a core structure, with the double aim to exploit additional interactions with the HIV-1 NNRTI binding pocket (NNIBP), as well as to improve the compound solubility. The antiviral evaluation result show that the most potent compounds I-8b2, I-8b3, I-8b4 and I-8c3 exhibited anti-HIV-1 (IIIB) strain activity ranging from 7.4 nM to 9.4 nM (SI = 168-1283), superior to FDA-approved drugs of nevirapine (NVP), lamivudine (3TC) and delavirdine (DLV), and comparable to etravirine (ETV), zidovudine (AZT) and efavirenz (EFV). Additionally, compounds I-8c2 and I-8c3 showed moderate activity against NNRTI resistant strains baring mutations K103N and Y181C with EC50 values of 6.2 μM and 6.8 μM, respectively. Preliminary structure-activity relationships (SARs), reverse transcriptase inhibition efficacy and molecular modeling of selected compounds are also presented. These outcomes support our design hypothesis and demonstrate that the piperidyl group modified pyridine-typed DAPY derivatives are highly potent NNRTIs with improved water solubility.

Substituted indoles as HIV-1 non-nucleoside reverse transcriptase inhibitors: a patent evaluation (WO2015044928)

The invention described in this patent (WO2015044928) is related to compounds based on the substituted indole scaffold, their synthetic process and application to inhibit HIV-1 replication as non-nucleoside reverse transcriptase inhibitors (NNRTIs). Some of the newly claimed compounds presented improved potency against wild-type (WT) HIV-1 strain in comparison to previously disclosed indole-based NNRTIs and were also shown to be effective against common resistant HIV-1 strains. In light of their novel structural characteristics, simple synthetic route and improved anti-HIV activity, these compounds deserve further study as promising NNRTIs.

Design, synthesis and anti-HIV evaluation of novel diarylpyridine derivatives targeting the entrance channel of NNRTI binding pocket

The development of novel NNRTIs with activity against variants of HIV-1RT is crucial for overcoming treatment failure. In the present study, a series of novel 6-substituted diarylpyridine derivatives targeting the entrance channel of the NNIBP of RT were designed through a molecular hybridization strategy. Encouragingly, these new diarylpyridine derivatives were found to be active against wild-type (WT) HIV-1 with an EC50 values ranging from 0.035 μM to 1.99 μM. Nearly half of them exhibited more potent inhibitory activities in cellular assays than the control drug nevirapine (NVP). Notably, three most promising compounds If (EC50 = 35 nM), Ia (EC50 = 43 nM) and IIa (EC50 = 41 nM) showed high potency against WT and were comparable to the reference drug delavirdine (DLV) (EC50 = 33 nM). Moreover, compounds Ib, IIb and IIh displayed effective activity against the most common clinically observed single and double-mutated HIV-1 strains in micromolar concentrations. In particular, the inhibition of IIb against the K103N mutation (EC50 = 49 nM), which confers resistance to a wide variety of NNRTIs, was about 140 times more effective than NVP (EC50 = 6.78 μM), 50 times more than DLV (EC50 = 2.48 μM) and about 3 times more than EFV (EC50 = 0.12 μM), indicating that the newly designed compounds have great potential to be further developed as new anti-HIV-1 agents. Preliminary structure-activity relationships (SARs) and molecular modeling of the new diarylpyridine derivatives were discussed in detail.

Halolactones are potent HIV-1 non-nucleoside reverse transcriptase inhibitors

Halolactones with an isobenzofuran-1(3H)-one core structure have been developed as efficient non-nucleoside reverse transcriptase inhibitors (NNRTIs). The best compound 13a showed excellent potency against WT HIV-1 with a low EC₅₀ value of 0.45 μM.

Copper catalyzed synthesis of unsymmetrical diaryl sulfones from an arenediazonium salt and sodium p-toluenesulfinate

Aryl sulfones have been synthesized by the reaction of sodium p-toluenesulfinate and arenediazonium salts using a CuI catalyzed homogeneous system.

Indolylarylsulfones carrying a heterocyclic tail as very potent and broad spectrum HIV-1 non-nucleoside reverse transcriptase inhibitors

We synthesized new indolylarylsulfone (IAS) derivatives carrying a heterocyclic tail at the indole-2-carboxamide nitrogen as potential anti-HIV/AIDS agents. Several new IASs yielded EC50 values <1.0 nM against HIV-1 WT and mutant strains in MT-4 cells. The (R)-11 enantiomer proved to be exceptionally potent against the whole viral panel; in the reverse transcriptase (RT) screening assay, it was remarkably superior to NVP and EFV and comparable to ETV. The binding poses were consistent with the one previously described for the IAS non-nucleoside reverse transcriptase inhibitors. Docking studies showed that the methyl group of (R)-11 points toward the cleft created by the K103N mutation, different from the corresponding group of (S)-11. By calculating the solvent-accessible surface, we observed that the exposed area of RT in complex with (S)-11 was larger than the area of the (R)-11 complex. Compounds 6 and 16 and enantiomer (R)-11 represent novel robust lead compounds of the IAS class.

A review on recent developments of indole-containing antiviral agents

Indole represents one of the most important privileged scaffolds in drug discovery. Indole derivatives have the unique property of mimicking the structure of peptides and to bind reversibly to enzymes, which provide tremendous opportunities to discover novel drugs with different modes of action. There are seven indole-containing commercial drugs in the Top-200 Best Selling Drugs by US Retail Sales in 2012. There are also an amazing number of approved indole-containing drugs in the market as well as compounds currently going through different clinical phases or registration statuses. This review focused on the recent development of indole derivatives as antiviral agents with the following objectives: 1) To present one of the most comprehensive listings of indole antiviral agents, drugs on market or compounds in clinical trials; 2) To focus on recent developments of indole compounds (including natural products) and their antiviral activities, summarize the structure property, hoping to inspire new and even more creative approaches; 3) To offer perspectives on how indole scaffolds as a privileged structure might be exploited in the future.

Design, synthesis and anti-HIV evaluation of novel diarylnicotinamide derivatives (DANAs) targeting the entrance channel of the NNRTI binding pocket through structure-guided molecular hybridization

Through a structure-based molecular hybridization approach, a novel series of diarylnicotinamide derivatives (DANAs) targeting the entrance channel of HIV-1 NNRTIs binding pocket (NNIBP) were rationally designed, synthesized and evaluated for their anti-HIV activities in MT-4 cells together with the inhibition against the reverse transcriptase (RT) in an enzymatic assay. Encouragingly, most of the new DANAs were found to be active against wild-type HIV-1 with an EC50 in the range of 0.027-4.54 μM. Among them, compound 6b11 (EC50 = 0.027 μM, SI > 12518) and 6b5 (EC50 = 0.029 μM, SI = 2471) were identified as the most potent inhibitors, which were more potent than the reference drugs nevirapine (EC50 = 0.31 μM) and delavirdine (EC50 = 0.66 μM). Some DANAs were also active at micromolar concentrations against the K103N + Y181C resistant mutant. Compound 6b11 exhibited the highest enzymatic inhibition activity (IC50 = 20 nM), which is equal to that of efavirenz (EC50 = 20 nM) and 31 times higher than that of nevirapine (EC50 = 0.62 μM). Preliminary structure-activity relationships (SARs) and molecular modeling of these new DANAs have been discussed.

Synthesis and SARs of indole-based α-amino acids as potent HIV-1 non-nucleoside reverse transcriptase inhibitors

A series of non-nucleoside reverse transcriptase inhibitors derived from indole-based α-amino acids were designed and synthesized. Their inhibitory activities were detected by a TZM-bl cell assay on HIV virus type HIV-1IIIB. The comprehensive understanding of the SAR was obtained by utilizing the variation of the substituents of the indole-based α-amino acids. From the screened compounds, the novel inhibitors 19 and 29 were identified to be highly potent candidates with EC50 values of 0.060 μM and 0.045 μM respectively (CC50 values of 109.545 μM and 49.295 μM and SI values of 1825.8 and 1095.4). In most cases, the variation of substituents at different positions had a significant effect on the potency of activities. The results also indicate that the indole-based α-amino acids as efficient NNRTIs displayed comparable anti-HIV-1 activities to the reference drug NVP. We hope the identification of these indole-based amino acids as efficient NNRTIs of RT could stimulate researchers to develop more diversified anti-HIV drugs.

Copper-catalyzed aerobic oxidative N-S bond functionalization for C-S bond formation: regio- and stereoselective synthesis of sulfones and thioethers

A regio- and stereoselective synthesis of sulfones and thioethers by means of Cu(I)-catalyzed aerobic oxidative N-S bond cleavage of sulfonyl hydrazides, followed by cross-coupling reactions with alkenes and aromatic compounds to form the C sp 2-S bond, is described herein. N2 and H2O are the byproducts of this transformation, thus offering an environmentally benign process with a wide range of potential applications in organic synthesis and medicinal chemistry.

Design, synthesis, and biological evaluation of novel trifluoromethyl indoles as potent HIV-1 NNRTIs with an improved drug resistance profile

A novel series of trifluoromethyl indole derivatives have been designed, synthesized and evaluated for anti-HIV-1 activities in MT-2 cells. The hydrophobic constant, acute toxicity, carcinogenicity and mutagenicity were predicted. Trifluoromethyl indoles 10i and 10k showed extremely promising activities against WT HIV-1 with IC50 values at the low nanomolar level, similar to efavirenz, better than nevirapine, and also possessed higher potency towards the drug-resistant mutant strain Y181C than nevirapine. Preliminary SAR and docking studies of detailed binding mode provided some insights for discovery of more potent NNRTIs.

Synthesis and biological evaluation of novel quinoxalinone-based HIV-1 reverse transcriptase inhibitors

A series of novel quinoxalinone derivatives were identified as potent anti-HIV-1 agents with IC₅₀ values at 10⁻⁸ μmol L⁻¹ level.

d-Glucosamine as a green ligand for copper catalyzed synthesis of aryl sulfones from aryl halides and sodium sulfinates

d-Glucosamine is reported for the first time as a green ligand for copper catalyzed coupling of aryl halides and sodium sulfinates, which provides a simple and extremely efficient new route to unsymmetrical diaryl sulfones.

Arylsulfone-based HIV-1 non-nucleoside reverse transcriptase inhibitors

HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) represent one of the most significant classes of drugs for the treatment of AIDS/HIV infection. Over the past two decades several potent arylsulfone-based HIV-1 NNRTIs and related analogs have been developed. This review provides an essential overview of the structure–activity relationships of the arylsulfone-based HIV-1 NNRTIs. Furthermore, structural information useful for the design and development of new sulfur containing NNRTIs with enhanced antiretroviral activity against HIV-1 wild type and clinically relevant drug resistant HIV-1 mutant strains will be discussed.

Enantioselective inhibition of reverse transcriptase (RT) of HIV-1 by non-racemic indole-based trifluoropropanoates developed by asymmetric catalysis using recyclable organocatalysts

Herein, we report the development of efficient inhibitors of reverse transcriptase (RT) of HIV-1 based on indole-alkyl trifluoropyruvate derivatives by a TZM-bl cell assay. The inhibitory activities of the two enantiomers and the corresponding racemic mixture have been compared. TZM-bl cells exhibited strong enantioselective discrimination for the (R)-configuration, among these indole derivatives, the most active compound R-12, with a 5-NO2 substituent, gave the best result when tested in the TZM-bl cells on HIV virus type HIV-1IIIB, with an EC50 value of 0.019 μM, CC50 value of 210.697 μM and SI (selectivity index, CC50/EC50) value of 11,089, respectively. The cell test showed that, in most cases, the R-enantiomer was superior to the Rac-mixture, which was better than the corresponding S-enantiomer. The results indicated that the R-enantiomer is the most favorable configuration as an efficient HIV-1 inhibitor. Molecular modeling studies suggested a structural basis for the enantioselectivity of RT towards this class of molecules.

The nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors in the treatment of HIV infections (AIDS)

The majority of the drugs currently used for the treatment of HIV infections (AIDS) belong to either of the following three classes: nucleoside reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs). At present, there are 7 NRTIs, 5 NNRTIs, and 10 PIs approved for clinical use. They are discussed from the following viewpoints: (i) chemical formulae; (ii) mechanism of action; (iii) drug combinations; (iv) clinical aspects; (v) preexposure prophylaxis; (vi) prevention of mother-to-child transmission; (vii) their use in children; (viii) toxicity; (ix) adherence (compliance); (x) resistance; (xi) new NRTIs, NNRTIs, or PIs in (pre)clinical development; and (xii) the prospects for a "cure" of the disease.