Biological Evaluation Research Articles

Key structural requirements of benzamide derivatives for histone deacetylase inhibition: design, synthesis and biological evaluation.

Background: Histone deacetylase inhibitors (HDACIs) are important as anticancer agents. Objective: This study aimed to investigate some key structural features of HDACIs viathedesign, synthesisand biological evaluation of novel benzamide-based derivatives. Methods: Novel structures, designed using amolecular modification approach, were synthesized and biologically evaluated. Results: The results indicated that asubset of molecules with CH3/NH2 at R2 position possessselective antiproliferative activity. However, only those with an NH2 group showed HDACI activity. Importantly, the shorter the molecule length, the stronger HDACI. Among all, 7j was the most potent HDAC1-3 inhibitor and antiproliferative compound. Conclusion: The results of the present investigation couldprovide valuable structural knowledge applicable for the development of the HDACIs and benzamide-based antiproliferative agents in the future.

Design, synthesis and biological evaluation of novel 3C-like protease inhibitors as lead compounds against SARS-CoV-2.

Background: The epidemic caused by SARS-CoV-2swept the world in 2019. The 3C-like protease (3CLpro) of SARS-CoV-2 plays a key role in viral replication, and its inhibition could inhibit viral replication. Materials & methods: The virtual screen based on receptor-ligand pharmacophore models and molecular docking were conducted to obtain the novel scaffolds of the 3CLpro. The molecular dynamics simulation was also carried out. All compounds were synthesized and evaluated in biochemical assays. Results: The compound C2 could inhibit 3CLpro with a 72% inhibitory rate at 10μM. The covalent docking showed that C2 could form a covalent bond with the Cys145 in 3CLpro. Conclusion: C2 could be a potent lead compound of 3CLpro inhibitors against SARS-CoV-2.

Design, Synthesis, and Biological Evaluation of Novel Tetrahydroacridin Hybrids with Sulfur-Inserted Linkers as Potential Multitarget Agents for Alzheimer’s Disease

Alzheimer’s disease (AD) is a complex neurodegenerative disease that can lead to the loss of cognitive function. The progression of AD is regulated by multiple signaling pathways and their associated targets. Therefore, multitarget strategies theoretically have greater potential for treating AD. In this work, a series of new hybrids were designed and synthesized by the hybridization of tacrine (4, AChE: IC50 = 0.223 μM) with pyrimidone compound 5 (GSK-3β: IC50 = 3 μM) using the cysteamine or cystamine group as the connector. The biological evaluation results demonstrated that most of the compounds exhibited moderate to good inhibitory activities against acetylcholinesterase (AChE) and glycogen synthase kinase 3β (GSK-3β). The optimal compound 18a possessed potent dual AChE/GSK-3β inhibition (AChE: IC50 = 0.047 ± 0.002 μM, GSK-3β: IC50 = 0.930 ± 0.080 μM). Further molecular docking and enzymatic kinetic studies revealed that this compound could occupy both the catalytic anionic site and the peripheral anionic site of AChE. The results also showed a lack of toxicity to SH-SY5Y neuroblastoma cells at concentrations of up to 25 μM. Collectively, this work explored the structure–activity relationships of novel tetrahydroacridin hybrids with sulfur-inserted linkers, providing a reference for the further research and development of new multitarget anti-AD drugs.

Biological evaluation of levofloxacin and its thionated derivatives: antioxidant activity, aldehyde dehydrogenase enzyme inhibition, and cytotoxicity on A549 cell line.

Levofloxacin (LVX) is among the fluoroquinolones antibiotics that has also been studied in vitro and in vivo for its anticancer effects. In this study, we used LVX and novel LVX thionated derivatives; compounds 2 and 3, to evaluate their antioxidant activity, aldehyde dehydrogenase (ALDH) enzymes activity inhibition, and anticancer activity. Combination treatments with doxorubicin (DOX) were investigated as well. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to determine the antioxidant activity. The NADH fluorescence spectrophotometric activity assay was used to determine the ALDH inhibitory effects. Resazurin dye method was applied for cell viability assays. Molecular Operating Environment software was used for the molecular docking experiments. Compared to ascorbic acid, DPPH assay showed that compound 3 had the highest antioxidant activity among the tested compounds with approximately 35% scavenging activity. On ALDH enzymes, compound 3 showed a significant ALDH activity inhibition compared to compound 2 at 200 µM. The IC50 values for the tested compounds were approximately 100 µM on A549 cell line, a non-small cell lung cancer (NSCLC) cell line. However, significant enhancement of cytotoxicity and reduction of IC50 values were observed by combining DOX and synergism was achieved with LVX with a combination index value of 0.4. The molecular docking test showed a minimum binding energy with a good affinity for compound 3 towards ALDH enzymes. Thionated LVX derivatives, may be repurposed for NSCLC therapy in combination with DOX, taking into account the antioxidant activity, ALDH activity inhibition, and the molecular docking results of compound 3.

Copper‐Catalyzed α‐Indolmethylation of 2‐Pyridylacetates with 3‐Indoleacetic Acids via Alkylideneindolenine Intermediates

This study reports the copper‐catalyzed α‐indolmethylation of 2‐pyridylacetates with 3‐indoleacetic acids. This reaction offers a approach to generating alkylideneindolenine electrophiles via the oxidative decarboxylation of 3‐indoleacetic acids. The developed reaction system demonstrates good versatility, extending beyond the indolmethylation of 2‐ pyridylacetates to include activated esters and nitroalkanes. Moreover, a biological evaluation revealed that several products exhibited antiproliferative activity against different cancer cell lines.

Design, Synthesis, Biological Evaluation and in Silico Studies of Curcumin Pyrrole Conjugates.

Curcumin conjugated heterocyclic compounds are potent candidates with drug likeness against various bacterial pathogens. A set of curcumin-based pyrrole conjugates (CPs) were synthesized and characterized by FT-IR, 1H and 13C NMR and HR-MS techniques. The results of free radical scavenging activity of the synthesized CPs, evaluated by FRAP and CUPRAC assays, showed the potency of these compounds as effective antioxidants. CP3 exhibits the highest antioxidant activity amongst the CPs. The bactericidal efficacy of CPs was screened against ESKAP bacterial pathogens, and CPs were found to possess better antibacterial property than curcumin, specifically against staphylococcus aureus bacteria. In addition, serum albumin (BSA and HSA) binding interaction of these CPs were determined by UV-visible and fluorescence spectrophotometric techniques. In-silico molecular docking study was performed to determine the binding patterns of molecular targets against Staphylococcus aureus tyrosyl tRNA synthetase, and serum albumin proteins. The structure-activity relationship showed that the presence of multiple phenolic hydroxyl groups, and electron withdrawing groups on the structure of CP molecule, enhances its antioxidant and antibacterial activity, respectively.

Design, Synthesis and Evaluation of 8‐(Piperazin‐1‐yl) Imidazo[1,2‐a]Pyrazine Derivatives as Acetylcholinesterase Inhibitors and Antioxidants

AbstractA series of 8‐(piperazin‐1‐yl) imidazo [1,2‐a] pyrazine derivatives were designed and synthesized as acetylcholinesterase inhibitors (AChEIs) and antioxidants for the treatment of Alzheimer's disease (AD). Moreover, the biological evaluation results demonstrated that these synthesized compounds exhibited moderate inhibitory activities toward acetylcholinesterase (AChE) and radical scavenging activities. Among them, the compound with the strongest inhibitory activity against AChE had an IC50 value of 0.55 μM, which was higher than that of galantamine as the reference compound (IC50 value=5.01 μM). The compound with the strongest antioxidant activity had an IC50 value of 57.94 μM, which was lower than that of the ascorbic acid (IC50 value=25.70 μM) as the control drug. Furthermore, the results of molecular docking studies indicated that the compound could simultaneously bind to both catalytic active site (CAS) and peripheral anionic site (PAS) of AChE, which was consistent with the mixed inhibition pattern shown by enzyme kinetic studies. The interaction's stability was also assessed using a conventional atomistic 100 ns dynamics simulation study, which revealed the conformational stability of representative compound in the cavity of the AChE. In addition, the molecular properties of all compounds were predicted online through the SwissADME, and most compounds matched the properties of most orally administered drugs. Based on the biological activity and molecular properties, 8‐(piperazin‐1‐yl) imidazo[1,2‐a] pyrazine derivatives as AChEI were valuable for further development.

Design, Synthesis, and Biological Evaluation of Novel Quinazoline Derivatives Possessing a Trifluoromethyl Moiety as Potential Antitumor Agents.

A novel series of trifluoromethyl-containing quinazoline derivatives with a variety of functional groups was designed, synthesized, and tested for their antitumor activity by following a pharmacophore hybridization strategy. Most of the 20 compounds displayed moderate to excellent antiproliferative activity against five different cell lines (PC3, LNCaP, K562, HeLa, and A549). After three rounds of screening and structural optimization, compound 10 b was identified as the most potent one, with IC50 values of 3.02, 3.45, and 3.98 μM against PC3, LNCaP, and K562 cells, respectively, which were comparable to the effect of the positive control gefitinib. To further explore the mechanism of action of 10 b against cancer, experiments focusing on apoptosis induction, cell cycle arrest, and cell migration assay were conducted. The results showed that 10 b was able to induce apoptosis and prevent tumor cell migration, but had no effect on the cell cycle of tumor cells.

Structure-Guided Design, Synthesis, and Biological Evaluation of Peripheral Anionic Site Selective and Brain Permeable Novel Oxadiazole-Piperazine Conjugates against Alzheimer’s Disease with Antioxidant Potential

Structure-Guided Design, Synthesis, and Biological Evaluation of Peripheral Anionic Site Selective and Brain Permeable Novel Oxadiazole-Piperazine Conjugates against Alzheimer’s Disease with Antioxidant Potential

Discovery of a Novel Chemo-Type for TAAR1 Agonism via Molecular Modeling

The search for novel effective TAAR1 ligands continues to draw great attention due to the wide range of pharmacological applications related to TAAR1 targeting. Herein, molecular docking studies of known TAAR1 ligands, characterized by an oxazoline core, have been performed in order to identify novel promising chemo-types for the discovery of more active TAAR1 agonists. In particular, the oxazoline-based compound S18616 has been taken as a reference compound for the computational study, leading to the development of quite flat and conformationally locked ligands. The choice of a “Y-shape” conformation was suggested for the design of TAAR1 ligands, interacting with the protein cavity delimited by ASP103 and aromatic residues such as PHE186, PHE195, PHE268, and PHE267. The obtained results allowed us to preliminary in silico screen an in-house series of pyrimidinone-benzimidazoles (1a–10a) as a novel scaffold to target TAAR1. Combined ligand-based (LBCM) and structure based (SBCM) computational methods suggested the biological evaluation of compounds 1a–10a, leading to the identification of derivatives 1a–3a (hTAAR1 EC50 = 526.3–657.4 nM) as promising novel TAAR1 agonists.

Preparation, Biological Evaluation, and First-in-Human Single-Photon Emission Computed Tomography (SPECT) Study of 99mTc-Labeled Prostate-Specific Membrane Antigen (PSMA)-Targeted Radiotracers Containing Triazole with Reduced Kidneys Accumulation

Preparation, Biological Evaluation, and First-in-Human Single-Photon Emission Computed Tomography (SPECT) Study of ^99mTc-Labeled Prostate-Specific Membrane Antigen (PSMA)-Targeted Radiotracers Containing Triazole with Reduced Kidneys Accumulation

Design, synthesis and biological activity evaluation of novel inhibitors targeting TNKS2, based on docking, virtual screening and molecular dynamics simulation studies

In recent years, tankyrases (TNKS) have garnered substantial interest as a promising new drug target. An escalating amount of research has been dedicated to the development of TNKS-targeting drugs, highlighting the substantial potential in anti-cancer therapeutics. In this study, a potential TNKS2 lead compound, ZINC11726230, was identified through docking-based virtual screening, molecular dynamics simulation and bioassay. Structural modification of the lead compound, ZINC11726230, yielded two new TNKS2 inhibitors (compound 1-2), which exhibited remarkable inhibitory activity, with an IC50 value of 0.013 μM, outperforming the positive control compound G007-LK (IC50 = 0.035 μM). This study offers unique insights into the discovery of effective TNKS2 inhibitors.

Design, Synthesis, and Biological Evaluation of Novel Arylomycins against Multidrug-Resistant Gram-Negative Bacteria.

G0775, an arylomycin-type SPase I inhibitor that is being evaluated in a preclinical study, exhibited potent antibacterial activities against some Gram-negative bacteria but meanwhile suffered defects such as a narrow antibacterial spectrum and poor pharmacokinetic properties. Herein, systematic structural modifications were carried out, including optimization of the macrocyclic skeleton, warheads, and lipophilic regions. The optimization culminated in the discovery of 138f, which showed more potent activity and a broader spectrum against clinically isolated carbapenem-resistant Gram-negative bacteria, especially against Acinetobacter baumannii and Pseudomonas aeruginosa. 162, the free amine of 138f, exhibited an excellent pharmacokinetic profile in rats. In a neutropenic mouse thigh model of infection with multidrug-resistant P. aeruginosa, the potent in vivo antibacterial efficacy of 162 was confirmed and superior to that of G0775 (3.5-log decrease vs 1.1-log decrease in colony-forming unit (CFU)). These results support 162 as a potential antimicrobial agent for further research.

Design, Synthesis, and Biological Evaluation of Newly Synthesized Cinnamide-Fluorinated Containing Compounds as Bioactive Anticancer Agents

Design, Synthesis, and Biological Evaluation of Newly Synthesized Cinnamide-Fluorinated Containing Compounds as Bioactive Anticancer Agents

Design, Synthesis, and Biological Evaluation of Novel Purine Derivatives as Herbicide Safeners.

Mesosulfuron-methyl, an inhibitor of acetolactate synthase (ALS), has been extensively used in wheats. However, it can damage wheat (Triticum aestivum) and even lead to crop death. Herbicide safeners selectively shield crops from such damage without compromising weed control. To mitigate the phytotoxicity of mesosulfuron-methyl in crops, several purine derivatives were developed based on active substructure splicing. The synthesized title compounds underwent thorough characterization using infrared spectroscopy, 1H nuclear magnetic resonance (1H NMR), 13C nuclear magnetic resonance (13C NMR), and high-resolution mass spectrometry. We evaluated chlorophyll and glutathione contents as well as various enzyme activities to evaluate the safer activity of these compounds. Compounds III-3 and III-7 exhibited superior activity compared with the safener mefenpyr-diethyl. Molecular structure analysis, along with predictions of absorption, distribution, metabolism, excretion, and toxicity, indicated that compound III-7 shared pharmacokinetic traits with the commercial safener mefenpyr-diethyl. Molecular docking simulations revealed that compound III-7 competitively bound to the ALS active site with mesosulfuron-methyl, elucidating the protective mechanism of the safeners. Overall, this study highlights purine derivatives as potential candidates for novel safener development.

Synthesis, Biological Evaluation, Molecular Docking and ADME Profiling of Methylpiperidin‐4‐ylphenyl‐nicotinamide Derivatives

AbstractIn this paper, we designed, synthesized, and biologically screened a series of methyl‐piperidine‐phenyl‐nicotinamide derivatives with the aim of novel derivatives as effective anticancer agents. Compounds (9 a), (9 e) and (9 k) exhibited potent anticancer activity with an IC50 value of 5.9 μM, 5.9 μM and 5.0 μM, respectively using MV411 (Acute Myeloid Leukemia) and K562 (Chronic Myeloid Leukemia) cell line. Our docking studies show good binding affinity of these compounds for ABL1 kinase. Furthermore, these compounds exhibited a favourable in silico ADME profile with good solubility and low clearance in Human Liver Microsomes (HLM). These derivatives represent a promising approach to initiate the development of new anticancer drugs in oncology programs.

New 1,3,4‒oxadiazole Quinazolines as Potential Anticancer Agents: Design, Synthesis, Biological Evaluation, and In silico Studies.

A novel series of 1,3,4‒oxadiazole connected to derivatives of quinazolinone (7a-e and 8a-f) was synthesized in the current investigation, and its anticancer and Topoisomerase‒ II inhibitory activity was evaluated. These findings inspired the design, synthesis, and biological analysis of these 1,3,4‒oxadiazole-quinazolinone analogues as antiproliferative Topo‒II inhibitors. The novel compound structures were determined using mass spectrometry and spectral methods (IR, NMR: 1H & 13C). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colourimetric assay has been used to evaluate the anticancer efficacy of these drugs, and Autodock 4.2 provides a description of the docking results. For the more active members, additional biological tests, such as the Topo‒II inhibition experiment, were performed. These compounds' physicochemical and ADMET characteristics were examined in more detail. In the experiment for antiproliferative activity, compounds 7d, 7e, 8c, 8e, and 8f demonstrated encouraging cytotoxicity findings against HCT‒116 and HepG2 cancer cell lines, with IC50 values ranging from 3.85 to 19.43 μM. Compounds 7d, 7e, and 8e were the most potent inhibitors of Topo II with IC50 values of 15.18, 17.55, and 12.59 μM, respectively. Additionally, the docked compound 8c showed the strongest conventional hydrogen bonds among the residues Leu507(B), Asn508(B), Asn520(B), and Glu522(B) in the Human topoisomerase‒IIβ active site in the DNA complex (4G0U) when compared to the findings of docking experiments. New findings have discovered the fact that fused 1,3,4‒oxadiazole bearing quinazolinone contributed great significance in the field of medicinal chemistry due to their diverse biological properties. Finally, the in silico pharmacokinetic profile of all the synthesized derivatives was estimated using SwissADME, where some of the compounds followed Lipinski, Veber, Egan, and Muegge rules without deviation. The result of this activity advises that with a simple modification in structure, a potent anticancer agent can be generated with good efficacy.

Design and Biological Evaluation of the Long-Acting C5-Inhibited Ornithodoros moubata Complement Inhibitor (OmCI) Modified with Fatty Acid.

Disorder of complement response is a significant pathogenic factor causing some autoimmune and inflammation diseases. The Ornithodoros moubata Complement Inhibitor (OmCI), a small 17 kDa natural protein, was initially extracted from soft tick salivary glands. The protein was found binding to complement C5 specifically, inhibiting the activation of the complement pathway, which is a successful therapeutic basis of complement-mediated diseases. However, a short half-life due to rapid renal clearance is a common limitation of small proteins for clinical application. In this study, we extended the half-life of OmCI by modifying it with fatty acid, which was a method used to improve the pharmacokinetics of native peptides and proteins. Five OmCI mutants were initially designed, and single-site cysteine mutation was introduced to each of them. After purification, four OmCI mutants were obtained that showed similar in vitro biological activities. Three mutants of them were subsequently coupled with different fatty acids by nucleophilic substitution. In total, 15 modified derivatives were screened and tested for anticomplement activity in vitro. The results showed that coupling with fatty acid would not significantly affect their complement-inhibitory activity (CH50 and AH50). OmCIT90C-CM02 and OmCIT90C-CM05 were validated as the applicable OmCI bioconjugates for further pharmacokinetic assessments, and both showed improved plasma half-life in mice compared with unmodified OmCI (15.86, 17.96 vs 2.57 h). In summary, our data demonstrated that OmCI conjugated with fatty acid could be developed as the potential long-acting C5 complement inhibitor in the clinic.

Evaluation of the cyclic single-chain Fv antibody derived from nivolumab by biophysical analyses and in vitro cell-based bioassay.

Single-chain Fv (scFv) is a recombinant small antibody in which a polypeptide linker connects the variable regions of the light chain (VL) and the heavy chain (VH). The practical use of scFv, however, has been prevented by its tendency to aggregate due to interchain VL-VH interactions. We recently developed a cyclic scFv whose N-terminus and C-terminus were connected by protein ligation techniques. Biophysical comparisons between cyclic and linear scFv have been conducted, but cell biological evaluations remain unexplored. Here we studied the properties of cyclic and linear scFv derived from nivolumab. Biophysical studies revealed that the thermal stability was not changed but that the antigen-binding activity was approximately 3-fold higher as a result of circularization. A cell-based PD-1/PD-L1 interaction inhibitory assay revealed that the biological activity of scFv was markedly higher in the circularized form. In addition, biophysical analysis of scFv proteins incubated in the presence of serum revealed that circularization suppressed the decrease in antigen-binding activity. It could be assumed that circularization of scFv improved stability in the presence of serum, which in turn would suggest the applicability of cyclic scFv as a biopharmaceutical format.

Design, Synthesis and Biological Evaluation of Novel Gypsogenin Derivatives as Potential Anticancer and Antimicrobial Agents.

Natural compounds are important sources for the treatment of chronic disorders such as cancer and microbial infectious disorders. In this research, Gypsogenin and its derivatives (2a-2f) have been tested against different cancer cell lines (MCF-7, HeLa, Jurkat and K562 cell lines) and further analyzed for cell proliferation, cell death type, and for act of the mechanism. Cell proliferation was determined by the MTT method and cell death types were analyzed with HO/PI staining. Fibroblast Growth Factor 1 (FGF-1), Interleukin 1 (IL-1), Interleukin 6 (IL-6), and Tumor Necrosis Factor Alpha (TNF-α), key players in breast cancer development and progression, were determined by Elisa kits. Results showed that compound 2e inhibited the MCF-7 cell line proliferation with an IC50 value of 0.66±0.17 µM with 93.38% apoptosis rate. Compound 2e also decreased FGF-1, IL-1, IL-6, and TNF-α levels. Molecular docking studies performed in the binding site of FGFR-1 indicated that compound 2e formed key hydrogen bonding with Arg627 and Asn568. Besides, compounds 2a-2f were evaluated for their antimicrobial activities against gram-negative and gram-positive bacteria and C. albicans via the microdilution method. Overall, compound 2e stands out as a potential anticancer agent for future studies.