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Romrawee Pratumwieng Atittaya Meenongwa Rosa F. Brissos Patrick Gamez Yanee Trongpanich Unchulee Chaveerach 《Transition Metal Chemistry》2017,42(4):311-322
Cu(II) complexes of the tridentate ligand N-(methylpyridin-2-yl)-amidino-O-methylurea (L), namely [Cu(L)Cl2] and [Cu(L)ClO4]ClO4, have been investigated for interactions with DNA by spectroscopic methods and viscosity measurements. Both complexes bind to DNA through non-intercalative interactions. [Cu(L)Cl2] (K b = 2.81 × 105 M?1) shows similar DNA-binding potential to [Cu(L)ClO4]ClO4 (K b = 1.57 × 105 M?1). Investigation of the chemical nuclease properties toward plasmid pBR322 DNA by gel electrophoresis and atomic force microscopy (AFM) suggests that both complexes are able to cleave the supercoiled form (Form I) to the nicked (Form II) and linear forms (Form III) through an oxidative pathway. The possible reactive oxygen species have been investigated by the use of scavengers, indicating that hydroxyl radicals may be involved in the DNA cleavage mechanism. Both of these complexes show similar activities against selected human cancer cell lines. 相似文献
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Unchulee Chaveerach Atittaya Meenongwa Yanee Trongpanich Chaiyaporn Soikum Prapansak Chaveerach 《Polyhedron》2010
The two designed copper(II) complexes, [Cu(L1m)2]Cl2 (1) (L1m = amidino-O-methylurea) and [Cu(L2m)2]Cl2 (2) (L2m = N-methylphenyl-amidino-O-methylurea), have been investigated for their interaction with calf thymus DNA by utilizing the absorption titration method, viscometric studies and thermal denaturation. The cleavage reaction on pBR322 DNA has been monitored by agarose gel electrophoresis. The results suggest that the two complexes can bind to DNA by non-intercalative modes and exhibit nuclease activities in which supercoiled plasmid DNA is converted to the linear form. Complex 2, with an intrinsic binding constant (Kb) of 1.16 × 105 M−1, shows a higher binding efficiency and a better nuclease activity than complex 1, with a Kb value of 5.67 × 104 M−1. Their DNA cleavage potential can be significantly enhanced by hydrogen peroxide, indicating an oxidative cleavage process. Further examination of the antibacterial activities against Campylobacter has revealed inhibition zones of 9.0 (for 1) and 14.5 mm (for 2), which are in agreement with their minimum inhibitory concentration (MIC) values of 1.56 and 0.78 mg mL−1, respectively. The substantially better reactivity of 2 results from the aromatic moieties on the side chain of the L2m ligand which act as an additional binding site. 相似文献
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Atittaya Meenongwa Unchulee Chaveerach Alexander J. Blake 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(6):m143-m146
The title complex, [Cu(ClO4)2(C9H13N5O)(CH3OH)], was synthesized from a methanolysis reaction of N‐(methylpyridin‐2‐yl)cyanoguanidine (L3) and copper(II) perchlorate hexahydrate in a 1:1 molar ratio. The CuII ion is six‐coordinated by an N3O3 donor set which confers a highly distorted and asymmetric octahedral geometry. Three N‐donor atoms from the chelating 1‐(methoxymethanimidoyl)‐2‐(pyridin‐2‐ylmethyl)guanidine (L3m) ligand and one O atom from the methanol molecule define the equatorial plane, with two perchlorate O atoms in the apical sites, one of which has a long Cu—O bond of 2.9074 (19) Å. The dihedral angle between the five‐ and six‐membered chelate rings is 8.21 (8)°. Two molecules are associated into a dimeric unit by intermolecular N—H...O(perchlorate) hydrogen bonds. Additionally, the weakly coordinated perchlorate anions also link adjacent [Cu(ClO4)2(L3m)(CH3OH)] dimers by hydrogen‐bonding interactions, resulting in a two‐dimensional layer in the (100) plane. Further C—H...O hydrogen bonds link the two‐dimensional layers along [100] to generate a three‐dimensional network. 相似文献
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