Synthesis,anticancer, apoptosis-inducing activities and EGFR and VEGFR2 assay mechanistic studies of 5,5-diphenylimidazolidine-2,4-dione derivatives: Molecular docking studies

A new series of 5,5-diphenylhydantoin derivatives containing benzylidene or isatin (4–19) was synthesized. Their anticancer activity against HeLa, a cervical cancer cell line, A549, a lung cancer cell line, and MDA-MB-231, a breast cancer cell line, was evaluated. Compounds 13, 16, 17 and 18 exhibited potent anticancer activity with average IC₅₀ values against the tested cell lines of 109, 59, 81 and 113 μM, respectively. Compound 16 showed potent EGFR and VEGFR2 inhibitory activity with IC₅₀ values of 6.17 and 0.09 μM, respectively. In addition, compound 16 induced caspase-dependent apoptosis and reactive oxygen species (ROS) production at 5 and 10 μM. Moreover, a molecular docking simulation was performed for compound 16 and sunitinib to predict the protein-ligand interactions with the active site of VEGFR2.     

Synthesis,cytotoxicity assay,and molecular docking study of hydroxychalcone derivatives as potential tyrosinase inhibitors

In this work, we studied the synthesis, cytotoxicity assay, and molecular docking of hydroxychalcone derivatives as tyrosinase inhibitors. Synthesis of chalcone derivatives was carried out through a Claisen-Schmidt condensation reaction between acetophenone and benzaldehyde derivatives under alkaline conditions for 48 h. The synthesized products were characterized by using Fourier transform infrared (FTIR), gas chromatography-mass spectrometry (GC-MS), proton and carbon nuclear magnetic resonance (¹H and ¹³C NMR) spectrometer. The in vitro inhibitory activity was evaluated against tyrosinase enzyme by employing L-3,4-dihydroxyphenylalanine (L-DOPA) as the substrate. We successfully synthesized 4-hydroxychalcone (HC) and 4-hydroxy-3-methoxychalcone (HMC) with a yield of 60% and 76%, respectively. While the tyrosinase inhibitory test of HC and HMC gave the IC₅₀ value of 64.35 and 21.56 μg/mL, respectively, demonstrating that their inhibitory activities against tyrosinase enzyme were better compared with kojic acid and hydroquinone as the positive controls. We also found that HC gave 2025 μg/mL as the IC₅₀ value against Vero cells, confirming that it was not toxic to the normal cell line. The molecular docking study gave the root-mean-square deviation value of less than 2 ?. Furthermore, the binding energies of hydroxychalcone derivatives were found as –30.13 and –31.38 kJ/mol, showing that those compounds could be potentially used as the alternative tyrosinase inhibitors in medical application.     

Synthesis, molecular docking, and biofilm formation inhibitory activity of 5-substituted 3,4-dihalo-5h-furan-2-one derivatives on Pseudomonas aeruginosa

Pseudomonas aeruginosa (P. aeruginosa) colonize on most wounds and live as biofilm, which causes antibiotic resistance and wounds unhealed. To investigate the effects of 5‐substituted 3,4‐dihalo‐5H‐furan‐2‐one compounds on biofilm formation of P. aeruginosa, a set of 5‐(aryl‐1′‐hydroxy‐methyl)‐ or 5‐(aryl‐2‐methylene)‐3,4‐dihalo‐5H‐furan‐2‐one compounds were designed and synthesized. Their inhibitory activities on biofilm formation of P. aeruginosa were studied by MIC assay, quantitative analysis of biofilm inhibition, and observation of biofilm formation with SEM. It was found that compounds 2i , 3f , 3i showed remarkable effects of biofilm formation inhibition on P. aeruginosa. Furthermore, molecular docking was performed to identify the key structural features of these compounds with the binding site of LasR receptor.     

Synthesis,characterization, biological evaluation,and molecular docking studies of some piperonyl-based 4-thiazolidinone derivatives

Heterocyclic compounds are of particular importance among pharmacologically active compounds. In this study, some piperonyl-based 4-thiazolidinone derivatives ( 2a–i ) were synthesized and characterized by spectroscopic assays. All molecules were tested as enzyme inhibitory factors. These compounds were effective inhibitors of the enzymes acetylcholinesterase (AChE), α-glycosidase (α-Gly), and the human carbonic anhydrase I and II isoforms (hCA I and II), with K_i values in the range of 8.90–66.51 nM for α-Gly, 94.8–289.5 nM for hCA I, 106.3–304.6 nM for hCA II, and 0.55–2.36 nM for AChE. The synthesized molecules were also studied theoretically. Molecular docking calculations were performed to investigate the interaction between the target protein and molecules. CA inhibitor compounds have been clinically used for almost 60 years as antiglaucoma and diuretic drugs. The inhibition of the AChE enzyme results in the blockage of ACh hydrolysis. On the contrary, the design of inhibitor compounds or/and modulators for AChE is of major interest as it is one of the most popular tools to prevent Alzheimer's disease.     

Synthesis,molecular docking studies,and biological evaluation of novel alkyl bis(4‐amino‐5‐cyanopyrimidine) derivatives

A series of bis(4‐amino‐5‐cyano‐pyrimidines) was synthesized and evaluated as dual inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). To further explore the multifunctional properties of the new derivatives, their antioxidant and antibacterial activities were also tested. The results showed that most of these compounds could effectively inhibit AChE and BChE. Particularly, compound 7c exhibited the best AChE inhibitory activity (IC₅₀ = 5.72 ± 1.53 μM), whereas compound 7h was identified as the most potent BChE inhibitor (IC₅₀ = 12.19 ± 0.57 μM). Molecular modeling study revealed that compounds 7c, 7f , and 7b showed a higher inhibitory activity than that of galantamine against both AChE and BChE. Anticholinesterase activity of compounds 7h, 7b , and 7c was significant in vitro and in silico for both enzymes, since these compounds have hydrophobic rings (Br‐phenyl, dimethyl, and methoxyphenyl), which bind very well in both sites. In addition to cholinesterase inhibitory activities, these compounds showed different levels of antioxidant activities. Indeed, in the superoxide–dimethyl sulfoxide alkaline assay, compound 7j showed very high inhibition (IC₅₀ = 0.37 ± 0.28 μM). Also, compound 7l exhibited strong and good antibacterial activity against Staphylococcus epidermidis and Staphylococcus aureus, respectively. Taking into account the results of biological evaluation, further modifications will be designed to increase potency on different targets. In this study, the obtained results can be a new starting point for further development of multifunctional agents for the treatment of Alzheimer's disease.     

Synthesis of flurbiprofen thiadiazole urea derivatives and assessment of biological activities and molecular docking studies

Totally 15 novel flurbiprofen urea derivatives were synthesized bearing the thiadiazole ring. Their inhibition effects on tyrosinase were determined. 3c was found to be the strongest inhibitor with the IC₅₀ value of 68.0 μM against tyrosinase. The enzyme inhibition types of the synthesized compounds were determined by examining the kinetic parameters. The inhibition type of 3c was determined as uncompetitive and the K_i value was calculated as 36.3 μM. Moreover, their cytotoxic effects on hepatocellular carcinoma (HepG2), colorectal carcinoma (HT-29), and melanoma (B16F10) cell lines were evaluated. According to the cytotoxicity results, 3l (IC₅₀ = 14.11 μM) showed the highest cytotoxicity on the HT-29 cells, while 3o (IC₅₀ = 4.22 μM) exhibited the strongest cytotoxic effect on HepG2 cell lines. Also, 3j (IC₅₀ = 7.55 μM strongly affected B16F10. The effects of synthesized compounds on the healthy cell line were evaluated on the CCD-986Sk cell line. Molecular modelling studies have indicated the potential binding interactions of the uncompetitive inhibitor 3c with the enzyme-substrate complex.     

Synthesis, anticancer, and molecular docking studies of pyranone derivatives

A series of novel Pyran scaffolds of Thiazolidin-4-one [RA-3(a–d)] and Piperazine [BR (1–4)] were synthesized as potent bi-heterocyclic molecules. All the newly synthesized compounds were confirmed by spectral studies. These synthesized compounds were screened for in vivo anticancer activity. Compounds RA-3a, RA-3c, and BR-3 displayed the highest anticancer activity against Ehrlich Ascites Carcinoma cells and docking study of all the synthesized title compounds was carried out using Molegro Virtual Docker on GABARAPL1 (GABA_A receptor-associated protein-1 cancer receptor). These studies revealed the importance of Pyranone, Thiazolidnones, and Piperazine nucleus for their anticancer activity.     

Structural insights into anticancer activity of D‐ring modified estrone derivatives using their lipophilicity in estimation of SAR and molecular docking studies

Many forms of breast carcinoma are hormone‐dependent and therefore development of novel aromatase inhibitors is of particular interest. Since brain metastases are frequent in patients with advanced breast carcinoma, one of the goals of modern drug development is the discovery of drugs with specific pharmacokinetic profile. High performance thin layer chromatography (HPTLC) is often used to determine lipophilicity of the molecules based on their retention constant. As a predictive analysis, multiple linear regression method was performed to connect pharmacokinetic‐dependent parameters with independent physicochemical properties such are: R_M⁰, TPSA and M_w of fourteen D‐ring modified oestrone derivatives. Additionally, docking studies were performed. Conducted correlation analysis indicates excellent dependence between experimental R _M parameter values and calculated values of pharmacokinetic parameters. Results show sufficient intestinal absorption of all the investigated molecules as well as moderate volumes of distribution and strong affinity for binding to plasma proteins. Crossing blood–brain barrier is predicted to be successful for 11 compounds. The created quantitative structure activity relationship model represents an excellent predictive tool and enables determination of pharmacokinetic properties of examined compounds. Docking analysis defined molecules I₃ and II₃ to be the best candidates; however, compound II₃ violates the Lipinski rule. It has been concluded that molecules with hydroxyl group at C‐3 more effectively pass through blood–brain barrier while structures with benzyloxy groups have stronger interactions with CYP1A19. Molecules II₂, II₄, II₆, and II₇ are regarded as most suitable candidates for further investigation considering their good pharmacokinetic and docking characteristics. Copyright © 2017 John Wiley & Sons, Ltd.     

Synthesis,characterization, molecular docking and biological activities of novel pyrazoline derivatives

In this study, synthesis of ethyl 2‐((4‐bromophenyl)diazenyl)‐3‐oxo‐phenylpropanoate 1 was carried out and a series of new 3H‐pyrazol‐3‐ones ( P1 – 7 ) were synthesized from 1 as well as various hydrazines. The obtained yields of the synthesized compounds were moderate (40–70%) and these compounds were confirmed by spectral data. These novel pyrazoline derivatives were effective inhibitor compounds of the human carbonic anhydrase I and II isozymes (hCAs I and II) and of the acetylcholinesterase (AChE) enzyme, with K_i values in the range of 17.4–40.7 nM for hCA I, 16.1–55.2 nM for hCA II, and 48.2–84.1 nM for AChE. In silico studies were performed on the compounds inhibiting hCA I, hCA II, and AChE receptors. On the basis of the findings, the inhibition profile of the new pyrazoline compounds at the receptors was determined.     

Design,synthesis, and molecular docking studies of novel quinoxaline derivatives as anticancer agents

As lung cancer was placed foremost part among other types of cancer in terms of mortality. Recent researches are widely focused on developing multi-targeted and site-specific targeted drug designs. In the present study, we designed and developed a series of quinoxaline pharmacophore derivatives as active EGFR inhibitors for the treatment of non-small cell lung cancer. The compounds were synthesized through a condensation reaction between hexane-3,4-dione and methyl 3,4-diaminobenzoate as a first step. Their structures were confirmed by ¹H-NMR, ¹³C-NMR, and HRMS spectroscopic methods. Cytotoxicity (MTT) were applied to determine anticancer activity of the compounds against breast (MCF7), fibroblast (NIH3 T3), and lung (A549) cell lines as EGFR inhibitors. Doxorubicin was used as a reference agent, compound 4i exhibited a significant effect among other derivatives with IC₅₀ = 3.902 ± 0.098 μM value against A549 cell line. The docking study showed that the best position on EGFR receptor could be observed with 4i . From the obtained evaluations of the designed series, compound 4i was a promising agent as EGFR inhibitor for further investigation and evaluation studies in the future.     

Synthesis, pharmacological evaluation and molecular docking studies of indanone derivatives

A new series of isoxazole fused indanones were synthesized form indane-1,3-dione. The newly synthesized derivatives were confirmed by IR, ¹H NMR, and mass spectral data. The synthesized title compounds were evaluated for analgesic, anti-inflammatory, and antimicrobial activities. The modifications carried out in indanone had a positive effect in anti-inflammatory activity when compared to that of other pharmacological activities. The compounds BD ₆ , BD ₇ , BD ₉ , BD ₁₀ , and BD ₁₁ showed good anti-inflammatory activity when compared to that of standard indomethacin. BD ₃ , BD ₄ , and BD ₅ compounds possess moderate anti-inflammatory activity. Some compounds possess moderate analgesic and antimicrobial activity. Docking study reveals that isoxazole nucleus is essential for biological activity. It was concluded that the fusion of isoxazole with indanone nucleus will increase anti-inflammatory activity than analgesic and antimicrobial activity.     

Synthesis,activity, and docking studies of eugenol‐based glucosides as new agents against Candida sp.

Seventeen new synthetic derivatives of eugenol ( 6 , 8 – 15 and 8 ′‐ 15 ′) were planned following literature reports on antifungal activities of nitroeugenol and eugenol glucoside. The anti‐Candida activity of these compounds was investigated by in vitro assay, and the cytotoxicity evaluation was performed with the most active compounds. The peracetylated glucosides presented better biological results than their hydroxylated analogues. The glucoside 11 , a 4‐nitrobenzamide, showed the best potency (MIC₅₀ range 11.0–151.84 μm ), the wider spectrum of action, and overall the best selectivity indexes, especially against C. tropicalis (~30) and C. krusei (~15). To investigate its possible mechanism of action, glucoside 11 was subjected to molecular docking studies with Candida sp. enzymes involved in ergosterol biosynthesis. Results have shown that the peracetyl glucosyl moiety and the 4‐nitrobenzamide group in 11 are effectively involved in its high affinity with the active site of squalene epoxidase.     

Synthesis, molecular docking, and biological evaluation of novel triazole derivatives as antifungal agents

Twenty-eight novel triazole derivatives (compounds 1a-v, 2a-f) have been synthesized for structure–activity relationship studies as antifungal agents. The compounds were designed on the basis of the structure of fluconazole and molecular modeling of the active site of the cytochrome P450 14α-demethylase (CYP51). All of them are reported for the first time. Their chemical structures are characterized by ¹H NMR, ¹³C NMR, LC-MS, and elemental analysis. The antifungal activities have been evaluated in vitro by measuring the minimal inhibitory concentrations (MICs). Compounds 1a-v exhibited higher activity against nearly all fungi tested except Aspergillus fumigatus (A. fum) than fluconazole (FCZ). The computational molecular docking experiments indicated that the inhibition of CYP51 involves a coordination bond with iron of the heme group, a hydrophilic H-bonding region, a hydrophobic region, and a narrow hydrophobic binding cleft.     

Novel 1,2,4-triazole derivatives: Design,synthesis, anticancer evaluation,molecular docking,and pharmacokinetic profiling studies

Three novel series of 1,2,4-triazole derivatives were designed and synthesized as potential adenosine A2B receptor antagonists. The design of the new compounds depended on a virtual screening of a previously constructed library of compounds targeting the human adenosine A2B protein. Spectroscopic techniques including ¹H nuclear magnetic resonance (NMR) and ¹³C NMR, and infrared and mass spectroscopy were used to confirm the structures of the synthesized compounds. The in vitro cytotoxicity evaluation was carried out against a human breast adenocarcinoma cell line (MDA-MB-231) using the MTT assay, and the obtained results were compared with doxorubicin as a reference anticancer agent. In addition, in silico studies to propose how the two most active compounds interact with the adenosine A2B receptor as a potential target were performed. Furthermore, a structure–activity relationship analysis was performed, and the pharmacokinetic profile to predict the oral bioavailability and other pharmacokinetic properties was also explained. Four of our designed derivatives showed promising cytotoxic effects against the selected cancer cell line. Compound 15 showed the highest activity with an IC₅₀ value of 3.48 µM. Also, compound 20 revealed an equipotent activity with the reference cytotoxic drug, with an IC₅₀ value of 5.95 µM. The observed IC₅₀ values were consistent with the obtained in silico docking scores. The newly designed compounds revealed promising pharmacokinetic profiles as compared with the reference marketed drug.     

Investigation of antioxidant and anti-nociceptive potential of isoxazolone,pyrazolone derivatives,and their molecular docking studies

A series of new isoxazolone ( 3a – d ) and pyrazolone ( 4a – d ) derivatives were synthesized and assessed for their antioxidant and analgesic activity. Among synthesized compounds, 3b and 4b having nitro (NO₂) group show high analgesic activity at a dose of 6 mg/kg. Analgesic activity was further proceeded to explore the contribution of opioidergic mechanisms in the mediation of analgesic effects. Animals were administered with naloxone, a nonselective opioid inverse agonist, at the dose of 0.5 mg/kg. The results obtained suggested that the analgesic effects of the synthesized compounds were not reversed by naloxone, specifying that the compounds 3b and 4b do not follow the opioidergic pathway in order to relieve pain in animal models. Further, the binding interactions of compounds 3b and 4b were analyzed by docking them against nonopioid receptors COX-1 (3N8X) and COX-2 (3LN1). The results demonstrate the analgesic potential of isoxazolone and pyrazolone derivatives, especially compounds 3b and 4b can be considered promising lead molecules for further investigation and development into potent analgesic drugs. In addition, the antioxidant potential of compounds was also found to be related to better analgesic activity, thus providing an insight into the role of oxidative stress in the mediation of analgesia.     

Synthesis,biological evaluation,and molecular docking studies of new pyrazol‐3‐one derivatives with aromatase inhibition activities

A new series derived from 4‐(2‐chloroacetyl)‐1,2‐dihydro‐1,5‐dimethyl‐2‐phenyl‐3H‐pyrazol‐3‐one was synthesized, characterized and its pharmacological activity toward aromatase enzyme inhibition was screened and compared to the reference native ligand letrozole. The most active compound of the series was 16 , showing IC₅₀ value of 0.0023 ± 0.0002 μm compared to letrozole with IC₅₀ of 0.0028 ± 0.0006 μm . In addition, compounds 26 and 36 exhibit good inhibition activities close to letrozole with IC₅₀ values 0.0033 ± 0.0001 and 0.0032 ± 0.0003 μm , respectively. Moreover, molecular docking studies were conducted to support the findings.     

Approaches to molecular modeling studies and specific application to serotonin ligands and receptors

Molecular modeling studies are useful in as much as they may allow us to understand the activity and selectivity of currently existing agents, and, furthermore, may aid in the design of completely novel therapeutic agents. There are two basic modelling strategies: the ligand-ligand approach and the ligand-receptor approach. Both approaches possess certain inherent advantages and disadvantages and, in addition, make certain assumptions about the agents and/or receptors being investigated. Keeping with the spirit of this minisymposium, we describe these two approaches, their general usefulness, and their limitations. Using serotonin (5-HT) receptors as a focal point, we review and provide novel examples of molecular modeling studies involving both strategies. Presented for the first time are examples of ligand-receptor models to account for the binding of serotonergic agents at 5-HT₂ and 5-HT_1C receptors.     

3,4-Methylenedioxymethamphetamine (MDMA): Stereoselective interactions at brain 5-HT1 and 5-HT2 receptors

3,4-Methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxy-amphetamine (MDA), and their optical isomers, were assayed for their affinities at radiolabeled brain serotonin (5-HT₁, 5-HT₂) and dopamine (D₂) binding sites. (R(–)-MDA and R(–)-MDMA) displayed moderate affinities for ³H-ketanserin-labeled 5-HT₂ sites (Ki=3425 and 3310 nM, respectively) whereas the affinities for their S(+)-enantiomers were lower (Ki=13,000 and 15,800 nM, respectively). Similar absolute and relative affinities were obtained at ³H-serotonin-labeled 5-HT₁ sites; binding at D₂ sites was very low (Ki>25,000 nM in each case). The (–)>(+) order of potency at 5-HT₂ sites is consistent with the observation that R(–)-MDA is a more potent psychoactive agent than its S(+)-enantiomer, but contrasts with the reported finding that S(+)-MDMA is more potent than R(–)-MDMA in humans. These results suggest that MDMA, unlike MDA and other hallucinogenic phenylisopropylamines, does not work primarily through a direct interaction at 5-HT sites.