ABSTRACT
A series of mono-peptide, di-peptide and tri-peptide derivatives linked to a coumarin scaffold (5a-c, 7a-c, and 9a-c) were synthesized via the azide-coupling method from corresponding hydrazides 4, 6, and 8. These compounds were tested for anticancer activity against HepG-2, PC-3, and Hct-116 cell lines. Compounds, 7c, and 5b showed significant cytotoxicity, outperforming doxorubicin, with IC50 values of 34.07, 16.06, and 16.02 µM for 7c and 42.16, 59.74, and 35.05 µM for 5b. Compound 7b also displayed promising results with IC50 values of 72.13, 70.82, and 61.01 µM. Moreover, the key structural features of amino acids indicated that mono-peptide and di-peptide derivatives play a key role in increasing their anticancer activities compared with tri-peptides. In addition, the most potent compound 5b also exhibited strong CK2 kinase inhibition with an IC50 value of 0.117 ± 0.005 µM compared with roscovetine as a control drug with an IC50 value of 0.251 ± 0.011 µM. Finally, the binding mode of the chemical inhibitors at the active site of CK2 receptor was also investigated using a docking study which confirmed that the presence of the amino acid functionality is an important feature for anticancer activity and the synthesized compounds showed favorable ADME properties. Besides that, SAR analysis was implemented for the target compounds.
ABSTRACT
BACKGROUND: Infections caused by Acinetobacter baumannii are becoming a rising public health problem due to its high degree of acquired and intrinsic resistance mechanisms. Bacterial lipases penetrate and damage host tissues, resulting in multiple infections. Because there are very few effective inhibitors of bacterial lipases, new alternatives for treating A. baumannii infections are urgently needed. In recent years, Brassica vegetables have received a lot of attention since their phytochemical compounds have been directly linked to diverse antimicrobial actions by inhibiting the growth of various Gram-positive and Gram-negative bacteria, yeast, and fungi. Despite their longstanding antibacterial history, there is currently a lack of scientific evidence to support their role in the management of infections caused by the nosocomial bacterium, A. baumannii. This study aimed to address this gap in knowledge by examining the antibacterial and lipase inhibitory effects of six commonly consumed Brassica greens, Chinese cabbage (CC), curly and Tuscan kale (CK and TK), red and green Pak choi (RP and GP), and Brussels sprouts (BR), against A. baumannii in relation to their chemical profiles. METHODS: The secondary metabolites of the six extracts were identified using LC-QTOF-MS/MS analysis, and they were subsequently correlated with the lipase inhibitory activity using multivariate data analysis and molecular docking. RESULTS: In total, 99 metabolites from various chemical classes were identified in the extracts. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) revealed the chemical similarities and variabilities among the specimens, with glucosinolates and phenolic compounds being the major metabolites. RP and GP showed the highest antibacterial activity against A. baumannii, followed by CK. Additionally, four species showed a significant effect on the bacterial growth curves and demonstrated relevant inhibition of A. baumannii lipolytic activity. CK showed the greatest inhibition (26%), followed by RP (21%), GP (21%), and TK (15%). Orthogonal partial least squares-discriminant analysis (OPLS-DA) pinpointed 9 metabolites positively correlated with the observed bioactivities. Further, the biomarkers displayed good binding affinities towards lipase active sites ranging from -70.61 to -30.91 kcal/mol, compared to orlistat. CONCLUSION: This study emphasizes the significance of Brassica vegetables as a novel natural source of potential inhibitors of lipase from A. baumannii.
Subject(s)
Acinetobacter baumannii , Brassica , Brassica/chemistry , Molecular Docking Simulation , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Tandem Mass Spectrometry , Gram-Negative Bacteria , Gram-Positive Bacteria , Phytochemicals/pharmacology , LipaseABSTRACT
Chitosan (CS) is a biopolymer and has reactive amine/hydroxyl groups facilitated its modifications. The purpose of this study is improvement of (CS) physicochemical properties and its capabilities as antiviral and antitumor through modification with 1-(2-oxoindolin-3-ylidene)thiosemicarbazide (3A) or 1-(5-fluoro-2-oxoindolin-3-ylidene)thiosemicarbazide (3B) via crosslinking of poly(ethylene glycol)diglycidylether (PEGDGE) using microwave-assisted as green technique gives (CS-I) and (CS-II) derivatives. However, (CS) derivatives nanoparticles (CS-I NPs) and (CS-II NPs) are synthesized via ionic gelation technique using sodium tripolyphosphate (TPP). Structures of new (CS) derivatives are characterized using different tools. The anticancer, antiviral efficiencies and molecular docking of (CS) and its derivatives are assayed. (CS) derivatives and its nanoparticles show enhancement in cell inhibition toward (HepG-2 and MCF-7) cancer cells in comparison with (CS). (CS-II NPs) reveals the lowest IC50 values are 92.70 ± 2.64 µg/mL and 12.64 µ g/mL against (HepG-2) cell and SARS-CoV-2 (COVID-19) respectively and the best binding affinity toward corona virus protease receptor (PDB ID 6LU7) -5.71 kcal / mol. Furthermore, (CS-I NPs) shows the lowest cell viability% 14.31 ± 1.48 % and the best binding affinity -9.98 kcal/moL against (MCF-7) cell and receptor (PDB ID 1Z11) respectively. Results of this study demonstrated that (CS) derivatives and its nanoparticles could be potentially employed for biomedical applications.
ABSTRACT
Due to numerous pharmaceutical and biological activities hydrazone (TC) based materials, it was important to investigate quantum chemical studies such as Density functional theory (DFT) calculations, natural bond orbital (NBO) analysis, molecular electrostatic potential (MESP), and local reactivity usage Fukui function for six TC derivatives compounds. DFT, NBO, MESP, and local reactivity calculations were obtained via utilizing CAM-Becke's three-parameter functional and Leee Yange Parr (CAM-B3LYP) functional and 6-311G + + (2d, 2p) basis set. Optimized molecular structures for all studied compounds were obtained usage the DFT/CAM-B3LYP/6-311G + + (2d, 2p) method. In addition, the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap (Eg), light harvest efficiency (LHE), and open-circuit voltage (Voc) of all studied MSs are calculated and illustrated. These properties indicate that these molecular modeling structures as good candidates for utilization in organic DSSCs. The calculated spectroscopic investigations of hydrazine derivatives have been obtained by applying the TD/CAM-B3LYP/6-311G + + (2d, 2p) method. the calculated UV-Vis absorption spectra for molecular structures under study show nice correlations with experimental spectra.
Subject(s)
Hydrazones , Spectrum Analysis, Raman , Density Functional Theory , Molecular Conformation , Quantum Theory , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , Static ElectricityABSTRACT
The antimicrobial assessments of two new series of nicotinonitriles and pyrido[2,3-d]pyrimidines were performed using amoxicillin and nystatin as reference standards. Outstanding antifungal activities were achieved by some target compounds; for instance, compounds 7 and 9 displayed a minimal inhibitory concentration (MIC) value of 1.95 µg/ml toward Candida albicans, compound 11 showed a potent anti-Rhizopus effect (MIC 1.95 µg/ml) and compound 14 elicited remarkable antifungal effects against both Aspergillis niger and C. albicans (MIC 1.95 µg/ml). However, pyrido[2,3-d]pyrimidines 12, 14, and 16 showed moderate antibacterial activities against some gram-negative bacteria. The antibiofilm results of these compounds against resistant strains of Proteus mirabilis were better than those of Pseudomonas aeruginosa. Docking studies of these hits at the DNA gyrase active site revealed affinity and docking scores comparable to that of the reference standards. Gyrase-inhibitory activities revealed that 14 (IC50 = 0.31 µM) is the most potent hit as DNA gyrase A inhibitor; it exhibited 1.66-fold the activity of ciprofloxacin (IC50 = 0.50 µM) and it was a 44.3 times more potent gyrase B inhibitor (IC50 = 0.04 µM) than novobiocin (IC50 = 1.77 µM). Regarding its antifungal activity, it displayed 0.78% of the fluconazole activity as a 14α-demethylase inhibitor. The cytotoxicity of 12, 14, and 16 on human diploid lung fibroblasts (WI38 cells) ensured their safety. Moreover, they are orally bioavailable with no permeation of the blood-brain barrier.
Subject(s)
Anti-Infective Agents , DNA Gyrase , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Biofilms , Candida albicans , DNA Gyrase/metabolism , Enzyme Inhibitors/pharmacology , Humans , Microbial Sensitivity Tests , Molecular Docking Simulation , Pyrimidines/pharmacology , Structure-Activity Relationship , Topoisomerase II Inhibitors/pharmacologyABSTRACT
A series of novel hybrid pyrazolo[3,4-d]pyramidine derivatives was designed and chemically synthesized in useful yields. The synthesized compounds were structurally characterized by the usual techniques. All the new synthesized compounds were biologically screened in vitro for their antiproliferative activities against a panel of four cancer cell lines, namely HepG-2, MCF-7, HCT-116, and Hela. The results of cytotoxic evaluation indicated that compound 14d was appeared to be the most prominent broad-spectrum cytotoxic activity and significantly more potent than sorafenib with IC50 values of 4.28, 5.18, 3.97, and 9.85 µM against four cell lines (HePG2, Hela, HCT-116 and MCF-7). In addition, compound 15 was displayed promising antiproliferative effect against all tested cell lines with IC50 value less than 11 µM compared with sorafenib as a control drug. Besides, structurally pharmacophoric features indicated that pyrazolo[3,4-d]pyrimidine scaffold having an amide linker and substituted with phenyl moiety at the 5-position was more potent than those possessing azomethine methyl, azomethine proton and carbomethene linkers, which lead to significant decrease in antiproliferative activity. The most potent compounds were further selected and evaluated for their activities against epidermal growth factor receptor (EGFR) kinase inhibitors according to homogenous time resolved fluorescence (HTRF) assay. The most potent compound 14d exhibited the most promising inhibitory activity against EGFRWT with IC50 value of 56.02 ± 1.38 µM compared with gefitinib as control drug with IC50 value of 41.79 ± 1.07 µM. Moreover, the inhibition of cell cycle progression and induction of apoptosis in the A549 cell line at G2/M and pre-G1 phases of cell cycle might contribute to cancer treatment that evaluated by Annexin V-FITC/PI double staining detection method. Finally, molecular docking studies were conducted to investigate that probable binding conformations of these anticancer agents and ADME properties were calculated to predict pharmacokinetics and toxic properties of the target compounds.
Subject(s)
Antineoplastic Agents/pharmacology , Drug Design , Molecular Docking Simulation , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Pyrimidines/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Apoptosis/drug effects , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/metabolism , Humans , Molecular Structure , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/chemistry , Pyrazoles/chemical synthesis , Pyrazoles/chemistry , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Structure-Activity RelationshipABSTRACT
Targeting the epidermal growth factor receptors (EGFRs) with small inhibitor molecules has been validated as a potential therapeutic strategy in cancer therapy. Pyrazolo[3,4-d]pyrimidine is a versatile scaffold that has been exploited for developing potential anticancer agents. On the basis of fragment-based drug discovery, considering the essential pharmacophoric features of potent EGFR tyrosine kinase (TK) inhibitors, herein, we report the design and synthesis of new hybrid molecules of the pyrazolo[3,4-d]pyrimidine scaffold linked with diverse pharmacophoric fragments with reported anticancer potential. These fragments include hydrazone, indoline-2-one, phthalimide, thiourea, oxadiazole, pyrazole, and dihydropyrazole. The synthesized molecules were evaluated for their anticancer activity against the human breast cancer cell line, MCF-7. The obtained results revealed comparable antitumor activity with that of the reference drugs doxorubicin and toceranib. Docking studies were performed along with EGFR-TK and ADMET profiling studies. The results of the docking studies showed the ability of the designed compounds to interact with key residues of the EGFR-TK through a number of covalent and noncovalent interactions. The obtained activity of compound 25 (IC50 = 2.89 µM) suggested that it may serve as a lead for further optimization and drug development.
ABSTRACT
Many shreds of evidence have recently correlated A2B receptor antagonism with anticancer activity. Hence, the search for an efficient A2B antagonist may help in the development of a new chemotherapeutic agent. In this article, 23 new derivatives of [1,2,4]triazolo[4,3-a]quinoxaline were designed and synthesized and its structures were confirmed by different spectral data and elemental analyses. The results of cytotoxic evaluation of these compounds showed six promising active derivatives with IC50 values ranging from 1.9 to 6.4 µM on MDA-MB 231 cell line. Additionally, molecular docking for all synthesized compounds was performed to predict their binding affinity toward the homology model of A2B receptor as a proposed mode of their cytotoxic activity. Results of molecular docking were strongly correlated with those of the cytotoxic study. Finally, structure activity relationship analyses of the new compounds were explored.
Subject(s)
Adenosine A2 Receptor Antagonists/pharmacology , Drug Design , Molecular Docking Simulation , Quinoxalines/chemistry , Quinoxalines/chemical synthesis , Triazoles/chemistry , Triazoles/chemical synthesis , Cell Line, Tumor , Humans , Inhibitory Concentration 50 , Structure-Activity RelationshipABSTRACT
The discovery of potent STAT3 inhibitors has gained noteworthy impetus in the last decade. In line with this trend, considering the proven biological importance of 1,2,4-triazoles, herein, we are reporting the design, synthesis, pharmacokinetic profiles, and in vitro anticancer activity of novel C3-linked 1,2,4-triazole-N-arylamide hybrids and their in silico proposed mechanism of action via inhibition of STAT3. The 1,2,4-triazole scaffold was selected as a privilege ring system that is embedded in core structures of a variety of anticancer drugs which are either in clinical use or still under clinical trials. The designed 1,2,4-triazole derivatives were synthesized by linking the triazole-thione moiety through amide hydrophilic linkers with diverse lipophilic fragments. In silico study to predict cytotoxicity of the new hybrids against different kinds of human cancer cell lines as well as the non-tumor cells was conducted. The multidrug-resistant human breast adenocarcinoma cells (MDA-MB-231) was found most susceptible to the cytotoxic effect of synthesized compounds and hence were selected to evaluate the in vitro anticancer activity. Four of the designed derivatives showed promising cytotoxicity effects against selected cancer cells, among which compound 12 showed the highest potency (IC50 = 3.61 µM), followed by 21 which displayed IC50 value of 3.93 µM. Also, compounds 14 and 23 revealed equipotent activity with the reference cytotoxic agent doxorubicin. To reinforce these observations, the obtained data of in vitro cytotoxicity have been validated in terms of ligand-protein interaction and new compounds were analyzed for ADMET properties to evaluate their potential to build up as good drug candidates. This study led us to identify two novel C3-linked 1,2,4-triazole-N-arylamide hybrids of interesting antiproliferative potentials as probable lead inhibitors of STAT3 with promising pharmacokinetic profiles.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Computer Simulation , STAT3 Transcription Factor/antagonists & inhibitors , Triazoles/chemical synthesis , Triazoles/pharmacology , Antineoplastic Agents/chemistry , Binding Sites , Cell Line, Tumor , Doxorubicin/pharmacology , Humans , Ligands , Molecular Docking Simulation , STAT3 Transcription Factor/metabolism , Structure-Activity Relationship , Thermodynamics , Triazoles/chemistry , Triazoles/pharmacokineticsABSTRACT
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 1 H nuclear magnetic resonance (NMR) and 13 C 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.
Subject(s)
Adenosine A2 Receptor Antagonists/pharmacology , Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Molecular Docking Simulation , Receptor, Adenosine A2B/drug effects , Triazoles/pharmacology , Adenosine A2 Receptor Antagonists/chemical synthesis , Adenosine A2 Receptor Antagonists/pharmacokinetics , Administration, Oral , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacokinetics , Biological Availability , Biotransformation , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Dose-Response Relationship, Drug , Drug Design , Female , Humans , Inhibitory Concentration 50 , Molecular Structure , Protein Binding , Receptor, Adenosine A2B/metabolism , Structure-Activity Relationship , Triazoles/chemical synthesis , Triazoles/pharmacokineticsABSTRACT
A novel series of [1,2,4]triazolo[4,3-a]quinoxaline derivatives of different heteroaromatization members were synthesized. The newly synthesized molecules were explored for their potential antimicrobial activities against a panel of pathogenic organisms. Among these derivatives, the chalcone compound 6e with a methoxy substituent exhibited broad potent antimicrobial activity against most of the bacterial and fungal strains. Furthermore, the analysis of the SAR disclosed that the linker and terminal aromatic fragments perform critical roles in exerting antibacterial activity. The molecular docking calculations were executed on two of the most bacterial targets, ATP-binding sites of DNA gyrase B, and the folate-binding site of DHFR enzymes. The results presented good binding data to the pockets of both enzymes showing different linkers contributions through the hydrogen-bonding and aromatic stacking interactions that stabilize the compounds in their pockets taking 6e compound as representative of most active analogs. In addition, good pharmacokinetic profiling data for the 6e compound was obtained and compared to reference drugs. Accordingly, our findings suggest that [1,2,4]triazolo[4,3-a]quinoxaline scaffold is an interesting precursor for the design of potent antimicrobial agents with multitarget inhibition.
Subject(s)
Anti-Bacterial Agents/pharmacology , Escherichia coli/enzymology , Folic Acid Antagonists/pharmacology , Quinoxalines/pharmacology , Topoisomerase II Inhibitors/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacokinetics , DNA Gyrase/metabolism , Escherichia coli/drug effects , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Folic Acid Antagonists/chemistry , Folic Acid Antagonists/pharmacokinetics , Humans , Models, Molecular , Quinoxalines/chemistry , Quinoxalines/pharmacokinetics , Structure-Activity Relationship , Tetrahydrofolate Dehydrogenase/metabolism , Topoisomerase II Inhibitors/chemistry , Topoisomerase II Inhibitors/pharmacokinetics , Triazoles/chemistry , Triazoles/pharmacokinetics , Triazoles/pharmacologyABSTRACT
PURPOSE: To examine the functional survival of the artificial urinary sphincter (AUS) AMS800 in a changing patient population. Because of increasing experience and dexterity of the operating team, we hypothesize that patients with known risk factors nowadays have a better survival of their prosthesis. However, due to a change to a more complex case mix, overall results appear to be worse. MATERIALS AND METHODS: All men who underwent implantation of an AUS between 2001 and 2016 because of urethral sphincter deficiency were retrospectively analyzed. Patients were divided in groups based on date of surgery and number of patients: 2001-2009 (G1), 2010-2013 (G2), 2014-2016 (G3). Baseline characteristics and additional therapies prior to implantation were analyzed in all groups. Risk factors for failure only in G1 and G2. Revision or explantation of the AUS was used as endpoint. Kaplan-Meier analysis was used to calculate survival of the device. RESULTS: A total of 129 patients (mean age 72 ± 9 years) underwent 129 primary implants, and 11 secondary implants. Median follow-up was 5.74 years in G1, 3.26 years G2 and 1.54 years G3. Approximately 25% of the patients in G1 had received adjuvant therapy for prostate cancer and 14% underwent previous surgery for incontinence. In G2, 51 and 55% underwent adjuvant therapy for prostate cancer and previous surgery for incontinence, respectively, G3 was comparable. The overall 50% survival improved in patients with radiotherapy and previous incontinence surgery in G2 as compared to G1. CONCLUSIONS: Despite the more complex patient population, the survival of the AUS did not decrease. In some patient categories, the AUS functional survival is even still improving over the past few years.
Subject(s)
Postoperative Complications/surgery , Prosthesis Failure , Urinary Incontinence, Stress/surgery , Urinary Sphincter, Artificial , Aged , Aged, 80 and over , Chemotherapy, Adjuvant , Diabetes Mellitus/epidemiology , Humans , Male , Prostatectomy , Radiotherapy, Adjuvant , Retrospective Studies , Risk Factors , Suburethral Slings , Urethral Stricture/epidemiology , Urethral Stricture/surgery , Urinary Bladder, Neurogenic/complications , Urinary Incontinence, Stress/etiology , Urologic Surgical Procedures, MaleABSTRACT
In our attempt to develop effective EGFR-TKIs, two series of 1H-pyrazolo[3,4-d]pyrimidine derivatives were designed and synthesized. All the newly synthesized compounds were evaluated in vitro for their inhibitory activities against EGFRWT. Compounds 15b, 15j, and 18d potently inhibited EGFRWT at sub-micro molar IC50 values comparable to that of erlotinib. Moreover, thirteen compounds that showed promising IC50 values against EGFRWT were tested in vitro for their inhibitory activities against mutant EGFRT790M. Compounds 17d and 17f exhibited potent inhibitory activities towards EGFRT790M comparable to osimertinib. Compounds that showed promising IC50 values against EGFRWT were further tested for their anti-proliferative activities against three cancer cell lines bearing EGFRWT (MCF-7, HepG2, A549), and two cancer cell lines bearing EGFRT790M (H1975 and HCC827). Compounds 15g, 15j, 15n, 18d and 18e were the most potent anticancer agents against the EGFRWT containing cells, while compounds 15e, 17d and 17f showed promising anti-proliferative activities against EGFRT790M containing cells. Furthermore, the most active compound 18d was selected for further studies regarding to its effects on cell cycle progression and induction of apoptosis in the HepG2 cell line. The results indicated that this compound is good apoptotic agent and arrests G0/G1and G2/M phases of cell cycle. Finally, molecular docking studies were performed to investigate binding pattern of the synthesized compounds with the prospective targets, EGFRWT (PDB: 4HJO) and EGFRT790M (PDB: 3W2O).
Subject(s)
Antineoplastic Agents/chemical synthesis , Drug Design , Protein Kinase Inhibitors/chemical synthesis , Pyrazoles/chemistry , Pyrimidines/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Binding Sites , Catalytic Domain , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , ErbB Receptors/metabolism , Humans , Hydrogen Bonding , Molecular Docking Simulation , Mutation , Protein Kinase Inhibitors/metabolism , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Pyrimidines/pharmacology , Structure-Activity Relationship , ThermodynamicsABSTRACT
Thymidylate synthase (TS), one of folate-dependent enzymes, is a key and well-recognized target for anticancer agents. In this study, a series of 6-aryl-5-cyano thiouracil derivatives were designed and synthesized in accordance with essential pharmacophoric features of known TS inhibitors. Nineteen compounds were screened in vitro for their anti-proliferative activities toward HePG-2, MCF-7, HCT-116, and PC-3 cell lines. Compounds [Formula: see text], [Formula: see text], and 24 exhibited high anti-proliferative activity, comparable to that of 5-fluorouracil. Additionally, ten compounds with potent anti-proliferative activities were further evaluated for their ability to inhibit TS enzyme. Six compounds ([Formula: see text], [Formula: see text], [Formula: see text], 22, 23 and 24) demonstrated potent dose-related TS inhibition with [Formula: see text] values ranging from 1.57 to [Formula: see text]. The in vitro TS activity results were consistent with those of the cytotoxicity assay where the most potent anti-proliferative compounds of the series showed good TS inhibitory activity comparable to that of 5-fluorouracil. Furthermore, molecular docking studies were carried out to investigate the binding pattern of the designed compounds with the prospective target, TS (PDB-code: 1JU6).
Subject(s)
Molecular Docking Simulation , Thiouracil/chemical synthesis , Thiouracil/pharmacology , Thymidylate Synthase/antagonists & inhibitors , Thymidylate Synthase/metabolism , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Chemistry Techniques, Synthetic , Drug Screening Assays, Antitumor , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/metabolism , Enzyme Inhibitors/pharmacology , Humans , Protein Conformation , Structure-Activity Relationship , Thiouracil/chemistry , Thiouracil/metabolism , Thymidylate Synthase/chemistryABSTRACT
The second extracellular loop (EL2) of G protein-coupled receptors (GPCRs), which represent important drug targets, may be involved in ligand recognition and receptor activation. We studied the closely related adenosine receptor (AR) subtypes A2A and A2B by exchanging the complete EL2 of the human A2BAR for the EL2 of the A2AAR. Furthermore, single amino acid residues (Asp148(45.27), Ser149(45.28), Thr151(45.30), Glu164(45.43), Ser165(45.44), and Val169(45.48)) in the EL2 of the A2BAR were exchanged for alanine. The single mutations did not lead to any major effects, except for the T151A mutant, at which NECA showed considerably increased efficacy. The loop exchange entailed significant effects: The A2A-selective agonist CGS21680, while being completely inactive at A2BARs, showed high affinity for the mutant A2B(EL2-A2A)AR, and was able to fully activate the receptor. Most strikingly, all agonists investigated (adenosine, NECA, BAY60-6583, CGS21680) showed strongly increased efficacies at the mutant A2B(EL2-A2A) as compared to the wt AR. Thus, the EL2 of the A2BAR appears to have multiple functions: besides its involvement in ligand binding and subtype selectivity it modulates agonist-bound receptor conformations thereby controlling signalling efficacy. This role of the EL2 is likely to extend to other members of the GPCR family, and the EL2 of GPCRs appears to be an attractive target structure for drugs.
Subject(s)
Receptor, Adenosine A2A/metabolism , Receptor, Adenosine A2B/metabolism , Adenosine A2 Receptor Agonists/pharmacology , Amino Acid Sequence , Amino Acid Substitution , Animals , CHO Cells , Cricetinae , Cricetulus , Cyclic AMP/biosynthesis , Humans , Molecular Docking Simulation , Molecular Sequence Data , Mutation , Protein Conformation , Radioligand Assay , Receptor, Adenosine A2A/genetics , Receptor, Adenosine A2B/genetics , Sequence Homology, Amino Acid , Signal TransductionABSTRACT
Adenosine A(2B) receptors, which play a role in inflammation and cancer, are of considerable interest as novel drug targets. To gain deeper insights into ligand binding and receptor activation, we exchanged amino acids predicted to be close to the binding pocket. The alanine mutants were stably expressed in CHO cells and characterized by radioligand binding and cAMP assays using three structural classes of ligands: xanthine (antagonist), adenosine, and aminopyridine derivatives (agonists). Asn282(7.45) and His280(7.43) were found to stabilize the binding site by intramolecular hydrogen bond formation as in the related A(2A) receptor subtype. Trp247(6.48), Val250(6.51), and particularly Ser279(7.42) were shown to be important for binding of nucleosidic agonists. Leu81(3.28), Asn186(5.42), and Val250(6.51) were discovered to be crucial for binding of the xanthine-derived antagonist PSB-603. Leu81(3.28), which is not conserved among adenosine receptor subtypes, may be important for the high selectivity of PSB-603. The N186(5.42)A mutant resulted in an increased potency for agonists. The interactions of the non-nucleosidic agonist BAY60-6583 were different from those of the nucleosides: while BAY60-6583 appeared not to interact with Ser279(7.42), its interactions with Trp247(6.48) and Val250(6.51) were significantly weaker compared to those of NECA. Moreover, our results discount the hypothesis of Trp247(6.48) serving as a "toogle switch" because BAY60-6583 was able to activate the corresponding mutant. This study reveals distinct interactions of structurally diverse ligands with the human A(2B) receptor and differences between closely related receptor subtypes (A(2B) and A(2A)). It will contribute to the understanding of G protein-coupled receptor function and advance A(2B) receptor ligand design.
Subject(s)
Receptor, Adenosine A2B/metabolism , Second Messenger Systems , Adenosine A2 Receptor Agonists/pharmacology , Adenosine A2 Receptor Antagonists/pharmacology , Adenosine-5'-(N-ethylcarboxamide)/pharmacology , Amino Acid Sequence , Amino Acid Substitution , Aminopyridines/pharmacology , Animals , Binding, Competitive , CHO Cells , Cricetinae , Cyclic AMP/metabolism , Humans , Molecular Dynamics Simulation , Molecular Sequence Data , Mutagenesis, Site-Directed , Protein Binding , Protein Structure, Tertiary , Receptor, Adenosine A2B/chemistry , Receptor, Adenosine A2B/genetics , Structural Homology, ProteinABSTRACT
A three-dimensional model of the human adenosine A2B receptor was generated by means of homology modelling, using the crystal structures of bovine rhodopsin, the beta2-adrenergic receptor, and the human adenosine A2A receptor as templates. In order to compare the three resulting models, the binding modes of the adenosine A2B receptor antagonists theophylline, ZM241385, MRS1706, and PSB601 were investigated. The A2A-based model was much better able to stabilize the ligands in the binding site than the other models reflecting the high degree of similarity between A2A and A2B receptors: while the A2B receptor shares about 21% of the residues with rhodopsin, and 31% with the beta2-adrenergic receptor, it is 56% identical to the adenosine A2A receptor. The A2A-based model was used for further studies. The model included the transmembrane domains, the extracellular and the intracellular hydrophilic loops as well as the terminal domains. In order to validate the usefulness of this model, a docking analysis of several selective and nonselective agonists and antagonists was carried out including a study of binding affinities and selectivities of these ligands with respect to the adenosine A2A and A2B receptors. A common binding site is proposed for antagonists and agonists based on homology modelling combined with site-directed mutagenesis and a comparison between experimental and calculated affinity data. The new, validated A2B receptor model may serve as a basis for developing more potent and selective drugs.
Subject(s)
Models, Molecular , Receptor, Adenosine A2B/chemistry , Receptors, Adrenergic, beta-2/chemistry , Rhodopsin/chemistry , Animals , Cattle , Humans , Molecular Structure , Mutagenesis, Site-Directed , Protein Binding , Protein Conformation , Receptor, Adenosine A2B/genetics , Receptor, Adenosine A2B/metabolism , Triazines/pharmacology , Triazoles/pharmacology , X-RaysABSTRACT
BACKGROUND AND OBJECTIVE: In the last few years, outbreaks of an apparently specific dermatosis occurred during the months of late summer and early autumn in our locality. Our aim in this study was to reveal the underlying etiology of this dermatosis. SUBJECTS AND METHODS: Sixty patients with the disease were studied clinically, epidemiologically, histopathologically, and ultrastructurally. RESULTS: The results of all methods suggest that the dermatosis is most probably a human cowpox infection. Electron microscopy showed unenveloped cowpox virons. CONCLUSIONS: This apparently specific dermatosis is due to human cowpox infection. Future investigations will be needed to better define this important zoonosis frequently passed by cats to humans and carried by rodents.
Subject(s)
Cowpox/pathology , Skin Diseases, Viral/pathology , Adolescent , Adult , Biopsy , Child , Cowpox/epidemiology , Cowpox/virology , Cowpox virus/ultrastructure , Egypt/epidemiology , Female , Humans , Male , Skin/pathology , Skin/virology , Skin Diseases, Viral/epidemiologyABSTRACT
BACKGROUND: This trial was carried out to assess the value of propranolol in the prevention of recurrent variceal bleeding when combined with longterm endoscopic sclerotherapy. PATIENTS AND METHODS: Two hundred patients (161 male, 39 female, age range 20-68 years) with portal hypertension resulting mainly from schistosomal periportal fibrosis or posthepatitic cirrhosis presenting with their first episode of haematemesis or melena, or both were included. This was confirmed endoscopically to result from ruptured oesophageal varices. After initial control of bleeding, patients were randomised into two groups: group 1 treated with endoscopic sclerotherapy alone and group 2 treated with sclerotherapy plus propranolol. They were followed up for two years. RESULTS: Group (2) had a lower rebleeding rate (14.3% v 38.6% in group 1), lower variceal recurrence after obliteration (17% v 34% in group 1), longer period between variceal obliteration and recurrence (36 weeks v 21 weeks in group 1); but no change in mortality (12% in both groups). CONCLUSIONS: Patients treated with sclerotherapy should be given propranolol for longterm management.
Subject(s)
Antihypertensive Agents/therapeutic use , Esophageal and Gastric Varices/therapy , Gastrointestinal Hemorrhage/etiology , Hypertension, Portal/complications , Propranolol/therapeutic use , Sclerotherapy , Adult , Aged , Combined Modality Therapy , Esophageal and Gastric Varices/etiology , Female , Follow-Up Studies , Humans , Hypertension, Portal/etiology , Male , Middle Aged , RecurrenceABSTRACT
In 282 patients 290 ureteral stones were treated with extracorporeal shock wave lithotripsy using the Lithostar lithotriptor. Stones were in the upper ureter in 198 units (68.3%), middle ureter in 36 (12.4%) and lower ureter in 56 (19.3%). The average stone mass was 11.9 mm. and the mean number of shock waves was 4,913 for all levels with a mean kv. of 16.9. The average number of sessions was 1.5 for all sites. Auxiliary measures in the form of ureteral catheterization were done in 24 patients (8.5%) and internal stenting in 12 (4.25%), all of whom had upper or middle ureteral stones. Disintegration of the stones was achieved in 99% of the upper, 93.7% of the middle and 91.7% of the lower ureteral stones. However, clearance of fragments within 3 months from the last session was achieved in 94.8% of the upper, 87.5% of the middle and 91.7% of the lower ureteral stones for an overall stone-free rate of 93.3%.