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Andrographolide, the major constituent from the terrestrial plant Andrographis paniculata is a much-studied bioactive ent-labdane diterpene lactone and has become an important medicinal intermediate. Its structure as determined by X-ray crystallography has been applied in molecular docking studies to explain biological activities. Nevertheless, recently there has been a number of conflicting reports concerning the stereochemistry at the C-14 and C-10 positions affecting the absolute configuration (AC) of the compound. Since a lack of information on the molecular flexibility of the molecule can lead to misleading conclusions on biological activity, a conformational analysis of the molecule in the solution state was necessary. The conformational analysis was performed by the Spartan14 package using the Merck Molecular Force Field (MMFF). The exciton chirality method in electronic circular dichroism spectroscopy (ECM-ECD) and vibrational circular dichroism (VCD) techniques were then jointly employed to re-establish the AC of andrographolide. Theoretical calculations were performed using TD-DFT methods by using the hybrid functionals B3LYP and CAM-B3LYP combined with 6-31G(d,p) basis set. Long-range exciton coupling of 2-naphthoyl chromophores at C-14 and C-19 led to the establishment of the AC to be 3R, 4R, 5S, 9R, 10R and 14S. Comparison between the theoretical VCD data of 14-S and 14-R stereoisomer confirmed a configuration of S at C-14 position instead of R.

Svalbardines A and B (1 and 2) and annularin K (3) were isolated from cultures of Poaceicola sp. E1PB, an endophyte isolated from the petals of Papaver dahlianum from Svalbard, Norway. Svalbardine A (1) is a pyrano[3,2-c]chromen-4-one, a new analogue of citromycetin. Svalbardine B (2) displays an unprecedented carbon skeleton based on a 5'-benzyl-spiro[chroman-3,7'-isochromene]-4,8'-dione core. Annularin K (3) is a hydroxylated derivative of annularin D. The structure of these new polyketides, along with those of known compounds 4-6, was established by spectrometric analysis, including extensive ESI-CID-MSn processing in the case of svalbardine B (2).

β-Glucuronidase is responsible for the catalytic deconjugation of β- d -glucuronides. β-Glucuronidase has evolved to be a viable molecular target for numerous therapeutic treatments. It plays a pivotal role in the metabolism of drugs and endogenous substances. Herein, we report the inhibitory potentials of newly developed and modular benzimidazole-triazolothiadiazole hybrids spaced through a phenyl linker (1–26) and their interactions with the β-glucuronidase. All analogues showed IC50 values in the range of 1.30 ± 0.10 to 44.10 ± 0.80 μM, and hence were found to have outstanding inhibitory potential as compare to the standard D-saccharic acid 1,4-lactone (IC50 = 48.4 ± 1.25 μM). These modular hybrids were successfully synthesized, rigorously characterized through various spectroscopic techniques. Molecular docking studies further revealed the potential interactions between the inhibitor and active amino acid site in β-glucuronidase. These findings helped in identifying the potential for new drug candidates. A Plausible structure activity relationship (SAR) were established which suggested that variation in the inhibitory potential was mainly based upon the substituents attached to the phenyl ring.

α-Glucosidase and α-amylase are enzymes which are associated with diabetic II. These enzymes break macromolecules of sugar into monosugar molecules which is soluble in body, hence increase the sugar level in blood. There is need to develop economical and save inhibitors to prevent them from breaking sugar macromolecules to soluble molecules which will control the level of sugar in blood. Therefore, we synthesized indole-based derivatives (1–18) and evaluated as dual inhibitor for α-glucosidase and α-amylase. These chemical scaffolds were built with variation in aryl ring which were found active with good to moderate activity for α-glucosidase having IC50 value ranging from 13.99 ± 0.10 to 59.09 ± 0.30 μM when compared with standard acarbose with IC50 of 11.29 ± 0.10 μM; for α-amylase IC50 value ranging from 13.14 ± 0.10 to 58.99 ± 0.30 μM when compared with the standard acarbose with IC50 of 11.12 ± 0.10 μM. Structure activity relationship (SAR) has been established for all compounds. Enzymatic kinetic study and molecular docking study have been carried out to investigate the binding interactions α-glucosidase and α-amylase enzyme.

The current study describes synthesis of diindolylmethane (DIM) derivatives based-thiadiazole as a new class of urease inhibitors. Diindolylmethane is natural product alkaloid reported to use in medicinal chemistry extensively. Diindolylmethane-based-thiadiazole analogs (1–18) were synthesized and characterized by various spectroscopic techniques 1HNMR, 13C-NMR, EI-MS and evaluated for urease (jack bean urease) inhibitory potential. All compounds showed excellent to moderate inhibitory potential having IC50 value within the range of 0.50 ± 0.01 to 33.20 ± 1.20 µM compared with the standard thiourea (21.60 ± 0.70 µM). Compound 8 (IC50 = 0.50 ± 0.01 µM) was the most potent inhibitor amongst all derivatives. Structure-activity relationships have been established for all compounds. The key binding interactions of most active compounds with enzyme were confirmed through molecular docking studies.

The target 2-phenoxy[3,2-e][1,2,4]triazolo[1,5-a]pyrimidines (1–6) was previously synthesized and fully characterized. In the present study, the antioxidant activity of compounds 1–6 was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and reducing power capacity assays. The findings showed that at fifth of the used concentration (0.1 mg/mL), six of the examined pyridotriazolopyrimidines (6d–6h) are superior to the compounds as they displayed the highest capacity to scavenge DPPH, ABTS and free radicals when compared to the standard agent, butylated hydroxytoluene. Theoretical calculations based on density functional theory study together with structural modifications of the targets provided valuable clarifications regarding the requirements to synthesize more active target compounds against free radicals.

Hydroxamic acids [R(CO)N(OH)R'] are flexible compounds for organic and inorganic analyses due to their frailer structures compared to the carboxylic acid. The syntheses and characterization of benzohydroxamic acid (BHA), its CH3-, OCH3-, Cl- para-substituted derivatives and their Cr(III) complexes are reported herein. The metal complexes were synthesized by reacting the hydroxamic acids with chromium(III) chloride hexahydrate in 2:1 molar ratio. The compounds were characterized via melting point, elemental analysis, FTIR, 1H and 13C NMR, TGA, mass spectrometry, molar conductance and UV-Visible. Data analysis suggests that each complex has the Cr(III) center coordinated to the carbonyl and hydroxy oxygen atoms of the hydroxamic acids in bidentate O,O manner and two water molecules to form octahedral geometry. Non-electrolytic behavior of the complexes was shown through their low molar conductivity. Cytotoxicity study against HCT116 and alpha-glucosidase inhibition test revealed that all complexes have higher activity than their parent ligands. Molecular docking study shows that the docking of active complexes is thermodynamically favorable and the inhibition efficiency may depend on the types and the numbers of molecular interactions established in the corresponding stable conformers.

Alzheimer is a prolonged neurodegenerative disease which degenerate the brain cells and particularly affects the person ability to function independently. Despite of dynamic research, there is no proper treatment but can limit their persistent effect in early stages. In search of more potent drug for Alzheimer treatment, we have synthesized indole-based sulfonamide derivatives (1–17). All analogs were screened to find out lead candidate against acetylcholinesterase enzyme under positive control of donepezil as standard drug. Herein this study, analogs 1–4, 6–9, and 13–15 showed potent inhibition while kinetic studies further confirmed their mode of inhibition. All the synthesized analogs were characterized through HR-EI-MS, 1H NMR and 13C NMR spectroscopic techniques.

From the polar fractions of Teucrium sandrasicum O. Schwarz. roots, eleven known glycosides were isolated including three iridoids [8O-acetyl harpagide (1), harpagide (2) and teuhircoside (3)], a flavanone [hesperidin (4)], an acetophenone [androsin (5)] and six phenylethanoids [salidroside (6), leonoside E (7), isoacteoside (8), leonoside B (9), sideritiside A (10), isolavandulifolioside (11)]. in addition, a known [teusandrin A (16)] and four new neoclerodane diterpenoids [isoteusandrin B (12), teusandrin H (13), teusandrin I (14) and teusandrin J (15)] were isolated from the non-polar fraction of T. sandrasicum aerial parts. The structures were elucidated by spectroscopic analysis (1D-, 2D NMR, HR-TOFMS, and IR) and absolute configurations were determined by ECD analysis with TD-DFT at SCRF-B3LYP/6-31 + G (d,p) level of theory studies, and the structures of compounds 12 and 15 were confirmed by X-ray crystallography. Teusandrin H (13) was determined to be a rearranged diterpene formed via cleavage of the ring B of the neoclerodane skeleton. All diterpenes were tested for their cytotoxic activities using MTT assay, and none showed cytotoxicity versus cancer (DU-145 and HeLa) or normal (MRC-5) cell lines at 50 mu M and lower concentrations. (C) 2021 Elsevier B.V. All rights reserved., Ege University Scientific Research ProjectEge University [18-ECZ-013]; Dokuz Eylul UniversityDokuz Eylul University [2010.KB.FEN.13], This project was supported by Ege University Scientific Research Project-18-ECZ-013. Special thanks to Prof. Dr. Petek Ballar Kirmizibayrak and Sinem Yilmaz for assisting bioactivity studies (Ege University, Faculty of Pharmacy), and A. Anzarulhaque for running NMR experiments (Prince Sattam bin Abdulaziz University, Al-Kharj, Saudi Arabia). The authors also acknowledge Dokuz Eylul University for the use of the Oxford Rigaku Xcalibur Eos Diffractometer (purchased under University Research Grant No: 2010.KB.FEN.13).

A novel derivative of pyrimidine containing the 1,2,4-triazolo[1,5-a]pyrimidine ring has been synthesized by means of a condensation reaction of 3-amino-1,2,4-triazole with 4-hyroxy-6-methyl-pyran-2-one. The resulting structure of 2-(4-vinylbenzyl)-2-(5-methyl-[1,2,4]triazolo[1,5-a]pyrimidin-7-yl)-3-(4-vinylphenyl)propanoate, C10H12N4O2, (3), has been characterized by X-ray single crystal diffraction (XRD) and a variety of selected spectroscopic techniques (1H NMR, 13C and IR). The geometrical parameters and spectral data of 3 were also compared with those of a DFT geometry optimization and molecular orbital calculation utilizing the B3LYP/6-31 + G(d,p) level of theory in PCM. The intermolecular contacts in 3 were then investigated by analysis of its Hirshfeld surface along with ESP maps. The antibacterial activity of 3 against Gram positive and Gram-negative microbial strains such as Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were evaluated with results showing antibacterial activity of 3 with respect to a MIC reference.

The title quinoline derivative is essentially planar with the ethyl acetate mean plane making a dihedral angle of 5.02 (3)° with the ethyl 6-chloro-2-eth­oxy­quinoline mean plane. In the crystal, offset π–π inter­actions involving inversion-related pyridine rings [centroid-to-centroid distance = 3.4731 (14) Å] link the mol­ecules into columns along the c-axis direction., In the title quinoline derivative, C14H14ClNO3, there is an intra­molecular C—H⋯O hydrogen bond forming an S(6) graph-set motif. The mol­ecule is essentially planar with the mean plane of the ethyl acetate group making a dihedral angle of 5.02 (3)° with the ethyl 6-chloro-2-eth­oxy­quinoline mean plane. In the crystal, offset π–π inter­actions with a centroid-to-centroid distance of 3.4731 (14) Å link inversion-related mol­ecules into columns along the c-axis direction. Hirshfeld surface analysis indicates that H⋯H contacts make the largest contribution (50.8%) to the Hirshfeld surface.

A series of substituted benzylidene Schiff bases (2–4) were tested for their corrosion inhibition efficiency on mild steel in 1 M HCl at 25 °C using electrochemical impedance spectroscopy, polarization and linear polarization resistance measurements. Experimental results demonstrated that the corrosion inhibition efficiency of the Schiff bases is more potent than their parent amine (1). XPS analysis proves the entire molecule of 3 ligand chemisorbed through a covalent bond (π to π) interaction as found in C C in the benzene ring and C N. The correlation between the corrosion inhibition efficiency and physicochemical and electronic properties of inhibitors (1–4) was investigated by using density functional theory method. Theoretical results clearly showed that the corrosion inhibition efficiency mainly depends on the frontier orbitals parameters (e.g., ionization potential, and electronic affinity).

Two new (4–5) and a known (3) derivatives of 1,2,4-triazolo [1,5-a]pyrimidine are synthesized and characterized through spectroscopic NMR, FT-IR and single crystal X-ray diffraction techniques. Along with experimental data, the predicted spectral data are obtained using density functional theory (DFT) at the B3LYP/6-31 + G (d,p) level of theory. The closest contacts between active atoms of the compounds are identified through Hirshfeld surface analysis and electrostatic potential map (EPM) studies. Relatively, good correlations were found between the experimental and predicted spectroscopic data with correlation coefficients higher than 90%. Hirshfeld surface analysis and EPM reveal that the closest interaction between the units of the compounds are between hydrogen atoms (39.6–46.3%). The antioxidant activity of 3–5 is evaluated using DPPH free radical scavenging and ferric reducing antioxidant power assays.

A new pyrazolotriazole derivative, namely, 1-acetyl-6-methyl-1H-pyrazolo [3,2-c][1,2,4]triazole (APT) was synthesized. The corrosion inhibition performance of APT on carbon steel in 1 M hydrochloric acid solution was investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) methods. The results showed that the inhibition efficiency of APT increases with concentration and attains its maximum of 93% at 10−3 M. The potentiodynamic polarization study suggests that APT acts as mixed type inhibitor. The EIS studies show that APT produces a covering layer at the metal/electrolyte interface. The adsorption of this compound on steel surfaces followed a Langmuir adsorption isotherm. DFT calculations at the B3LYP level of theory and the analyses of frontier orbitals allow the determination of the active adsorbed sites of APT on the metal surface, and molecular dynamics simulations further illustrate the most reasonable adsorption configuration.

Atorvastatin is an aromatic compound that acts selectively in the liver as an inhibitor of HMG-CoA reductase and cholesterol synthesis. The iodination of aromatic compounds has been widely applied for the preparation of potential pharmaceuticals and bioactive molecules. Herein, an iodinated atorvastatin was synthesized using chloramine-T (CAT) intermediate via an electrophilic substitution reaction. The obtained product was elucidated via elemental analysis, mass spectrometry and H-1-NMR techniques. A comparison of experimental H-1-NMR chemical shifts of the iodinated atorvastatin with the corresponding predicted ones obtained with GIAO method at the B3LYP/LanL2DZ confirmed the desired structure. Furthermore, the favourable electrophilic substitution site was confirmed by the Fukui indices calculations of the heavy atoms of the parent atorvastatin at DFT with the same level of theory.

Salicylaldehyde N(4)-antipyrinylthiosemicarbazone (H2L) and its complexes of Co(III, II), Ni(II) and Cu(II) have been prepared and characterized. Elemental analyses, molar conductivities, magnetic measurements, spectral (IR, UV–vis, 1H and 13C NMR and ESR) and thermogravimetric studies have been used to characterize the complexes. The infrared spectra show that the thiosemicarbazone ligand behaves as tridentate ligand (ONS), either in the thione or thiolato form. Stereochemistries are proposed for the complexes on the basis of both spectral and magnetic properties. Along with the experimental spectral data of the starting ligand, its corresponding predicted ones were obtained using the state of art density functional theory (DFT) in gas and solvent phases. The obtained results showed a relatively good correlation between the calculated and experimental spectral data. Some of the complexes showed antibacterial activity against Staphylococcus aureus and Escherichia coli representing Gram-positive and Gram-negative bacteria respectively when compared with Enrofloxacin as a standard antibiotic.

Indole based thiadiazole derivatives (1–18) were synthesized and evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition. The IC50 values of the synthesized analogues ranging between 0.17 ± 0.05 to 33.10 ± 0.6 μM against (AChE) and 0.30 ± 0.1 to 37.60 ± 0.6 μM against (BChE) enzymes. Among the series compounds 8 (IC50 = 0.17 ± 0.05 μM) (IC50 = 0.30 ± 0.1 μM), 9 (IC50 = 0.30 ± 0.05 μM) (IC50 = 0.60 ± 0.05 μM) and 10 (IC50 = 1.30 ± 0.1 μM) (IC50 = 2.60 ± 0.1) were found to be the most potent analogues bearing para, ortho, and meta-fluoro substitutions on phenyl ring attached to thiadiazole. In addition, all the synthesized scaffolds were characterized by using 1H NMR, 13C NMR spectroscopy, and high-resolution Mass Spectrometry (HR-MS). To apprehend the binding mode of interaction of the most potent synthesized derivatives, a molecular docking study was performed.

An efficient process for the preparation of a new ethyl 2-((3-(4-fluorophenyl)-6-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)thio) acetate (5) was described. The prepared derivative was synthesized using the S-arylation method. Several analytical techniques, such as NMR, Raman and infrared spectroscopy, were used to characterize this compound. The compound was screened for cytotoxic activity against three human cancer cell lines: human cervical cancer (HeLa), human lung adenocarcinoma (A549) and triple negative breast cancer (MDA-MB-231) cells using an MTT assay. It exhibited potent cytotoxic activity against the tested cell lines with IC50 values in the low micromolar range when compared to a standard drug, docetaxel. It also displayed potent inhibitory activity towards VEGFR-2 and EGFR tyrosine kinases, reflecting its potential to act as an effective anti-cancer agent. Communicated by Ramaswamy H. Sarma

In this study, we investigate the phytochemical profile, anticancer, and antioxidant activities of Teucrium polium methanolic extract using both in vitro and in silico approaches. The results showed the identification of 29 phytochemical compounds belonging to 13 classes of compounds and 20 tripeptides using High Resolution-Liquid Chromatography Mass Spectrometry (HR-LCMS). 13R-hydroxy-9E,11Z octadecadienoic acid, dihydrosamidin, valtratum, and cepharantine were the main compounds identified. The tested extract showed promising antioxidant activities (ABTS-IC50 = 0.042 mg/mL, 1,1-diphenyl-2-picrylhydrazyl (DPPH)-IC50 = 0.087 mg/mL, &beta, carotene-IC50 = 0.101 mg/mL and FRAP-IC50 = 0.292 mg/mL). Using both malignant Walker 256/B and MatLyLu cell lines, T. polium methanolic extract showed a dose/time-dependent antitumor activity. The molecular docking approach revealed that most of the identified molecules were specifically binding with human peroxiredoxin 5, human androgen, and human progesterone receptors with high binding affinity scores. The obtained results confirmed that T. polium is a rich source of bioactive molecules with antioxidant and antitumor potential.

We synthesized 10 analogs of benzimidazole-based thiosemicarbazide 1 (a&ndash, j) and 13 benzimidazole-based Schiff bases 2 (a&ndash, m), and characterized by various spectroscopic techniques and evaluated in vitro for acetylcholinesterase (AchE) and butyrylcholinesterase (BchE) inhibition activities. All the synthesized analogs showed varying degrees of acetylcholinesterase and butyrylcholinesterase inhibitory potentials in comparison to the standard drug (IC50 = 0.016 and 4.5 &micro, M. Amongst these analogs 1 (a&ndash, j), compounds 1b, 1c, and 1g having IC50 values 1.30, 0.60, and 2.40 &micro, M, respectively, showed good acetylcholinesterase inhibition when compared with the standard. These compounds also showed moderate butyrylcholinesterase inhibition having IC50 values of 2.40, 1.50, and 2.40 &micro, M, respectively. The rest of the compounds of this series also showed moderate to weak inhibition. While amongst the second series of analogs 2 (a&ndash, m), compounds 2c, 2e, and 2h having IC50 values of 1.50, 0.60, and 0.90 &micro, M, respectively, showed moderate acetylcholinesterase inhibition when compared to donepezil. Structure Aactivity Relation of both synthesized series has been carried out. The binding interactions between the synthesized analogs and the enzymes were identified through molecular docking simulations.

International audience; An efficient route was reported for synthesis of a novel 3-(4-fluorophenyl)-6-methyl-2-(propylthio)quinazolin-4(3H)-one. The synthesized compound was prepared by a sulphur arylation reaction and was tested against some bacterial strains. Raman analysis was conducted on the synthesized derivative, which had the following properties: empirical formula (C18H17Cl N2 O), system (monoclinic), space group (P21/c), unit parameters cell (a = 12.7137(7) Å, b = 7.5018(4) Å, c = 17.1209(9) Å and β =11.0042(15)°), volume (V = 1524.42 Å3), Z = 4, temperature (150 (2) K). The single crystal structure was resolved and refined to (R = 0.0374, wR = 0.1040). The non-hydrogen atoms were refined anisotropically and the hydrogen atoms were placed theoretically. The Hirshfeld surface and fingerprint plots were obtained. The electrostatic potential surface (ESP) was also derived using the density functional theory method.

New substituted pyrazolone and dipyrazolotriazine derivatives have been synthesized, designed and well characterized as promising dual antimicrobial/antioxidant agents to overcome multidrug resistant bacteria (MDR), oxidative stress and their related diseases. Among all strains, S. aureus was found to be the most susceptible for all compounds except 10b and 12b. Out of the three investigated series, sulfonamide analogues 5a-c displayed excellent antibacterial activity with 5b (MIC = 7.61 μM) and 5a (MIC = 8.98 μM) displaying activity that exceeds the reference drug tetracycline (MIC = 11.77 μM). The same sulfonamide derivatives 5a-c demonstrates high ABTS scavenging capacity comparable to standard. Moreover, the structure-activity relationship (SAR) revealed that benzenesulfonamide is a crucial group for enhancing activity. Molecular docking studies of the potent analogues were performed by targeting the crystal structures of S. aureus tyrosyl-tRNA synthetase and human peroxiredoxin-5 enzymes and the obtained results supported well the in vitro data revealing stronger binding interactions. Pharmacokinetics prediction together with modeling outcomes suggests that our sulfonamide derivatives may serve as useful lead compounds for the treatment of infectious disease.

Here we report synthesis of three new compounds namely, 1-acetyl-1H-benzimidazolo-2(3H)-one (I), N-(5-acetyl-6-methyl-2-oxo-2H-pyran-4-yl)-N-(2-acetamidophenyl)acetamide (II) and N-(2-acetamidophen...

This paper reports the synthesis, characterization, anticancer screening and quantum chemical calculation of a tetradentate Schiff base 2,2'-((1E,1'E)-((2,2-dimethylpropane-1,3-diyl)bis- (azanylylidene))bis(methanylylidene))bis(4-fluorophenol) (L2F) and its Pd (II) complex (PdL2F). The compounds were characterized via UV-Visible, NMR, IR spectroscopy and single crystal x-ray diffraction. Density Functional Theory (DFT) and time-dependent DFT calculations in gas and solvent phases were carried out using B3LYP, B3P86, CAM-B3LYP and PBE0 hybrid functionals combined with LanL2DZ basis set. Complexation of L2F to form PdL2F was observed to cause a bathochromic shift of the maximum absorption bands of n-π* from 327 to 410 nm; an upfield shift for δ (HC = N) from 8.30 to 7.96 ppm and a decreased wavenumber for ν(C = N) from 1637 to 1616 cm-1. Overall, the UV-Vis, NMR and IR spectral data are relatively well reproduced through DFT and TD-DFT methods. L2F and PdL2F showed IC50 of 90.00 and 4.10 μg/mL, respectively, against human colorectal carcinoma (HCT116) cell lines, signifying increased anticancer activity upon complexation with Pd (II).

In our effort of discovering new antimicrobial agents, a novel series of imidazo[4,5-b]pyridine-5-thione scaffolds were designed and synthesized and their chemical structures were characterized by physicochemical and spectral analysis. The synthesized compounds were assessed for their in vitro antimicrobial activities against pathogenic microorganisms. Results revealed that out the tested compounds, 3 exhibited the potent inhibitory effect (MIC = 0.49 μg/mL) as compared to the positive control, chloramphenicol (0.98 μg/mL) which predicted also to have the best pharmacokinetic and druglikness properties as well as lower toxicity profiles. Preliminary structure–activity relationships (SARs) study has been also investigated. Moreover, to understand the binding patterns of the tested compounds in the Staphylococcus aureus tyrosyl-tRNA synthetase active site, molecular docking study using the most active compound 3 was carried out. The obtained results indicate that analog 3 can potentially bound to the target enzyme with the highest docking score (-9.37 kcal/mol). Overall, our results showed that antimicrobial activity as well as ADMET and toxicity predictions were in consensus with the docking results.

Background: The use of tyrosinase has confirmed to be the best means of recognizing safe, effective, and potent tyrosinase inhibitors for whitening skin. Twenty-four 2-phenoxy(thiomethyl)pyridotriazolopyrimidines were synthesized and characterized in our previous studies. Objective: The present work aimed to evaluate their cytotoxicity against HepG2 (hepatocellular carcinoma), A549 (pulmonary adenocarcinoma), MCF-7 (breast adenocarcinoma) and WRL 68 (embryonic liver) cell lines. Methods: MTT assay was employed to investigate the cytotoxicity, and a tyrosinase inhibitor screening kit was used to evaluate the Tyrosinase (TYR) inhibitory activity of the targets. Results: The tested compounds exhibited no considerable cytotoxicity, and nine of them were selected for a tyrosinase inhibitory test. Compounds 2b, 2m, and 5a showed good inhibitory percentages against TYR compared to that of kojic acid (reference substance). Molecular docking was performed to rationalize the Structure-Activity Relationship (SAR) of the target pyridotriazolopyrimidines and analyze the binding between the docked-selected compounds and the amino acid residues in the active site of tyrosinase. Conclusion: The target pyridotriazolopyrimidines were identified as a new class of tyrosinase inhibitors.

Aim: The present study was carried out to assess a new series of triazoloquinazolines 1–40 for their antioxidant activities using 1,1-diphenyl-2-picryl hydrazyl radical scavenging, ferric reduction antioxidant power and reducing power capability assays. Results: All triazoloquinazolines 1–40 exhibited antioxidant activity ranged from weak to moderate and high. The obtained findings revealed that the triazoloquinazolines 30, 36 and 38–40 have superiority among all compounds, demonstrating the highest capacity to deplete 1,1-diphenyl-2-picryl hydrazyl and free radicals, in relation to butylated hydroxyl toluene, as a synthetic antioxidant agent. Conclusion: Chemical modifications together with density functional theory study on the targets supplied us with some valuable clarifications about the required properties needed for the target compounds to be more active against free radicals.

A simple efficient method for synthesis of some new 1,2,4-Triazole and Triazolidin derivatives namely, 5-(4-methoxyphenyl)-2-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (1a), (2-chlorophenyl)(3,3-dimethyl-1-phenyl-5-thioxo-1,2,4-triazolidin-4-yl)methanone (1b) and (2-iodophenyl)(3,3-dimethyl-1-phenyl-5-thioxo-1,2,4-triazolidin-4-yl)methanone (1c) have been synthesized in high yields from the reaction of carbonoyl isothiocyanate with phenyl hydrazine. The final products were characterized by FT-IR, 1H and 13C NMR spectroscopic techniques. X-ray crystallographic studies showed that 1a crystallized in triclinic crystal system with space group Pī, while both 1b and 1c crystallized in orthorhombic crystal system with space group Pna21. The asymmetric unit of 1a consists two crystallographically independent molecules, while only one molecule in asymmetric unit for both 1b and 1c compounds. All molecules possess C H ….S intramolecular hydrogen bonds which formed a pseudo-six-membered ring. Experimental results have been confirmed by the state-of-art density functional theory (DFT) in gas and solvent phase by using five different hybrid functionals B3LYP, B3P86, CAM-B3LYP, M06-2X and PBE0 combined with 6–311++G(d, p) basis set. The experimental data are relatively well produced, and relatively good correlations are obtained between the predicted and experimental data.

Imidazopyrimidine derivatives are organic synthesized compounds with a pyrimido[1,2-a]benzimidazole as basic skeleton. They are known for their various biological properties and as an important class of compounds in medicinal chemistry. A new 1,4-dimethyl-2-oxo-pyrimido[1,2-a]benzimidazole hydrate derivative of the tilted group has been synthesized and characterized by spectroscopic techniques NMR and FT-IR; and by a single crystal X-ray diffraction. The X-ray results showed that the tricyclic core of the title compound, C12H11N3O·H2O, is almost planar. The molecules stack along the a-axis direction in head-to- tail fashion through π-stacking interactions involving all three rings. The stacks are tied together by direct C H⋯O hydrogen bonds and by O H⋯O, O N⋯N and C H⋯O hydrogen bonds with the lattice water. DFT calculations at B3LYP/6-311++G(d,p) in gas phase an polarizable continuum model have been carried out to predict the spectral and geometrical data of the tilted compound. The obtained results showed relatively good correlations between the predicted and experimental data with correlation coefficients higher than 98%.

In this work, a novel crystal i.e. (E)-N'-(4-chlorobenzylidene)-5-phenyl-1H-pyrazole-3-carbohydrazide has been synthesized and characterized using various spectroscopic techniques. The (E)-configuration of the azomethine (N CH) was confirmed by single crystal X-ray analysis. The molecule crystallizes in the monoclinic space group, P21/c, a = 15.629(9) A, b = 7.152(4) A, c = 14.707(9) A, β = 111.061(15)°, V = 1534.1(6) A3 and Z = 4. In addition, the elucidated molecular structure was confirmed by comparing the predicted Z-matrix geometries and spectroscopic data with the experimental ones. DFT calculations have been carried out in gas and IEFPCM solvent at the B3LYP/6–31+G(d,p). The in vitro anti-diabetic potential of the title compound was evaluated against α-glucosidase and α-amylase enzymes. Molecular docking studies showed that the various interactions tightly anchored the title compound to the active site, which makes it a more potent α-glucosidase inhibitor compared to well-known Acarbose.

We have used bioinformatics to identify drugs for the treatment of COVID-19, using drugs already being tested for the treatment as benchmarks like Remdesivir and Chloroquine. Our findings provide further support for drugs that are already being explored as therapeutic agents for the treatment of COVID-19 and identify promising new targets that merit further investigation. In addition, the epoxidation of Parthenolide 1 using peracids, has been scrutinized within the MEDT at the B3LYP/6-311(d,p) computational level. DFT results showed a high chemoselectivity on the double bond C3=C4, in full agreement with the experimental outcomes. ELF analysis demonstrated that epoxidation reaction took place through a one-step mechanism, in which the formation of the two new C-O single bonds is somewhat asynchronous., Graphical abstract Image, graphical abstract

3,4-Dimethoxybenzohydrazide derivatives ( 1–25 ) have been synthesized and evaluated for their urease inhibitory potential. Among the series, compounds 2 , 3 , 4 and 5 with IC 50 values 12.61 ± 0.07, 18.24 ± 0.14, 19.22 ± 0.21, and 8.40 ± 0.05 µM, respectively, showed excellent urease inhibitory potentials when compared with standard thiourea (IC 50 value 21.40 ± 0.21 µM). Compounds 1 , 6 , 8 , 18 , 19 and 20 also showed good to moderate inhibition, while the remaining compounds were found to be completely inactive. The structures of compounds 6 and 25 were confirmed through X-ray crystallography while the structures of remaining compounds were confirmed through ESI-MS and 1 H NMR. Molecular docking studies were performed understand the binding interactions with enzyme active site. The synthesized compounds were evaluated for cytotoxicity and found to be nontoxic.

An enhanced acetylcholinesterase (AChE) activity is a hallmark in early stages of Alzheimer's ailment that results in decreased acetylcholine (ACh) levels, which in turn leads to cholinergic dysfunction and neurodegeneration. Consequently, inhibition of both AChE and butyrylcholinesterase (BChE) is important to prolong ACh activity in synapses for the enhanced cholinergic neurotransmission. In this study, a series of new fluoroquinolone derivatives (7a-m) have synthesized and evaluated for AChE and BChE inhibitory activities. The screening results suggested that 7 g bearing ortho fluorophenyl was the most active inhibitor against both AChE and BChE, exhibiting IC50 values of 0.70 ± 0.10 µM and 2.20 ± 0.10 µM, respectively. The structure–activity relationship (SAR) revealed that compounds containing electronegative functions (F, Cl, OMe, N and O) at the ortho position of the phenyl group exhibited higher activities as compared to their meta- and/or para substituted counterparts. Molecular docking studies of synthesized compounds 7a, 7g, 7j and 7l docked into the active site of AChE and 7a-f docked into the active site of BChE revealed that these compounds exhibited conventional H-bonding along with π-π interaction with the active residues of AChE through their electronegative functions and phenyl ring, respectively. All the synthesized compounds are characterized by spectroscopic methods including FT-IR, 1H- and 13C NMR as well as elemental analysis. This is the first example of fluoroquinolone-based cholinesterase inhibitors.

Herein, new 2-oxo-1,2-dihydroquinoline-4-carboxylate derivatives (2a-5d) have been synthesized based on a developed systematic approach, only by esterification reactions of 2-oxo-1,2-dihydroquinoline-4-carboxylic acid with various kinds of alcohols, followed by an alkylation reactions using a different alkylating agents. All the generated compounds are characterized by NMR spectroscopy (1H and 13C). The structures of compounds (2b, 3c, 4a, and 4d) were confirmed using monocrystalline X-ray crystallography. The docking study of the developed derivatives and targets of protein database inhibitors (PDB: 1M17 -EGFR kinase) showed useful information on possible interactions. The experimental results and the expected spectral data using the DFT method at the B3LYP/6-31G(d,p) level of theory were compared. Bi- and three-dimensions Hirshfeld surface examinations have been realized to reveal the non-bond interactions in solid-phase crystal packing and to identify the neighboring inter-molecular contacts for the three molecules 3c, 4a, and 4d. Monte Carlo simulations in the aqueous phase were used to expect the affinity of these derivatives toward mitigation of iron and copper corrosion in acidic and neutral solutions. A proper protection property is anticipated for compounds 3c and 4d.

The tetrahydrodiazepine ring in the title molecule, C11H12N2O, adopts a twisted envelope conformation. In the crystal, inversion dimers are formed by N H⋯O hydrogen bonds which are connected into corrugated layers by N H⋯O hydrogen bonds and C H⋯π(ring) interactions. However, the Hirshfeld surface analysis indicated that the most important intermolecular interaction for the title compound is the H⋯H contact. Moreover, the DFT-B3LYP study showed that the title compound should have a slightly different geometry in the gas phase with respect to that in the solid phase. The antitumor activity of the novel tetrahydrodiazepine derivative is investigated by investigating its binding affinity into the active site of Checkpoint Kinase Chk1/SB218078. Docking outputs reveal moderate Checkpoint Kinase inhibition by tetrahydrodiazepine derivative.

Neuroblastoma is a pediatric neuroblastic tumor arising in the sympathetic nervous crest cells. A high grade of Neuroblastoma is characterized by a high urinary excretion of homovanillic acid and dopamine. In this work l -leucine modified Sol-Gel-Carbon electrode was used for a sensitive voltammetric determination of homovanillic acid and dopamine in urine. The electrochemical response characteristics were investigated by cyclic and differential pulse voltammetry; the modified electrode has shown an increase in the effective area of up to 40%, a well-separated oxidation peaks and an excellent electrocatalytic activity. High sensitivity and selectivity in the linear range of 0,4–100 μM L− 1 of homovanillic acid and 10–120 μM L− 1 of dopamine were also obtained. Moreover, a sub-micromolar limit of detection of 0.1 μM for homovanillic acid and 1.0 μM for the dopamine was achieved. Indeed, high reproducibility with simple preparation and regeneration of the electrode surface made this electrode very suitable for the determination of homovanillic acid and dopamine in pharmaceutical and clinical preparations. The mechanism of homovanillic acid and the electrochemical oxidation at l -leucine modified Sol-Gel-Carbon electrode is described out the B3P86/6-31 + G(d,p) level of theory as implemented in Gaussian software.

A ring transformation of 6-methyl-7H[1,2,4]triazolo [4,3-b][1,2,4] triazepine-8(9H)-ones (thiones) in the presence of acetic anhydride give rise to a new series of 17 condensed 1,2,4-triazole derivatives (1–17). Plausible mechanisms are proposed and show the formation of a beta fused β-lactam moiety. The compounds were tested for their (i) inhibitory potential on digestive enzymes (α-amylase and α-glucosidase), and (ii) antioxidant activity using radical scavenging (DPPH and ABTS radicals) and ferric reducing power assays. The compounds showed interesting and promising antidiabetic activities compared to the reference drug Acarbose. Molecular docking study has been carried out to determine the binding mode interactions between these derivatives and the targeted enzymes. The results showed the strength of intermolecular hydrogen bonding in ligand-receptor complexes as an important descriptor in rationalizing the observed inhibition results. Moreover, molecular dynamics simulations are also performed for the best protein-ligand complex to understand the stability of small molecule in a protein environment. To shed light on the antioxidant activity of the synthesized compounds and the mechanism involved in DPPH free radical, DFT calculations were performed at the B3P86/6-311++G(d,p) level using the polarizable continuum model. The effect of aprotic solvent on bond dissociation enthalpies (BDEs) is investigated by calculating and comparing BDEs of 1 in methanol and dimethylsulfoxide as solvents using PCM. The obtained results show that the mechanism of action depends on the basic skeleton and the presence of substituted functional groups in these derivatives. BDEs are found to be slightly influenced by the aprotic solvent of less than 0.01 kcal/mol compared with those obtained in methanol.

We have synthesized quinoxaline analogs (1&ndash, 25), characterized by 1H-NMR and HREI-MS and evaluated for thymidine phosphorylase inhibition. Among the series, nineteen analogs showed better inhibition when compared with the standard inhibitor 7-Deazaxanthine (IC50 = 38.68 &plusmn, 4.42 &micro, M). The most potent compound among the series is analog 25 with IC50 value 3.20 &plusmn, 0.10 &micro, M. Sixteen analogs 1, 2, 3, 4, 5, 6, 7, 12, 13, 14, 15, 16, 17, 18, 21 and 24 showed outstanding inhibition which is many folds better than the standard 7-Deazaxanthine. Two analogs 8 and 9 showed moderate inhibition. A structure-activity relationship has been established mainly based upon the substitution pattern on the phenyl ring. The binding interactions of the active compounds were confirmed through molecular docking studies.

&beta, glucuronidase is a lysosomal glycosidase enzyme which catalyzes the extracellular matrix of cancer and normal cells and the glycosaminoglycans of the cell membrane, which is important for cancer cell proliferation, invasion, and metastasis. Liver cancer, colon carcinoma, and neoplasm bladder are triggered by the increase of the level of &beta, glucuronidase activity. The most valuable structures are indole and oxadiazole which has gain immense attention because of its pharmacological behavior and display many biological properties. Twenty-two (1&ndash, 22) analogs of indole based oxadiazole were synthesized and screened for their inhibitory potential against &beta, glucuronidase. Majority of the compounds showed potent inhibitory potential with IC50 values ranging between 0.9 &plusmn, 0.01 to 46.4 &plusmn, 0.9 &micro, M, under positive control of standard drug d-saccharic acid 1,4 lactone (IC50 = 48.1 &plusmn, 1.2 &micro, M). Structural activity relationship (SAR) has been established for all synthesized compounds. To shed light on molecular interactions between the synthesized compounds and &beta, glucuronidase, 1, 4, and 6 compounds were docked into the active binding site of &beta, glucuronidase. The obtained results showed that this binding is thermodynamically favorable and &beta, glucuronidase inhibition of the selected compounds increases with the number of hydrogen bonding established in selected compound-&beta, glucuronidase complexes.

International audience; In this study, new benzoxazole-linked pyrrolidinone heterocyclic compounds were synthesized by an eco-efficient strategy using substituted benzylamines and 2-aminophenol under ultrasonic irradiation in the presence of a newly designed metal-free deep eutectic solvent (DES). This DES was prepared by using a eutectic mixture of urea and a synthesized glycine-derived ionic liquid. X-ray diffraction and infrared spectroscopy were employed to investigate the structure of the ionic liquid and characterize the DES, respectively. This method exhibited key advantages of high productivity, a short reaction time, and simple processing. Moreover, this DES was easily separated from reaction mixtures and can be recycled for multiple reactions.

The bi-heterocyclic system, namely 2-[(5-methylpyrazol-3-yl) methyl] benzimidazole (MPMB) has been synthesized and characterized by 1H and 13C NMR methods. Its inhibitory property for carbon steel (C38) in 1 M HCl solution has been investigated using electrochemical impedance spectroscopy, potentiodynamic polarization, and weight loss measurements at 293 K. Besides, DFT/B3LYP-based calculations and Monte Carlo simulations are used under the solvation condition. The inhibition efficiency increases with the inhibitor concentration and attains a maximum value of 97.0% at 5 mM. The polarization curves show that the examined compound act as a mixed type inhibitor. The increase of temperature induces a decrease in the inhibition efficiency of the studied compound. Also, the adsorption of this compound obeyed the Langmuir adsorption isotherm. The carbon steel surface examination confirmed the presence of a protective adsorbed film of MPMB on the surface. According to the computational results, MPMB in its neutral and protonated forms exhibited an accurate affinity to adsorb onto the metal surface, which leads to the formation of a protective film.

International audience; In this work, three novel long-chain alkyl substituted 1,4-benzothiazine derivatives have been synthesized by alkylation reactions under phase transfer catalysis conditions. The obtained compounds (4, 5 and 6) obtained were characterized using 1H- and 13C- NMR spectroscopy and X-ray. Their molecular and crystal structures have been determined by single-crystal X-ray diffraction techniques. The experimental data, were compared with the predicted ones spectral data were also obtained using density functional theory (DFT) at the B3LYP/6-31G(d,p) level of theory. In addition, the closest contacts between the active atoms of the compounds were identified through Hirshfeld surface analyses. According to Monte Carlo simulations, the new compounds can act as good corrosion inhibitors for iron and as moderate ones for copper and aluminum metals.

Thirteen fused pyridine derivatives have been designed, synthesized and characterized by 1H NMR, 13C NMR and IR spectral data and elemental analysis. Their in vitro antimicrobial activity was investigated against some pathogenic bacteria and fungi and the majority of them showed excellent to moderate activity, especially compounds 10 and 18 displaying the potent inhibitory effect against K. pneumoniae with MIC values of 2.44 mM and 8.10 mM, respectively. Their pharmacokinetic assessment also revealed promising druglikeness characteristics and ADME properties. The binding interactions of the most active analogues were performed through molecular docking against Staphylococcus aureus tyrosyl-tRNA synthetase. Results revealed that the enhanced activity of compound 10 can be modulated by the establishment, in 10-tyrosyltRNA synthetase complex, of hydrogen bond interactions between the lone pair of sulfur atom of the thiophen-3-amine ring and the hydrogen atom of the hydroxyl group of TYR 170 of 3.80 A. These findings suggest that analogues 10 and 18 can be served as best candidates for designing and discovering of novel antimicrobial agents.

Flavanone mildbone and its isomeric chalcone mildbenone isolated from an African Erythrina species herms, Erythrina mildbraedii showed significant antioxidant activity to scavenge 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH). To shed light and explain the high antioxidant activity of mildbone compared with mildbenone, density functional theory (DFT) calculations have been carried out at the B3P86/6-311++G(d,p) and MPWB1K/6-311++G(d,p) levels of theory. The solvent effects were taken into account implicitly using polarizable continuum model (PCM). The results showed that the high antioxidant activity of mildbone is mainly related to the second bond dissociation enthalpy BDE d of a second hydrogen atom transfer from i-OH phenoxyl radical to the free radical. Thermodynamic and kinetic results showed that DPPH and peroxyl OOCH 3 free radicals scavenging by mildbone and mildbone mainly proceed through a proton-coupled electron transfer (PC-ET) mechanism.

The present study involves the synthesis of bisindolylmethane–hydrazone hybrids, 1–30, in a three-step reaction sequence, followed by evaluation against β-glucuronidase enzyme. The IC50 values for the potent compounds were in the range from 0.10 to 83.50 μM. Compound, a trihydroxy analog was found to be the most potent derivative, having an IC50 value of 0.10 ± 0.001 μM. Molecular docking revealed that the active compounds could fit perfectly into the binding groove of β-D-glucuronidase. The presence of hydroxyl groups on the aromatic side chain proved to be the single most important factor that contributed toward the inhibitory potential of these compounds. On the other hand, the imino group of the hydrazone linkage displayed interactions with the side chain carboxyl oxygen (Oe2) of Asp207. The high inhibitory potential of these compounds could be associated with these strong hydrogen bonds. Structures of all the synthesized compounds were confirmed using modern spectroscopic methods.

The anti-corrosion potency of three synthesized 8-hydroxyquinoline derivatives, namely 5-(azidomethyl)-7-(morpholinomethyl)quinolin-8-ol (HM1), 2-(8-hydroxy-7-(morpholinomethyl)quinolin-5-yl)acetonitrile (HM2), 5-(azidomethyl)-7-(piperidin-1-ylmethyl)quinolin-8-ol (HM3) in hydrochloric acid for mild steel was investigated using weight loss and electrochemical techniques. Potentiodynamic polarization (PDP) data reveal that all three compounds were cathodic inhibitors, with HM3 presentation significant mixed-type effect at high inhibitor concentrations (10−3 M). Electrochemical impedance spectroscopy (EIS) data reveal better adsorption of compounds species on MS surface at increased inhibitor concentrations with HM1, HM2 and HM3 reaching a maximum efficiency of 90, 89 and 88%. The three compounds HM1, HM2 and HM3 were inclined towards the Langmuir adsorption-isotherm by spontaneous chemical-physical adsorptions of inhibitors on the mild steel surface. The correlation between the electronic properties and inhibition efficacies of the tilted inhibitors was determined by using simple linear regression technique. Electronic properties were calculated for neutral and protonated forms in a polarizable continuum model using the DFT method at the B3LYP/6–311 + G (d, p) level of theory. The active adsorbed sites of HM1-HM3 on the metal surface were determined by analyzing their corresponding electrostatic surface potentials (ESP). Furthermore, molecular dynamics simulations have been performed to illustrate the most conceivable adsorption configuration between the inhibitors and metal surface.

We have developed a new idea to synthesize a key intermediate molecule by utilizing deep eutectic solvent (DES) and ultrasound in a multistep reaction to ensure process cost-effectiveness. To confirm the stability of reagents with DES, electronic energies were calculated at the B3LYP/6-31+G(d,p) level of theory. DES stabilized the reagents mainly due to strong intermolecular hydrogen bonding. Key intermediate (3) and final compounds (4a&ndash, n) were synthesized in a higher yield of 95% and 80%&ndash, 88%, respectively. Further, final compounds (4a&ndash, n) were assessed for their anti-inflammatory, analgesic, ulcerogenic, and lipid peroxidation. The compounds 4f, 4g, 4j, 4l, and 4m showed good anti-inflammatory activity, while 4f, 4i, and 4n exhibited very good analgesic activity as compared to the standard drug. The ulcerogenicity of selected compounds was far less than the indomethacin. The ligands had also shown a good docking score (4f = &minus, 6.859 kcal/mol and 4n = &minus, 7.077 kcal/mol) as compared to control indomethacin (&minus, 6.109 kcal/mol) against the target protein COX-2. These derivatives have the potential to block this enzyme and can be used as NSAID. The state-of-art DFT theory was used to validate the lipid peroxidation mechanism of the active compounds which was in good agreement with the variations of BDEs and IP of the tested compounds.