Synthesis and anti-integrase evaluation of novel calix[4]arene derivatives containing the triazolyl 1,3-diketo moiety

Identification of Potential Drug Targets of Calix[4]arene by Reverse Docking

Calixarenes are displaying great potential for the development of new drug delivery systems, diagnostic imaging, biosensing devices and inhibitors of biological processes. In particular, calixarene derivatives are able to interact with many different enzymes and function as inhibitors. By screening of the potential drug target database (PDTD) with a reverse docking procedure, we identify and discuss a selection of 100 proteins that interact strongly with calix[4]arene. We also discover that leucine (23.5 %), isoleucine (11.3 %), phenylalanines (11.3 %) and valine (9.5 %) are the most frequent binding residues followed by hydrophobic cysteines and methionines and aromatic histidines, tyrosines and tryptophanes. Top binders are peroxisome proliferator-activated receptors that already are targeted by commercial drugs, demonstrating the practical interest in calix[4]arene. Nuclear receptors, potassium channel, several carrier proteins, a variety of cancer-related proteins and viral proteins are prominent in the list. It is concluded that calix[4]arene, which is characterized by facile access, well-defined conformational characteristics, and ease of functionalization at both the lower and higher rims, could be a potential lead compound for the development of enzyme inhibitors and theranostic platforms.

1,3-Diketone Calix[4]arene Derivatives-A New Type of Versatile Ligands for Metal Complexes and Nanoparticles

The present review is aimed at highlighting outlooks for cyclophanic 1,3-diketones as a new type of versatile ligands and building blocks of the nanomaterial for sensing and bioimaging. Thus, the main synthetic routes for achieving the structural diversity of cyclophanic 1,3-diketones are discussed. The structural diversity is demonstrated by variation of both cyclophanic backbones (calix[4]arene, calix[4]resorcinarene and thiacalix[4]arene) and embedding of different substituents onto lower or upper macrocyclic rims. The structural features of the cyclophanic 1,3-diketones are correlated with their ability to form lanthanide complexes exhibiting both lanthanide-centered luminescence and magnetic relaxivity parameters convenient for contrast effect in magnetic resonance imaging (MRI). The revealed structure–property relationships and the applicability of facile one-pot transformation of the complexes to hydrophilic nanoparticles demonstrates the advantages of 1,3-diketone calix[4]arene ligands and their complexes in developing of nanomaterials for sensing and bioimaging.

1,2,3-Triazole hybrids with anti-HIV-1 activity

The human immunodeficiency virus type 1 (HIV-1) is the major etiological agent responsible for the acquired immunodeficiency syndrome (AIDS), which is a serious infectious disease and remains one of the most prevalent problems at present. Currently, combined antiretroviral therapy is the primary modality for the treatment and management of HIV/AIDS, but the long-term use can result in major drawbacks such as the development of multidrug-resistant viruses and multiple side effects. 1,2,3-Triazole is the common framework in the development of new drugs, and its derivatives have the potential to inhibit various HIV-1 enzymes such as reverse transcriptase, integrase, and protease, consequently possessing a potential anti-HIV-1 activity. This review covers the recent advances regarding the 1,2,3-triazole hybrids with potential anti-HIV-1 activity; it focuses on the chemical structures, structure-activity relationship, and mechanisms of action, covering articles published from 2010 to 2020.

Synthesis, Biochemical Characterization, and Theoretical Studies of Novel β-Keto-enol Pyridine and Furan Derivatives as Potent Antifungal Agents

In the present study, we report the design and synthesis of new derivatives of the β-keto-enol grafted on pyridine and furan moieties (L ₁ -L ₁₁ ). Structures of compounds were fully confirmed by Fourier transform infrared spectroscopy (FT-IR), ¹H NMR, ¹³C NMR, electrospray ionization/liquid chromatography-mass spectrometry (ESI/LC-MS), and elemental analysis. The compounds were screened for antifungal and antibacterial activities (Escherichia coli, Bacillus subtilis, and Micrococcus luteus). In vitro evaluation showed significant fungicidal activity for L ₁ , L ₄ , and L ₅ against fungal strains (Fusarium oxysporum f.sp albedinis) compared to the reference standard. Especially, the exceptional activity has been demonstrated for L ₁ with IC₅₀ = 12.83 μg/mL. This compound and the reference benomyl molecule also showed a correlation between experimental antifungal activity and theoretical predictions by Petra/Osiris/Molinspiration (POM) calculations and molecular coupling against the Fgb1 protein. The highest inhibition of bacterial growth for L ₁ is due to its strongest binding to the target protein. This report may stimulate the further synthesis of examples of this substance class for the development of new drugs.

(Thia)calixarenephosphonic Acids as Potent Inhibitors of the Nucleic Acid Chaperone Activity of the HIV-1 Nucleocapsid Protein with a New Binding Mode and Multitarget Antiviral Activity

The nucleocapsid protein (NC) is a highly conserved protein that plays key roles in HIV-1 replication through its nucleic acid chaperone properties mediated by its two zinc fingers and basic residues. NC is a promising target for antiviral therapy, particularly to control viral strains resistant to currently available drugs. Since calixarenes with antiviral properties have been described, we explored the ability of calixarene hydroxymethylphosphonic or sulfonic acids to inhibit NC chaperone properties and exhibit antiviral activity. By using fluorescence-based assays, we selected four calixarenes inhibiting NC chaperone activity with submicromolar IC₅₀ values. These compounds were further shown by mass spectrometry, isothermal titration calorimetry, and fluorescence anisotropy to bind NC with no zinc ejection and to compete with nucleic acids for the binding to NC. Molecular dynamic simulations further indicated that these compounds interact via their phosphonate or sulfonate groups with the basic surface of NC but not with the hydrophobic plateau at the top of the folded fingers. Cellular studies showed that the most soluble compound CIP201 inhibited the infectivity of wild-type and drug-resistant HIV-1 strains at low micromolar concentrations, primarily targeting the early steps of HIV-1 replication. Moreover, CIP201 was also found to inhibit the flipping and polymerization activity of reverse transcriptase. Calixarenes thus form a class of noncovalent NC inhibitors, endowed with a new binding mode and multitarget antiviral activity.

The inhibitory influence of calix[4]Arene of C-90 on the activity of Ca2+,Mg2+-ATPases in plasma membrane and sarcoplasmic reticulum in myometrium cells

Our study on the plasma membrane vesicles and myometrium cells treated with 0.1% digitonin showed that inhibitory effect of calix[4]arene C-90 (5,11,17,23-tetra(trifluoro)methyl(phenylsulphonylimino)-methylamino- 25,26,27,28-tetrapropoxy-calix[4]arene) on the plasma membrane Ca2+,Mg2+-ATPase was more significant than on the Ca2+,Mg2+-ATPase in sarcoplasmic reticulum (the inhibition coefficient I0.5 values were 20.2 ± 0.5 μM and 57.0 ± 1.4 μM for the plasma membrane Ca2+,Mg2+-ATPase and Ca2+,Mg2+-ATPase in sarcoplasmic reticulum, respectively (n = 5)). Inhibition kinetics of calix[4]arene C-90 effect on the Ca2+,Mg2+- ATPase activities in plasma membrane and sarcoplasmic reticulum were studied. This substance inhibited both pumps as complete noncompetitive inhibitor. Calix[4]arene C-90 caused the increase of intracellular Ca2+ concentration and decrease of hydrodynamic diameter in smooth muscle cells similar to the action of uterotonic drug oxytocin.

Synthesis of Novel β-Keto-Enol Derivatives Tethered Pyrazole, Pyridine and Furan as New Potential Antifungal and Anti-Breast Cancer Agents

Recently, a new generation of highly promising inhibitors bearing β-keto-enol functionality has emerged. Reported herein is the first synthesis and use of novel designed drugs based on the β-keto-enol group embedded with heterocyclic moieties such as pyrazole, pyridine, and furan, prepared in a one-step procedure by mixed Claisen condensation. All the newly synthesized compounds were characterized by FT-IR, ¹H-NMR, (13)C-NMR, ESI/LC-MS, elemental analysis, and evaluated for their in vitro antiproliferative activity against breast cancer (MDA-MB241) human cell lines and fungal strains (Fusarium oxysporum f.sp albedinis FAO). Three of the synthesized compounds showed potent activity against fungal strains with IC50 values in the range of 0.055-0.092 µM. The results revealed that these compounds showed better IC50 values while compared with positive controls.

Synthesis, biological evaluation and molecular docking of calix[4]arene-based β-diketo derivatives as HIV-1 integrase inhibitors

In this publication, we design and report the synthesis of calix[4]arene-based β-diketo derivatives as novel HIV-1 integrase (IN) inhibitors. The target compounds were obtained using Claisen condensation, and their structures were characterized by NMR and ESI-MS. Preliminary bioassays showed that calix[4]arene-based β-diketo derivatives inhibit strand transfer (ST) with IC50 values between 5.9 and 21.2 µM. Docking studies revealed the predominant binding modes that were distinct from the binding modes of raltegravir, which suggests a novel binding region in the IN active site. Moreover, these compounds are predicted not to interact with some of the key amino acids (GLN148 and ASN155) implicated in viral resistance. Therefore, this series of compounds can further be investigated for a possible chemotype to circumvent resistance to clinical HIV-1 IN inhibitors.