26
|
Sobha S, Mahalakshmi R, Raman N. Studies on DNA binding behaviour of biologically active transition metal complexes of new tetradentate N2O2 donor Schiff bases: inhibitory activity against bacteria. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 92:175-183. [PMID: 22446764 DOI: 10.1016/j.saa.2012.02.063] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 02/09/2012] [Accepted: 02/17/2012] [Indexed: 05/31/2023]
Abstract
A series of Cu(II), Ni(II) and Zn(II) complexes of the type ML have been synthesized with Schiff bases derived from o-acetoacetotoluidide, 2-hydroxybenzaldehyde and o-phenylenediamine/1,4-diaminobutane. The complexes are insoluble in common organic solvents but soluble in DMF and DMSO. The measured molar conductance values in DMSO indicate that the complexes are non-electrolytic in nature. All the six metal complexes have been fully characterized with the help of elemental analyses, molecular weights, molar conductance values, magnetic moments and spectroscopic data. The analytical data helped to elucidate the structure of the metal complexes. The Schiff bases are found to act as tetradentate ligands using N(2)O(2) donor set of atoms leading to a square-planar geometry for the complexes around all the metal ions. The binding properties of metal complexes with DNA were investigated by absorption spectra, viscosity measurements and cyclic voltammetry. Detailed analysis reveals that the metal complexes intercalate into the DNA base stack as intercalators. All the metal complexes cleave the pUC19 DNA in presence of H(2)O(2.) The Schiff bases and their complexes have been screened for their antibacterial activity against five bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, Klebsiella pneumoniae) by disk diffusion method. All the metal complexes have potent biocidal activity than the free ligands.
Collapse
|
27
|
Raman N, Ravichandran S. Synthesis and Characterization of a New Schiff Base and its Metal Complexes Derived from the Mannich Base, N-(1-piperidinobenzyl)acetamide. ACTA ACUST UNITED AC 2012. [DOI: 10.1081/sim-200066974] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
28
|
Raman N, Sobha S. Exploring the DNA binding mode of transition metal based biologically active compounds. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 85:223-234. [PMID: 22020164 DOI: 10.1016/j.saa.2011.09.065] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 09/06/2011] [Accepted: 09/30/2011] [Indexed: 05/31/2023]
Abstract
Few novel 4-aminoantipyrine derived Schiff bases and their metal complexes were synthesized and characterized. Their structural features and other properties were deduced from the elemental analysis, magnetic susceptibility and molar conductivity as well as from mass, IR, UV-vis, (1)H NMR and EPR spectral studies. The binding of the complexes with CT-DNA was analyzed by electronic absorption spectroscopy, viscosity measurement, and cyclic voltammetry. The interaction of the metal complexes with DNA was also studied by molecular modeling with special reference to docking. The experimental and docking results revealed that the complexes have the ability of interaction with DNA of minor groove binding mode. The intrinsic binding constants (K(b)) of the complexes with CT-DNA were found out which show that they are minor groove binders. Gel electrophoresis assay demonstrated the ability of the complexes to cleave the pUC19 DNA in the presence of AH(2) (ascorbic acid). Moreover, the oxidative cleavage studies using distamycin revealed the minor groove binding for the newly synthesized 4-aminoantipyrine derived Schiff bases and their metal complexes. Evaluation of antibacterial activity of the complexes against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, and Klebsiella pneumoniae exhibited that the complexes have potent biocidal activity than the free ligands.
Collapse
|
29
|
Raman N, Sudharsan S. Phase-assisted synthesis and DNA unpacking evaluation of biologically inspired metallo nanocomplexes using peptide as unique building block. J Colloid Interface Sci 2011; 364:140-7. [DOI: 10.1016/j.jcis.2011.08.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 08/12/2011] [Accepted: 08/13/2011] [Indexed: 11/24/2022]
|
30
|
Raman N, Pothiraj K, Baskaran T. Synthesis, characterization, and DNA damaging of bivalent metal complexes incorporating tetradentate dinitrogen–dioxygen ligand as potential biocidal agents. J COORD CHEM 2011. [DOI: 10.1080/00958972.2011.638979] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
31
|
Raman N, Pothiraj K, Baskaran T. DNA-binding, oxidative DNA cleavage, and coordination mode of later 3d transition metal complexes of a Schiff base derived from isatin as antimicrobial agents. J COORD CHEM 2011. [DOI: 10.1080/00958972.2011.634005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
32
|
Raman N, Selvan A, Sudharsan S. Metallation of ethylenediamine based Schiff base with biologically active Cu(II), Ni(II) and Zn(II) ions: synthesis, spectroscopic characterization, electrochemical behaviour, DNA binding, photonuclease activity and in vitro antimicrobial efficacy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 79:873-883. [PMID: 21550840 DOI: 10.1016/j.saa.2011.03.017] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/17/2011] [Accepted: 03/09/2011] [Indexed: 05/30/2023]
Abstract
A new ligand [C28H20N6O8] (L2) has been synthesized by the condensation reaction of 3-hydroxy-4-nitrobenzaldehydenephenylhydrazine (L1) with diethyloxalate. This ligand L2 is allowed to react with bis(ethylenediamine)Cu(II)/Ni(II)/Zn(II) complexes. It affords [(L2)Cu(en)2]Cl2(1)/[(L2)Ni(en)2]Cl2(2)/[(L2)Zn(en)2]Cl2(3) complexes, respectively. These complexes (1-3) have been characterized by the spectral and analytical techniques. The interaction of these complexes with calf thymus (CT) DNA is characterized by the absorption spectra which exhibit a slight red shift with hypochromic effect. Electrochemical analyses and viscosity measurements have also been carried out to determine the mode of binding. The shift in ΔEp, E1/2 and Ipc values explores the interaction of CT DNA with the above metal complexes. The slight increase in the viscosity of CT DNA indicates that these complexes bind to CT DNA through a partial non-classical intercalative mode. Cleavage experiments using pBR322 DNA in presence of H2O2 indicate that these complexes behave as efficient artificial chemical nucleases in the order of 1>2>3. Moreover, the antibacterial and antifungal studies reveal that complex 1 is highly active against the bacterial and fungal growth.
Collapse
|
33
|
Monsen K, Melton-Meaux G, Timm J, Westra B, Kerr M, Raman N, Farri O, Hart C, Martin K. An empiric analysis of omaha system targets. Appl Clin Inform 2011; 2:317-30. [PMID: 23616878 PMCID: PMC3631930 DOI: 10.4338/aci-2010-12-ra-0076] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/15/2011] [Indexed: 11/23/2022] Open
Abstract
Interface terminologies used in electronic health records must be re-evaluated and revised to reflect current health care practice and knowledge. To enable future revisions of the Omaha System Intervention Scheme, investigators evaluated formal semantic structure of target terms and concept duplication of problem and target terms. Using linguistic principles and qualitative analysis, five themes were found. A multidimensional formal semantic structure for the intervention target term was proposed. Concept duplication was examined for 16 problem-target matches. Clinical data enabled assessment of the validity of a proposed formal semantic structure and concept duplication. Recommendations are suggested for future development of the Omaha System Intervention Scheme.
Collapse
|
34
|
Raman N, Selvan A. Synthesis, spectroscopic, electrochemical, DNA binding and photocleavage studies on coordination compounds of bis(4-aminophenyl)methane based novel Schiff bases. RUSS J INORG CHEM+ 2011. [DOI: 10.1134/s0036023611050202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
35
|
Raman N, Sobha S, Thamaraichelvan A. A novel bioactive tyramine derived Schiff base and its transition metal complexes as selective DNA binding agents. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:888-898. [PMID: 21215688 DOI: 10.1016/j.saa.2010.12.056] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 12/06/2010] [Accepted: 12/14/2010] [Indexed: 05/30/2023]
Abstract
A novel tyramine derived Schiff base, 3-4-dimethoxybenzylidene-4-aminoantipyrinyl-4-aminoethylphenol(L) and a series of its transition metal complexes of the type, ML2Cl2 where, M=Cu(II), Ni(II), Co(II) and Zn(II) have been designed and synthesized. Their structural features and other properties were deduced from the elemental analysis, magnetic susceptibility and molar conductivity as well as from mass, IR, UV-vis, 1H NMR and EPR spectral studies. The binding properties of these complexes with calf thymus DNA (CT-DNA) were investigated using electronic absorption spectroscopy, viscosity measurement, cyclic voltammetry and molecular docking analysis. The results reveal that the metal(II) complexes interact with DNA through minor groove binding. The interaction has also been investigated by gel electrophoresis. Interestingly, it was found that all the complexes could cleave the circular plasmid pUC19 super coiled (SC) DNA efficiently in the presence of AH2 (ascorbic acid). The complexes showed enhanced antifungal and antibacterial activities compared to the free ligand.
Collapse
|
36
|
Raman N, Selvan A. Studies on DNA binding, electrochemical activation, DNA photocleavage, and biopotency of N and O donor bidentate ligands with Cu(II), Co(II), and Zn(II). J COORD CHEM 2011. [DOI: 10.1080/00958972.2010.551767] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
37
|
Raman N, Sakthivel A, Jeyamurugan R. Synthesis, structural characterization, antimicrobial, DNA-binding, and photo-induced DNA cleavage activity of some bio-sensitive Schiff base copper(II) complexes. J COORD CHEM 2010. [DOI: 10.1080/00958972.2010.539212] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
38
|
Raman N, Kulandaisamy A, Thangaraja C. Synthesis, Spectral, and Cyclic Voltammetric Studies of Tetraaza Copper(II), Oxovanadium(IV), and Zinc(II) Complexes Derived from 1,2‐(Diimino‐4′‐antipyrinyl)‐1,2‐diphenylethane and para‐Substituted Anilines. ACTA ACUST UNITED AC 2010. [DOI: 10.1081/sim-120039266] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
39
|
Raman N, Sakthivel A, Jeyamurugan R. Synthesis, characterization, DNA binding, photo-induced DNA cleavage, and antimicrobial activity of metal complexes of a Schiff base derived from bis(3-aminophenyl)malonamide. J COORD CHEM 2010. [DOI: 10.1080/00958970903288294] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
40
|
Raman N, Jeyamurugan R, Senthilkumar R, Rajkapoor B, Franzblau SG. In vivo and in vitro evaluation of highly specific thiolate carrier group copper(II) and zinc(II) complexes on Ehrlich ascites carcinoma tumor model. Eur J Med Chem 2010; 45:5438-51. [PMID: 20864225 DOI: 10.1016/j.ejmech.2010.09.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 08/30/2010] [Accepted: 09/01/2010] [Indexed: 11/19/2022]
Abstract
A new series of copper(II) and zinc(II) complexes have been designed and synthesized using a new type of Schiff bases derived from the reaction of 3-(3-phenyl-allylidene)-pentane-2,4-dione with para substituted aniline and benzene-1,2-dithiol. Their structures have been established by analytical and spectral data. The higher ɛ and low A(‖) values together with positive reduction potentials for these copper complexes suggest that they can mimic the functional properties of naturally occurring proteins. In vivo and in vitro antitumor functions of the complexes against Ehrlich ascites carcinoma tumor model have been investigated. The minimum inhibitory concentration of the complexes has also been investigated against Mycobacterium tuberculosis strain H37Rv. These complexes exhibit significant antitumor, cytotoxic and antituberculosis activity.
Collapse
|
41
|
Raman N, Joseph J. Synthesis, spectral characterization and antimicrobial activity of macrocyclic Schiff-base copper(II) complexes containing polycrystalline nanosized grains. J COORD CHEM 2010. [DOI: 10.1080/00958970802389763] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
42
|
Raman N, Joseph J. Novel metal-based antimicrobial agents of copper(II) complexes: Synthesis, spectral characterization and DNA interaction study. RUSS J INORG CHEM+ 2010. [DOI: 10.1134/s0036023610070120] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
43
|
Raman N, Selvan A, Manisankar P. Spectral, magnetic, biocidal screening, DNA binding and photocleavage studies of mononuclear Cu(II) and Zn(II) metal complexes of tricoordinate heterocyclic Schiff base ligands of pyrazolone and semicarbazide/thiosemicarbazide based derivatives. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 76:161-173. [PMID: 20363662 DOI: 10.1016/j.saa.2010.03.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 02/24/2010] [Accepted: 03/11/2010] [Indexed: 05/29/2023]
Abstract
We depict the synthesis and characterization of copper(II) and zinc(II) coordination compounds of 4-(3',4'-dimethoxybenzaldehydene)2-3-dimethyl-1-phenyl-3-pyrazolin-5-semicarbazone (1a), 4-(3',4'-dimethoxybenzaldehydene)2-3-dimethyl-1-phenyl-3-pyrazolin-5-thiosemicarbazone (1b), 4-(3'-hydroxy-4'-nitrobenzaldehydene)2-3-dimeth yl-1-phenyl-3-pyrazolin-5-semicarbazone (1c) and 4-(3'-hydroxy-4'-nitrobenzal dehydene)2-3-dimethyl-1-phenyl-3-pyrazolin-5-thiosemicarbazone (1d). All the remote compounds have the general composition [ML(2)] (M=Cu(II) and Zn(II)); L=Schiff base (1a-1d). All the complexes were characterized by elemental analysis, molar conductivity, IR, (1)H NMR, UV-vis, ESI-Mass, magnetic susceptibility measurements, cyclic voltammetric measurements, and EPR spectral studies. It has been originated that the Schiff bases with Cu(II) and Zn(II) ions form mononuclear complexes on 1:2 (metal:ligand) stoichiometry. Distorted octahedral environment is suggested for the metal complexes. The conductivity data confirm the non-electrolytic nature of the complexes. The interaction of CuL(2)(1a-1d) complexes with CT DNA was investigated by spectroscopic, electrochemical and viscosity measurements. Results suggest that the copper complexes bind to DNA via an intercalative mode. Moreover, the complexes have been found to promote the photocleavage of plasmid DNA pBR322 under irradiation at 365 nm. The Schiff bases and their metal complexes were screened for their antifungal and antibacterial activities against different species of pathogenic fungi and bacteria and their biopotency has been discussed.
Collapse
|
44
|
Raman N, Jeyamurugan R, Rani RU, Baskaran T, Mitu L. Synthesis, characterization, DNA binding, oxidative damage of DNA strand scission, and antimicrobial activities of β-diketone condensed Schiff-base transition metal complexes. J COORD CHEM 2010. [DOI: 10.1080/00958972.2010.485643] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
45
|
Raman N, Sakthivel A, Jeyamurugan R. Binuclear copper and zinc complexes possessing bio-potential ligands: synthesis, characterization, antimicrobial, SOD mimetic, DNA binding, and cleavage studies. J COORD CHEM 2010. [DOI: 10.1080/00958971003699745] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
46
|
Raman N, Jeyamurugan R, Sakthivel A, Mitu L. Novel metal-based pharmacologically dynamic agents of transition metal(II) complexes: designing, synthesis, structural elucidation, DNA binding and photo-induced DNA cleavage activity. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 75:88-97. [PMID: 19910242 DOI: 10.1016/j.saa.2009.09.047] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2009] [Revised: 09/20/2009] [Accepted: 09/25/2009] [Indexed: 05/28/2023]
Abstract
Novel Schiff base Cu(II), Ni(II), Co(II) and Zn(II) complexes have been designed and synthesized using the macrocyclic ligand derived from the condensation of diethylphthalate with Schiff base, obtained from benzene-1,2-diamine and 3-benzylidene-pentane-2,4-dione. The ligand and its complexes have been characterized by analytical and spectral techniques. DNA binding properties of these complexes have been investigated by UV-vis, viscosity measurements, cyclic voltammetric and differential pulse voltammogram studies. The intrinsic binding constants for Co(II), Ni(II), Cu(II) and Zn(II) complexes are 1.6x10(6), 1.8x10(6), 2.0x10(6) and 1.5x10(6) M(-1) respectively which are obtained from electronic absorption experiment. Control DNA cleavage experiments using pUC19 supercoiled (SC) DNA and minor groove binder (distamycin) suggest the major groove binding tendency for the synthesized complexes. In the presence of a reducing agent like 3-mercaptopropionic acid (MPA), the synthesized complexes show chemical nuclease activity under dark reaction condition. The complexes also show efficient photo-induced DNA cleavage activity on irradiation with a monochromatic UV light of 360 nm in the presence of inhibitors. Control experiments show inhibition of cleavage in the presence of singlet oxygen quencher like sodium azide and enhancement of cleavage in D(2)O, suggesting the formation of singlet oxygen as a reactive species in a type-II process.
Collapse
|
47
|
Raman N, Jeyamurugan R, Rajkapoor B, Magesh V. Metal‐based antitumor, cytotoxic and antimicrobial activity: pharmacological evaluation of Knoevenagel condensate β‐diketone Schiff base thiosemicarbazone Cu(II) and Zn(II) complexes. Appl Organomet Chem 2009. [DOI: 10.1002/aoc.1512] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
48
|
Raman N, Jeyamurugan R. Synthesis, characterization, and DNA interaction of mononuclear copper(II) and zinc(II) complexes having a hard–soft NS donor ligand. J COORD CHEM 2009. [DOI: 10.1080/00958970902825195] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
49
|
Raman N, Sakthivel A, Rajasekaran K. Design, structural elucidation, DNA interaction and antimicrobial activities of metal complexes containing tetraazamacrocyclic Schiff bases. J COORD CHEM 2009. [DOI: 10.1080/00958970802687554] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
50
|
Raman N. Antifungal active tetraaza macrocyclic transition metal complexes: Designing, template synthesis, and spectral characterization. RUSS J COORD CHEM+ 2009. [DOI: 10.1134/s1070328409030129] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|