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Coordination behaviours of new (bidentate N,O-chelating) Schiff bases towards copper(II) and nickel(II) metal ions: synthesis, characterization, antimicrobial, antioxidant, and DFT studies

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Abstract

Two Schiff bases, HL1 and HL2, were synthesized in two different reactions involving 2-hydroxynaphthaldehyde with 2-amino-6-methylbenzothiazole and 2-amino-6-florobenzothiazole respectively. Copper(II) and nickel(II) complexes of the Schiff bases were subsequently prepared in 1:1 metal-to-ligand stoichiometric reactions. The compounds were characterized extensively by 1H NMR, 13C NMR, Dept-90, UV–Vis, and IR spectroscopic techniques, magnetic susceptibility, TGA, DTG, and molar conductivity analysis. The spectroscopic results confirm bidentate nature of the Schiff bases and a four coordinate geometry for all the complexes: [CuL1ClH2O], [NiL1ClH2O], [Cu(L2)2], and [NiL2ClH2O]. Quantum chemical studies gave fully optimized geometries of the Schiff bases and metal complexes using the 6-31+g(d,p) basis set. The compounds were studied for their in vitro antibacterial activities against some selected Gram-positive and Gram-negative bacteria, using agar well diffusion. The metal complexes exhibited better antibacterial activities compared to the free ligand due to the effects of chelation, which improved the lipophilicity. Furthermore, the antioxidant potentials of the compounds were ascertained using DPPH radical scavenging and ferrous chelating assay. The copper complexes had the best antioxidant properties of all the tested compounds. The results of the biological analysis were in agreement with the theoretical data from quantum chemical calculations. The study presented biologically active coordination compounds with benzothiazole moiety that could be used as compounds of interest in the drug discovery processes.

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References

  1. N.B. Patel, F.M. Shaikh, New 4-thiazolidinones of nicotinic acid with 2-amino-6-methylbenzothiazole and their biological activity. Sci. Pharm. 78, 753–765 (2010)

    Article  CAS  Google Scholar 

  2. R. Abdul (2005) Synthesis and Biological Studies of Some Schiff bases Compounds and Their Transition Metal Complexes. A Ph.D. thesis submitted to the Bahuaddin Zakariya University, Multan Pakistan

  3. P. Chaudhary, P. Sharma, A. Sharma, J. Varshney, Recent advances in pharmacological activity of benzothiazole derivatives. Int. J. Curr. Pharm. Res. 4, 5–11 (2010)

    Google Scholar 

  4. A. Rana, N. Siddiqui, S.A. Khan, Benzothiazoles: a new profile of biological activities. Int. J. Curr. Pharm. Res. 69, 10–17 (2007)

    CAS  Google Scholar 

  5. J. Malik, F.V. Manvi, B.K. Nanjwade, P. Purohit, New 2-amino substituted benzothiazoles: a new profile of biological activities. J. Pharm. Res. 11, 1687–1690 (2009)

    Google Scholar 

  6. J.K. Malik, F.V. Manvi, B.K. Nanjwade, S. Singh, P. Purohit, Review of the 2-amino substituted benzothiazoles: different methods of the synthesis. Der Pharm. Lett. 2, 347–359 (2010)

    CAS  Google Scholar 

  7. J.H. Block, J.H. Beale, Wilson and Gisvold, Textbook of Organic, Medicinal and Pharmaceutical Chemistry, 10th edn. (Lipincott William & Wilkins, New York, 1998)

    Google Scholar 

  8. L.S. Khokra, K. Arora, H. Mehta, A. Aggarwal, M. Yadav, Essential oil composition and antibacterial studies of Vitex negundo Linn. extracts. Int. J. Pharm. Sci. Res. 2, 1356–1377 (2011)

    CAS  Google Scholar 

  9. H.A. Bhuva, S.G. Kini, Synthesis, anticancer activity and docking of some substituted benzothiazoles as tyrosine kinase inhibitors. J. Mol. Graph. Model. 29, 32–37 (2010)

    Article  CAS  Google Scholar 

  10. C.G. Mortimer, G. Wells, J.P. Crochard, E.L. Stone, T.D. Bradshaw, M.F.G. Stevens, A.D. Westwell, Antitumor benzothiazoles. 26. 2-(3,4-dimethoxyphenyl)-5-fluorobenzothiazole (GW 610, NSC 721648), a simple fluorinated 2-arylbenzothiazole, shows potent and selective inhibitory activity against lung, colon and breast cancer cell lines. J. Med. Chem. 49, 179–185 (2006)

    Article  CAS  Google Scholar 

  11. S. Nagarjan, G. Crescenzo, D. Getman, H. Lu, J. Sikorski, J. Walker, J. McDonald, K. Houseman, G. Kocan, N. Kishore, P. Mehta, C. Shippy, L. Blystone, Discovery of novel benzothiazolesulfonamides as potent inhibitors of HIV-1 protease. Bioorg. Med. Chem. 11, 4769–4777 (2003)

    Article  Google Scholar 

  12. S. Hout, N. Azas, A. Darque, M. Robin, C. Giorgio, M. Gasquet, J. Galy, P. David, Activity of benzothiazoles and chemical derivatives on Plasmodium falciparum. Parasitology 129, 525–542 (2004)

    Article  CAS  Google Scholar 

  13. M. Maharan, S. William, F. Ramzy, A. Sembel, Synthesis and in vitro evaluation of new benzothiazole derivatives as schistosomicidal agents. Molecules 12, 622–623 (2007)

    Article  Google Scholar 

  14. V. Kumar, T.S. Ngaraja, H. Shameer, E. Jayachandran, G.M. Sreenivasa, N-substituted-3-chloro-2-azetidinones: synthesis and characterization of new novel anti-inflammatory agents. J. Pharm. Sci. Res. 2, 83–92 (2009)

    Google Scholar 

  15. S. Hibi, Y. Okamoto, K. Tagami, H. Numata, N. Kobayashi, M. Shinoda, T. Kawahara, M. Murakami, K. Oketani, T. Inoue, H. Shibata, I. Yamatsu, Novel dual inhibitors of 5-lipoxygenase and thromboxane A2 synthetase: synthesis and structure-activity relationships of 3-pyridylmethyl-substituted 2-amino-6-hydroxybenzothiazole derivatives. J. Med. Chem. 37, 3062–3070 (1994)

    Article  CAS  Google Scholar 

  16. N. Siddiqui, A. Rana, S. Khan, S. Haque, M. Arshad, S. Ahmed, W. Ahsan, Syntheis and preliminary screening of benzothiazol-2yl-thiadiazole derivatives for anticonvulsant activity. Acta Pharm. 59, 441–451 (2009)

    Article  CAS  Google Scholar 

  17. N. Siddiqui, A. Rana, S. Khan, S. Haque, M. Alam, W. Ahsan, M. Arshad, Anticonvulsant and toxicity evaluation of newly synthesized 1-[2-(3,4-disubstitutedphenyl)-3-chloro-4-oxoazetidin-1-yl]-3-(6-substituted-1,3-benzothiazol-2-yl)ureas. Acta Chim. Slov. 59, 462–469 (2009)

    Google Scholar 

  18. A. Nitta, H. Fujii, S. Sakami, Y. Nishimura, T. Ohyama, M. Satoh, J. Nakaki, S. Satoh, C. Inada, H. Kozono, H. Kumagai, M. Shimamura, T. Fukazawa, H. Kawai, (3R)-3-amino-4-(2,4,5-trifluorophenyl)-N-{4-[6-(2-methoxyethoxy)benzothiazol-2-yl]tetrahydropyran-4-yl}butanamide as a potent dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes. Bioorg. Med. Chem. Lett. 18, 5435–5438 (2008)

    Article  CAS  Google Scholar 

  19. H. Diaz, R. Molina, R. Andrade, D. Coutino, J. Franco, S. Webster, M. Binniie, S. Estrada-Soto, M.I. Brajas, I.L. Rivera, G.N. Vazquez, Antidiabetic activity of N-(6-substituted-1,3-benzothiazol-2-yl)benzenesulfonamides. Bioorg. Med. Chem. Lett. 18, 2871–2877 (2008)

    Article  Google Scholar 

  20. P. Arora, S. Das, M.S. Ranawat, N. Arora, M.M. Gupta, Synthesis and biological evaluation of some novel chrome-2-one derivatives for antipsychotic activity. J. Chem. Pharm. Res. 2, 317–323 (2010)

    CAS  Google Scholar 

  21. S.Y. Shahar, Z.H. Ansari, Synthesis and in vivo diuretic activity of biphenyl benzothiazole-2-carboxamide derivatives. Acta Pol. Pharm. Drug Res. 66, 387–392 (2009)

    Google Scholar 

  22. T.D. Bradshaw, M.S. Chua, H.L. Browne, V. Trapani, E.A. Sausville, M.F.G. Stevens, In vitro evaluation of amino acid prodrugs of novel antitumour 2-(4-amino-3-methylphenyl)benzothiazoles. Br. J. Cancer 86, 1348 (2002)

    Article  CAS  Google Scholar 

  23. F. Delmas, A. Avellaneda, C.D. Gioegia, M. Robin, E.D. Clercq, D.P. Timol, J.P. Galy, Synthesis and antileishmanial activity of (1,3-benzothiazol-2-yl) amino-9-(10H)-acridinone derivatives. Eur. J. Med. Chem. 39, 685 (2004)

    Article  CAS  Google Scholar 

  24. S.R. Pattan, S.N.N. Babu, J. Angadi, Synthesis and biological activity of 2-amino [5′-(4′-sulphonylbenzylidene)-2,4-thiazolidine dione]-7-(substituted)-6-fluoro benzothiazoles. Indian J. Heterocycl. Chem. 11, 333 (2002)

    CAS  Google Scholar 

  25. A.A. Osowole, A.C. Ekennia, B.O. Achugbu, Synthesis, spectroscopic characterization and antibacterial properties of some metal (II) complexes of 2-(6-methoxybenzothiazol-2-ylimino) methyl)-4-nitrophenol. Res. Rev. J. Pharm. Anal. 2, 1–5 (2013)

    Google Scholar 

  26. H.R.I. Tomi, J.H. Tomma, A.H.R. Al-Daraji, A.H. Al-Dujaili, Synthesis, characterization and comparative study the microbial activity of some heterocyclic compounds containing oxazole and benzothiazole moieties. J. Saudi Chem. Soc. 2012, 213–232 (2012)

    Google Scholar 

  27. H. Mahmood-ul, Z.H. Chohan, C.T. Supuran, Antibacterial Zn(II) compounds of Schiff bases derived from some benzothiazoles. Main Group Met. Chem. 25, 291 (2002)

    Google Scholar 

  28. S.P. Vartale, D.B. Kadam, N.K. Halikar, Synthesis of novel 4-thiazolidinone derivatives incorporated with benzothiazole and its antimicrobial activity. Der Pharma Chem. 3, 213–223 (2011)

    CAS  Google Scholar 

  29. R. Ali, N. Siddiqui, Biological aspects of emerging benzothiazoles: a short review. J. Chem 2013, 12 (2013). doi:10.1155/2013/345198

    Google Scholar 

  30. R. Caputo, M.L. Calabro, N. Micale, Synthesis and biological evaluation of new 2-amino-6-(trifluoromethoxy)benzoxazole derivatives, analogues of riluzole. Med. Chem. Res. 21, 2644–2651 (2012)

    Article  CAS  Google Scholar 

  31. A.C. Ekennia, D.C. Onwudiwe, A.A. Osowole, Spectral, thermal stability ans antibacterial studies of copper complexes of N-methyl-N-phenyl dithiocarbamate. J. Sulfur Chem. 36, 96–104 (2015)

    Article  CAS  Google Scholar 

  32. G.A. Kolawole, A.A. Osowole, Synthesis and characterization of some metal (II) complexes of isomeric unsymmetrical Schiff bases and their adducts with triphenylphosphine. J. Coord. Chem. 62, 1437–1444 (2009)

    Article  CAS  Google Scholar 

  33. A.A. Osowole, R. Kempe, R. Schobert, Synthesis, spectral, thermal, in-vitro antibacterial and anticancer activities of some metal (II) complexes of 3-(-1-(4-methoxy-6-methyl)-2-pyrimidinylimino)methyl-2-napthol. Int. Res. J. Pure Appl. Chem. 2, 105–129 (2012)

    Article  CAS  Google Scholar 

  34. A.C. Ekennia, D.C. Onwudiwe, C. Ume, E.E. Ebenso, Mixed ligand complexes of N-methyl-N-phenyldithiocarbamate: synthesis, characterisation, antifungal activity and solvent extraction studies of the ligand. Bioinorg. Chem. Appl. (2015). doi:10.1155/2015/913424

  35. A.D. Becke, Density-functional exchange-energy approximation with correct asymptotic behaviour. Phys. Rev. A 38, 3098–3100 (1988)

    Article  CAS  Google Scholar 

  36. C. Lee, W. Yang, R.G. Parr, Development of the Colle–Salvetti correlation-energy formula into a functional of the electron density. Phys. Rev. B 37, 785–789 (1988)

    Article  CAS  Google Scholar 

  37. X. Xu, W.A. Goddard, The X3LYP extended density functional for accurate descriptions of nonbond interactions, spin states, and thermochemical properties. Proc. Natl. Acad. Sci. 101, 2673–2677 (2003)

    Article  Google Scholar 

  38. I. Georgieva, N. Trendafilova, Bonding analyses, formation energies, and vibrational properties of M-R2dtc complexes (M = Ag (I), Ni (II), Cu (II), or Zn (II)). J. Phys. Chem. A 111, 13075–13087 (2007)

    Article  CAS  Google Scholar 

  39. L. Chen, T. Liu, C. Ma, Metal complexation and biodegradation of EDTA and S, S-EDDS: a density functional theory study. J. Phys. Chem. A 114, 443–454 (2007)

    Article  Google Scholar 

  40. Y. Niu, S. Feng, Y. Ding, R. Qu, D. Wang, J. Han, Theoretical investigation on sulfur-containing chelating resin-divalent metal complexes. Int. J. Quantum Chem. 110, 1982–1993 (2010)

    CAS  Google Scholar 

  41. S.I. Gorelsky, L. Basumallick, J. Vura-Weis, R. Sarangi, K.O. Hodgson, B. Hedman, K. Fujisawa, E.I. Solomon, Spectroscopic and DFT investigation of [M{HB(3,5-iPr2pz)3}(SC6F5)] (M = Mn, Fe Co, Ni, Cu, and Zn) model complexes: periodic trends in metal–thiolate bonding. Inorg. Chem. 44, 4947–4960 (2005)

    Article  CAS  Google Scholar 

  42. T. Marino, M. Toscano, N. Russo, A. Grand, Structural and electronic characterization of the complexes obtained by the interaction between bare and hydrated first-row transition-metal ions (Mn 2 + , Fe 2 + , Co 2 + , Ni 2 + , Cu 2 + , Zn 2 +) and glycine. J. Phys. Chem. B 110, 24666–24673 (2006)

    Article  CAS  Google Scholar 

  43. R. Terreux, M. Domard, C. Viton, A. Domard, Interactions study between the copper II ion and constitutive elements of chitosan structure by DFT calculation. Biomacromolecules 7, 31–37 (2006)

    Article  CAS  Google Scholar 

  44. T.H. Dunning, P.Y. Hay, in Modern Theoretical Chemistry, 3rd edn., ed. by H.F. Schaefer (Plenum, New York, 1976)

    Google Scholar 

  45. P.J. Hay, W.R. Wadt, Ab initio effective core potentials for molecular calculations. Potentials for the transition metal atoms Sc to Hg. J. Chem. Phys. 82, 270–283 (1985)

    Article  CAS  Google Scholar 

  46. W.R. Wadt, P.J. Hay, Ab initio effective core potentials for molecular calculations. Potentials for main group elements Na to Bi. J. Chem. Phys. 82, 284–298 (1985)

    Article  CAS  Google Scholar 

  47. P.J. Hay, W.R. Wadt, Ab initio effective core potentials for molecular calculations. Potentials for K to Au including the outermost core orbitals. J. Chem. Phys. 82, 299–310 (1985)

    Article  CAS  Google Scholar 

  48. M.Y. Combariza, R.W. Vachet, J. Phys. Chem. A 108, 757–1763 (2004)

    Article  Google Scholar 

  49. M.A. Carvajal, J.J. Novoa, S. Alvarez, Choice of coordination number in d10 complexes of group 11 metals. J. Am. Chem. Soc. 126, 1465–1477 (2004)

    Article  CAS  Google Scholar 

  50. B.D. Alexander, T.J. Dines, Ab initio calculations of the structures and vibrational spectra of ethene complexes. J. Phys. Chem. A 108, 146–156 (2004)

    Article  CAS  Google Scholar 

  51. M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman, G. Scalmani, V. Barone, B. Mennucci, G.A. Petersson, H. Nakatsuji, M. Caricato, X. Li, Gaussian 09, Revision D.01 (Gaussian, Inc., Wallingford CT, 2009)

  52. W. Brands-Williams, M.E. Cuvelier, C.L.W. Berset, Use of a free radical method to evaluate antioxidant activity. LWT Food Sci. Technol. 18, 25–30 (1995)

    Article  Google Scholar 

  53. T.C.P. Dinis, V.M.C. Madeira, L.M. Almeida, Action of phenolic derivatives (acetaminophen, salicylate, and 5-aminosalicylate) as inhibitors of membrane lipid peroxidation and as peroxyl radical scavengers. Arch. Biochem. Biophys. 315, 161–169 (1994)

    Article  CAS  Google Scholar 

  54. A.A. Osowole, S.M. Wakil, M.O. Emmanuel, Synthesis, characterization, antioxidant and antimicrobial activities of some metal(II) complexes of the mixed-ligands, vitamin B2 and benzoic acid. Elixir Appl. Chem. 79, 30370–30374 (2015)

    Google Scholar 

  55. A.R.H. Pramanik, P.C. Paul, P. Mondal, C.R. Bhattacharjee, Mixed ligand complexes of cobalt(III) and iron(III) containing N2O2-chelating Schiff base: synthesis, characterisation, antimicrobial activity, antioxidant and DFT study. J. Mol. Struct. 1100, 496–505 (2015)

    Article  CAS  Google Scholar 

  56. T. Prateek, C. Sulekh, B.S. Saraswat, S. Deepansh, Design, spectral characterization, DFT and biological studies of transition metal complexes of Schiff base derived from 2-aminobenzamide, pyrrole and furan aldehyde. Spectrochim. Acta Part A Mol. Biomol. Spectrosc. 143, 1–11 (2015)

    Article  Google Scholar 

  57. D.C. Onwudiwe, A.C. Ekennia, Synthesis, characterisation, thermal, antimicrobial and antioxidant studies of some transition metal dithiocarbamates. Res. Chem. Intermed. (2016). doi:10.1007/s1116-016-2709-2

    Google Scholar 

  58. W.J. Geary, The use of conductivity measurements in organic solvents for the characterisation of coordination compounds. Coord. Chem. Rev. 7, 81–122 (1971)

    Article  CAS  Google Scholar 

  59. M. Belcastro, T. Marino, N. Russo, M. Toscano, Interaction of cysteine with Cu2+ and group IIb (Zn2+, Cd2+, Hg2+) metal cations: a theoretical study. J. Mass Spectrom. 40, 300–306 (2005)

    Article  CAS  Google Scholar 

  60. R.A. Lal, S. Adhikari, A. Kumar, M.L. Pal, Oxoperoxomolybdenum(vi) complexes derived from n-benzamidosalicylaldimine. J. Indian Chem. Soc. 75, 345–349 (1998)

    CAS  Google Scholar 

  61. S. Majumder, G.S. Panda, S.K. Choudhuri, Synthesis, characterization and biological properties of a novel copper complex. Eur. J. Med. Chem. 38, 893–898 (2003)

    Article  CAS  Google Scholar 

  62. C.S. Marvel, S.A. Aspey, E.A. Dudley, Quadridentate and sexadentate chelates. Some preliminary studies in their preparation and thermal stability. J. Am. Chem. Soc. 78, 4905–4909 (1956)

    Article  CAS  Google Scholar 

  63. S.N. Rao, K.N. Munshi, N.N. Rao, M.M. Bhadbhade, E. Suresh, Synthesis, spectral and X-ray structural characterization of [cis-MoO 2 (L)(solv)](L = salicylidene salicyloyl hydrazine) and its use as catalytic oxidant. Polyhedron 18, 2491–2497 (1999)

    Article  CAS  Google Scholar 

  64. M.G. Abd El-Wahed, M.S. Refat, S.M. El-Megharbel, Metal complexes of antiuralethic drug: synthesis, spectroscopic characterization and thermal study on allopurinol complexes. J. Mol. Struct. 888, 416–429 (2008)

    Article  CAS  Google Scholar 

  65. D. Nicholls, Comprehensive Inorganic Chemistry, vol. 3 (Wiley, Hoboken, 1973)

    Google Scholar 

  66. B. Tang, J.H. Ye, X.H. Ju, Computational study of coordinated Ni(II) complex with high nitrogen content ligands. ISRN Org. Chem. (2011). doi:10.5402/2011/920753

    Google Scholar 

  67. A. Nimmermark, L. Ohrstrom, Z. Reedijk, Metal-ligand bond lengths and strengths: are they correlated? A detailed CSD analysis. Z. Kristallogr. 228, 311–317 (2013)

    Article  CAS  Google Scholar 

  68. T.H. Lu, C.S. Chung, T.J. Ashida, Chin. Chem. Soc. 38, 147–154 (1991)

    Article  CAS  Google Scholar 

  69. C. Ravikumar, I.H. Joe, V.S. Jayakumar, Charge transfer interactions and nonlinear optical properties of push–pull chromophore benzaldehyde phenylhydrazone: a vibrational approach. Chem. Phys. Lett. 460, 552–558 (2008)

    Article  CAS  Google Scholar 

  70. J.V. Burda, J. Sponer, P. Hobza, Ab initio study of the interaction of guanine and adenine with various mono- and bivalent metal cations (Li+, Na+, K+, Rb+, Cs+; Cu+, Ag+, Au+; Mg2+, Ca2+, Sr2+, Ba2+; Zn2+, Cd2+, and Hg2+). J. Phys. Chem. 100, 7250–7255 (1996)

    Article  CAS  Google Scholar 

  71. A.C. Ekennia, D.C. Onwudiwe, L.O. Olasunkanmi, A.A. Osowole, E.E. Ebenso, Synthesis, biological and quantum chemical studies of Zn (II) and Ni(II) mixed ligand complexes derived from N,-disubstituted dithiocarbamate and benzoic acid. Bioinorg. Chem. Appl. 2015, 1–12 (2015)

  72. J. Chocholousova, V. Spirko, P. Hobza, First local minimum of the formic acid dimer exhibits simultaneously red-shifted O–H···O and improper blue-shifted C–H···O hydrogen bonds. Phys. Chem. Chem. Phys. 6, 37–41 (2004)

    Article  CAS  Google Scholar 

  73. V. Uivarosi, M. Badea, V. Aldea, L. Chirigiu, R. Olar, Thermal and spectral studies of palladium(II) and platinum(IV) complexes with dithiocarbamate derivatives. J. Therm. Anal. Calorim. 111, 1177–1182 (2013)

    Article  CAS  Google Scholar 

  74. N. Raman, J.D. Raja, Synthesis, structural characterization and antibacterial studies of some biosensitive mixed ligand copper(II) complexes. Indian J. Chem. 46A, 1611–1614 (2007)

    CAS  Google Scholar 

  75. B.D. Corbin, E.H. Seeley, A. Raab, J. Feldmann, M.R. Miller, V.J. Torres, K.L. Anderson, B.M. Dattilo, P.M. Dunman, R. Gerads, R.M. Caprioli, W. Nacken, W.J. Chazin, E.P. Skaar, Metal chelation and inhibition of bacterial growth in tissue abscesses. Science 319, 962–965 (2008)

    Article  CAS  Google Scholar 

  76. N. Dharmaraj, P. Viswanathamurthi, K. Nataraj, Ruthenium(II) complexes containing bidentate Schiff bases and their antifungal activity. Transit. Met. Chem. 26, 105–109 (2001)

    Article  CAS  Google Scholar 

  77. M.E. De-Leo, A. Tranghee, M. Passantino, A. Mordente, M.M. Lizzio, T. Galeotti, A. Zoli, Manganese superoxide dismutase, glutathione peroxidase, and total radical trapping antioxidant capacity in active rheumatoid arthritis. J. Rheumatol. 29, 2245–2246 (2002)

    Google Scholar 

  78. A. Mahajan, V.R. Tandon, Antioxidants and rheumatoid arthritis. J. Indian Rheumatol. Assoc. 12, 139–142 (2004)

    Google Scholar 

  79. B. Halliwell, J.M.C. Gutteridge, Oxygen toxicity, oxygen radicals, transition metals and disease. Biochem. J. 219, 1–14 (1984)

    Article  CAS  Google Scholar 

  80. A. Guder, H. Korkmaz, Investigation of antioxidant activity and total anthocyanins from blackberry (Rubus hirtus Waldst. and Kit) and cherry laurel (Laurocerasus officinalis Roem.). Asian J. Chem. 24, 4525–4531 (2012)

    CAS  Google Scholar 

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Ekennia, A.C., Osowole, A.A., Olasunkanmi, L.O. et al. Coordination behaviours of new (bidentate N,O-chelating) Schiff bases towards copper(II) and nickel(II) metal ions: synthesis, characterization, antimicrobial, antioxidant, and DFT studies. Res Chem Intermed 43, 3787–3811 (2017). https://doi.org/10.1007/s11164-016-2841-z

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