1
|
Raj Adhikari B, Sinha S, Lyons N, Pletzer D, Lamont I, Gordon KC, Das SC. Inhalable ceftazidime-roflumilast powder targeting infection and inflammation: Influence of incorporating roflumilast into ceftazidime-leucine co-amorphous formulation. Eur J Pharm Biopharm 2022; 180:260-268. [DOI: 10.1016/j.ejpb.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 09/21/2022] [Accepted: 10/07/2022] [Indexed: 11/26/2022]
|
2
|
Adhikari BR, Sinha S, Gordon KC, Das SC. Amino Acids Improve Aerosolization and Chemical Stability of Potential Inhalable Amorphous Spray-dried Ceftazidime for Pseudomonas aeruginosa Lung Infection. Int J Pharm 2022; 621:121799. [PMID: 35525472 DOI: 10.1016/j.ijpharm.2022.121799] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/26/2022] [Accepted: 04/30/2022] [Indexed: 11/30/2022]
Abstract
Pseudomonas aeruginosa infection is common in cystic fibrosis as well non-cystic fibrosis bronchiectasis. The pathogen presents challenges for treatment due to its adaptive antibiotic-resistance, mainly pertaining to its biofilm-forming ability, as well as limitations associated with conventional drug delivery in achieving desired therapeutic concentration in the infection site. Hence, therapeutic approach has shifted towards the inhalation of antibiotics. Ceftazidime is a potent antibiotic against the pathogen; however, it is currently only available as a parenteral formulation. Here, spray-dryer was employed to generate inhalable high dose ceftazidime microparticles. In addition, the use of amino acids (valine, leucine, methionine, phenylalanine, and tryptophan) to improve aerosolization as well as chemical stability of amorphous ceftazidime was explored. The particles were characterized using X ray diffraction, infrared (IR) spectroscopy, calorimetry, electron microscopy, particle size analyzer, and next generation impactor. The chemical stability at 25 °C/<15% was assessed using chromatography. All co-spray dried formulations were confirmed as monophasic amorphous systems using calorimetry. In addition, principal component analysis of the IR spectra suggested potential interaction between tryptophan and ceftazidime in the co-amorphous matrix. Inclusion of amino acids improved aerosolization and chemical stability in all cases. Increase in surface asperity was clear with the use of amino acids which likely contributed to the improved aerosol performance, and potential interaction between amino acids and ceftazidime was plausibly the reason for improved chemical stability. Leucine offered the best aerosolization enhancement with a fine particle fraction of 78% and tryptophan showed stabilizing superiority by reducing chemical degradation by 51% over 10 weeks in 1:1 molar ratio. The protection against ceftazidime degradation varied with the nature of amino acids. Additionally, there was a linear relationship between degradation protection and molar mass of amino acids or percentage weight of amino acids in the formulations. None of the amino acids were successful in completely inhibiting degradation of ceftazidime in amorphous spray-dried powder to prepare a commercially viable product with desired shelf-life. All the amino acids and ceftazidime were non-toxic to A549 alveolar cell line.
Collapse
Affiliation(s)
| | - Shubhra Sinha
- School of Pharmacy, University of Otago, Dunedin 9054, New Zealand
| | - Keith C Gordon
- The Dodd-Walls Centre for Photonic and Quantum Technologies, Department of Chemistry, University of Otago, Dunedin 9016, New Zealand
| | - Shyamal C Das
- School of Pharmacy, University of Otago, Dunedin 9054, New Zealand.
| |
Collapse
|
3
|
Hassanzadeh F, Jafari E, Shojaei F, Sadeghi-Aliabadi H. Synthesis and cytotoxic activity evaluation of some new 1, 3, 4-oxadiazole, 1, 3, 4-thiadiazole and 1, 2, 4- triazole derivatives attached to phthalimide. Res Pharm Sci 2021; 16:634-642. [PMID: 34760011 PMCID: PMC8562411 DOI: 10.4103/1735-5362.327509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/26/2021] [Accepted: 08/23/2021] [Indexed: 11/04/2022] Open
Abstract
Background and purpose In the last few decades, nitrogen-rich heterocyclic compounds such as 1, 3, 4-thiadiazoles, 1, 2, 4-triazoles and 1, 3, 4-oxadiazoles have received considerable attention because of their notable biological properties, especially cytotoxic effects. The small molecules of mentioned azole derivatives revealed very intensive antitumor activity. In addition, phthalimide-thiadiazole and naphthalimide-triazole hybrid derivatives have shown remarkable cytotoxic effects. According to these observations, some of the hybrid derivatives containing the phthalimide-five-membered azoles were prepared in three steps in this research. Experimental approach The thiol group of azoles was treated with ethyl chloroacetate which was followed by a reaction with hydrazine hydrate to provide acid hydrazide derivatives. Subsequently, the corresponding acid hydrazides were utilized to prepare the final derivatives through the reaction with phthalic anhydride. Cytotoxic activity of final compounds was evaluated against MCF-7 and HeLa cell lines using MTT assay. Findings/Results Compound 3d containing two phthalimide moieties in its structure showed a significant improvement in cytotoxic activity with an IC50 value of 29 μM against HeLa cell line. Compounds 3a-3c showed less cytotoxic effects against both cell lines. Conclusion and implications The combination of the thiadiazole nucleus with two phthalimide structures increased the cytotoxic activity against the HeLa cell line. This increase in cytotoxic activity is probably due to its being more lipophilic characteristic and interaction of this derivative with the biological targets of two directions.
Collapse
Affiliation(s)
- Farshid Hassanzadeh
- Department of Medicinal Chemistry and Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Elham Jafari
- Department of Medicinal Chemistry and Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Faezeh Shojaei
- Department of Medicinal Chemistry and Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Hojjat Sadeghi-Aliabadi
- Department of Medicinal Chemistry and Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| |
Collapse
|
4
|
Senthilkumar S, Seralathan J, Muthukumaran G. Synthesis, structure analysis, biological activity and molecular docking studies of some hydrazones derived from 4-aminobenzohydrazide. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129354] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
5
|
Martínez RF, Matamoros E, Cintas P, Palacios JC. Imine or Enamine? Insights and Predictive Guidelines from the Electronic Effect of Substituents in H-Bonded Salicylimines. J Org Chem 2020; 85:5838-5862. [PMID: 32259438 DOI: 10.1021/acs.joc.0c00130] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Imine and enamine bonds decorate the skeleton of numerous reagents, catalysts, and organic materials. However, it is difficult to isolate at will a single tautomer, as dynamic equilibria occur easily, even in the solid state, and are sensitive to electronic and steric effect, including π-conjugation and H-bonding. Here, using as model Schiff bases generated from salicylaldehydes and TRIS in a set of linear free energy relationships (LFER), we disclose how the formation of either imines or enamines can be controlled and provide a comprehensive framework that captures the structural underpinning of this prediction. This work highlights the potentiality of tailor-made designs en route to compounds with desirable functionality.
Collapse
Affiliation(s)
- R Fernando Martínez
- Departamento de Quı́mica Orgánica e Inorgánica, Facultad de Ciencias and IACYS-Unidad de Quı́mica Verde y Desarrollo Sostenible, Universidad de Extremadura, E-06006 Badajoz, Spain
| | - Esther Matamoros
- Departamento de Quı́mica Orgánica e Inorgánica, Facultad de Ciencias and IACYS-Unidad de Quı́mica Verde y Desarrollo Sostenible, Universidad de Extremadura, E-06006 Badajoz, Spain
| | - Pedro Cintas
- Departamento de Quı́mica Orgánica e Inorgánica, Facultad de Ciencias and IACYS-Unidad de Quı́mica Verde y Desarrollo Sostenible, Universidad de Extremadura, E-06006 Badajoz, Spain
| | - Juan C Palacios
- Departamento de Quı́mica Orgánica e Inorgánica, Facultad de Ciencias and IACYS-Unidad de Quı́mica Verde y Desarrollo Sostenible, Universidad de Extremadura, E-06006 Badajoz, Spain
| |
Collapse
|
6
|
Jafari E, Hassanzadeh F, Saeedi M, Saberi S. Synthesis and evaluation of thiadiazole-based antileishmanial agents. JOURNAL OF REPORTS IN PHARMACEUTICAL SCIENCES 2020. [DOI: 10.4103/jrptps.jrptps_3_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
7
|
Othman AA, Kihel M, Amara S. 1,3,4-Oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole derivatives as potential antibacterial agents. ARAB J CHEM 2019. [DOI: 10.1016/j.arabjc.2014.09.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
8
|
Synthesis, X-ray crystal structure, vibrational spectroscopy, DFT calculations, electronic properties and Hirshfeld analysis of (E) -4-Bromo- N '-(2,4-dihydroxy-benzylidene) benzohydrazide. J Mol Struct 2018. [DOI: 10.1016/j.molstruc.2018.03.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
9
|
Benzotriazole-Mediated Synthesis and Antibacterial Activity of Novel N-Acylcephalexins. Sci Pharm 2016; 84:484-496. [PMID: 28117314 PMCID: PMC5064239 DOI: 10.3390/scipharm84030484] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 02/18/2016] [Indexed: 11/17/2022] Open
Abstract
Cephalexin (1) was acylated using N-acylbenzotriazoles (3a–k′) derived from various carboxylic acids including aromatic, heterocyclic and N-Pg-α-amino acid to afford N-acylcephalexins in excellent yields (82%–96%). Antibacterial screening of the novel cephalosporins revealed that all targets (4a–j) retained the antibacterial activity of cephalexin against Staphylococcus aureus (ATCC 6538). N-Nicotinylcephalexin (4c) and N-(3,4,5-trimethoxybenzoyl)cephalexin (4g) exhibited a broader spectrum of antibacterial activity towards standard strains of Staphylococcus aureus (ATCC 6538), Paenibacillus polymyxa (ATCC 842), and Escherichia coli (ATCC 10536) as well as a resistant strain of Pseudomonas aeruginosa (ATCC 27853).
Collapse
|
10
|
El-Sayed HA, Said SA, Moustafa AH, Baraka MM, Abdel-Kader RT. Synthesis and Biological Evaluation of 2-Oxo/Thioxoquinoxaline and 2-Oxo/Thioxoquinoxaline-Based Nucleoside Analogues. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2016; 35:16-31. [PMID: 26810144 DOI: 10.1080/15257770.2015.1114124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Several O- and S-quinoxaline glycosides have been prepared by glycosidation of 3-methyl-2-oxo(thioxo)-1,2-dihydroquinoxalines 1a,b with α-D-glucopyranosyl, α-D-galactopyranosyl, and α-D-lactosyl bromide in the presence of K2CO3 followed by deacetylation with Et3N/H2O. Furthermore, alkylation of 1a,b with 4-bromobutyl acetate, 2-acetoxyethoxymethyl bromide, and 3-chloropropanol afforded the corresponding O- and S-acycloquinoxaline nucleosides. Reaction of 1b with chloroacetic acid followed by condensation with sulfacetamide and sulfadiazine in the presence of Et3N/THF and ethyl chloroformate gave the corresponding sulfonamide derivatives 14 and 15, respectively. The structures of new compounds were confirmed by using IR, (1)H, (13)C NMR spectra and microanalysis. Some of these compounds were screened in vitro for antitumor and antifungal activities.
Collapse
Affiliation(s)
- Hassan A El-Sayed
- a Department of Chemistry , Faculty of Science, Zagazig University , Zagazig , Egypt
| | - Said A Said
- a Department of Chemistry , Faculty of Science, Zagazig University , Zagazig , Egypt
| | - Ahmed H Moustafa
- a Department of Chemistry , Faculty of Science, Zagazig University , Zagazig , Egypt
| | - Mohamed M Baraka
- b Department of Medicinal Chemistry , Faculty of Pharmacy, Zagazig University , Zagazig , Egypt
| | - Rimaa T Abdel-Kader
- a Department of Chemistry , Faculty of Science, Zagazig University , Zagazig , Egypt
| |
Collapse
|
11
|
Antipathogenic effects of structurally-related Schiff base derivatives: Structure–activity relationship. ARAB J CHEM 2015. [DOI: 10.1016/j.arabjc.2013.03.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
12
|
Tunç T, Karacan MS, Ertabaklar H, Sarı M, Karacan N, Büyükgüngör O. Antimony(III) complexes with 2-amino-4,6-dimethoxypyrimidines: Synthesis, characterization and biological evaluation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2015; 153:206-14. [PMID: 26427018 DOI: 10.1016/j.jphotobiol.2015.09.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 08/28/2015] [Accepted: 09/21/2015] [Indexed: 01/23/2023]
Abstract
Novel pyrimidine compound bearing disulfide bridge, 5,5'-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine) (3) was synthesized by reduction of 2-amino-4,6-dimethoxy-5-thiocyanatopyrimidine for the first time, and its structure was confirmed by X-ray crystallographic analysis. Novel binuclear antimony(III) compound of (3), {Sb[5,5'-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine)]Cl3}2 (4) and mononuclear antimony(III) compounds, SbL2Cl3, [L: 2-amino-5-thiol-4,6-dimethoxy pyrimidine (2) and 2-amino-5-(1H-tetrazol-5-ylthio)-4,6-dimethoxypyrimidine (6)] were synthesized and characterized with the help of elemental analysis, molecular conductivity, FT-IR, (1)H-NMR and LC-MS techniques. The geometrical structures optimized by a DFT/B3LYP/LANL2DZ method of the compounds, indicated that monomeric compounds have square pyramidal shape. Both antileishmanial activity against Leishmania tropica promastigote and glutathione reductase inhibitory activity were determined in vitro. The results showed that (3) has the best biological activity.
Collapse
Affiliation(s)
- Turgay Tunç
- Ahi Evran University, Faculty of Engineering-Architecture, Departmant of Chemistry and Process Engineering, Kirsehir, Turkey
| | | | - Hatice Ertabaklar
- Department of Physics, Faculty of Science and Arts, Ondokuz Mayıs University, Samsun, Turkey
| | - Musa Sarı
- Department of Physics Education, Gazi University, Ankara, Turkey
| | - Nurcan Karacan
- Gazi University, Science Faculty, Chemistry Department, Ankara, Turkey
| | - Orhan Büyükgüngör
- Adnan Menderes University, Medicine Faculty, Parasitology Department, Aydin, Turkey
| |
Collapse
|
13
|
Alam MS, Lee DU. Syntheses, crystal structure, Hirshfeld surfaces, fluorescence properties, and DFT analysis of benzoic acid hydrazone Schiff bases. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 145:563-574. [PMID: 25804368 DOI: 10.1016/j.saa.2015.03.071] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/03/2015] [Accepted: 03/05/2015] [Indexed: 06/04/2023]
Abstract
Two hydrazone Schiff base analogues, namely, (E)-N'-(4-hydroxy-3-methoxybenzylidene)benzohydrazide (3a) and (E)-N'-(4-methoxybenzylidene)benzohydrazide (3b), were synthesized using a mild, efficient method and characterized by (1)H NMR, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction. X-ray analysis of a single crystal of 3a revealed a tetragonal, space group I4(1)/a structure, with an E-configuration around the azomethine (C8N2) double bond. In this structure, the NH and OH groups act as proton donors and the >CO and N groups as proton acceptors, and these facilitate hydrogen bond formation in the crystal state. Plausible intermolecular interactions were studied using 3D Hirshfeld surfaces and related 2D fingerprint plots. The optimized geometry, vibrational frequencies, Mulliken charge distribution, molecular electrostatic potential (MEP) maps, frontier molecular orbitals (FMOs), and associated energies of the ground state and the first single excited state were calculated using density functional theory (DFT) and time-dependant DFT calculations using the B3LYP/6-311G method. Vibrational frequencies calculated in the gaseous phase compared with experimental values measured in the solid state and showed good agreement with each other. The chemical reactivities of 3a and 3b were predicted by mapping MEP surface over optimized geometries and comparing these with MEP map generated over crystal structures. Mulliken charge distribution analysis and MEP map of 3a and 3b revealed that N(1), O(1), O(2) and O(3) atoms could act as electron donors and coordinate with metals and that these represented the most suitable sites for electrophilic attack. In fluorescence spectra, the absorption and emission spectra of 3a and 3b were similar in different polar solvents with few exceptions. In addition, both compounds exhibited dual emission spectra in acetone due to keto-enol tautomerism induced by photoexcitation.
Collapse
Affiliation(s)
- Mohammad Sayed Alam
- Division of Bioscience, Dongguk University, Gyeongju 780-714, Republic of Korea; Department of Chemistry, Jagannath University, Dhaka 1100, Bangladesh
| | - Dong-Ung Lee
- Division of Bioscience, Dongguk University, Gyeongju 780-714, Republic of Korea.
| |
Collapse
|
14
|
Khalil A, Edwards JA, Rappleye CA, Tjarks W. Design, synthesis, and biological evaluation of aminothiazole derivatives against the fungal pathogens Histoplasma capsulatum and Cryptococcus neoformans. Bioorg Med Chem 2015; 23:532-47. [PMID: 25543205 PMCID: PMC4302056 DOI: 10.1016/j.bmc.2014.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 11/25/2014] [Accepted: 12/03/2014] [Indexed: 11/25/2022]
Abstract
Invasive fungal disease constitutes a growing health burden and development of novel antifungal drugs with high potency and selectivity against new fungal molecular targets are urgently needed. Previously, an aminothiazole derivative, designated as 41F5, was identified in our laboratories as highly active against Histoplasma yeast (MIC50 0.4-0.8 μM) through phenotypic high-throughput screening of a commercial library of 3600 purine mimicking compounds (Antimicrob. Agents Chemother.2013, 57, 4349). Consequently, 68 analogues of 41F5 were designed and synthesized or obtained from commercial sources and their MIC50s of growth inhibition were evaluated in Histoplasma capsulatum to establish a basic structure-activity-relationship (SAR) for this potentially new class of antifungals. The growth inhibiting potentials of smaller subsets of this library were also evaluated in Cryptococcus neoformans and human hepatocyte HepG2 cells, the latter to obtain selectivity indices (SIs). The results indicate that a thiazole core structure with a naphth-1-ylmethyl group at the 5-position and cyclohexylamide-, cyclohexylmethylamide-, or cyclohexylethylamide substituents at the 2-position caused the highest growth inhibition of Histoplasma yeast with MIC50s of 0.4 μM. For these analogues, SIs of 92 to >100 indicated generally low host toxicity. Substitution at the 3- and 4-position decreased antifungal activity. Similarities and differences were observed between Histoplasma and Cryptococcus SARs. For Cryptococcus, the naphth-1-ylmethyl substituent at the 5-position and smaller cyclopentylamide- or cyclohexylamide groups at the 2-position were important for activity. In contrast, slightly larger cyclohexylmethyl- and cyclohexylethyl substituents markedly decreased activity.
Collapse
Affiliation(s)
- Ahmed Khalil
- Division of Medicinal Chemistry & Pharmacognosy, The Ohio State University, 500 West 12th Avenue, Columbus, OH 43210, USA; Chemistry Department, Faculty of Science, Zagazig University, Zagazig, Egypt
| | - Jessica A Edwards
- Department of Microbiology, The Ohio State University, USA; Department of Microbial Infection and Immunity, The Ohio State University, USA; The Center for Microbial Interface Biology, The Ohio State University, USA
| | - Chad A Rappleye
- Department of Microbiology, The Ohio State University, USA; Department of Microbial Infection and Immunity, The Ohio State University, USA; The Center for Microbial Interface Biology, The Ohio State University, USA
| | - Werner Tjarks
- Division of Medicinal Chemistry & Pharmacognosy, The Ohio State University, 500 West 12th Avenue, Columbus, OH 43210, USA; The Center for Microbial Interface Biology, The Ohio State University, USA.
| |
Collapse
|
15
|
Chen KY, Tsai HY. Synthesis, X-ray structure, spectroscopic properties and DFT studies of a novel Schiff base. Int J Mol Sci 2014; 15:18706-24. [PMID: 25329613 PMCID: PMC4227241 DOI: 10.3390/ijms151018706] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/23/2014] [Accepted: 10/09/2014] [Indexed: 11/25/2022] Open
Abstract
A series of Schiff bases, salicylideneaniline derivatives 1-4, was synthesized under mild conditions and characterized by 1H NMR, HRMS, UV-Vis and fluorescence spectra, and single-crystal X-ray diffraction. In solid and aprotic solvents 1-4 exist mainly as E conformers that possess an intramolecular six-membered-ring hydrogen bond. A weak intramolecular C-H···F hydrogen bond is also observed in fluoro-functionalized Schiff base 4, which generates another S(6) ring motif. The C-H···F hydrogen bond further stabilizes its structure and leads it to form a planar configuration. Compounds 1-3 exhibit solely a long-wavelength proton-transfer tautomer emission, while dipole-functionalized Schiff base 4 shows remarkable dual emission originated from the excited-state intramolecular charge transfer (ESICT) and excited-state intramolecular proton transfer (ESIPT) states. Furthermore, the geometric structures, frontier molecular orbitals (MOs) and the potential energy curves for 1-4 in the ground and the first singlet excited state were fully rationalized by density functional theory (DFT) and time-dependent DFT calculations.
Collapse
Affiliation(s)
- Kew-Yu Chen
- Department of Chemical Engineering, Feng Chia University, Taichung 40724, Taiwan.
| | - Hsing-Yang Tsai
- Department of Chemical Engineering, Feng Chia University, Taichung 40724, Taiwan.
| |
Collapse
|
16
|
Al-Mohammed NN, Alias Y, Abdullah Z, Shakir RM, Taha EM, Hamid AA. Synthesis and antibacterial evaluation of some novel imidazole and benzimidazole sulfonamides. Molecules 2013; 18:11978-95. [PMID: 24077176 PMCID: PMC6270528 DOI: 10.3390/molecules181011978] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 09/11/2013] [Accepted: 09/12/2013] [Indexed: 11/16/2022] Open
Abstract
Several new substituted sulfonamide compounds were synthesized and their structures were confirmed by ¹H-NMR, ¹³C-NMR, FT-IR, and mass spectroscopy. The antibacterial activities of the synthesized compounds were screened against standard strains of six Gram positive and four Gram negative bacteria using the microbroth dilution assay. Most of the compounds studied showed promising activities against both types of bacteria.
Collapse
Affiliation(s)
- Nassir N. Al-Mohammed
- Chemistry Department, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
- Authors to whom correspondence should be addressed; E-Mails: (Z.A.); or (N.Al-M.); Tel.: +603-7967-5410 (Z.A. & N.Al-M); Fax: +603-7967-5427 (Z.A. & N.Al-M)
| | - Yatimah Alias
- Chemistry Department, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Zanariah Abdullah
- Chemistry Department, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
- Section for Co-curricular Courses, External Faculty Electives and TITAS (SKET), University of Malaya, Kuala Lumpur 50603, Malaysia
- Authors to whom correspondence should be addressed; E-Mails: (Z.A.); or (N.Al-M.); Tel.: +603-7967-5410 (Z.A. & N.Al-M); Fax: +603-7967-5427 (Z.A. & N.Al-M)
| | - Raied M. Shakir
- Chemistry Department, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Ekhlass M. Taha
- Department of Chemistry, Collage of Science for Women, Baghdad University, Aljadriya 10071, Baghdad, Iraq
| | - Aidil Abdul Hamid
- School of Biosciences and Biotechnology, Faculty of Science and Technology, University Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia
| |
Collapse
|