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Synthesis, structure and interactions with DNA of novel tetranuclear, [Mn-4(II/II/II/IV)] mixed valence complexes

Dimitrakopoulou, Anastasia; Dendrinou-Samara, Catherine; Pantazaki, Anastasia A; Alexiou, Maria; Nordlander, Ebbe LU and Kessissglou, Dimitris P (2008) In Journal of Inorganic Biochemistry 102(4). p.618-628
Abstract
Reaction of Mn(II) with phenoxyalkanoic acids and di-2-pyridyl ketone oxime (Hpko) leads to neutral tetranuclear complexes of the general formula Mn-4(O)(pko)(4)(phenoxyalkanoato)(4) (phenoxyalkanoic acids: H-mcpa = 2-methyl-4-chloro-phenoxy-acetic acid, H-2,4,5-T = 2,4.5-trichloro-phenoxy-acetic acid or H3,4-D = 3,4-dichloro-phenoxy-acetic acid). The compounds were synthesized by adding di2-pyridyl ketone oxime to MnCl2 in the presence of the sodium salts of the alkanoic acids in methanol. The crystal structure of Mn-4(II/II/ II/IV)(O)(pko)4(()2,4,5-T)(4) . 2.5CH(3)OH . 0.25H(2)O 1 shows that the complex consists of a [Mn-4( mu(4)-O)](8+) core with a Mn(IV) and 3 Mn(II) ions in octahedral environment and a mu(4)-O atom bridging the four... (More)
Reaction of Mn(II) with phenoxyalkanoic acids and di-2-pyridyl ketone oxime (Hpko) leads to neutral tetranuclear complexes of the general formula Mn-4(O)(pko)(4)(phenoxyalkanoato)(4) (phenoxyalkanoic acids: H-mcpa = 2-methyl-4-chloro-phenoxy-acetic acid, H-2,4,5-T = 2,4.5-trichloro-phenoxy-acetic acid or H3,4-D = 3,4-dichloro-phenoxy-acetic acid). The compounds were synthesized by adding di2-pyridyl ketone oxime to MnCl2 in the presence of the sodium salts of the alkanoic acids in methanol. The crystal structure of Mn-4(II/II/ II/IV)(O)(pko)4(()2,4,5-T)(4) . 2.5CH(3)OH . 0.25H(2)O 1 shows that the complex consists of a [Mn-4( mu(4)-O)](8+) core with a Mn(IV) and 3 Mn(II) ions in octahedral environment and a mu(4)-O atom bridging the four manganese ions. Spectroscopic studies of the interaction of these tetranuclear clusters with DNA showed that these compounds bind to dsDNA. The binding strength of the Mn-4(II/II/II/ IV)(O)(pko)(4)(2,4,5-T)(4) complex for calf thymus DNA is equal to 1.1 X 10(4) M-1. Among the deoxyribonucleotides they bind preferentially to deoxyguanylic acid (dGMP). Competitive studies with ethidium bromide (EthBr) showed that the Mn-4(II/II/II/ IV)(O)(pko)(4)(2,4,.5-T)(4) complex exhibited the ability to displace the DNA-bound EthBr indicating that the complex binds to DNA via intercalation in strong competition with EthBr for the intercalative binding site. Additionally, DNA electrophoretic mobility experiments showed that all three complexes, at low cluster concentration, are obviously capable of binding to pDNA causing its cleavage (relaxation) at physiological pH and temperature. At higher cluster concentration, catenated dimer forms of pDNA was formed. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
phenoxyalkanoic acids, manganese complexes, mixed valence, DNA, interaction
in
Journal of Inorganic Biochemistry
volume
102
issue
4
pages
618 - 628
publisher
Elsevier
external identifiers
  • wos:000255131500003
  • scopus:40649125555
ISSN
1873-3344
DOI
10.1016/j.jinorgbio.2007.10.005
language
English
LU publication?
yes
id
6ec9595f-bcf7-4065-9bd5-199a3f0d9edf (old id 1206359)
date added to LUP
2008-09-19 12:46:44
date last changed
2017-09-17 06:03:18
@article{6ec9595f-bcf7-4065-9bd5-199a3f0d9edf,
  abstract     = {Reaction of Mn(II) with phenoxyalkanoic acids and di-2-pyridyl ketone oxime (Hpko) leads to neutral tetranuclear complexes of the general formula Mn-4(O)(pko)(4)(phenoxyalkanoato)(4) (phenoxyalkanoic acids: H-mcpa = 2-methyl-4-chloro-phenoxy-acetic acid, H-2,4,5-T = 2,4.5-trichloro-phenoxy-acetic acid or H3,4-D = 3,4-dichloro-phenoxy-acetic acid). The compounds were synthesized by adding di2-pyridyl ketone oxime to MnCl2 in the presence of the sodium salts of the alkanoic acids in methanol. The crystal structure of Mn-4(II/II/ II/IV)(O)(pko)4(()2,4,5-T)(4) . 2.5CH(3)OH . 0.25H(2)O 1 shows that the complex consists of a [Mn-4( mu(4)-O)](8+) core with a Mn(IV) and 3 Mn(II) ions in octahedral environment and a mu(4)-O atom bridging the four manganese ions. Spectroscopic studies of the interaction of these tetranuclear clusters with DNA showed that these compounds bind to dsDNA. The binding strength of the Mn-4(II/II/II/ IV)(O)(pko)(4)(2,4,5-T)(4) complex for calf thymus DNA is equal to 1.1 X 10(4) M-1. Among the deoxyribonucleotides they bind preferentially to deoxyguanylic acid (dGMP). Competitive studies with ethidium bromide (EthBr) showed that the Mn-4(II/II/II/ IV)(O)(pko)(4)(2,4,.5-T)(4) complex exhibited the ability to displace the DNA-bound EthBr indicating that the complex binds to DNA via intercalation in strong competition with EthBr for the intercalative binding site. Additionally, DNA electrophoretic mobility experiments showed that all three complexes, at low cluster concentration, are obviously capable of binding to pDNA causing its cleavage (relaxation) at physiological pH and temperature. At higher cluster concentration, catenated dimer forms of pDNA was formed.},
  author       = {Dimitrakopoulou, Anastasia and Dendrinou-Samara, Catherine and Pantazaki, Anastasia A and Alexiou, Maria and Nordlander, Ebbe and Kessissglou, Dimitris P},
  issn         = {1873-3344},
  keyword      = {phenoxyalkanoic acids,manganese complexes,mixed valence,DNA,interaction},
  language     = {eng},
  number       = {4},
  pages        = {618--628},
  publisher    = {Elsevier},
  series       = {Journal of Inorganic Biochemistry},
  title        = {Synthesis, structure and interactions with DNA of novel tetranuclear, [Mn-4(II/II/II/IV)] mixed valence complexes},
  url          = {http://dx.doi.org/10.1016/j.jinorgbio.2007.10.005},
  volume       = {102},
  year         = {2008},
}