Inhibitors of human immunodeficiency virus type 1 (HIV-1) attachment. 12. Structure-activity relationships associated with 4-fluoro-6-azaindole derivatives leading to the identification of 1-(4-benzoylpiperazin-1-yl)-2-(4-fluoro-7-[1,2,3]triazol-1-yl-1h-pyrrolo[2,3-c]pyridin-3-yl)ethane-1,2-dione (BMS-585248)

Medicinal chemistry perspectives on the development of piperazine-containing HIV-1 inhibitors

The Human immunodeficiency virus (HIV) is the causative agent of acquired immunodeficiency syndrome (AIDS), one of the most perilous diseases known to humankind. A 2023 estimate put the number of people living with HIV around 40 million worldwide, with the majority benefiting from various antiretroviral therapies. Consequently, the urgent need for the development of effective drugs to combat this virus cannot be overstated. In the realm of medicinal and organic chemistry, the synthesis and identification of novel compounds capable of inhibiting HIV enzymes at different stages of their life cycle are of paramount importance. Notably, the spotlight is on the progress made in enhancing the potency of HIV inhibitors through the use of piperazine-based compounds. Multiple studies have revealed that the incorporation of a piperazine moiety results in a noteworthy enhancement of anti-HIV activity. The piperazine ring assumes a pivotal role in shaping the pharmacophore responsible for inhibiting HIV-1 at critical stage, including attachment, reverse transcription, integration, and protease activity. This review also sheds light on the various opportunities that can be exploited to develop effective antiretroviral targets and eliminate latent HIV reservoirs. The advancement of highly potent analogues in HIV inhibitor research has been greatly facilitated by contemporary medicinal strategies, including molecular/fragment hybridization, structure-based drug design, and bioisosterism. These techniques have opened up new avenues for the development of compounds with enhanced efficacy in combating the virus.

Development of Azaindole-Based Frameworks as Potential Antiviral Agents and Their Future Perspectives

The azaindole (AI) framework continues to play a significant role in the design of new antiviral agents. Modulating the position and isosteric replacement of the nitrogen atom of AI analogs notably influences the intrinsic physicochemical properties of lead compounds. The intra- and intermolecular interactions of AI derivatives with host receptors or viral proteins can also be fine tuned by carefully placing the nitrogen atom in the heterocyclic core. This wide-ranging perspective article focuses on AIs that have considerable utility in drug discovery programs against RNA viruses. The inhibition of influenza A, human immunodeficiency, respiratory syncytial, neurotropic alpha, dengue, ebola, and hepatitis C viruses by AI analogs is extensively reviewed to assess their plausible future potential in antiviral drug discovery. The binding interaction of AIs with the target protein is examined to derive a structural basis for designing new antiviral agents.

Pyrazole Containing Anti-HIV Agents: An Update

BACKGROUND

Pyrazole scaffolds have gained importance in drug discovery and development for various pharmacological activities like antiviral, antifungal, anticancer, antidepressant, anti-inflammatory, antibacterial, etc. Additionally, the pyrazole moiety has shown potent anti-HIV activity as a core heterocycle or substituted heterocycles derivatives (mono, di, tri, tetra, and fused pyrazole derivatives). To assist the development of further potential anti-HIV agents containing pyrazole nucleus, here we have summarized pyrazole containing anti-HIV compounds that have been reported by researchers all over the world for the last two decades.

OBJECTIVE

The present review concentrates on an assortment of pyrazole containing compounds, particularly for potential therapeutic activity against HIV.

METHODS

Google Scholar, Pubmed, and SciFinder were searched databases with ''pyrazol'' keywords. Further, the year of publication and keywords ''Anti-HIV'' filter was applied to obtain relevant reported literature for anti-HIV agents containing pyrazole as a core or substituted derivatives.

RESULTS

This review article has shown the comprehensive compilation of 220 compounds containing pyrazole nucleus and possessing anti-HIV activity by sorting approximately 40 research articles from 2001 to date. 1-(4-Benzoylpiperazin-1-yl)-2-(4-fluoro-7-(1H-pyrazol-3-yl)-1H-pyrrolo[2,3-c]pyridin-3-yl)ethane-1,2-dione (13), 3-(3-(2-(4-benzoylpiperazin-1-yl)-2-oxoacetyl)-4-fluoro-1H-pyrrolo[2,3-c]pyridin-7-yl)-1H-pyrazole-5-carboxamide (31), 3-(3-(2-(4-benzoylpiperazin-1-yl)-2-oxoacetyl)-4-fluoro-1H-pyrrolo[2,3-c]pyridin-7-yl)-1H-pyrazole-5-carboxamide (88), 3-cyanophenoxypyrazole derivative (130), and 4-(4-chlorophenyl)-5-(4-methyl-5-((4-nitrophenyl)diazenyl)thiazol-2-yl)-3-phenyl-5,6-dihydro-4H-pyrazolo[4,3-d]isoxazole (178) were the most potent mono-, di-, tri-, tetra-substituted, and fused pyrazole derivatives, respectively, which have shown potent anti-HIV activity among all the described derivatives as compared with standard anti-HIV drugs.

CONCLUSION

This review article provides an overview of the potential therapeutic activity of pyrazole derivatives against HIV that will be helpful for designing pyrazole containing compounds for anti-HIV activity.

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.

Innovation in the discovery of the HIV-1 attachment inhibitor temsavir and its phosphonooxymethyl prodrug fostemsavir

The discovery and development of fostemsavir (2), the tromethamine salt of the phosphonooxymethyl prodrug of temsavir (1), encountered significant challenges at many points in the preclinical and clinical development program that, in many cases, stimulated the implementation of innovative solutions in order to enable further progression. In the preclinical program, a range of novel chemistry methodologies were developed during the course of the discovery effort that enabled a thorough examination and definition of the HIV-1 attachment inhibitor (AI) pharmacophore. These discoveries helped to address the challenges associated with realizing a molecule with all of the properties necessary to successfully advance through development and this aspect of the program is the major focus of this retrospective. Although challenges and innovation are not unusual in drug discovery and development programs, the HIV-1 AI program is noteworthy not only because of the serial nature of the challenges encountered along the development path, but also because it resulted in a compound that remains the first and only example of a mechanistically novel class of HIV-1 inhibitor that is proving to be very beneficial for controlling virus levels in highly treatment-experienced HIV-1 infected patients.

Recent developments in the synthesis of azaindoles from pyridine and pyrrole building blocks

The azaindole framework is ubiquitous in bioactive natural products and pharmaceuticals. This review highlights the synthetic approaches to azaindoles with advantages and limitations, mechanistic pathways and biological importance.

Azaindole therapeutic agents

Azaindole structural framework is an integral part of several biologically active natural and synthetic organic molecules; and several FDA approved drugs for various diseases. In the last decade, quite a number of literature reports appeared describing the pharmacology, biological activity and therapeutic applications of a variety of azaindole molecules. This prompted the organic and medicinal chemistry community to develop novel synthetic methods for various azaindoles and test them for a bioactivity against a variety of biological targets. Herein, we have summarized the biological activity of therapeutically advanced clinical candidates and several preclinical candidate drugs that contain azaindole structural moiety.

Usnic Acid Enaminone-Coupled 1,2,3-Triazoles as Antibacterial and Antitubercular Agents

(+)-Usnic acid, a product of secondary metabolism in lichens, has displayed a broad range of biological properties such as antitumor, antimicrobial, antiviral, anti-inflammatory, and insecticidal activities. Interested by these pharmacological activities and to tap into its potential, we herein present the synthesis and biological evaluation of new usnic acid enaminone-conjugated 1,2,3-triazoles 10-44 as antimycobacterial agents. (+)-Usnic acid was condensed with propargyl amine to give usnic acid enaminone 8 with a terminal ethynyl moiety. It was further reacted with various azides A1-A35 under copper catalysis to give triazoles 10-44 in good yields. Among the synthesized compounds, saccharin derivative 36 proved to be the most active analogue, inhibiting Mycobacterium tuberculosis (Mtb) at an MIC value of 2.5 μM. Analogues 16 and 27, with 3,4-difluorophenacyl and 2-acylnaphthalene units, respectively, inhibited Mtb at MIC values of 5.4 and 5.3 μM, respectively. Among the tested Gram-positive and Gram-negative bacteria, the new derivatives were active on Bacillus subtilis, with compounds 18 [3-(trifluoromethyl)phenacyl] and 29 (N-acylmorpholinyl) showing inhibitory concentrations of 41 and 90.7 μM, respectively, while they were inactive on the other tested bacterial strains. Overall, the study presented here is useful for converting natural (+)-usnic acid into antitubercular and antibacterial agents via incorporation of enaminone and 1,2,3-triazole functionalities.

Synthesis of Novel Bis-pyrazole Derivatives as Antimicrobial Agents

BACKGROUND

Bis-heterocycles especially those containing pyrazole moiety display much better antibacterial activity than mono heterocycles.

OBJECTIVE

Herein, we synthesised a series of new bis-pyrazoles and investigated their antimicrobial agents.

METHODS

A novel series of bis-pyrazole derivatives have been synthesized in good yield by coupling reaction of cyanoacetic acid {4-[(2-cyano-acetyl)-hydrazonomethyl]-benzylidene}-hydrazide with a number of diazonium salts of aromatic amines in DMF in the presence of NaOH. Refluxing of the produced hydrazones with hydrazine-hydrate in ethanolic solution afforded the respective bis-pyrazoles. On the other hand, the reaction of bis(cyanoacetic acid hydrazide) derivative with a diversity of hydrazonoyl chlorides in dioxane under reflux gave bis-pyrazoles.

RESULTS

The structures of all the products were discussed and assured from all possible spectral data as well as for the elemental analysis. In addition, the results of the antimicrobial activity examination of selected derivatives revealed a high strength of some tested compounds compared to standard bactericides and fungicides utilized. Molecular docking of the newly synthesized compounds into the Enoyl ACP reductase active site supported the in vitro antimicrobial activity. All the tested compounds could fit in the enzyme binding pocket with significant binding affinities (-7.040 to -9.141 Kcal/mol).

CONCLUSION

The good results of the antimicrobial examination of the newly synthesized bis-pyrazoles comprise the considerable evidence of the importance of bis-heterocyclic compounds which encourages us to continue designing and synthesising a novel series with potent biological activity in the future.

Discovery of the Human Immunodeficiency Virus Type 1 (HIV-1) Attachment Inhibitor Temsavir and Its Phosphonooxymethyl Prodrug Fostemsavir

The optimization of the 4-methoxy-6-azaindole series of HIV-1 attachment inhibitors (AIs) that originated with 1 to deliver temsavir (3, BMS-626529) is described. The most beneficial increases in potency and pharmacokinetic (PK) properties were attained by incorporating N-linked, sp²-hybridized heteroaryl rings at the 7-position of the heterocyclic nucleus. Compounds that adhered to a coplanarity model afforded targeted antiviral potency, leading to the identification of 3 with characteristics that provided for targeted exposure and PK properties in three preclinical species. However, the physical properties of 3 limited plasma exposure at higher doses, both in preclinical studies and in clinical trials as the result of dissolution- and/or solubility-limited absorption, a deficiency addressed by the preparation of the phosphonooxymethyl prodrug 4 (BMS-663068, fostemsavir). An extended-release formulation of 4 is currently in phase III clinical trials where it has shown promise as part of a drug combination therapy in highly treatment-experienced HIV-1 infected patients.

Inhibitors of HIV-1 Attachment: The Discovery and Development of Temsavir and its Prodrug Fostemsavir

Human immunodeficiency virus-1 (HIV-1) infection currently requires lifelong therapy with drugs that are used in combination to control viremia. The indole-3-glyoxamide 6 was discovered as an inhibitor of HIV-1 infectivity using a phenotypic screen and derivatives of this compound were found to interfere with the HIV-1 entry process by stabilizing a conformation of the virus gp120 protein not recognized by the host cell CD4 receptor. An extensive optimization program led to the identification of temsavir (31), which exhibited an improved antiviral and pharmacokinetic profile compared to 6 and was explored in phase 3 clinical trials as the phosphonooxymethyl derivative fostemsavir (35), a prodrug designed to address dissolution- and solubility-limited absorption issues. In this drug annotation, we summarize the structure-activity and structure-liability studies leading to the discovery of 31 and the clinical studies conducted with 35 that entailed the development of an extended release formulation suitable for phase 3 clinical trials.

Advanced Prodrug Strategies in Nucleoside and Non-Nucleoside Antiviral Agents: A Review of the Recent Five Years

Background: Poor pharmacokinetic profiles and resistance are the main two drawbacks from which currently used antiviral agents suffer, thus make them excellent targets for research, especially in the presence of viral pandemics such as HIV and hepatitis C. Methods: The strategies employed in the studies covered in this review were sorted by the type of drug synthesized into ester prodrugs, targeted delivery prodrugs, macromolecular prodrugs, other nucleoside conjugates, and non-nucleoside drugs. Results: Utilizing the ester prodrug approach a novel isopropyl ester prodrug was found to be potent HIV integrase inhibitor. Further, employing the targeted delivery prodrug zanamivir and valine ester prodrug was made and shown a sole delivery of zanamivir. Additionally, VivaGel, a dendrimer macromolecular prodrug, was found to be very efficient and is now undergoing clinical trials. Conclusions: Of all the strategies employed (ester, targeted delivery, macromolecular, protides and nucleoside analogues, and non-nucleoside analogues prodrugs), the most promising are nucleoside analogues and macromolecular prodrugs. The macromolecular prodrug VivaGel works by two mechanisms: envelope mediated and receptor mediated disruption. Nucleotide analogues have witnessed productive era in the recent past few years. The era of non-interferon based treatment of hepatitis (through direct inhibitors of NS5A) has dawned.

Identification of Novel Potential gp120 of HIV-1 Antagonist Using Per-Residue Energy Contribution-Based Pharmacophore modelling

Inhibition of HIV-1 target cell entry, by targeting gp120, has been identified as a promising approach for the identification and development of prophylactic and salvage HIV infection inhibitors. A small molecule compound 18A is an important chemotype in the development of novel and diverse viral cell entry inhibitors, as it inhibits a wide variety of HIV strains by disrupting allosteric structuring on gp120. This study combines residue energy contribution (REC) pharmacophore mapping of 18A and in silico molecular docking in a virtual screening campaign to identify novel and diverse antagonists of gp120. The binding free energy of a validated docked complex of gp120-18A and the quantitative contribution of interacting residues were obtained with a more accurate molecular mechanics/generalised born surface area (MM/GBSA) method followed by mapping the energetically favourable residue contributions onto atom centres in 18A to obtain a pharmacophore model. The generated pharmacophore hypothesis was used to search the ZINC database for 3D structures that match the pharmacophore. Further, molecular docking, molecular dynamics simulations and binding free energy analysis were performed on retrieved hits in order to rank hits based on their affinity and interactions in the CD4 binding cavity of a gp120. Interestingly, the top scoring compound designated with ZINC database ID as ZINC64700951 (docking score = -8.8 kcal/mol, ∆G = -43.77 kcal/mol) showed higher affinity compared to compound 18A docking score = -7.3 kcal/mol, ∆G = -31.97 kcal/mol) and interaction of ZN64700951 with validated allosteric hot spot residues, Asp368 and Met426, and binding hot spot residues, Asn425, Glu370, Gly473, Trp427 and Met475 in gp120, suggest that ZN64700951 is a promising antagonist of gp120. Thus, ZN64700951 could serve as an additional prototype for further optimisation as an HIV target cell viral entry inhibitor.

Inhibitors of HIV-1 attachment: The discovery and structure-activity relationships of tetrahydroisoquinolines as replacements for the piperazine benzamide in the 3-glyoxylyl 6-azaindole pharmacophore

6,6-Fused ring systems including tetrahydroisoquinolines and tetrahydropyrido[3,4-d]pyrimidines have been explored as possible replacements for the piperazine benzamide portion of the HIV-1 attachment inhibitor BMS-663068. In initial studies, the tetrahydroisoquinoline compounds demonstrate sub-nanomolar activity in a HIV-1 pseudotype viral infection assay used as the initial screen for inhibitory activity. Analysis of SARs and approaches to optimization for an improved drug-like profile are examined herein.

A broad spectrum anti-HIV inhibitor significantly disturbs V1/V2 domain rearrangements of HIV-1 gp120 and inhibits virus entry

Inhibition of human immunodeficiency virus (HIV) entry into target human cells is considered as a critical strategy for preventing HIV infection. Conformational shifts of the HIV-1 envelope glycoprotein (gp120) facilitates the attachment of the virus to target cells, therefore gp120 remains an attractive target for antiretroviral therapy development. Compound 18A has been recently identified as a broad-spectrum anti-HIV inhibitor. It was proposed that 18A disrupts rearrangements of V1/V2 region in gp120; however, the precise mechanism by which 18A interferes with the inherent motion of V1/V2 domain remains obscure. In this report, we elaborate on the binding mode of compound 18A to the closed conformation of a soluble cleaved gp120 and further examine the dynamic motion of V1/V2 region in both gp120 and the gp120-18A complex via all-atom molecular dynamics simulations. In this work, comparative molecular dynamic analyses revealed that 18A makes contact with Leu179, Ile194, Ile424, Met426 W427, E370 and Met475 in the main hydrophobic cavity of the unliganded gp120 and disrupts the restructuring of V1/V2 domain observed in apo gp120. The unwinding of α1 and slight inversion of β2 in gp120 leads to the shift of VI/V2 domain away from the V3 N-terminal regions and toward the outer domain. Stronger contacts between Trp425 and Trp112 rings may contribute to the reduced flexibility of α1 observed upon 18A binding thereby inhibiting the shifts of the V1/V2 region. Binding of 18A to gp120: (1) decreases the overall flexibility of the protein and (2) inhibits the formation a gp120 conformation that closely ressembles a CD4-bound-like conformation. Information gained from this report not only elaborates on important dynamic features of gp120, but will also assist with the future designs of potent gp120 inhibitors as anti-HIV.

Pyrroloaryls and pyrroloheteroaryls: Inhibitors of the HIV fusion/attachment, reverse transcriptase and integrase

Heterocyclic compounds execute a very important role in drug design and discovery. This article provides the basic milestones of the research for pyrroloaryl and pyrroloheteroaryl based components targeting HIV viral replication cycle. Anti-HIV activity is elaborated for several classes of pyrrolo-compounds as pyrrolopyridines, pyrrolopyrimidines, pyrrolopyridazines, pyrrolobenzodiazepinones, pyrrolobenzothiazepines, pyrrolobenzoxazepinones, pyrrolophenanthridines, pyrroloquinoxalines, pyrrolotriazines, pyrroloquinolines, pyrrolopyrazinones, pyrrolothiatriazines, arylthiopyrroles and pyrrolopyrazolones targeting two essential HIV enzymes, reverse transcriptase and integrase as well as attachment/fusion of HIV virons to the host CD-4 cell. Such attempts were resulted in a discovery of highly potent anti-HIV agents suitable for clinical trials, for example, BMS-378806, BMS-585248, BMS-626529, BMS-663068, BMS-488043 and BMS-663749, etc. as anti-HIV attachment agents, triciribine, QX432, BI-1 and BI-2 as HIV RT inhibitors which are in preclinical or clinical development. Mechanism of action of compounds presented in this article towards the suppression of HIV attachment/fusion as well as against the activities of HIV enzymes reverse transcriptase and integrase has been discussed. Relationships of new compounds' molecular framework and HIV viral target has been overviewed in order to facilitate further construction of promising anti-HIV agents in future drug discovery process.

Applications of Bartoli indole synthesis

In 1989, the reaction of vinyl magnesium halides with ortho-substituted nitroarenes leading to indoles was discovered. This reaction is now frequently reported as the "Bartoli reaction" or the "Bartoli indole synthesis" (BIS). It has rapidly become the shortest and most flexible route to 7-substituted indoles, because the classical indole syntheses generally fail in their preparation. The flexibility of the Bartoli reaction is great as it can be extended to heteroaromatic nitro derivatives and can be run on solid support. This review will focus on the use of the Bartoli indole synthesis as the key step in preparations of complex indoles, which appeared in the literature in the last few years.

An expedient route to highly diversified [1,2,3]triazolo[1,5-a][1,4]benzodiazepines and their evaluation for antimicrobial, antiproliferative and in silico studies

A simple and facile synthesis of a series of diversified [1,2,3]triazolo[1,5-a][1,4]benzodiazepines has been achieved successfully via a one-pot method under milder conditions and evaluated for their biological activity.

Homology models of the HIV-1 attachment inhibitor BMS-626529 bound to gp120 suggest a unique mechanism of action

HIV-1 gp120 undergoes multiple conformational changes both before and after binding to the host CD4 receptor. BMS-626529 is an attachment inhibitor (AI) in clinical development (administered as prodrug BMS-663068) that binds to HIV-1 gp120. To investigate the mechanism of action of this new class of antiretroviral compounds, we constructed homology models of unliganded HIV-1 gp120 (UNLIG), a pre-CD4 binding-intermediate conformation (pCD4), a CD4 bound-intermediate conformation (bCD4), and a CD4/co-receptor-bound gp120 (LIG) from a series of partial structures. We also describe a simple pathway illustrating the transition between these four states. Guided by the positions of BMS-626529 resistance substitutions and structure-activity relationship data for the AI series, putative binding sites for BMS-626529 were identified, supported by biochemical and biophysical data. BMS-626529 was docked into the UNLIG model and molecular dynamics simulations were used to demonstrate the thermodynamic stability of the different gp120 UNLIG/BMS-626529 models. We propose that BMS-626529 binds to the UNLIG conformation of gp120 within the structurally conserved outer domain, under the antiparallel β20-β21 sheet, and adjacent to the CD4 binding loop. Through this binding mode, BMS-626529 can inhibit both CD4-induced and CD4-independent formation of the "open state" four-stranded gp120 bridging sheet, and the subsequent formation and exposure of the chemokine co-receptor binding site. This unique mechanism of action prevents the initial interaction of HIV-1 with the host CD4+ T cell, and subsequent HIV-1 binding and entry. Our findings clarify the novel mechanism of BMS-626529, supporting its ongoing clinical development.

Discovery of small molecular inhibitors targeting HIV-1 gp120-CD4 interaction drived from BMS-378806

The HIV-1 entry into host cells is a complex, multi-factors involved, and multi-step process. Especially, the attachment of HIV-1 envelope glycoprotein gp120 to the host cell receptor CD4 is the first key step during entry process, representing a promising antiviral therapeutic target. Among the HIV-1 attachment inhibitors blocking the interaction between gp120 and CD4 cells, BMS-378806 and NBD-556 are two representative small molecular chemical entities. Particularly, BMS-378806 and its derivatives are newly identified class of orally bioavailable HIV-1 inhibitors that interfere gp120-CD4 interaction. In this review, we focused on describing the structure-activity relationships (SARs), structural modifications, in vitro or even in vivo pharmacodynamics and pharmacokinetics of BMS-378806 and its analogues as HIV-1 gp120 attachment inhibitors. In addition, the brief SARs, structural modifications of NBD-556 and its derivatives targeting the "Phe-43 cavity" as CD4 mimics were also described.

A broad HIV-1 inhibitor blocks envelope glycoprotein transitions critical for entry

Binding to the primary receptor, CD4, triggers conformational changes in the metastable envelope glycoprotein (Env) trimer (gp120₃/gp41₃) of human immunodeficiency virus (HIV-1) that are important for virus entry into host cells. These changes include an “opening” of the trimer, creation of a binding site for the CCR5 coreceptor, and formation/exposure of a gp41 coiled coil. Here we identify a new compound, 18A (1), that specifically inhibits the entry of a wide range of HIV-1 isolates. 18A does not interfere with CD4 or CCR5 binding, but inhibits the CD4-induced disruption of quaternary structures at the trimer apex and the formation/exposure of the gp41 HR1 coiled coil. Analysis of HIV-1 variants exhibiting increased or reduced sensitivity to 18A suggests that the inhibitor can distinguish distinct conformational states of gp120 in the unliganded Env trimer. The broad-range activity and observed hypersensitivity of resistant mutants to antibody neutralization support further investigation of 18A.

Facile one-pot assembly of imidazotriazolobenzodiazepines via indium(III)-catalyzed multicomponent reactions

An operationally simple, one-pot multicomponent reaction has been developed for the assembly of 9H-benzo[f]imidazo[1,2-d][1,2,3]triazolo[1,5-a][1,4]diazepines adorned with three diversification points via an atom-economical transformation incorporating α-diketones, o-azidobenzaldehydes, propargylic amines, and ammonium acetate. This process involves tandem InCl3-catalyzed cyclocondensation and intramolecular azide-alkyne 1,3-dipolar cycloaddition reactions; optimization data, substrate scope, and mechanistic insights are discussed.

Chemically Programmed Antibodies AS HIV-1 Attachment Inhibitors

Herein we describe the design and application of two small-molecule anti-HIV compounds for the creation of chemically programmed antibodies. N-acyl-β-lactam derivatives of two previously described molecules BMS-378806 and BMS-488043 that inhibit the interaction between HIV-1 gp120 and T-cells were synthesized and used to program the binding activity of aldolase antibody 38C2. Discovery of a successful linkage site to BMS-488043 allowed for the synthesis of chemically programmed antibodies with affinity for HIV-1 gp120 and potent HIV-1 neutralization activity. Derivation of a successful conjugation strategy for this family of HIV-1 entry inhibitors enables its application in chemically programmed antibodies and vaccines and may facilitate the development of novel bispecific antibodies and topical microbicides.