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Kita, Ewa; Łączna, Monika

doi:10.1023/a:1011097613148

Cited by 16 publications

(21 citation statements)

References 5 publications

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“…The weak pyridine ring deformation at 1570 cm -1 is insensitive to coordination and remains unaltered. This type of coordination is also reported for other transition metal complexes [55][56][57]. The appearance of bands at 460-490 cm -1 and 280-320 are assigned to v(M-N) and v(M-Cl) respectively further confirming coordination through nitrogen atom [57].…”

Section: A Ir Spectroscopysupporting

confidence: 80%

Synthesis, Characterization and Interaction of Drug Based Cobalt (II) Complex with Herring Sperm DNA and Biological Activity

Tak¹

2017

IJRASET

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Novel complexes of copper (II), cobalt (II) and nickel (II) with sulphapyridine and aminothiazole were synthesized and characterized using spectral and analytical techniques. The interaction of cobalt (II) complexes with herring sperm DNA has been performed using absorption titration, viscometric measurements and cyclic voltammetry. The protective activity of metal complexes has been carried out using arose gel electrophoresis. The results indicate that cobalt (II) complex bind to DNA via electrostatic or groove binding with binding constant K b = 4.5 x 10 4 M -1. The antioxidant activity for cobalt (II) complex was also checked. Keywords: hypochromism, peak potential and binding constant. I. INTRODUCTIONThe binding of metal complexes to DNA has been extensively studied over the past decade. Many coordination compounds are able to bind DNA as structural probes[1], DNA foot printing [2], DNA cleaving agents [3][4] and as potential anticancer drugs [5][6]. It is generally believed that many anticancer, antiviral, and antiseptic agents take action through binding DNA [4,[7][8], since the interaction between small molecules and DNA can often cause DNA damage in cancer cells, blocking the division of cancer cells and resulting in cell death [9][10][11]. Many studies indicate that transition metal complexes can bind to DNA via both covalent (replacement of labile coordinating ligand by nitrogen base of DNA (i.e. adenine, Cytosine, guanine, thymine) and or non covalent interaction (intercalation, electrostatic or groove binding) [12]. Many important applications of these complexes require that they can bind via intercalative mode or groove binding [13]. Therefore interaction of complexes especially with planar aromatic heterocyclic ligands, which can insert into the base pairs of DNA duplex has attracted considerable attention [14][15][16]. is an essential element widely distributed in biological system [6,[17][18]. Numerous cobalt complexes has been studied as hydrolytic agent for DNA cleavage [19-20], antitumor, antproli-ferative[21-23], antimicrobial[24-26] and antifungal [21,27], antiviral [28,29], antioxidant [12 ,30] and ant inflammatory activity [30]. They have exhibited antitumorogenic activity by reducing the number and size of carcinogen induced colon tumors and play synergistic role on the activity of certain antitumor drugs, although the mechanism has not been completely clarified [31][32][33]. Ligands having nitrogen donors received considerable attention because of their mixed hard-soft donor character, versatile coordination behavior [34][35] and for their biological activity (i.e., toxicity against bacterial growth [36], anticancer [37] and other biochemical properties [38]). The coordination geometry and nature of donor atoms play key roles in determining the binding extent of complexes to DNA. The importance of central metal ion at the core of the structure is noteworthy [39,40]. Many DNA heterocyclic compounds such as benzothiazole and benzopyra zine derivatives have been evaluated and f...

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Section: A Ir Spectroscopysupporting

confidence: 80%

Synthesis, Characterization and Interaction of Drug Based Cobalt (II) Complex with Herring Sperm DNA and Biological Activity

Tak¹

2017

IJRASET

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“…These results can be compared with those obtained for other chromium(III)-pyridinecarboxylic acid complexes aquation [2][3][4]6]. Kinetic parameters determined for the Cr-N and Cr-O bond breaking reaction paths are shown in Table 6.…”

Section: )(H 2 O)] ) [10] and [Cr(oo-cch 3 )(H 2 O) 5 ] 2+ Complexes mentioning

confidence: 97%

“…Chromium picolinate and chromium nicotinate are the most popular chromium complexes applied in drugs production. In our recent studies [2][3][4], the kinetics and mechanism of acid-catalyzed aquation of chromium-picolinate and chromium 2-hydroxynicotinate complexes was established. The conclusion was that an aquation mechanism depends on the coordination mode of the ligand: (i) in the case of the N,O-bonded pyridine ligands, the reversible chelate-ring opening at the Cr-N bond precedes the rate determined step -the Cr-O (carboxylate) bond breaking; (ii) in the case of the O,O¢-bonded pyridine ligands, a very fast chelate-ring opening at the Cr-O (carboxylate) bond is followed by the rate determining step -the Cr-O (phenolate) bond fission; (iii) the intermediate with a one-end O-bonded picolinate ligand is a relatively stable species.…”

Section: Introductionmentioning

confidence: 99%

New chromium(III)–nicotinate complexes. Kinetics and mechanism of nicotinate ligand liberation in acidic media

Szabłowicz

Kita

2005

Transition Met Chem

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Two new chromium(III)-nicotinate complexes, cis-[Cr(C 2 O 4 ) 2 (O-nic)(H 2 O)] ) and cis-[Cr(C 2 O 4 ) 2 (N-nic)(H 2 O)] ) , were obtained and characterized in solution (where O-nic ¼ O-bonded and N-nic ¼ N-bonded nicotinic acid). The kinetics of nicotinate ligand liberation were studied spectrophotometrically in the 0.1-1.0 M HClO 4 range, at I ¼ 1.0 M. The rate equations were determined and a mechanism is proposed. The rate of Cr-O bond breaking is [H + ] dependent: k obs ¼ k H Q H [H + ], where k H is the acid-catalyzed rate constant and Q H is the protonation constant of the nonbonded oxygen atom in the O-coordinated ligand. The Cr-N bond breaking proceeds via two paths: spontaneous and acid-catalyzed; k obs ¼ k 0 + k H Q H [H + ], where k 0 and k H are the spontaneous and acid catalyzed rate constants and Q H is the protonation constant of the carboxylic group in the N-bonded nicotinic acid. The results demonstrate by comparison that Cr-N bond breaking is a much slower process than Cr-O bond fission.

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“…The rate law, for each aquation-stage, derived from Scheme 3 is analogous to those expressed by Equations (2)(3)(4), in which k 0 =0. Thus the meaning of the b parameter in Equation (5) is as follows: Table 3.…”

Section: Resultsmentioning

confidence: 99%

“…However, because they provide less than 5% of absorbable chromium(III) it is necessary to obtain other chromium-pyridinecarboxylates, which could serve as a better bio-available chromium(III) source. Recently, several new complexes with picolinic [2], 3-hydroxypicolinic [3], 2-hydroxynicotinic [3] and nicotinic acids [4] were obtained and characterized in solution. The results indicate that liberation of picolinate-like and salicylate-like bonded ligands is described by different mechanisms.…”

Section: Introductionmentioning

confidence: 99%

Chromium(III)-isonicotinate Complexes. Kinetics and Mechanism of Isonicotinate Ligand Liberation in HClO4 Solutions

Szabłowicz

Kita

2006

Transition Met Chem

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Chromium(III)-isonicotinate complexes, cis-½CrðC 2 O 4 Þ 2 (N-inic)ðH 2 OÞ À and ½CrðC 2 O 4 ÞðH 2 OÞ 3 -OH-CrðC 2 O 4 Þ 2 (O-inic) À (N-inic = N-bonded and O-inic = O-bonded isonicotinic acid) were obtained and characterized in solution. Kinetics of acid-catalyzed isonicotinate ligand liberation were studied spectrophotometrically in the 0.1-1.0 M HClO 4 range, at I=1.0 M. The dependencies of the pseudo-first order rate constant on [H + ] were established: k obs ¼ k 0 þ k H Q H ½H þ and k obs ¼ k H Q H ½H þ for the N-inic and O-inic complex, respectively, where k 0 and k H are the rate constants of the spontaneous and the acid-catalyzed reaction paths, and Q H is the protonation constant of the carboxylic group in isonicotinic ligand. The obtained results indicate that N-bonded isonicotinic acid liberation occurs mainly via a spontaneous reaction path and is much slower than O-bonded inic liberation. The mechanisms for these processes are proposed.

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Untitled

Cited by 16 publications

References 5 publications

Synthesis, Characterization and Interaction of Drug Based Cobalt (II) Complex with Herring Sperm DNA and Biological Activity

Synthesis, Characterization and Interaction of Drug Based Cobalt (II) Complex with Herring Sperm DNA and Biological Activity

New chromium(III)–nicotinate complexes. Kinetics and mechanism of nicotinate ligand liberation in acidic media

Chromium(III)-isonicotinate Complexes. Kinetics and Mechanism of Isonicotinate Ligand Liberation in HClO4 Solutions

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