Synthesis and Structural Studies of Mn(II), Co(III), and Ni(II) Complexes with Schiff Base Ligands Derived from 2-Acetylpyridine

Koo, Bon Kweon

doi:10.5012/bkcs.2011.32.5.1729

Cited by 5 publications

(5 citation statements)

References 25 publications

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“…The ligands share the same NNS, tridentate donor set as the HDp44mT and HPKTBH analogues, but the terminal substituent is a mercaptomethyl or mercaptobenzyl group rather than an amine or aromatic ring. Dithiocarbazate Schiff bases are well described and a number of transition metal complexes are known [31][32][33][34][35][36][37][38][39][40][41] and these compounds have shown a wide spectrum of biological activity. Little is known about the Fe coordination chemistry of these dithiocarbazate Schiff base ligands 42,43 and given the resemblance to the highly active thiosemicarbazone Fe chelators we have studied previously, 21,[28][29][30] this was the focus of the current work.…”

Section: Introductionmentioning

confidence: 99%

Heterocyclic dithiocarbazate iron chelators: Fe coordination chemistry and biological activity

et al. 2012

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The iron coordination and biological chemistry of a series of heterocyclic dithiocarbazate Schiff base ligands is reported with regard to their activity as Fe chelators for the treatment of Fe overload and also cancer. The ligands are analogous to tridentate heterocyclic hydrazone and thiosemicarbazone chelators we have studied previously which bear NNO and NNS donor sets. The dithiocarbazate Schiff base ligands in this work also are NNS chelators and form stable low spin ferric and ferrous complexes and both have been isolated. In addition an unusual hydroxylated ligand derivative has been identified via an Fe-induced oxidation reaction. X-ray crystallographic and spectroscopic characterisation of these complexes has been carried out and also the electrochemical properties have been investigated. All Fe complexes exhibit totally reversible Fe(III/II) couples in mixed aqueous solvents at potentials higher than found in analogous thiosemicarbazone Fe complexes. The ability of the dithiocarbazate Schiff base ligands to mobilise Fe from cells and also to prevent Fe uptake from transferrin was examined and all ligands were effective in chelating intracellular Fe relative to known controls such as the clinically important Fe chelator desferrioxamine. The Schiff base ligands derived from 2-pyridinecarbaldehyde were non-toxic to SK-N-MC neuroepithelioma (cancer) cells but those derived from the ketones 2-acetylpyridine and di-2-pyridyl ketone exhibited significant antiproliferative activity.

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Section: Introductionmentioning

confidence: 99%

Heterocyclic dithiocarbazate iron chelators: Fe coordination chemistry and biological activity

et al. 2012

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“…In recent years, heterocyclic thiosemicarbazones and Schiff bases derived from S-alkyl dithiocarbazates have been considered as useful model compounds for sulphur-containing analogues of purine and pyrimidine bases [11][12][13]. The π-delocalisation of charge and the configurational flexibility of their molecular chain give rise to a great variety of coordination modes [14][15][16][17][18]. Their chemistry and pharmacological applications have been widely investigated as well [1][2][3][4][5][6][15][16][17][18].…”

mentioning

confidence: 99%

“…The π-delocalisation of charge and the configurational flexibility of their molecular chain give rise to a great variety of coordination modes [14][15][16][17][18]. Their chemistry and pharmacological applications have been widely investigated as well [1][2][3][4][5][6][15][16][17][18].Coordination compounds, especially those that contain nitrogen-sulphur ligands are synthesized via relatively simple, cost-effective procedures and it has been observed that small changes in their structure, such as change of substituents and their chelation to different metal ions cause great changes in their bioactivities. The coordination of these compounds often lead to enhanced biological activity in several pathogenic fungi [3,[19][20][21].…”

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confidence: 99%

Synthesis, characterisation and biological activities of S-2- or S-4-methylbenzyl-β-N-(di-2-pyridyl)methylenedithiocarbazate and Cu(II), Ni(II), Zn(II) and Cd(II) complexes

et al. 2017

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Metal complexes of general formula, [M(NNS)2] (M = Cu(II), Ni(II), Zn(II) and Cd(II); NNS'= S-2-methylbenzyl-β-N-(di-2-pyridyl)methylenedithiocarbazate (1), NNS''= S-3-methylbenzyl-β-N-(di-2-pyridyl)methylenedithiocarbazate (2) and NNS'''= S-4-methylbenzyl-β-N-(di-2-pyridyl)methylenedithiocarbazate (3) have been synthesized by reacting the respective metal acetates with the Schiff bases in an ethanol/acetonitrile mixture. negative estrogen receptor) cell lines. Only 9 was active against MCF-7 whereas 10 and 13were active against the MDA-MB-231 cell line. Cytotoxic activity was observed to be enhanced upon complexation particularly for the Ni(II) complexes.Keywords: biological activities, S-R-methylbenzyldithiocarbazate, di-2-pyridylketone, Schiff bases IntroductionDithiocarbazate Schiff bases and their transition metal complexes [1-10] have been of considerable interest to scientists for many years as they show a wide range of therapeutic properties against various diseases, with different anti-bacterial, anti-malarial, anti-viral and anti-tumour properties [1][2][3][4][5][6][7][8][9][10]. In recent years, heterocyclic thiosemicarbazones and Schiff bases derived from S-alkyl dithiocarbazates have been considered as useful model compounds for sulphur-containing analogues of purine and pyrimidine bases [11][12][13]. The π-delocalisation of charge and the configurational flexibility of their molecular chain give rise to a great variety of coordination modes [14][15][16][17][18]. Their chemistry and pharmacological applications have been widely investigated as well [1][2][3][4][5][6][15][16][17][18].Coordination compounds, especially those that contain nitrogen-sulphur ligands are synthesized via relatively simple, cost-effective procedures and it has been observed that small changes in their structure, such as change of substituents and their chelation to different metal ions cause great changes in their bioactivities. The coordination of these compounds often lead to enhanced biological activity in several pathogenic fungi [3,[19][20][21]. Some of these metal complexes have been known to accelerate drug action and the efficacy of a therapeutic agent [1][2][3][4][5][6][19][20][21].The Schiff bases synthesized in this study are the di-2-pyridylketone Schiff bases of isomeric dithiocarbazates, S-2-methylbenzyldithiocarbazate, S-3-methylbenzyl dithiocarbazate and S-4-methylbenzyldithiocarbazate (Fig. 1). Investigations have shown that di-2-pyridylketone thiosemicarbazone and an analogue, 2-benzoylpyridine thiosemicarbazone, demonstrated marked and selective antitumour activity in vitro and also in vivo against many tumours. Di-2-pyridylketone thiosemicarbazone has also been found to possess several structural characteristics important for iron chelating efficacy and potent anti-proliferative activity, and can be further modified as anti-neoplastic agents. Iron has a crucial role in the active site of ribonuclease reductase which is the rate-limiting step of DNA synthesis. This Schiff base and other similar compounds h...

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“…In addition, all the complexes show sharp absorption peaks in the range 846-993 cm −1 , which corresponds to the S-C-S stretching vibration. [76] The electronic absorption spectra of 1-4 obtained in acetonitrile solution (Figure 3) contain many spectral features in the range 240-885 nm, which are identified based on assignments made previously for bis(thiosemicarbazone) iron(III) complexes. [63] Thus, the intense absorption bands in the range 238-345 nm are assigned to intraligand π !…”

Section: Spectral Studies Of the Complexesmentioning

confidence: 66%

“…A medium to strong intensity peak detected in the range 1072–1107 cm −1 is assigned to the υ(N–N) vibration. In addition, all the complexes show sharp absorption peaks in the range 846–993 cm −1 , which corresponds to the S–C–S stretching vibration …”

Section: Resultsmentioning

confidence: 99%

Iron(III) bis‐complexes of Schiff bases of S‐methyldithiocarbazates: Synthesis, structure, spectral and redox properties and cytotoxicity

Sohtun

Khamrang

Kannan

et al. 2020

Applied Organom Chemis

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A series of iron(III) bis‐complexes of the type [FeL2]X 1‐4, X = OH− (1), Cl¯ (3), and FeCl4¯ (2, 4), where LH is a tridentate (N,N,S) ligands such as N′‐(1‐pyridin‐2‐ylethylidene)‐hydrazinecarbodithioic acid methyl ester (HL1), N′‐(phenylpyridin‐2‐ylmethylene)‐hydrazinecarbodithioic acid methyl ester (HL2), N′‐quinolin‐2‐ylmethylene‐hydrazinecarbodithioic acid methyl ester (HL3), or N′‐(1‐methyl‐1H‐imidazol‐2‐yl‐methylene)hydrazinecarbodithioic acid methyl ester (HL4) has been isolated in moderate to good yields and completely characterized by elemental analyses, conductivity studies, and infrared and UV‐visible spectral measurements. The single crystal X‐ray structures of 1, 2 and 4 revealed that two deprotonated tridentate (NNS) ligands are meridionally coordinated to constitute a distorted octahedral coordination geometry around iron(III). In acetonitrile solution, all the complexes show quasi‐reversible Fe(III)/Fe(II) redox behavior. The in vitro cytotoxicity of the ligands HL1–HL4 (IC50: HL1, 64.5; HL2, 51.0; HL3, 124.0; HL4, 45.0 μM at 24 h) and complexes 1–4 (IC50: 1, 84.5; 2, 40.0; 3, 168.5; 4, 50.5 μM at 24 h) towards A549 lung cancer cell lines are similar to cisplatin (69.0 μM), revealing that free ligands cause cancer cell death with potency higher than the corresponding iron(III) complexes. Also, both the ligands and the complexes cause cell death mainly through apoptotic mode, as revealed by the observation of a higher percentage of apoptotic cells in acridine orange (AO)/ ethidium bromide (EB), and Annexin V‐Cy3 stained cancer cells.

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Synthesis and Structural Studies of Mn(II), Co(III), and Ni(II) Complexes with Schiff Base Ligands Derived from 2-Acetylpyridine

Cited by 5 publications

References 25 publications

Heterocyclic dithiocarbazate iron chelators: Fe coordination chemistry and biological activity

Heterocyclic dithiocarbazate iron chelators: Fe coordination chemistry and biological activity

Synthesis, characterisation and biological activities of S-2- or S-4-methylbenzyl-β-N-(di-2-pyridyl)methylenedithiocarbazate and Cu(II), Ni(II), Zn(II) and Cd(II) complexes

Iron(III) bis‐complexes of Schiff bases of S‐methyldithiocarbazates: Synthesis, structure, spectral and redox properties and cytotoxicity

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