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

Deciphering the enigmas of non-nucleoside reverse transcriptase inhibitors (NNRTIs): A medicinal chemistry expedition towards combating HIV drug resistance

The pivotal involvement of reverse transcriptase activity in the pathogenesis of the progressive HIV virus has stimulated gradual advancements in drug discovery initiatives spanning three decades. Consequently, nonnucleoside reverse transcriptase inhibitors (NNRTIs) have emerged as a preeminent category of therapeutic agents for HIV management. Academic institutions and pharmaceutical companies have developed numerous NNRTIs, an essential component of antiretroviral therapy. Six NNRTIs have received Food and Drug Administration approval and are widely used in clinical practice, significantly improving the quality of HIV patients. However, the rapid emergence of drug resistance has limited the effectiveness of these medications, underscoring the necessity for perpetual research and development of novel therapeutic alternatives. To supplement the existing literatures on NNRTIs, a comprehensive review has been compiled to synthesize this extensive dataset into a comprehensible format for the medicinal chemistry community. In this review, a thorough investigation and meticulous analysis were conducted on the progressions achieved in NNRTIs within the past 8 years (2016-2023), and the experiences and insights gained in the development of inhibitors with varying chemical structures were also summarized. The provision of a crucial point of reference for the development of wide-ranging anti-HIV medications is anticipated.

Synthetic approaches and application of clinically approved small-molecule Anti-HIV drugs: An update

Application of chemotherapeutic agents to inhibit the HIV replication process has brought about a significant metamorphosis in the landscape of AIDS. Substantial declines in morbidity and mortality rates have been attained, accompanied by notable decreases in healthcare resource utilization. However, treatment modalities do not uniformly inhibit HIV replication in every patient, while the emergence of drug-resistant viral strains poses a substantial obstacle to subsequent therapeutic interventions. Furthermore, chronic administration of therapy may lead to the manifestation of toxicities. These challenges necessitate the exploration of novel pharmacological agents and innovative therapeutic approaches aimed at effectively managing the persistent viral replication characteristic of chronic infection. This review examines the role of clinically approved small-molecule drugs in the treatment of HIV/AIDS, which provides an in-depth analysis of the major classes of small-molecule drugs, including nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), integrase inhibitors, entry inhibitors, and pharmacokinetic enhancers. The review mainly discusses the application, synthetic routes, and mechanisms of action of small-molecule drugs employed in the treatment of HIV, as well as their use in combination with antiretroviral therapy, presenting viewpoints on forthcoming avenues in the development of novel anti-HIV drugs.

Design and Synthesis of Novel HIV-1 NNRTIs with Bicyclic Cores and with Improved Physicochemical Properties

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) represent cornerstones of current regimens for treatment of human immunodeficiency virus type 1 (HIV-1) infections. However, NNRTIs usually suffer from low aqueous solubility and the emergence of resistant viral strains. In the present work, novel bicyclic NNRTIs derived from etravirine (ETV) and rilpivirine (RPV), bearing modified purine, tetrahydropteridine, and pyrimidodiazepine cores, were designed and prepared. Compounds 2, 4, and 6 carrying the acrylonitrile moiety displayed single-digit nanomolar activities against the wild-type (WT) virus (EC50 = 2.5, 2.7, and 3.0 nM, respectively), where the low nanomolar activity was retained against HXB2 (EC50 = 2.2-2.8 nM) and the K103N and Y181C mutated strains (fold change, 1.2-6.7×). Most importantly, compound 2 exhibited significantly improved phosphate-buffered saline solubility (10.4 μM) compared to ETV and RPV (≪1 μM). Additionally, the binding modes of compounds 2, 4, and 6 to the reverse transcriptase were studied by X-ray crystallography.

An Overview of the Biological Evaluation of Selected Nitrogen-Containing Heterocycle Medicinal Chemistry Compounds

Heterocyclic compounds are a class of compounds of natural origin with favorable properties and hence have major pharmaceutical significance. They have an exceptional adroitness favoring their use as diverse smart biomimetics, in addition to possessing an active pharmacophore in a complex structure. This has made them an indispensable motif in the drug discovery field. Heterocyclic compounds are usually classified according to the ring size, type, and the number of heteroatoms present in the ring. Among different heterocyclic ring systems, nitrogen heterocyclic compounds are more abundant in nature. They also have considerable pharmacological significance. This review highlights recent pioneering studies in the biological assessment of nitrogen-containing compounds, namely: triazoles, tetrazoles, imidazole/benzimidazoles, pyrimidines, and quinolines. It explores publications between April 2020 and February 2022 and will benefit researchers in medicinal chemistry and pharmacology. The present work is organized based on the size of the heterocyclic ring.

Structure-Based Discovery of Novel NH2-Biphenyl-Diarylpyrimidines as Potent Non-Nucleoside Reverse Transcriptase Inhibitors with Significantly Improved Safety: From NH2-Naphthyl-Diarylpyrimidine to NH2-Biphenyl-Diarylpyrimidine

Results from recently completed studies suggested that the NH₂-naphthyl-diarylpyrimidine JX-7 displayed remarkable inhibitory activity against wild-type HIV-1 (EC₅₀ = 5 nM) and numerous clinically observed variants in MT-4 cells; however, its high cytotoxicity (CC₅₀ = 19 μM) precluded its further development as a clinical candidate. One approach we took to improve the safety involved replacing the naphthyl of JX-7 with biphenyl to provide a series of novel NH₂-biphenyl-DAPYs. Investigation of the structure-activity relationships (SARs) led to the identification of 4ab, a potent NNRTI with significantly reduced cytotoxicity (CC₅₀ = 120 μM), approximately 6-fold lower than JX-7, which maintained remarkable anti-HIV-1 activity against wild-type HIV-1 (EC₅₀ = 1.9 nM) and multiple mutant strains simultaneously. Also, 4ab displayed weak CYP sensitivity, little inhibition of hERG, and no apparent in vivo acute toxicity. These promising results demonstrate that 4ab can be used as a drug candidate for HIV-1 therapy.

Approved HIV reverse transcriptase inhibitors in the past decade

HIV reverse transcriptase (RT) inhibitors are the important components of highly active antiretroviral therapies (HAARTs) for anti-HIV treatment and pre-exposure prophylaxis in clinical practice. Many RT inhibitors and their combination regimens have been approved in the past ten years, but a review on their drug discovery, pharmacology, and clinical efficacy is lacking. Here, we provide a comprehensive review of RT inhibitors (tenofovir alafenamide, rilpivirine, doravirine, dapivirine, azvudine and elsulfavirine) approved in the past decade, regarding their drug discovery, pharmacology, and clinical efficacy in randomized controlled trials. Novel RT inhibitors such as islatravir, MK-8504, MK-8507, MK8583, IQP-0528, and MIV-150 will be also highlighted. Future development may focus on the new generation of novel antiretroviral inhibitors with higher bioavailability, longer elimination half-life, more favorable side-effect profiles, fewer drug-drug interactions, and higher activities against circulating drug-resistant strains.