Diarylaniline derivatives as a distinct class of HIV-1 non-nucleoside reverse transcriptase inhibitors

Identification of the inhibition mechanism of carbonic anhydrase II by fructooligosaccharides

Polygonatum sibiricum (P. sibiricum), recognized as a precious nourishing Chinese traditional medicine, exhibits the pharmacological effect of anti-aging. In this work, we proposed a novel mechanism underlying this effect related to the less studied bioactive compounds fructooligosaccharides in P. sibiricum (PFOS) to identify the inhibition effect of the small glycosyl molecules on the age-related zinc metalloprotease carbonic anhydrase II (CA II). Molecular docking and molecular dynamics simulation were used to investigate the structural and energetic properties of the complex systems consisting of the CA II enzyme and two possible structures of PFOS molecules (PFOS-A and PFOS-B). The binding affinity of PFOS-A (-7.27 ± 1.02 kcal/mol) and PFOS-B (-8.09 ± 1.75 kcal/mol) shows the spontaneity of the binding process and the stability of the combination in the solvent. Based on the residue energy decomposition and nonbonded interactions analysis, the C-, D- and G-sheet fragments of the CA II were found to be crucial in binding process. Van der Waals interactions form on the hydrophobic surface of CAII mainly with 131PHE and 135VAL, while hydrogen bonds form on the hydrophilic surface mainly with 67ASN and 92GLN. The binding of PFOS results in the blocking of the zinc ions pocket and then inhibiting its catalytic activity, the stability of which has been further demonstrated by free energy landscape. These findings provide evidence of the effective inhibition of PFOS to CA II enzyme, which leads to a novel direction for exploring the mechanism of traditional Chinese medicine focused on small molecule fructooligosaccharides.

Structure-based approaches for the design of 6-aryl-1-(3,4,5-trimethoxyphenyl)-1H-benzo[d][1,2,3]triazoles as tubulin polymerization inhibitors

The colchicine binding site on tubulin has been widely acknowledged as an attractive target for anticancer drug exploitation. Here, we reported the structural optimization of the lead compound 4, which was proved in our previous work as a colchicine binding site inhibitor (CBSI). Based on docking researches for the active binding conformation of compound 4, a series of novel 6-aryl-1-(3,4,5-trimethoxyphenyl)-1H-benzo[d][1,2,3]triazole derivatives (9a-9x) were developed by replacing a CH group in the 1H-benzo[d]imidazole skeleton of compound 4 with a nitrogen atom as a hydrogen bond acceptor. Among them, compound 9a showed the strongest antiproliferative activity with IC50 values ranging from 14 to 45 nM against three human cancer cell lines (MCF-7, SGC-7901 and A549), lower than that of compound 4. Mechanistic studies indicated that compound 9a could inhibit tubulin polymerization, destroy the microtubule skeleton, block the cell cycle in G2/M phase, induce cancer cell apoptosis, prevent cancer cell migration and colony formation. Moreover, compound 9a significantly inhibited tumor growth in vivo without observable toxicity in the mice 4T1 xenograft tumor model. In conclusion, this report shows a successful case of the structure-based design approach of a potent tubulin polymerization inhibitor for cancer treatment.

Contemporary Medicinal Chemistry Strategies for the Discovery and Development of Novel HIV-1 Non-nucleoside Reverse Transcriptase Inhibitors

Currently, HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) are a major component of the highly active anti-retroviral therapy (HAART) regimen. However, the occurrence of drug-resistant strains and adverse reactions after long-term usage have inevitably compromised the clinical application of NNRTIs. Therefore, the development of novel inhibitors with distinct anti-resistance profiles and better pharmacological properties is still an enormous challenge. Herein, we summarize state-of-the-art medicinal chemistry strategies for the discovery of potent NNRTIs, such as structure-based design strategies, contemporary computer-aided drug design, covalent-binding strategies, and the application of multi-target-directed ligands. The strategies described here will facilitate the identification of promising HIV-1 NNRTIs.

Design of the naphthyl-diarylpyrimidines as potent non-nucleoside reverse transcriptase inhibitors (NNRTIs) via structure-based extension into the entrance channel

A series of novel naphthyl-diarylpyrimidine (DAPY) derivatives were designed and synthesized to explore the entrance channel of the non-nucleoside reverse transcriptase inhibitors binding pocket (NNIBP) by incorporating different flexible side chains at the C-6 position. The biological evaluation results showed that all analogues possessed promising HIV-1 inhibitory activity at the nanomolar concentration range. Three compounds (7, 9 and 39) displayed excellent potency against WT HIV-1 strain with EC₅₀ values ranging from 5 to 10 nM and high selectivity indexes (SI = 3504, 30488 and 22846, respectively), which were higher than for nevirapine and comparable to the values for etravirine. The RT inhibition activity, preliminary structure-activity relationship and molecular docking study showed that the side chain at the C-6 position of the DAPYs occupied the entrance channel and significantly influenced anti-HIV activity and selectivity. Additionally, the physicochemical properties were investigated to evaluate the drug-like features, which indicated that introducing various substituents on the pyrimidine ring can improve solubility.

The Fellowship of Privileged Scaffolds-One Structure to Inhibit Them All

Over the past few years, the application of privileged structure has emerged as a powerful approach to the discovery of new biologically active molecules. Privileged structures are molecular scaffolds with binding properties to the range of different biological targets. Moreover, privileged structures typically exhibit good drug-like properties, thus assuring more drug-like properties of modified compound. Our main objective is to discuss the privileged structures used for the development of antiviral agents.

Molecular Mechanism of Small-Molecule Inhibitors in Blocking the PD-1/PD-L1 Pathway through PD-L1 Dimerization

Programmed cell death-1 (PD-1), which is a molecule involved in the inhibitory signal in the immune system and is important due to blocking of the interactions between PD-1 and programmed cell death ligand-1 (PD-L1), has emerged as a promising immunotherapy for treating cancer. In this work, molecular dynamics simulations were performed on complex systems consisting of the PD-L1 dimer with (S)-BMS-200, (R)-BMS-200 and (MOD)-BMS-200 (i.e., S, R and MOD systems) to systematically evaluate the inhibitory mechanism of BMS-200-related small-molecule inhibitors in detail. Among them, (MOD)-BMS-200 was modified from the original (S)-BMS-200 by replacing the hydroxyl group with a carbonyl to remove its chirality. Binding free energy analysis indicates that BMS-200-related inhibitors can promote the dimerization of PD-L1. Meanwhile, no significant differences were observed between the S and MOD systems, though the R system exhibited a slightly higher energy. Residue energy decomposition, nonbonded interaction, and contact number analyses show that the inhibitors mainly bind with the C, F and G regions of the PD-L1 dimer, while nonpolar interactions of key residues Ile54, Tyr56, Met115, Ala121 and Tyr123 on both PD-L1 monomers are the dominant binding-related stability factors. Furthermore, compared with (S)-BMS-200, (R)-BMS-200 is more likely to form hydrogen bonds with charged residues. Finally, free energy landscape and protein-protein interaction analyses show that the key residues of the PD-L1 dimer undergo remarkable conformational changes induced by (S)-BMS-200, which boosts its intimate interactions. This systematic investigation provides a comprehensive molecular insight into the ligand recognition process, which will benefit the design of new small-molecule inhibitors targeting PD-L1 for use in anticancer therapy.

Druggability modification strategies of the diarylpyrimidine-type non-nucleoside reverse transcriptase inhibitors

Drug discovery of human immunodeficiency virus (HIV) is a hot field in medicinal chemistry community for many years. The diarylpyrimidines (DAPYs) are the second-generation non-nucleoside reverse transcriptase inhibitors (NNRTIs) targeting reverse transcriptase, playing a great irreplaceable role in HIV transcriptional therapy. However, fast-growing drug-resistant mutations as nonnegligible challenge are still unpredictably appeared in the clinical practice, leading to deactivate or reduce the existing drugs. In the last 20 years, more and more novel DAPY derivatives have developed with the purpose to counter the mutants. Nevertheless, most of them have dissatisfactory pharmacokinetics (PK) or poor antiviral activity toward resistant mutant strains. In this article, we will analyze the NNRTI derivatives with promising druggability, and summarize a series of druggability modification strategies to improve the antiviral activity, reduce toxicity and improve the PK properties in recent years. The prospects of DAPYs and the directions for future efforts will be discussed.

Scaffold Hopping in Discovery of HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors: From CH(CN)-DABOs to CH(CN)-DAPYs

Scaffold hopping is a frequently-used strategy in the development of non-nucleoside reverse transcriptase inhibitors. Herein, CH(CN)-DAPYs were designed by hopping the cyano-methylene linker of our previous published CH(CN)-DABOs onto the etravirine (ETR). Eighteen CH(CN)-DAPYs were synthesized and evaluated for their anti-HIV activity. Most compounds exhibited promising activity against wild-type (WT) HIV-1. Compounds B4 (EC50 = 6 nM) and B6 (EC50 = 8 nM) showed single-digit nanomolar potency against WT HIV-1. Moreover, these two compounds had EC50 values of 0.06 and 0.08 μM toward the K103N mutant, respectively, which were comparable to the reference efavirenz (EFV) (EC50 = 0.08 μM). The preliminary structure-activity relationship (SAR) indicated that introducing substitutions on C2 of the 4-cyanophenyl group could improve antiviral activity. Molecular docking predicted that the cyano-methylene linker was positioned into the hydrophobic cavity formed by Y181/Y188 and V179 residues.

Data Mining Approach for Extraction of Useful Information About Biologically Active Compounds from Publications

A lot of high quality data on the biological activity of chemical compounds are required throughout the whole drug discovery process: from development of computational models of the structure-activity relationship to experimental testing of lead compounds and their validation in clinics. Currently, a large amount of such data is available from databases, scientific publications, and patents. Biological data are characterized by incompleteness, uncertainty, and low reproducibility. Despite the existence of free and commercially available databases of biological activities of compounds, they usually lack unambiguous information about peculiarities of biological assays. On the other hand, scientific papers are the primary source of new data disclosed to the scientific community for the first time. In this study, we have developed and validated a data-mining approach for extraction of text fragments containing description of bioassays. We have used this approach to evaluate compounds and their biological activity reported in scientific publications. We have found that categorization of papers into relevant and irrelevant may be performed based on the machine-learning analysis of the abstracts. Text fragments extracted from the full texts of publications allow their further partitioning into several classes according to the peculiarities of bioassays. We demonstrate the applicability of our approach to the comparison of the endpoint values of biological activity and cytotoxicity of reference compounds.

Advances in diarylpyrimidines and related analogues as HIV-1 nonnucleoside reverse transcriptase inhibitors

HIV-1 nonnucleoside reverse transcriptase inhibitors (NNRTIs) have been playing an important role in the fight against acquired immunodeficiency syndrome (AIDS). Diarylpyrimidines (DAPYs) as the second generation NNRTIs, represented by etravirine (TMC125) and rilpivirine (TMC278), have attracted extensive attention due to their extraordinary potency, high specificity and low toxicity. However, the rapid emergence of drug-resistant virus strains and dissatisfactory pharmacokinetics of DAPYs present new challenges. In the past two decades, an increasing number of novel DAPY derivatives have emerged, which significantly enriched the structure-activity relationship of DAPYs. Studies of crystallography and molecular modeling have afforded a lot of useful information on structural requirements of NNRTIs, which contributes greatly to the improvement of their resistance profiles. In this review, we reviewed the discovery history and their evolution of DAPYs including their structural modification, derivatization and scaffold hopping in continuous pursuit of excellent anti-HIV drugs. And also, we discussed the prospect of DAPYs and the directions of future efforts.

Drug-like property-driven optimization of 4-substituted 1,5-diarylanilines as potent HIV-1 non-nucleoside reverse transcriptase inhibitors against rilpivirine-resistant mutant virus

On the basis of our prior structure-activity relationship (SAR) results, our current lead optimization of 1,5-diarylanilines (DAANs) focused on the 4-substituent (R1) on the central phenyl ring as a modifiable position related simultaneously to improved drug resistance profiles and drug-like properties. Newly synthesized p-cyanovinyl-DAANs (8a-8g) with different R1 side chains plus prior active p-cyanoethyl-DAANs (4a-4c) were evaluated not only for anti-HIV potency against both wild-type HIV virus and rilpivirine-resistant (E138K, E138K+M184I) viral replication, but also for multiple drug-like properties, including aqueous solubility, lipophilicity, and metabolic stability in human liver microsomes and human plasma. This study revealed that both ester and amide R1 substituents led to low nanomolar anti-HIV potency against wild-type and rilpivirine-resistant viral strains (E138K-resistance fold changes<3). The N-substituted amide-R1 side chains were superior to ester-R1 likely due to improved aqueous solubility, lipophilicity, and higher metabolic stability in vitro. Thus, three amide-DAANs 8e, 4a, and 4b were identified with high potency against wild-type and rilpivirine-resistant viral strains and multiple desirable drug-like properties.

Novel HIV-1 Non-nucleoside Reverse Transcriptase Inhibitor Agents: Optimization of Diarylanilines with High Potency against Wild-Type and Rilpivirine-Resistant E138K Mutant Virus

Three series (6, 13, and 14) of new diarylaniline (DAAN) analogues were designed, synthesized, and evaluated for anti-HIV potency, especially against the E138K viral strain with a major mutation conferring resistance to the new-generation non-nucleoside reverse transcriptase inhibitor drug rilpivirine (1b). Promising new compounds were then assessed for physicochemical and associated pharmaceutical properties, including aqueous solubility, log P value, and metabolic stability, as well as predicted lipophilic parameters of ligand efficiency, ligand lipophilic efficiency, and ligand efficiency-dependent lipophilicity indices, which are associated with ADME property profiles. Compounds 6a, 14c, and 14d showed high potency against the 1b-resistant E138K mutated viral strain as well as good balance between anti-HIV-1 activity and desirable druglike properties. From the perspective of optimizing future NNRTI compounds as clinical trial candidates, computational modeling results provided valuable information about how the R(1) group might provide greater efficacy against the E138K mutant.

Novel diarylpyrimidines and diaryltriazines as potent HIV-1 NNRTIs with dramatically improved solubility: a patent evaluation of US20140378443A1

Diarylpyrimidine and diaryltriazine derivatives, two representative structurally related classes of HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) with robust potencies against wild-type and several mutant strains of HIV-1, have attracted more and more attention in the last decade. However, they have been suffering from poor aqueous solubility. A series of novel diarylpyrimidines and diaryltriazines with solubilizing substituents attached to the central rings were reported as potent NNRTIs in the patent US20140378443A1. Some compounds exhibited potencies against wild-type HIV-1 which were comparable or even superior to those of dapivirine, etravirine and rilpivirine. In addition, dramatically enhanced solubilities were observed for these new compounds. Moreover, some structure optimization strategies for improving aqueous solubility are detailed in this review, providing new insights into development of next-generation NNRTIs endowed with favorable solubility. We anticipate that application of these strategies will ultimately lead to discovery of new anti-HIV drug candidates.

Synthesis and Preliminary Antiviral Activities of Piperidine-substituted Purines against HIV and Influenza A/H1N1 Infections

We have developed a series of N(2) -(1-(substituted-aryl)piperidin-4-yl)-N(6) -mesityl-9H-purine-2,6-diamine derivatives as potent antiviral agents. Preliminary biological evaluation indicated that nearly half of them possessed remarkable HIV inhibitory potencies in cellular assays. In particular, FZJ13 appeared to be the most notable one, which displayed anti-HIV-1 activity compared to 3TC. Moreover, an unexpected finding was that FZJ05 displayed significant potency against influenza A/H1N1 (strain A/PR/8/34) in Madin-Darby canine kidney cells with EC50 values much lower than those of ribavirin, amantadine, and rimantadine. The results suggest that these novel purine derivatives have the potential to be further developed as new therapeutic agents against HIV-1 or influenza virus.

Computational insights into the inhibition and destabilization of morin on the oligomer of full-length human islet amyloid polypeptide

In this work, we simulated the full-length human islet amyloid peptide (hIAPP) pentamer with and without morins to investigate the mechanism of inhibition and destabilization of this inhibitor on hIAPP oligomer, and identify its possible binding sites on hIAPP.

Molecular mechanism of the inhibition and remodeling of human islet amyloid polypeptide (hIAPP(1-37)) oligomer by resveratrol from molecular dynamics simulation

Natural polyphenols are one of the most actively investigated categories of amyloid inhibitors, and resveratrol has recently been reported to inhibit and remodel the human islet amyloid polypeptide (hIAPP) oligomers and fibrils. However, the exact mechanism of its action is still unknown, especially for the full-length hIAPP1-37. To this end, we performed all-atom molecular dynamics simulations for hIAPP1-37 pentamer with and without resveratrol. The obtained results show that the binding of resveratrol is able to cause remarkable conformational changes of hIAPP1-37 pentamer, in terms of secondary structures, order degree, and morphology. By clustering analysis, two possible binding sites of resveratrol on the hIAPP1-37 pentamer were found, located at the grooves of the top and bottom surfaces of β-sheet layer, respectively. After the binding free energy calculation and residue energy decomposition, it can be concluded that the bottom site is the more possible one, and that the nonpolar interactions act as the driving force for the binding of hIAPP1-37 to resveratrol. In addition, Arg11 is the most important residue for the binding of resveratrol. The full understanding of inhibitory mechanism of resveratrol on the hIAPP1-37 oligomer, and the identification of its binding sites on this protein are helpful for the future design and discovery of new amyloid inhibitors.

Physicochemical property-driven optimization of diarylaniline compounds as potent HIV-1 non-nucleoside reverse transcriptase inhibitors

Using physicochemical property-driven optimization, twelve new diarylaniline compounds (DAANs) (7a-h, 11a-b and 12a-b) were designed and synthesized. Among them, compounds 12a-b not only showed high potency (EC50 0.96-4.92 nM) against both wild-type and drug-resistant viral strains with the lowest fold change (FC 0.91 and 5.13), but also displayed acceptable drug-like properties based on aqueous solubility and lipophilicity (LE>0.3, LLE>5, LELP<10). The correlations between potency and physicochemical properties of these DAAN analogues are also described. Compounds 12a-b merit further development as potent clinical trial candidates against AIDS.

Optimization of the antiviral potency and lipophilicity of halogenated 2,6-diarylpyridinamines as a novel class of HIV-1 NNRTIS

Nineteen new halogenated diarylpyridinamine (DAPA) analogues modified at the phenoxy C-ring were synthesized and evaluated for anti-HIV activity and certain drug-like properties. Ten compounds showed high anti-HIV activity (EC50 <10 nM). In particular, (E)-6-(2''-bromo-4''-cyanovinyl-6''-methoxy)phenoxy-N(2) -(4'-cyanophenyl)pyridin-2,3-diamine (8 c) displayed low-nanomolar antiviral potency (3-7 nM) against wild-type and drug-resistant viral strains bearing the E138K or K101E mutations, which are associated with resistance to rilvipirine (1 b). Compound 8 c exhibited much lower resistance fold changes (RFC: 1.1-2.1) than 1 b (RFC: 11.8-13.0). Compound 8 c also exhibited better metabolic stability (in vitro half-life) than 1 b in human liver microsomes, possessed low lipophilicity (clog D: 3.29; measured log P: 3.31), and had desirable lipophilic efficiency indices (LE>0.3, LLE>5, LELP<10). With balanced potency and drug-like properties, 8 c merits further development as an anti-HIV drug candidate.

Synthesis and biological evaluation of pyridazine derivatives as novel HIV-1 NNRTIs

In continuation of our efforts toward identification and optimization of novel non-nucleoside reverse transcriptase inhibitors (NNRTIs), we have employed a structure-based bioisosterism strategy, with which a new series of diarylpyridazine (DAPD) derivatives were synthesized and evaluated for their anti-HIV-1 (human immunodeficiency virus type 1) activity. Most of the title compounds displayed excellent anti-HIV-1 activity at submicromolar concentrations ranging from 34 nM to 5.08 μM. The most promising compound 8g inhibited HIV-1 IIIB in MT-4 cells at a low EC50 value (0.034 μM), which was lower than the reference drug nevirapine and delavirdine. The structure activity relationships (SARs) were discussed and rationalized by docking simulations.

Synthesis and biological evaluation of N-alkyl-N-(4-methoxyphenyl)pyridin-2-amines as a new class of tubulin polymerization inhibitors

Based on our prior antitumor hits, 32 novel N-alkyl-N-substituted phenylpyridin-2-amine derivatives were designed, synthesized and evaluated for cytotoxic activity against A549, KB, KB(VIN), and DU145 human tumor cell lines (HTCL). Subsequently, three new leads (6a, 7g, and 8c) with submicromolar GI(50) values of 0.19-0.41 μM in the cellular assays were discovered, and these compounds also significantly inhibited tubulin assembly (IC(50) 1.4-1.7 μM) and competitively inhibited colchicine binding to tubulin with effects similar to those of the clinical candidate CA-4 in the same assays. These promising results indicate that these tertiary diarylamine derivatives represent a novel class of tubulin polymerization inhibitors targeting the colchicine binding site and showing significant anti-proliferative activity.

Design, synthesis, and preclinical evaluations of novel 4-substituted 1,5-diarylanilines as potent HIV-1 non-nucleoside reverse transcriptase inhibitor (NNRTI) drug candidates

Twenty-one new 4-substituted diarylaniline compounds (DAANs) (series 13, 14, and 15) were designed, synthesized, and evaluated against wild-type and drug resistant HIV-1 viral strains. As a result, approximately a dozen new DAANs showed high potency with low nano- to subnanomolar EC(50) values ranging from 0.2 to 10 nM. The three most promising compounds 14e, 14h, and 15h exhibited high potency against wild-type and drug-resistant viral strains with EC(50) values at the subnanomolar level (0.29-0.87 nM) and were comparable to or more potent than the new NNRTI drug riplivirine (2) in the same assays. Druglike physicochemical property assessments revealed that the most active DAANs (EC(50) < 10 nM) have better aqueous solubility (>1-90 μg/mL at pH 7.4 and pH 2) and metabolic stability in vitro than 2, as well as desirable log P values (<5) and polar surface areas (PSA) (<140 Å(2)). These promising results warrant further development of this novel compound class as potential potent anti-AIDS clinical trial candidates.

Optimization of 2,4-diarylanilines as non-nucleoside HIV-1 reverse transcriptase inhibitors

The current optimization of 2,4-diarylaniline analogs (DAANs) on the central phenyl ring provided a series of new active DAAN derivatives 9a-9e, indicating an accessible modification approach that could improve anti-HIV potency against wild-type and resistant strains, aqueous solubility, and metabolic stability. A new compound 9e not only exhibited extremely high potency against wild-type virus (EC(50) 0.53 nM) and several resistant viral strains (EC(50) 0.36-3.9 nM), but also showed desirable aqueous solubility and metabolic stability, which were comparable or better than those of the anti-HIV-1 drug TMC278 (2). Thus, new compound 9e might be a potential drug candidate for further development of novel next-generation NNRTIs.

Designing hypothesis of substituted benzoxazinones as HIV-1 reverse transcriptase inhibitors: QSAR approach

A linear quantitative structure activity relationship (QSAR) model is presented for predicting human immunodeficiency virus-1 (HIV-1) reverse transcriptase enzyme inhibition. The 2D QSAR and 3D-QSAR models were developed by stepwise multiple linear regression, partial least square (PLS) regression and k-nearest neighbor-molecular field analysis, PLS regression, respectively using a database consisting of 33 recently discovered benzoxazinones. The primary findings of this study is that the number of hydrogen atoms, number of (-NH2) group connected with solitary single bond alters the inhibition of HIV-1 reverse transcriptase. Further, presence of electrostatic, hydrophobic and steric field descriptors significantly affects the ability of benzoxazinone derivatives to inhibit HIV-1 reverse transcriptase. The selected descriptors could serve as a primer for the design of novel and potent antagonists of HIV-1 reverse transcriptase.

HIV-1 NNRTIs: structural diversity, pharmacophore similarity, and implications for drug design

Nonnucleoside reverse transcriptase inhibitors (NNRTIs) nowadays represent very potent and most promising anti-AIDS agents that specifically target the HIV-1 reverse transcriptase (RT). However, the effectiveness of NNRTI drugs can be hampered by rapid emergence of drug-resistant viruses and severe side effects upon long-term use. Therefore, there is an urgent need to develop novel, highly potent NNRTIs with broad spectrum antiviral activity and improved pharmacokinetic properties, and more efficient strategies that facilitate and shorten the drug discovery process would be extremely beneficial. Fortunately, the structural diversity of NNRTIs provided a wide space for novel lead discovery, and the pharmacophore similarity of NNRTIs gave valuable hints for lead discovery and optimization. More importantly, with the continued efforts in the development of computational tools and increased crystallographic information on RT/NNRTI complexes, structure-based approaches using a combination of traditional medicinal chemistry, structural biology, and computational chemistry are being used increasingly in the design of NNRTIs. First, this review covers two decades of research and development for various NNRTI families based on their chemical scaffolds, and then describes the structural similarity of NNRTIs. We have attempted to assemble a comprehensive overview of the general approaches in NNRTI lead discovery and optimization reported in the literature during the last decade. The successful applications of medicinal chemistry strategies, crystallography, and computational tools for designing novel NNRTIs are highlighted. Future directions for research are also outlined.

Design, synthesis, and evaluation of diarylpyridines and diarylanilines as potent non-nucleoside HIV-1 reverse transcriptase inhibitors

On the basis of the structures and activities of our previously identified non-nucleoside reverse transcriptase inhibitors (NNRTIs), we designed and synthesized two sets of derivatives, diarylpyridines (A) and diarylanilines (B), and tested their anti-HIV-1 activity against infection by HIV-1 NL4-3 and IIIB in TZM-bl and MT-2 cells, respectively. The results showed that most compounds exhibited potent anti-HIV-1 activity with low nanomolar EC50 values, and some of them, such as 13m, 14c, and 14e, displayed high potency with subnanomolar EC50 values, which were more potent than etravirine (TMC125, 1) in the same assays. Notably, these compounds were also highly effective against infection by multi-RTI-resistant strains, suggesting a high potential to further develop these compounds as a novel class of NNRTIs with improved antiviral efficacy and resistance profile.