Determination of structural, spectral, electronic and biological properties of tosufloxacin boron complexes and investigation of substituent effect

The Derivative Difluoroboranyl-Fluoroquinolone "7a" Generates Effective Inhibition Against the S. aureus Strain in a Murine Model of Acute Pneumonia

During the last decades, most bacterial strains have become increasingly resistant to antibiotics. This led the WHO to declare a global emergency in 2017 and urge the development of new active compounds. Some families of antibiotics still show high antibacterial efficacy, as is the case of fluoroquinolones, which have a broad spectrum of action. For this reason, our research group derived several compounds from fluoroquinolones, selecting a compound with good antibacterial activity for further evaluations, a difluoroboranil-fluoroquinolone complex labeled 7a. Antibacterial activity was evaluated using the Kirby-Bauer method against S. aureus (clinical isolate HGZ2201#ID). The MIC and MBC were obtained by macrodilutions and reseeding. In vivo antimicrobial activity was evaluated in a Balb/c mouse model infected intratracheally with S. aureus and subsequently treated with ciprofloxacin or 7a (80 mg/kg/day) for five days. A mean of 8.55 ± 0.395 cm2 inhibition area was observed using 7a, while ciprofloxacin generated a mean inhibition of 7.86 ± 0.231 cm2. Compound 7a showed a MIC and MBC of 0.25 μg/mL. This reduced the generation of pneumonic lung tissue to 5.83%, while the untreated infected group generated 60.51% of pneumonic tissue. Compound 7a proved to be an antimicrobial agent capable of inhibiting the in vitro development of S. aureus. Furthermore, 7a showed effectiveness in decreasing the progression of acute pneumonia induced by S. aureus in a murine model.

Virtual screening, molecular dynamics and density functional theory on pain inhibitors against TRPV1 associating inflammatory conditions

Transient receptor potential vanilloid 1 protein (TRPV1) is expressed widely in skin and sensory neurons that contribute to pain/heat sensation in the human system. TRPV1 gene polymorphisms are susceptible to multiple diseases and it is considered a therapeutic target for various inflammatory conditions. Among the TRPV1 variants, rs8065080 (1911 A > G) plays a vital role in painful osteoarthritis and migraine. The presence of rs8065080 polymorphism may render drug efficacy. This study aimed to identify better antagonists against wild-type and variant TRPV1 that may help in the relief of pain/inflammation. We constructed suitable TRPV1 protein structures for wild-type and rs8065080 variant through a homology modelling approach. A total of 3363 anti-inflammatory compounds with high chemical diversity and good drug-like properties were collected and screened against the generated structures. Molecular docking showed that nobilamide B had the highest binding affinity (-5.83 kcal/mol) towards the wild-type. Whereas, isoquinoline analogue displayed highest binding potency with the variant TRPV1 (-11.65 kcal/mol). Besides those, C18H15F3N4O showed affinity towards both wild-type (-5.53 kcal/mol) and variant TRPV1 (-9.75 kcal/mol). Then, molecular dynamic simulation revealed stable conformation in wild-type and variant TRPV1 upon binding of nobilmaide B, isoquinoline analogue and C18H15F3N4O. Additionally, density functional theory (DFT) using B3LYP hybrid function showed high chemical reactiveness of nobilamie B, isoquinoline analogue and C18H15F3N4O. Overall, our systematic investigations provide, C18H15F3N4O could be a potential analgesic inhibiting both wild-type and variant TRPV1 against inflammatory conditions.

Molecular docking studies, anti-Alzheimer's disease, antidiabetic, and anti-acute myeloid leukemia potentials of narcissoside

In this research, we explored their capacity for Narcissoside antioxidant and anticholinergic, antidiabetic, and anti-acute myeloid leukaemia. Narcissoside's antioxidant activities were elucidated by the use of various bioanalytical assays. Narcissoside's radical scavenging activities were evaluated by DPPH^• and ABTS^•+ scavenging activities. On the other hand, IC₅₀ values were calculated for DPPH^•, and ABTS^•+ scavenging, acetylcholinesterase, and α-glucosidase inhibition effects of narcissoside. IC₅₀ values narcissoside, as 11.54 nM for AChE and 65.58 nM for α-glucosidase were calculated with % Activity-[Inhibitory] graphs. Then, ADME/T analysis of narcissoside molecule was performed to calculate the drug becoming parameters.

Anti-human Glioma Cancer Potentials of Neobavaisoflavone as Natural Antioxidant Compound and Its Inhibition Profiles for Acetylcholinesterase and Butyrylcholinesterase Enzymes with Molecular Modeling and Spin Density Distributions Studies

In this study, the carcinogenic potential of Neobavaisoflavone as a natural antioxidant compound and the inhibitory profiles of acetylcholinesterase and butyrylcholinesterase were investigated by molecular modeling and spin density distribution studies. To evaluate the antioxidant properties of neobavaisoflavone, DPPH test was performed in the presence of butyl hydroxytoluene as a control. Neobavaisoflavone cell viability was low compared to normal human glioma cancer cell lines, namely LN-229, U-87 and A-172 cell lines, without any effect of cytotoxicity on normal cell line. Neobavaisoflavone inhibited half of DPPH at 125 μg/mL. The best effects of Neobavaisoflavone antihypertensive glioma against the above cell lines were in the LN-229 cell line. In addition, the significant anti-cancer potential of human glioma Neobavaisoflavone against the popular human glioma cancer cell lines is related in this study. IC₅₀ values were calculated by Neobavaisoflavone diagrams, 63.87 nM for AChE and 112.98 nM for BuChE, % Activity- [Inhibitor]. According to the above results, Neobavaisoflavone can be used to treat a variety of human glioma cancers in humans. In addition, molecular modeling calculations were performed to compare the biochemical activities of the Neobavaisoflavone molecule with enzymes. After molecular insertion calculations, ADME/T analysis was performed to investigate the properties of the neobavaisoflavone molecule, which will be used as a drug in the future. Then, different parameters for the antioxidant activity of the neobavaisoflavone molecule were calculated.

A Pre-clinical Trial Study: Anti-human Colon Cancer Effect of Thalassiolin B in vitro with Enzymes Inhibition Effects and Molecular Docking Studies

In this study, it is recorded the inhibition effect of Thalassiolin B on aldose reductase, alpha-glucosidase and alpha-amylase enzymes. In the next step, the molecular docking method was used to compare the biological activities of the Thalassiolin B molecule against enzymes formed from the assembly of proteins. In these calculations, the enzymes used are Aldose reductase, Alpha-Amylase, and Alpha-Glucosidase, respectively. After the docking method, ADME/T analysis of Thalassiolin B molecule was performed to be used as a drug in the pharmaceutical industry. In the MTT assay, the anti-human colon cancer properties of Thalassiolin B against EB, LS1034, and SW480 cell lines were investigated. The cell viability of Thalassiolin B was very low against human colon cancer cell lines without any cytotoxicity on the human normal (HUVEC) cell line. The IC₅₀ of the Thalassiolin B against EB, LS1034, and SW480 were 483, 252, and 236 µg/mL, respectively. Thereby, the best cytotoxicity results and anti-human colon cancer potentials of our Thalassiolin B were observed in the case of the SW480 cell line. Maybe the anti-human colon cancer properties of Thalassiolin B are related to their antioxidant effects.

Novel amino acid Schiff base Zn(II) complexes as new therapeutic approaches in diabetes and Alzheimer's disease: Synthesis, characterization, biological evaluation, and molecular docking studies

Schiff bases are compounds that have gained importance in the paint industry due to their colorful nature and in the field of chemistry and biochemistry due to their biological activities. Various biological applications of Schiff bases, such as antitumor, antifungal, antibacterial, antioxidant, antituberculosis, and anthelmintic, have been widely studied. Within the scope of the study, 5-bromo-2-hydroxybenzaldehyde and amino acid methyl esters (isoleucine, phenylalanine, and methionine) and amino acid Schiff bases were synthesized first. The synthesis of the new Zn(II) complexes of these Schiff bases was carried out by the reaction of synthesized Schiff bases and Zn(OAc)₂ ·2H₂ O. The structures of the synthesized complexes were elucidated using elemental analysis, Fourier transform infrared, nuclear magnetic resonance, UV-visible, and thermal analysis spectroscopy techniques. These synthesized salts were found to be effective inhibitor compounds for the α-glycosidase, and acetylcholinesterase enzyme with Ki values in the range of 30.50 ± 3.82-38.17 ± 6.26 µM for α-glycosidase, 3.68 ± 0.54-10.27 ± 1.68 µM for butyrylcholinesterase, and 6.26 ± 0.83-15.73 ± 4.73 µM for acetylcholinesterase, respectively.

1,8-Naphthyridine Derivatives: A Privileged Scaffold for Versatile Biological Activities

1, 8- Naphthyridine nucleus belongs to significant nitrogen-containing heterocyclic compounds which has garnered the interest of researchers due to its versatile biological activities. It is known to be used as an antimicrobial, anti-psychotic, anti-depressant, anti-convulsant, anti- Alzheimer's, anti-cancer, analgesic, anti-inflammatory, antioxidant, anti-viral, anti-hypertensive, antimalarial, pesticides, anti-platelets, and CB2 receptor agonist, etc. The present review highlights the framework of biological properties of synthesized 1, 8-naphthyridine derivatives developed by various research groups across the globe.

Synthesis, biological activity and docking calculations of bis-naphthoquinone derivatives from Lawsone

Some metabolic enzyme inhibitors can be used as Multi-target-Directed-Ligands (MTDL) in Medicinal chemistry therefore, synthesis and determination of alternative inhibitors are essential. In this study, novel bis-napthoquinone derivatives (5a-o) were synthesized through a multi-component cascade reaction of two molecules of 2-hydroxy-1,4-naphthoquinone with an aromatic aldehyde in basic media using triethylamine as a catalyst. This novel heterocyclic derivatives (5a-o) are applied to inhibit the carbonic anhydrase (hCA I and hCA II) isoform in low levels of nano molecules with Ki values exist between 4.62 ± 1.01 to 70.45 ± 9.03 nM for hCA I and for hCA II which is physiologically dominant K_is values are in the range of 5.61 ± 1.04 to 73.26 ± 10.25 nM. Further these novel derivatives (5a-o) efficiently inhibit AChE with Ki values in the range of 0.13 ± 0.02 to 3.16 ± 0.56 nM. The compounds are also applied for BChE with Ki values varying between 0.50 ± 0.10 to 9.23 ± 1.15 nM. For α-glycosidase, the most efficient Ki values of 5e and 5f are 76.14 ± 9.60 and 95.27 ± 12.55 nM respectively. Finally, molecular docking calculations against enzymes (acetylcholinesterase, butyrylcholinesterase, and the human carbonic anhydrase I and II) are compared using biological activities of heterocyclic derivatives. After these calculations, an ADME/T analysis is performed to study the future medicinal use of heterocyclic derivatives from lawsone.

ADME properties, bioactivity and molecular docking studies of 4-amino-chalcone derivatives: new analogues for the treatment of Alzheimer, glaucoma and epileptic diseases

In this study, in vitro inhibition effects of (E)-1-(4-aminophenyl)-3-(aryl) prop-2-en-1-one (4-amino-chalcones) derivatives (3a-o) on acetylcholinesterase (AChE) enzyme and human erythrocyte carbonic anhydrase I and II isoenzymes (hCA I- II) were investigated. And also, the biological activities of 4-amino-chalcone derivatives against enzymes which names are acetylcholinesterase (PDB ID: 1OCE), human Carbonic Anhydrase I (PDB ID: 2CAB), human carbonic anhydrase II (PDB ID: 3DC3), were compared. After the results obtained, ADME/T analysis was performed in order to use 4-amino-chalcone derivatives as a drug in the future. Effective inhibitors of carbonic anhydrase I and II isozymes (hCAI and II) and acetylcholinesterase (AChE) enzymes with Ki values in the range of 2.55 ± 0.35-11.75 ± 3.57 nM for hCA I, 4.31 ± 0.78-17.55 ± 5.86 nM for hCA II and 96.01 ± 25.34-1411.41 ± 32.88 nM for AChE, respectively, were the 4-amino-chalcone derivatives (3a-o) molecules.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-021-00094-x.

Synthesis and docking calculations of tetrafluoronaphthalene derivatives and their inhibition profiles against some metabolic enzymes

Syntheses of tetrahydroepoxy, O-allylic, O-prenylic, and O-propargylic tetrafluoronaphthalene derivatives, starting from 1-bromo-2,3,4,5,6-pentafluorobenzene, are reported here for the first time. The O-substituted tetrafluoronaphthalene derivatives were designed and also synthesized via a one-pot nucleophilic substitution reaction in excellent yields, whereas the tetrafluorotetrahydroepoxynaphthalene derivate was synthesized via a reduction reaction in excellent yield. The chemical structures of all the synthesized molecules were characterized by nuclear magnetic resonance, infrared spectroscopy, and high-resolution mass spectrometry techniques. In this study, a series of novel tetrafluoronaphthalene derivatives (2, 2a, 4-6) was tested toward several enzymes including α-glucosidase, acetylcholinesterase (AChE), and human carbonic anhydrase I and II (hCA I/II). The tetrafluoronaphthalene derivatives 2, 2a, and 4-6 showed IC₅₀ and K_i values in the range of 0.83-1.27 and 0.71-1.09 nM against hCA I, 1.26-1.85 and 1.45-5.31 nM against hCA II, 39.02-56.01 and 20.53-56.76 nM against AChE, and 15.27-34.12 and 22.58-30.45 nM against α-glucosidase, respectively. Molecular docking calculations were made to determine the biological activity values of the tetrafluoronaphthalene derivatives against the enzymes. After the calculations, ADME/T analysis was performed to examine the effects on human metabolism. Finally, these compounds had antidiabetic and anticholinesterase potentials.

Synthesis, molecular docking, and biological activities of new cyanopyridine derivatives containing phenylurea

A new class of cyanopyridine derivatives (10a-e and 11a-e) containing the phenylurea unit was synthesized and tested against some metabolic enzymes including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase (α-Gly). The new cyanopyridine derivatives showed K_i values in the range of 40.73 ± 6.54 to 87.05 ± 16.98 µM against AChE, 29.17 ± 4.88 to 124.03 ± 22.43 µM against BChE, and 3.66 ± 0.93 to 26.33 ± 5.05 µM against α-Gly. These inhibition effects were compared with standard enzyme inhibitors like tacrine (for AChE and BChE) and acarbose (for α-Gly). Also, these cyanopyridine derivatives with the best inhibition score were docked into the active site of the indicated metabolic enzymes. Finally, molecular docking calculations were made to compare the biological activities of the compounds against AChE (-8.81 kcal/mol for molecule 11d), BChE (-3.52 kcal/mol for molecule 11d), and α-Gly (-2.98 kcal/mol for molecule 11a). After molecular docking calculations, the ADME/T analysis was performed to examine the future drug use properties of the new cyanopyridine derivatives containing phenylurea.

Metal contained Phthalocyanines with 3,4-Dimethoxyphenethoxy substituents: their anticancer, antibacterial activities and their inhibitory effects on some metabolic enzymes with molecular docking studies

The compounds (3-6) used in this study were re-synthesized in accordance with our previous study. The inhibitory effect of the complexes on some metabolic enzymes was examined and it was demonstrated that the enzymes inhibited by ligands and their complex molecules at micromolar level. The best Ki value for α-glycosidase enzyme was absorved 1.01±0.08 µM for compound 6. The biological activity of ligand and metal complexes against enzymes was compared with molecular docking method. The enzymes used against ligand and metal complexes respectively: Achethylcholinesterase for ID 4M0E (AChE), butyrylcholinesterase for ID 5NN0 (BChE), α-glycosidase for ID 1XSI (α-Gly). ADME analysis was performed to examine the drug properties of the compounds (3-6). Besides, the anticancer properties of the complexes were studied. The doses of all compounds caused significant reductions in MCF-7 cell viability. The 3 and 5 compounds administered to PC-3 cells exhibited a more pronounced cytotoxic effect than the other two compounds (4 and 6). Furthermore, antibacterial activities of these compounds against Escherichia coli and Staphylococcus aureus were examined.Communicated by Ramaswamy H. Sarma.

Determination of the inhibition profiles of pyrazolyl-thiazole derivatives against aldose reductase and α-glycosidase and molecular docking studies

Aldose reductase (AR) is the first and rate-limiting enzyme of the polyol pathway, which converts glucose to sorbitol in an NADPH-dependent reaction. α-Glycosidase breaks down starch and disaccharides to glucose. Hence, inhibition of these enzymes can be regarded a considerable approach in the treatment of diabetic complications. AR was purified from sheep liver using simple chromatographic methods. The inhibitory effects of pyrazolyl-thiazoles ((3aR,4S,7R,7aS)-2-(4-{1-[4-(4-bromophenyl)thiazol-2-yl]-5-(aryl)-4,5-dihydro-1H-pyrazol-3-yl}phenyl)-3a,4,7,7a-tetrahydro-1H-4,7-methanoisoindole-1,3(2H)-dione derivatives; 3a-i) on AR and α-glycosidase enzymes were investigated. All compounds showed a good inhibitory action against AR and α-glycosidase. Among these compounds, compound 3d exhibited the best inhibition profiles against AR, with a K_i value of 7.09 ± 0.19 µM, whereas compound 3e showed the lowest inhibition effects, with a K_i value of 21.89 ± 1.87 µM. Also, all compounds showed efficient inhibition profiles against α-glycosidase, with K_i values in the range of 0.43 ± 0.06 to 2.30 ± 0.48 µM, whereas the K_i value of acarbose was 12.60 ± 0.78 µM. Lastly, molecular modeling approaches were implemented to predict the binding affinities of compounds against AR and α-glycosidase. In addition, the ADME analysis of the molecules was performed.

The biological activities, molecular docking studies, and anticancer effects of 1-arylsuphonylpyrazole derivatives

This work is devoted to definition of the direction of reaction between 1-benzenesulfonylimino pyridinium chloride and α- or β-halo-containing sulfamides, chloroacetic acid, 1-chloro-2,3-dihydroxypropane, etc. The optimal conditions for the synchronous reaction of heterocyclization are determined. Benzenesulfonyliminopyridinium chloride was obtained to form pyrazolopyridines with 1,2-polarophiles, and pyridazine pyridines with 1,3-polarophiles. These novel derivatives were found as effective inhibitors of the α-glycosidase with K_i values in the range of 13.66 ± 2.63-60.63 ± 12.71 nM. The molecules (II-X) against enzyme were compared theoretically with the help of molecular docking to compare biological activities. The results were compared with the numerical values of the parameters obtained from molecular docking calculations and found to be in great agreement with the experimental results. However, ADME analysis of molecules was performed. Also, the compounds exhibited significant anticancer effect depending on the doses administered.Communicated by Ramaswamy H. Sarma.

Structural, spectral characterization and molecular docking analyses of mer-ruthenium (II) complexes containing the bidentate chelating ligands

In this study, we analyzed some monofunctional Ru (II) complexes containing chlorine, bromine and fluorine atoms around the central atom. The best calculation level among HF, B3LYP and M062X methods for [Ru (Cl-Ph-tpy)(NN)X]⁺ (X = F, Cl, Br) was determined in the light of Benchmark analysis and according to this analysis results, the best level is shown as B3LYP-LANL2DZ/6-31G(d). In addition to this, the spectroscopic data (IR, NMR and UV-Vis) were also obtained in agreement with experimental results. The tendency of anticancer activity and structural activity relationship (SAR) parameters are predicted with some quantum chemical methods. Surface and contour diagrams, as well as electron densities on mentioned complexes were interpreted through theoretically obtained results. Finally, the anticancer activity tendency of the relevant complexes on the human cervical carcinoma cell line (ID: 1 M17) is supported by molecular docking calculations.

Investigations over optical properties of boron complexes of benzothiazolines

Quantum chemical analyses over benzothiazolines and their boron complexes are performed. In calculations, M06-2X method was selected with 6-31 + G(d,p) level. Structural and spectral (IR and NMR) characterization of studied compounds are done in detail. Quantum chemical descriptors (QCDs) are calculated to investigate the optical properties. Furthermore, molecular electrostatic potential (MEP) maps of the studied compounds are calculated by using electro-static potential (ESP) charges. According to QCDs and MEP maps, NLO properties of boron complexes are more than those of benzothiazolines and (Z)-2-((pyridin-2-ylmethylene)amino) benzenethiolatebutane-1,3-bis(olate)boron(III), complex (7), has the most NLO activity in studied compounds. Finally, solvent effect on NLO activity are investigated by calculating UV-vis spectrum in gas phase (ε = 1), toluene (ε = 2.3741), chloroform (ε = 4.7113), methanol (ε = 32.613), water (ε = 78.3553) and n-methylformamide-mixture (ε = 181.56). According to these spectra results, NLO activity mainly increases with increasing of polarizability of media.

Investigation of structural, electronic properties and docking calculations of some boron complexes with norfloxacin: A computational research

Quantum chemical calculations are performed over BF₂R (1), B(NO)₂R (2), B(CN)₂R (3) and B(CH₃)₂R (4) [R: 1-ethyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylate]. Mentioned boron complex with fluorine atoms which is BF₂R are optimized at HF/6-31+G(d), B3LYP/6-31+G(d) and M062X/6-31+G(d) level and the best level is determined by comparison of experimental and calculated results. The best calculation level is determined as M06-2X/6-31+G(d) level. The other complexes are optimized at this level. Structural properties, IR and NMR spectrum are examined in detail. Additionally, biological activities of mentioned complexes are investigated by some quantum chemical descriptors (E_HOMO, E_LUMO, I, A, E_GAP, η, σ, χ, CP, ω, N, ΔN_max and S) and molecular docking analyses. The interaction energies for complex (1), (2), (3) and (4) are calculated as -480.1, -443.6, -433.6 and -402.1 kJ mol^-1, respectively. As a result, it is found that boron complex with fluorine atoms (BF₂R) is the best candidate for anticancer drug.

Antiproliferative, antioxidant, computational and electrochemical studies of new azo-containing Schiff base ruthenium(ii) complexes

A new series of ruthenium(ii) complexes 7–11 containing the –NN– group are synthesized and characterized via elemental analysis, and IR, UV-visible and ¹H–¹³C NMR spectroscopy.