Imidazolium-based ionic liquids disrupt saccharomyces cerevisiae cell membrane integrity.

Ionic liquids (ILs) are interesting chemical compounds that have a wide range of industrial and scientific applications. They have extraordinary properties, such as the tunability of many of their physical properties and, accordingly, their activities; and the ease of synthesis methods. Hence, they became important building blocks in catalysis, extraction, electrochemistry, analytics, biotechnology, etc. This study determined antifungal activities of various imidazolium-based ionic liquids against yeast Saccharomyces cerevisiae via minimum inhibitory concentration (MIC) estimation method. Increasing the length of the alkyl group attached to the imidazolium cation, enhanced the antifungal activity of the ILs, as well as their ability of the disruption of the cell membrane integrity. FTIR studies performed on the S. cerevisiae cells treated with the ILs revealed alterations in the biochemical composition of these cells. Interestingly, the alterations in fatty acid content occurred in parallel with the increase in the activity of the molecules upon the increase in the length of the attached alkyl group. This trend was confirmed by statistical analysis and machine learning methodology. The classification of antifungal activities based on FTIR spectra of S. cerevisiae cells yielded a prediction accuracy of 83%, indicating the pharmacy and medicine industries could benefit from machine learning methodology. Furthermore, synthesized ionic compounds exhibit significant potential for pharmaceutical and medical applications.

Chalcone Schiff bases disrupt cell membrane integrity of Saccharomyces cerevisiae and Candida albicans cells.

Chalcones have a variety of cellular protective and regulatory functions that may have therapeutic potential in many diseases. In addition, they are considered to affect key metabolic processes in pathogens. Nevertheless, our current knowledge of the action of these compounds against fungal cell is scarce. Therefore, in this study, various substituted chalcone Schiff bases were investigated to reveal their cellular targets within the yeasts Saccharomyces cerevisiae and Candida albicans. First, their antifungal activities were determined via minimum inhibitory concentration method. Surprisingly, parent chalcone Schiff bases showed little or no antifungal activity, while the nitro-substituted derivatives were found to be highly active against yeast cells. Next, we set out to determine the cellular target of active compounds and tested the involvement of the cell wall and cell membrane in this process. Our conductivity assay confirmed that the yeast cell membrane was compromised, and that ion leakage occurred upon treatment with nitro-substituted chalcone Schiff bases. Therefore, the cell membrane came to the fore as a possible target for the active chalcone derivatives. We also showed that exogenous ergosterol added to the growth medium reduced the inhibitory effect of chalcones. Our findings open up new possibilities for the design of future antimicrobial agents based on this appealing backbone structure.

Bis-1,2,4-triazol derivatives: Synthesis, characterization, DFT, antileishmanial activity and molecular docking study.

In this study, triazol derivatives, 4,4'-(((1E, 1E')-1,2-phenylenebis (methanylyidene)) bis (azanylidene)) bis (5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (2), 4,4'-(((1E, 1E')-1,3-phenylenebis (methanylyidene)) bis (azanylidene)) bis (5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (3) and 4,4'-(((1E, 1E')-1,4-phenylene bis (methanyl yidene)) bis (azanylidene)) bis (5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one (4) were synthesized from the reaction of 4-amino-5-methyl-2,4-dihydro-3H-1,2,4-triazol-3-one and phthalaldehyde/isophthalaldehyde/terephthalaldehyde, respectively. Compounds 2-4 were characterized by Fourier transform infrared (FTIR), proton and carbon-13 nuclear magnetic resonance (1H- and 13C- NMR) spectroscopic methods. Theoretical study for compounds 2-4 were carried out by DFT/B3LYP/6-311++G(d,p). Structural and spectroscopic parameters were determined theoreticaly and compared with experimental ones. Also, the molecular electrostatic potential (MEP) maps of compounds were obtained. Leishmanicidal activity of compounds 2-4 against to Leishmania infantum was determined by microdilution broth method containing alamar blue. As a result of the study, compounds 2-4 were found to be effective against the specie of Leishmania. Molecular docking analysis against Trypanothione Reductase (TRe) with compound 2 was carried out to see the necessary interactions responsible for antileishmanial activity. The docking calculations of compound 2 supported the antileishmanial activity exhibiting high inhibition constant.Communicated by Ramaswamy H. Sarma.

3-(5-(1H-imidazol-1-yl) pent-1-en-1-yl)-9-ethyl-9H-carbazole: synthesis, characterization (IR, NMR), DFT, antimicrobial-antioxidant activities and docking study.

3-(5-(1H-imidazol-1-yl) pent-1-en-1-yl)-9-ethyl-9H-carbazole called as compound 1 was synthesized and characterized by proton and carbon-13 nuclear magnetic resonance (1H- and 13C- NMR) and Fourier transform infrared (FTIR) spectroscopic methods. Density Functional Theory/Becke, 3-parameter (DFT/B3LYP), for compound 1 were performed with 6-311++G(d,p) method. Optimized geometry, frontier molecular orbitals (HOMO; highest occupied molecular orbital; LUMO: lowest unoccupied molecular orbital), IR and NMR parameters of compound 1 were obtained. The evaluations reveal that the calculation results support the experimental results. In addition, the antimicrobial (a microwell dilution method) and antioxidant activities (2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) ferric ion reducing antioxidant power (FRAP) of compound 1 were evaluated. According to the results obtained, it showed higher antimicrobial activity (Minimal inhibition concentration (MIC): 78.12 µg/mL) against B. subtilis subsp. Spizizenii. Morever, molecular docking studies were carried out to investigate the interactions of an antimicrobial agent on some important enzymes played important roles in nucleic acid (Deoxyribo nucleic acid (DNA) synthesis, cell wall synthesis, protein synthesis, and metabolism etc. The compound 1 was strongly bound to tyrosyl-tRNA synthetase enzyme (binding energy: -11.18 and Ki: 6.37 nM) and Beta-Ketoacyl-Acp Synthase III enzyme (binding energy: -10.29 and Ki: 28.47 nM).Communicated by Ramaswamy H. Sarma.

New chalcone derivative, ethyl 2-(4-(3-(benzo[b]thiophen-2-yl)acryloyl)phenoxy)acetate: synthesis, characterization, DFT study, enzyme inhibition activities and docking study.

Chalcone derivative, ethyl 2-(4-(3-(benzo[b]thiophen-2yl)acryloyl)phenoxy)acetate (I), was synthesized. Compound I was characterized by proton and carbon-13 nuclear magnetic resonance (1H- and 13C- NMR), fourier transform infrared (FTIR) and mass (LC-ESI-MS/MS) spectroscopic methods. Density Functional Theory (DFT) calculations for compound I were performed at B3LYP/6-311++G(d,p) level. Optimized geometry, frontier molecular orbitals (HOMO; highest occupied molecular orbital; LUMO: lowest unoccupied molecular orbital), IR and NMR parameters of compound I were obtained. The evaluations reveal that the calculation results support the experimental results. The inhibition effects of compound I on cholinesterases and GST enzyme were investigated. Ki and inhibition concentration (IC50) values were calculated separately. Ki values of compound I were found for GST 14.19 ± 2.15, for AChE 11.13 ± 1.22 and for BChE 8.74 ± 0.76 recpectively. The docking analysis of compound I supported the enzym inhibition activity exhibiting high inhibition constant and binding energy for three receptors. Compound I is strongly bound to AChE, huBChE and Glutathione S-transferase with binding energies -11.24, -8.56 and -10.39 kcal/mol, respectively.Communicated by Ramaswamy H. Sarma.

Phenolic chalcones lead to ion leakage from Gram-positive bacteria prior to cell death.

Chalcones, valuable precursors for flavonoids, have important antibacterial and antifungal activities against bacteria, pathogens, harmful fungi and even antibiotic-resistant microorganisms that cause food spoilage and infectious diseases. It is widely known that chalcones target various vital metabolic pathways of the bacterial cells, but little is known about their action on the cell membrane integrity. In the present study, we studied the antibacterial activity of 12 different substituted chalcones in a comparative way and revealed that the phenolic chalcones are superior to other substituted derivatives against both Gram-negative and Gram-positive bacteria. We also demonstrate that the cell membrane is the first barrier that the chalcone molecules face for their action, and that phenolic chalcones increase ionic cell membrane permeability to a greater extent than the other substituted members. Especially, ion leakage can be detected at lower concentrations than the minimum inhibitory levels against Gram-positive bacteria. Phenolic chalcones are superior to other substituted derivatives in their antibacterial action and cause leakage of ions from Gram-positive bacteria even in concentrations lower than the inhibitory levels. Ion leakage from Gram-positive bacterial cytoplasm is prior to the membrane deformation and cell death. Thus, we propose that ion leakage contribute to the greater activity of phenolic chalcones in comparison to non-phenolic ones, on Gram-positive bacteria. Even though, disruption of metabolic pathways may be the principal mode of action of chalcones; in accord with our observations, we propose that the ion leakage precedes other inhibitory effects and contribute to the antibacterial action of phenolic chalcones.

Synthesis of nonperipherally tetra-[5-(diethylamino)-2-formylphenoxy] substituted metallophthalocyanines and their electrochemistry.

3-[5-(diethylamino)-2-formylphenoxy]phthalonitrile ( n-TY-CN ), metallophthalocyanines n-TY-Co , n-TY-Cu , and n-TY-Mn bearing [5-(diethylamino)-2-formylphenoxy] groups at nonperipheral positions were prepared for the first time. These compounds were characterized with IR, NMR (only for n-TY-CN ), mass and UV-vis (except n-TY-CN ) spectroscopy. Voltammetric characterizations of n-TY-Co , n-TY-Cu , and n-TY-Mn revealed that while n-TY-Co , n-TY-Cu , and n-TY-Mn showed characteristic Pc ring and/or metal-based reduction reaction, n-TY-Co , n-TY-Cu , and n-TY-Mn were coated on the working electrode during the oxidation processes owing to the cationic electropolymerizations of the [5-(diethylamino)-2-formylphenoxy] substituents.

Synthesis of novel 1,2,3 triazole derivatives and assessment of their potential cholinesterases, glutathione S-transferase enzymes inhibitory properties: An in vitro and in silico study.

In this study, new 1,2,3-triazole derivatives containing chalcone core (1-7) were synthesized. Obtained compounds were characterized by IR, 1H NMR, 13C NMR, and mass studies. Characterized compounds (1-7) inhibitory effects were tested against the glutathione S-transferase (GST), acetylcholinesterase (AChE), and Butyrylcholinesterase (BChE). Their Ki values were in the range of 5.88-11.13 µM on AChE, 5.08-15.12 µM on BChE, and 9.82-13.22 µM on GST. Remarkable inhibitory effects were obtained against three tested metabolic enzymes. Also, binding scores of the best-inhibitors against AChE, BChE, and GST enzymes were detected as -9.969 kcal/mol, -10.672 kcal/mol, and -8.832 kcal/mol, respectively. Isoindoline-1,3-dione and benzothiophene moieties played a critical role in the inhibition of AChE and BChE enzymes, respectively. Phenylene and triazole moieties had the most important interactions for inhibition of the GST enzyme. Therefore, in vivo and in silico results indicated that these compounds can be considered in drug design processes for the treatment of some diseases including Alzheimer's disease (AD), leukemia, and some type of cancer.

Antileishmanial Activity of New Synthesized Schiff and Mannich (Morpholine) Base Compounds.

OBJECTIVE: Leishmaniasis is an important parasitic disease in many countries, including ours. A variety of drugs are currently used for its treatment. However, certain side effects of these drugs, such as teratogenicity, hepatotoxicity and nephrotoxicity, have been reported in some patients. The goal of this research is to determine the antileishmanial effects of eight different previously synthesised compounds containing Schiff and Mannich bases (morpholine) against Leishmania infantum (L. infantum) promastigotes by the liquid microdilution method utilising alamarBlue. METHODS: Compounds containing Schiff bases (a-d) and both Schiff bases and morpholine rings (e-h) were tested. Compounds were diluted in the range of 20000-39 µg/mL. L. infantum promastigotes were added to the wells, which were then incubated at 27 °C. The proliferation of Leishmania promastigotes was evaluated after 24, 48 and 72 hours. RESULTS: In this study, compounds b, c and d (MIC values 156 µg/mL, 78 µg/mL and 156 µg/mL) were found to be effective against L. infantum promastigotes, whereas compound f (MIC >20000 µg/mL) was found to be more the most ineffective compound. CONCLUSION: These compounds may be potential drug candidates for the treatment of leishmaniasis. According to the results, there is a need for further studies, such as in vivo experimental animal models and ex vivo Leishmania amastigote macrophage cultures for compounds showing antileishmanial effects.

Bis benzothiophene Schiff bases: synthesis and in silico-guided biological activity studies.

Since benzo [ b ] thiophene scaffold is one of the privileged structures in drug discovery as this core exhibitsactivities for different biological problems, in this study bis (benzo[ b ]thiophene-2-yl) alkyl methanimine derivatives (1-9) were synthesized by reacting benzo[ b ]thiophene-2-carbaldehyde with diamines. All newly compounds were characterized by IR, 1H NMR and 13C NMR spectroscopic methods. Synthesized compounds were investigated using binary QSARbased models on therapeutic activity prediction of synthesized compounds and they showed high predicted activities in following diseases: bacterial, angina, allergy, depression and obesity. Thus, they were then tested for their antimicrobial and antileishmanial activities as a result of this theoretical study. Compound 1(N, N'- (propane-1,3-diyl) bis (1-(benzo [ b ] thiophene-2-yl)) methanimine) was found the most active compound in both diseases. Thus, its molecular docking studies were also carried out.

Synthesis, Characterization and Biological Activities of New Symmetric Bis-1,2,3-Triazoles with Click Chemistry.

BACKGROUND: 1,2,3-Triazole and its derivatives have important biological activities such as antimicrobial, anti-allergic, analgesic, anti-HIV, antiinflammatory, anticancer, antimalarial and antituberculosis. Other significant triazole derivatives are 1,2,4-triazoles which play a very important role in the medicinal chemistry due to the antiinflammatory, antimicrobial, antimigraine, anticancer, antimicrobial and antimycotic activities. In this study, we aimed to synthesize a new series of bis-1,2,3-triazole derivatives including 1,2,4-triazole to obtain more effective biological activities. METHODS: In this study, a new series of bis-1,2,3-triazole compounds (9,10,11) were synthesized. Antimicrobial Activity: Disc diffusion method was used. Enzyme Inhibition: α-Glucosidase Inhibition was investigated. Antioxidant Activities: DPPH Radical Scavenging, Phosphomolybdenum- Reducing Antioxidant Power (PRAP) and Ferrous Ion-Chelating methods were used. RESULTS: Compounds 9a, 9c, 9e, 9f, 10a, 10b, 10d, 11a, 11b and 11f showed significant antibacterial and antifungal activity against all the strains tested. Compound 9g exhibited the highest AChE inhibition. Compounds 10f, 11a and 11g showed remarkable activity against the BuChE enzyme. Compound 10f has the highest antioxidant activities. CONCLUSION: The compounds 9a, 9c, 9e, 9f, 10a, 10b, 10d, 11a, 11b and 11f exhibit the best antimicrobial activity against the bacteria and fungi C.albicans, Y. enterocolitica, E. coli, Candida albicans, Yersinia enterocolitica. Compound 9g exhibit the highest AChE inhibition with 72.67 ± 3.92% at 100 µg/mL. Compounds 10f, 11a and 11g showed remarkable activity against the BuChE enzyme compared to galantamine. Many of the compounds exhibited significant α-glucosidase inhibition activities. Compound 10f has the highest antioxidant activities (DPPH, PRAP, ferrous ionchelating) with 27.71 ± 0.85%, 0.689 ± 0.005, 42.07 ± 2.48 at 100 µg/mL, respectively.

Synthesis of new 1,2,4-triazole compounds containing Schiff and Mannich bases (morpholine) with antioxidant and antimicrobial activities.

Compound 2 was synthesized by reacting CS2/KOH with compound 1. The treatment of compound 2 with hydrazine hydrate produced compound 3. Then, compound 3 was converted to Schiff bases (4a-d) by the handling with several aromatic aldehydes. The treatment of triazole compounds 4a-d containing Schiff base with morpholine gave compounds 5a-d. All compounds were tested for their antioxidant and antimicrobial activities. The antioxidant test results of DPPH• radical scavenging and ferric reducing/antioxidant power methods showed good antioxidant activity. The triazole-thiol (3) was the most active, and the effect of the substituent type of the thiophene ring on the activity was same for both Schiff bases (4a-d) and Mannich bases (5a-d). Among the newly synthesized triazole derivatives, the Schiff base 4d and the Mannich base 5d carrying nitro substituent on the thiophene ring showed promising antibacterial and antifungal activity, with lower MIC values than the standard antibacterial ampicillin.

New thiophene-1,2,4-triazole-5(3)-ones: highly bioactive thiosemicarbazides, structures of Schiff bases and triazole-thiols.

Key compound 2-(4-amino-5-oxo-3-(thiophene-2-ylmethyl)-4,5-dihydro-1,2,4-tiazole-1-yl) acetohydrazide (3) was synthesized by reacting hydrazine hydrate with ethyl-2-(4-amino-5-oxo-3-(thiophene-2-ylmethyl)-4,5-dihydro-1,2,4-tiazole-1yl)acetate (2), obtained in basic media from 4-amino-5-(thiophene-2-ylmethyl)-2H-1,2,4-triazole-3(4H)-one (1). Compound 3 was converted to thiosemicarbazide derivatives (4a-d) and Schiff base derivatives 6a-e and 7a-e. The treatment of compound 4 with NaOH gave 4-amino-2-((4-(4-aryl)-5-mercapto-4H-1,2,4-triazole-3-yl)methyl)-5-(thiophene-2-ylmethyl)-2H-1,2,4-triazole-3(4H)-ones (5a-d). All newly compounds, well characterized by elemental analyses, IR, (1)H NMR, (13)C NMR and mass spectral studies were tested for their antioxidant and antimicrobial activities. Thiosemicarbazide derivatives (4a-d) were highly active in two antioxidant tests with 69.0-88.2% DPPH· scavenging and 503-1257 µM TEAC values, while the others showed lower or no activity. The results of the two antioxidant tests correlated well. Moreover, Thiosemicarbazide derivatives (4a-d) also showed antibacterial activity against Staphylococcus aureus, Bacillus cereus, and Mycobacterium smegmatis. Thiosemicarbazide group deserves attention in the synthesis of bioactive compounds.

Synthesis and biological properties of novel triazole-thiol and thiadiazole derivatives of the 1,2,4-Triazole-3(5)-one class.

2,2'-(4,4'(Butane-1,4-diyl/hexane-1,6-diyl)bis(3-methyl-5-oxo-4,5-dihydro-1,2,4- triazole-4,1-diyl)) diacetohydrazides 3a,b were obtained via the formation of diethyl 2,2'-(4,4'(butane-1,4-diyl/hexane-1,6-diyl)bis(3-methyl-5-oxo-4,5-dihydro-1,2,4-triazole-4,1- diyl))diacetates 2a,b, obtained starting from di-[3(methyl-2-yl-methyl)-4,5-dihydro-1H-[1,2,4]-triazole-5-one-4yl]-n-alkanes 1a,b in two steps. The synthesis of the compounds 7a,b-9a,b incorporating the 1,3,4-thiadiazole, and 10a,b-11a,b with a 1,2,4-triazole-thiol nucleus as the second heterocycle, was performed by the acidic or basic treatment of compounds 4a,b-6a,b which were obtained from the reaction of 3a,b with several isothiocyanates. Newly synthesized compounds were screened for antimicrobial activities and their antioxidant properties by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method. Compounds 4a,b, 5a,b, and 6a,b were found to possess good antioxidant properties. Almost all compounds have significant antimicrobial activities.

Synthesis, structural characterization and comparison of experimental and theoretical results by DFT level of molecular structure of 4-(4-methoxyphenethyl)-3,5-dimethyl-4H-1,2,4-triazole.

4-(4-Methoxyphenethyl)-3,5-dimethyl-4H-1,2,4-triazole (3) was synthesized from the reaction of ethyl N'-acetylacetohydrazonate (1) with 2-(4-methoxyphenyl)ethanamine (2). The structure of the title compound 3 has been inferred through IR, (1)H/(13)C NMR, mass spectrometry, elemental analyses and combination of X-ray crystallography and theoretical methods. In addition to the molecular geometry from X-ray determination, the molecular geometry and vibrational frequencies of the title compound 3 in the ground state, were calculated using the density functional method (B3LYP) with the 6-31G(d) basis set. The calculated results show that the optimized geometry can well reproduce the crystal structure and the theoretical vibrational frequencies show good agreement with experimental values. The nonlinear optical properties are also addressed theoretically. The predicted nonlinear optical properties of 3 are greater than ones of urea. In addition, DFT calculations of molecular electrostatic potentials and frontier molecular orbitals of the title compound were carried out at the B3LYP/6-31G(d) level of theory.

Ethyl 4-(3-ethyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-4-yl)benzoate.

In the title compound, C(13)H(15)N(3)O(3), the dihedral angle between the two aromatic ring is 51.06 (1)°. In the crystal, mol-ecules are connected by pairs of N-H⋯O hydrogen bonds into centrosymmetric dimers.

2-Benzoylmethyl-4-[(2-benzylidene-ethylidene)amino]-5-(2-thienylmethyl)-2H-1,2,4-triazol-3(4H)-one.

In the mol-ecule of the title compound, C(24)H(20)N(4)O(2)S, the dihedral angle between the triazole and thio-phene rings is 66.80 (4)° and the dihedral angle between the two benzene rings is 63.37 (4)°. An intra-molecular C-H⋯O inter-action results in the formation of a six-membered ring. A π⋯π contact between the benzene rings, [centroid-centroid distance = 3.918 (2) Å] may stabilize the structure. Weak C-H⋯π inter-actions are also present. The S, C and H atoms of the thiophene ring are disordered over two positions and were refined with occupancies of 0.654 (3) and 0.346 (3).

4,4'-Butane-1,4-diylbis[3-ethyl-1H-1,2,4-triazol-5(4H)-one] and 4-hydroxy-3-n-propyl-1H-1,2,4-triazol-5(4H)-one.

The title compounds, C12H20N6O2, (I), and C5H9N3O2, (II), display the characteristic features of 1,2,4-triazole derivatives. Compound (I) lies about an inversion centre which is at the mid-point of the central C-C bond. Compound (II) also contains a planar 1,2,4-triazole ring but differs from (I) in that it has a hydroxy group attached to the ring. Molecules of (I) are held together in the crystal structure by intermolecular N-H...O contacts and by weak pi-pi stacking interactions between the 1,2,4-triazole moieties. Compound (II) contains intermolecular O-H...O and N-H...O hydrogen bonds.