Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
Articles by Zong-Wan Mao
Total Records ( 3 ) for Zong-Wan Mao
  Jing Sun , Shu-Yi Deng , Li Zhang , Juan He , Long Jiang , Zong-Wan Mao and Liang-Nian Ji
  Two copper(II) complexes with naphthalene ring [Cu(L1)(H2O)](ClO4)2 · H2O (1) or [Cu2(L2)(ClO4)(H2O)3](ClO4)3 · H2O (2) (L1 = 1-[bis(pyridine-2-ylmethyl)aminomethyl]naphthalene and L2 = 1,4-di[bis(pyridine-2-ylmethyl)aminomethyl]naphthalene) were synthesized. Structural characterization of complex 2 by X-ray crystallography showed that the cations form a double-forficiform structure and each Cu(II) ion is bound by an in-plane N3Ow-coordination. Thermal melting curves and fluorescence spectroscopes of complex-DNA binding indicate that both complexes can efficiently interact with calf thymus DNA and that the binding ability of complex 2 is greater than that of complex 1. Viscosity measurements suggest that complex 2 partially intercalates between DNA base pairs via the naphthalene ring, whereas complex 1 most likely interacts with DNA through the electrostatic binding. In the presence of H2O2 and ascorbic acid, dinuclear complex 2 was more efficient than mononuclear complex 1 in cleaving double-stranded circular DNA into linear DNA. The interaction modes between the complexes and DNA were also discussed.
  Jin-Tao Wang , Xiao-Hui Zheng , Liang-Nian Ji and Zong-Wan Mao
  A new copper(II) complex bearing 2,2'-bipyridine (bpy) derivatives with cytosine nucleobases [Cu(L)Cl2] · 2H2O has been synthesized and characterized, where L = 5,5'-di[(4-amino-2-oxo-1(2H)-pyrimidinyl)methyl]-2,2'-bipyridine. Circular dichroism spectra reveal interactions between ligand and pBR322 DNA and showed that the local DNA structure was perturbed by the ligand. Cleavage of pBR322 DNA by the title complex was carried out in 20 mmol L-1 HEPES (pH 7.5) at 37°C. The calculated pseudo-Michaelis-Menten kinetic parameter (kcat) of the complex was 8.80 h-1. The cleavage efficiency was 17-fold higher than that of its simple analog [Cu(bpy)Cl2] (kcat = 0.50 h-1). Hydrolytic mechanisms involved in DNA cleavage were explored using radical scavengers and T4 ligase. Competitive experiments with special binding agents showed that the complex could preferentially bind to the minor groove of double-stranded DNA, suggesting specific DNA binding characteristics. High DNA cleavage reactivity and selectivity of the complex could be attributed to the synergic effects of the metal center and the cytosine pendants.
  Si-Ping Tang , Lei Hou , Zong-Wan Mao and Liang-Nian Ji
  Two new copper(II) complexes with aminothioether ligands, [Cu(L1)(ClO4)](ClO4)·0.5H2O (1) and [Cu(L2)(H2O)](ClO4)2·H2O (2) (L1=2-benzyl-1,3-bis(aminoethylthio)propane and L2=2-(4-butylbenzyl)-1,3-bis(aminoethylthio)propane), have been synthesized and characterized. The single crystal X-ray diffraction analysis reveals that both 1 and 2 adopt distorted square pyramidal geometries. The binding modes of both complexes with calf thymus DNA were investigated by UV–Vis and CD spectroscopies. The results show that both complexes mainly adopt an electrostatic attraction binding mode with DNA and the binding constants are (1.62±0.02)×103 and (2.02±0.02)×103M−1, respectively. Both complexes are able to cleave pBR322 plasmid DNA efficiently in the presence of ascorbic acid and the activity of 2 is higher than that of 1. The DNA cleavage by 1 and 2 were inhibited strongly in the presence of DMSO and tert-butyl alcohol, which suggests that hydroxyl radicals are the reactive oxygen species for the cleavage.
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility