An insight on medicinal aspects of novel HIV-1 capsid protein inhibitors

Evaluating HIV-1 Infectivity and Virion Maturation across Varied Producer Cells with a Novel FRET-Based Detection and Quantification Assay

The maturation of HIV-1 virions is a crucial process in viral replication. Although T-cells are a primary source of virus production, much of our understanding of virion maturation comes from studies using the HEK293T human embryonic kidney cell line. Notably, there is a lack of comparative analyses between T-cells and HEK293T cells in terms of virion maturation efficiency in existing literature. We previously developed an advanced virion visualization system based on the FRET principle, enabling the effective distinction between immature and mature virions via fluorescence microscopy. In this study, we utilized pseudotyped, single-round infectious viruses tagged with FRET labels (HIV-1 Gag-iFRET∆Env) derived from Jurkat (a human T-lymphocyte cell line) and HEK293T cells to evaluate their virion maturation rates. HEK293T-derived virions demonstrated a maturity rate of 81.79%, consistent with other studies and our previous findings. However, virions originating from Jurkat cells demonstrated a significantly reduced maturation rate of 68.67% (p < 0.0001). Correspondingly, viruses produced from Jurkat cells exhibited significantly reduced infectivity compared to those derived from HEK293T cells, with the relative infectivity measured at 65.3%. This finding is consistent with the observed relative maturation rate of viruses produced by Jurkat cells. These findings suggest that initiation of virion maturation directly correlates with viral infectivity. Our observation highlights the dynamic nature of virus-host interactions and their implications for virion production and infectivity.

Therapeutic stapled peptides: Efficacy and molecular targets

Peptide stapling, by employing a stable, preformed alpha-helical conformation, results in the production of peptides with improved membrane permeability and enhanced proteolytic stability, compared to the original peptides, and provides an effective solution to accelerate the rapid development of peptide drugs. Various reviews present peptide stapling chemistries, anchoring residues and one- or two-component cyclization, however, therapeutic stapled peptides have not been systematically summarized, especially focusing on various disease-related targets. This review highlights the latest advances in therapeutic peptide drug development facilitated by the application of stapling technology, including different stapling techniques, synthetic accessibility, applicability to biological targets, potential for solving biological problems, as well as the current status of development. Stapled peptides as therapeutic drug candidates have been classified and analysed mainly by receptor- and ligand-based stapled peptide design against various diseases, including cancer, infectious diseases, inflammation, and diabetes. This review is expected to provide a comprehensive reference for the rational design of stapled peptides for different diseases and targets to facilitate the development of therapeutic peptides with enhanced pharmacokinetic and biological properties.

Evaluating HIV-1 Infectivity and Virion Maturation Across Varied Producer Cells with a Novel FRET-Based Detection and Quantification Assay

The maturation of HIV-1 virions is a crucial process in viral replication. Although T cells are a primary source of virus production, much of our understanding of virion maturation comes from studies using the HEK293T human embryonic kidney cell line. Notably, there is a lack of comparative analyses between T cells and HEK293T cells in terms of virion maturation efficiency in existing literature. We previously developed an advanced virion visualization system based on the FRET principle, enabling the effective distinction between immature and mature virions via fluorescence microscopy. In this study, we utilized pseudotyped, single-round infectious viruses tagged with FRET labels (HIV-1 Gag-iFRETΔEnv) derived from Jurkat (a human T lymphocyte cell line) and HEK293T cells to evaluate their virion maturation rates. HEK293T-derived virions demonstrated a maturity rate of 81.79%, consistent with other studies and our previous findings. However, virions originating from Jurkat cells demonstrated a significantly reduced maturation rate of 68.67% (p < 0.0001). Correspondingly, viruses produced from Jurkat cells exhibited significantly reduced infectivity compared to those derived from HEK293T cells, with the relative infectivity measured at 65.3%. This finding is consistent with the observed relative maturation rate of viruses produced by Jurkat cells. These findings suggest that initiation of virion maturation directly correlates with viral infectivity. Our observation highlights the dynamic nature of virus-host interactions and their implications for virion production and infectivity.

Discovery of low-molecular-weight phenylalanine derivatives as novel HIV capsid modulators with improved antiretroviral activity and metabolic stability

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

Discovery, Crystallographic Studies, and Mechanistic Investigations of Novel Phenylalanine Derivatives Bearing a Quinazolin-4-one Scaffold as Potent HIV Capsid Modulators

Optimization of compound 11L led to the identification of novel HIV capsid modulators, quinazolin-4-one-bearing phenylalanine derivatives, displaying potent antiviral activities against both HIV-1 and HIV-2. Notably, derivatives 12a2 and 21a2 showed significant improvements, with 2.5-fold over 11L and 7.3-fold over PF74 for HIV-1, and approximately 40-fold over PF74 for HIV-2. The X-ray co-crystal structures confirmed the multiple pocket occupation of 12a2 and 21a2 in the binding site. Mechanistic studies revealed a dual-stage inhibition profile, where the compounds disrupted capsid-host factor interactions at the early stage and promoted capsid misassembly at the late stage. Remarkably, 12a2 and 21a2 significantly promoted capsid misassembly, outperforming 11L, PF74, and LEN. The substitution of easily metabolized amide bond with quinolin-4-one marginally enhanced the stability of 12a2 in human liver microsomes compared to controls. Overall, 12a2 and 21a2 highlight their potential as potent HIV capsid modulators, paving the way for future advancements in anti-HIV drug design.

Bibliometric analysis and visualization of research trends on HIV-1 capsid inhibitors (2000-2022)

Background: Acquired immunodeficiency syndrome (AIDS) has seriously endangered human life and health, the main pathogenic agent is human immunodeficiency virus type 1 (HIV-1). The combination antiretroviral therapy (cART) has shown serious drug resistance and side effects, and the discovery of HIV-1 capsid inhibitors is an effective way to solve the problem. Recent studies have shown significant progress in the research of HIV-1 capsid inhibitors. However, there is still a lack of comprehensive overview of bibliometric analysis in this field. This study aimed to provide the research trends and hotspots of HIV-1 capsid inhibitors. Method: Publications related to HIV-1 capsid inhibitors from 2000 to 2022 were searched on the Web of Science Core Collection (WoSCC) database and screened according to inclusion criteria. VOSviewer was conducted to evaluate the results. Results: 96 publications from 25 countries were finally included, and the number of annual publications related to HIV-1 capsid inhibitors showed an increasing trend. The United States was the most productive country with the most publication number, H-index, and total citation number, as well as the widest international cooperation. The most popular journal in this field was Journal of Virology. Drexel University was the most productive institution, and Simon Cocklin participated in the most publications. Keywords co-occurrence analysis exhibited that studying the molecular mechanism of capsid protein, discovering drug candidates, and improving antiretroviral therapy are the main and hot topics in this field. Conclusion: This is the first bibliometric study in the field of HIV-1 capsid inhibitors, which comprehensively analyzed the research trends and hotspots in this direction. This work is expected to provide the scientific community with new insights to promote the research of HIV-1 capsid inhibitors.

Advances in long-acting slow effective release antiretroviral therapies for treatment and prevention of HIV infection

Adherence to daily oral antiretroviral therapy (ART) is a barrier to both treatment and prevention of human immunodeficiency virus (HIV) infection. To overcome limitations of life-long daily regimen adherence, long-acting (LA) injectable antiretroviral (ARV) drugs, nanoformulations, implants, vaginal rings, microarray patches, and ultra-long-acting (ULA) prodrugs are now available or in development. These medicines enable persons who are or at risk for HIV infection to be treated with simplified ART regimens. First-generation LA cabotegravir, rilpivirine, and lenacapavir injectables and a dapivirine vaginal ring are now in use. However, each remains limited by existing dosing intervals, ease of administration, or difficulties in finding drug partners. ULA ART regimens provide an answer, but to date, such next-generation formulations remain in development. Establishing the niche will require affirmation of extended dosing, improved access, reduced injection volumes, improved pharmacokinetic profiles, selections of combination treatments, and synchronization of healthcare support. Based on such needs, this review highlights recent pharmacological advances and a future treatment perspective. While first-generation LA ARTs are available for HIV care, they remain far from ideal in meeting patient needs. ULA medicines, now in advanced preclinical development, may close gaps toward broader usage and treatment options.

Design, synthesis, and mechanistic study of 2-piperazineone-bearing peptidomimetics as novel HIV capsid modulators

HIV-1 capsid (CA) is an attractive target for its indispensable roles in the viral life cycle. We report the design, synthesis, and mechanistic study of a novel series of 2-piperazineone peptidomimetics as HIV capsid modulators by mimicking the structure of host factors binding to CA. F-Id-3o was the most potent compound from the synthesized series, with an anti-HIV-1 EC50 value of 6.0 μM. However, this series of compounds showed a preference for HIV-2 inhibitory activity, in which Id-3o revealed an EC50 value of 2.5 μM (anti-HIV-2 potency), an improvement over PF74. Interestingly, F-Id-3o did bind HIV-1 CA monomers and hexamers with comparable affinity, unlike PF74, consequently showing antiviral activity in the early and late stages of the HIV-1 lifecycle. Molecular dynamics simulations shed light on F-Id-3o and Id-3o binding modes within the HIV-1/2 CA protein and provide a possible explanation for the increased anti-HIV-2 potency. Metabolic stability assays in human plasma and human liver microsomes indicated that although F-Id-3o has enhanced metabolic stability over PF74, further optimization is necessary. Moreover, we utilized computational prediction of drug-like properties and metabolic stability of F-Id-3o and PF74, which correlated well with experimentally derived metabolic stability, providing an efficient computational pipeline for future preselection based on metabolic stability prediction. Overall, the 2-piperazineone-bearing peptidomimetics are a promising new chemotype in the CA modulators class with considerable optimization potential.

Fluorine in anti-HIV drugs approved by FDA from 1981 to 2023

Human immunodeficiency virus (HIV) is the etiological agent of acquired immunodeficiency syndrome (AIDS). Nowadays, FDA has approved over thirty antiretroviral drugs grouped in six categories. Interestingly, one-third of these drugs contain different number of fluorine atoms. The introduction of fluorine to obtain drug-like compounds is a well-accepted strategy in medicinal chemistry. In this review, we summarized 11 fluorine-containing anti-HIV drugs, focusing on their efficacy, resistance, safety, and specific roles of fluorine in the development of each drug. These examples may be of help for the discovery of new drug candidates bearing fluorine in their structures.

Tracing the recent updates on vaccination approaches and significant adjuvants being developed against HIV

INTRODUCTION

Human Immunodeficiency Virus type 1 (HIV1); the causative agent of Acquired Immunodeficiency Syndrome (AIDS), has been a major target of the scientific community to develop an anti-viral therapy. Some successful discoveries have been made during the last two decades in the form of availability of antiviral therapy in endemic regions. Nevertheless, a total cure and safety vaccine has not yet been designed to eradicate HIV from the world.

AREAS COVERED

The purpose of this comprehensive study is to compile recent data regarding therapeutic interventions against HIV and to determine future research needs in this field. A systematic research strategy has been used to gather data from recent, most advanced published electronic sources. Literature based results show that experiments at the invitro level and animal models are continuously in research annals and are providing hope for human trials.

EXPERT OPINION

There is still a gap and more work is needed in the direction of modern drug and vaccination designs. Moreover coordination is necessary among researchers, educationists, public health workers, and the general community to communicate and coordinate the repercussions associated with the deadly disease. It is important for taking timely measures regarding mitigation and adaptation with HIV in future.

Medicinal chemistry insights into antiviral peptidomimetics

The (re)emergence of multidrug-resistant viruses and the emergence of new viruses highlight the urgent and ongoing need for new antiviral agents. The use of peptidomimetics as therapeutic drugs has often been associated with advantages, such as enhanced binding affinity, improved metabolic stability, and good bioavailability profiles. The development of novel antivirals is currently driven by strategies of converting peptides into peptidomimetic derivatives. In this review, we outline different structural modification design strategies for developing novel peptidomimetics as antivirals, involving N- or C-cap terminal structure modifications, pseudopeptides, amino acid modifications, inverse-peptides, cyclization, and molecular hybridization. We also present successful recent examples of peptidomimetic designs.

The discovery and design of novel HIV-1 capsid modulators and future perspectives

INTRODUCTION

Although combination antiretroviral therapy (cART) has achieved significant success in treating HIV, the emergence of multidrug-resistant viruses and cumulative medication toxicity make it necessary to find new classes of antiretroviral agents with novel mechanisms of action. With high sequence conservation, the HIV-1 capsid (CA) protein has attracted attention as a prospective therapeutic target due to its crucial structural and regulatory functions in the HIV-1 replication cycle.

AREA COVERED

Herein, the authors provide a cutting-edge overview of current advances in the design and discovery of CA modulators, PF74, GS-6207 and their derivativeswhich targets a therapeutically attractive NTD-CTD interprotomer pocket within the hexameric configuration of HIV-1 CA. The discovery and development of these compounds, and derivatives thereof, have provided valuable information for the design of second-generation CA-targeting antivirals.

EXPERT OPINION

Despite some successes in designing and discovering HIV-1 CA modulators, more studies are required to decipher which chemical groups confer specific desirable properties. The future of CA-modulating compounds may lie in covalent inhibition and the creation of proteolysis-targeting chimeras (PROTACs). Moreover, biological interrogation of the process of CA uncoating, virus-host interactions, and studies on the lattice-binding restriction factors may improve our knowledge of HIV-1 CA and support the design of new antiviral agents.

Discovery of novel 1,2,4-triazole phenylalanine derivatives targeting an unexplored region within the interprotomer pocket of the HIV capsid protein

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

Discovery and Mechanistic Investigation of Piperazinone Phenylalanine Derivatives with Terminal Indole or Benzene Ring as Novel HIV-1 Capsid Modulators

HIV-1 capsid (CA) performs multiple roles in the viral life cycle and is a promising target for antiviral development. In this work, we describe the design, synthesis, assessment of antiviral activity, and mechanistic investigation of 20 piperazinone phenylalanine derivatives with a terminal indole or benzene ring. Among them, F₂-7f exhibited moderate anti-HIV-1 activity with an EC₅₀ value of 5.89 μM, which was slightly weaker than the lead compound PF74 (EC₅₀ = 0.75 μM). Interestingly, several compounds showed a preference for HIV-2 inhibitory activity, represented by 7f with an HIV-2 EC₅₀ value of 4.52 μM and nearly 5-fold increased potency over anti-HIV-1 (EC₅₀ = 21.81 μM), equivalent to PF74 (EC₅₀ = 4.16 μM). Furthermore, F₂-7f preferred to bind to the CA hexamer rather than to the monomer, similar to PF74, according to surface plasmon resonance results. Molecular dynamics simulation indicated that F₂-7f and PF74 bound at the same site. Additionally, we computationally analyzed the ADMET properties for 7f and F₂-7f. Based on this analysis, 7f and F₂-7f were predicted to have improved drug-like properties and metabolic stability over PF74, and no toxicities were predicted based on the chemotype of 7f and F₂-7f. Finally, the experimental metabolic stability results of F₂-7f in human liver microsomes and human plasma moderately correlated with our computational prediction. Our findings show that F₂-7f is a promising small molecule targeting the HIV-1 CA protein with considerable development potential.

Design, Synthesis, and Mechanistic Study of 2-Pyridone-Bearing Phenylalanine Derivatives as Novel HIV Capsid Modulators

The AIDS pandemic is still of importance. HIV-1 and HIV-2 are the causative agents of this pandemic, and in the absence of a viable vaccine, drugs are continually required to provide quality of life for infected patients. The HIV capsid (CA) protein performs critical functions in the life cycle of HIV-1 and HIV-2, is broadly conserved across major strains and subtypes, and is underexploited. Therefore, it has become a therapeutic target of interest. Here, we report a novel series of 2-pyridone-bearing phenylalanine derivatives as HIV capsid modulators. Compound FTC-2 is the most potent anti-HIV-1 compound in the new series of compounds, with acceptable cytotoxicity in MT-4 cells (selectivity index HIV-1 > 49.57; HIV-2 > 17.08). However, compound TD-1a has the lowest EC50 in the anti-HIV-2 assays (EC50 = 4.86 ± 1.71 μM; CC50= 86.54 ± 29.24 μM). A water solubility test found that TD-1a showed a moderately increased water solubility compared with PF74, while the water solubility of FTC-2 was improved hundreds of times. Furthermore, we use molecular simulation studies to provide insight into the molecular contacts between the new compounds and HIV CA. We also computationally predict drug-like properties and metabolic stability for FTC-2 and TD-1a. Based on this analysis, TD-1a is predicted to have improved drug-like properties and metabolic stability over PF74. This study increases the repertoire of CA modulators and has important implications for developing anti-HIV agents with novel mechanisms, especially those that inhibit the often overlooked HIV-2.

Metabolite Identification of HIV-1 Capsid Modulators PF74 and 11L in Human Liver Microsomes

PF74 and 11L, as potent modulators of the HIV-1 capsid protein, have been demonstrated to act at both early and late stages in the HIV-1 life cycle. However, their clearance is high in human liver microsomes (HLMs). The main goal of this study was to clarify the metabolism of PF74 and 11L in HLMs, and provide guidance for future structural optimization. To accomplish this, the phase-I metabolites of PF74 and 11L, resulting from in vitro incubation with HLMs, were investigated via ultra-performance liquid chromatography–ultraviolet–high-resolution mass spectrometry (UPLC–UV–HRMS). The results show that 17 phase-I metabolites were putatively annotated for PF74, whereas 16 phase-I metabolites were found for 11L. The main metabolic pathways of PF74 in HLMs were oxidation and demethylation, and the secondary metabolic pathway was hydrolysis; thus, the di-oxidation and demethylation products (M7, M9, M11, and M14) were found to be major metabolites of PF74 in HLMs. In comparison, the main metabolic pathways of 11L in HLMs were oxidation, demethylation, dehydrogenation, and oxidative deamination, with M6′, M11′, M15′, and M16′ as the main metabolites. We suggest that the indole ring and N-methyl group of PF74, and the aniline group, benzene ring R1′, N-methyl, and methoxy group of 11L, were the main metabolic soft spots. Therefore, our research illuminates structural optimization options in seeking improved HIV-1 CA modulators.

Design, synthesis, and mechanism study of dimerized phenylalanine derivatives as novel HIV-1 capsid inhibitors

HIV-1 capsid (CA) plays indispensable and multiple roles in the life cycle of HIV-1, become an attractive target in antiviral therapy. Herein, we report the design, synthesis, and mechanism study of a novel series of dimerized phenylalanine derivatives as HIV-1 capsid inhibitors using 2-piperazineone or 2,5-piperazinedione as a linker. The structure-activity relationship (SAR) indicated that dimerized phenylalanines were more potent than monomers of the same chemotype. Further, the inclusion of fluorine substituted phenylalanine and methoxyl substituted aniline was found to be beneficial for antiviral activity. From the synthesized series, Q-c4 was found to be the most potent compound with an EC₅₀ value of 0.57 μM, comparable to PF74. Interestingly, Q-c4 demonstrated a slightly higher affinity to the CA monomer than the CA hexamer, commensurate with its more significant effect in the late-stage of the HIV-1 lifecycle. Competitive SPR experiments with peptides from CPSF6 and NUP153 revealed that Q-c4 binds to the interprotomer pocket of hexameric CA as designed. Single-round infection assays showed that Q-c4 interferes with the HIV-1 life cycle in a dual-stage manner, affecting both pre-and post-integration. Stability assays in human plasma and human liver microsomes indicated that although Q-c4 has improved stability over PF74, this kind of inhibitor still requires further optimization. And the results of the online molinspiration software predicted that Q-c4 has desirable physicochemical properties but some properties still have some violation from the Lipinski rule of five. Overall, the dimerized phenylalanines are promising novel platforms for developing future HIV-1 CA inhibitors with considerable potential for optimization.

Update and latest advances in antiretroviral therapy

Since the first cases of AIDS appeared in 1981, human immunodeficiency virus type 1 (HIV-1) infection has reached pandemic proportions. Forty years later, research has led to the approval of more than 30 antiretroviral drugs, while combination therapies have turned HIV-1 infection into a chronic, but manageable disease. Still, drug toxicity and acquired and transmitted drug resistance remain as major threats to therapy success. In this review, we provide an overview on currently available anti-HIV drugs and the latest developments in antiretroviral therapy, focused on new antiretroviral agents acting on known and unexploited antiviral targets, prevention therapies aimed to improve available drug combinations, and research on new long-acting therapies, particularly those involving novel drug candidates such as lenacapavir or islatravir.

Design, synthesis, and antiviral activity of phenylalanine derivatives as HIV-1 capsid inhibitors

The HIV-1 Capsid (CA) is considered as a promising target for the development of potent antiviral drugs, due to its multiple roles during the viral life cycle. Herein, we report the design, synthesis, and antiviral activity evaluation of series of novel phenylalanine derivatives as HIV-1 CA protein inhibitors. Among them, 4-methoxy-N-methylaniline substituted phenylalanine (II-13c) and indolin-5-amine substituted phenylalanine (V-25i) displayed exceptional anti-HIV-1 activity with the EC₅₀ value of 5.14 and 2.57 μM respectively, which is slightly weaker than that of lead compound PF-74 (EC₅₀ = 0.42 μM). Besides, surface plasmon resonance (SPR) binding assay demonstrated II-13c and V-25i prefer to combine with CA hexamer rather than monomer, which is similar to PF-74. Subsequently, molecular dynamics simulation (MD) revealed potential interactions between representative compounds with HIV-1 CA hexamer. Overall, this work laid a solid foundation for further structural optimization to discover novel promising HIV-1 CA inhibitors.

Design, synthesis, and mechanistic investigations of phenylalanine derivatives containing a benzothiazole moiety as HIV-1 capsid inhibitors with improved metabolic stability

Further clinical development of PF74, a lead compound targeting HIV-1 capsid, is impeded by low antiviral activity and inferior metabolic stability. By modifying the benzene (region I) and indole of PF74, we identified two potent compounds (7m and 7u) with significantly improved metabolic stability. Compared to PF74, 7u displayed greater metabolic stability in human liver microsomes (HLMs) with half-life (t_1/2) 109-fold that of PF74. Moreover, mechanism of action (MOA) studies demonstrated that 7m and 7u effectively mirrored the MOA of compounds that interact within the PF74 interprotomer pocket, showing direct and robust interactions with recombinant CA, and 7u displaying antiviral effects in both the early and late stages of HIV-1 replication. Furthermore, MD simulation corroborated that 7u was bound to the PF74 binding site, and the results of the online molinspiration software predicted that 7m and 7u had desirable physicochemical properties. Unexpectedly, this series of compounds exhibited better antiviral activity than PF74 against HIV-2, represented by compound 7m whose anti-HIV-2 activity was almost 5 times increased potency over PF74. Therefore, we have rationally redesigned the PF74 chemotype to inhibitors with novel structures and enhanced metabolic stability in this study. We hope that these new compounds can serve as a blueprint for developing a new generation of HIV treatment regimens.