Studies On The Synthesis, Characterization, Theoretical Calculation And DNA-bind Activities Of The Complexes Deirved From Marine Micromolecule

The diversity and specificity of the marine organisms produce and accumulate a large number of substance which have special chemical structure and biological activity, those substance are lead compounds for synthetic new drugs. In this paper, the small molecules(3,5-dibromotrysine and3-indole formaldehyde) from marine organism are regarded as the forequarters material, three new series complexes are synthetized and two single crystals are cultivated. The complexes are characterized using a combination of elemental analysis, IR spectrometry and UV-Vis spectrometry. The single crystals are measured by X-ray single crystal diffraction. Based on crystal data, density functional theory (DFT) studies of the complexes are performed using the Gaussian03program suite. The Mullikene charges distribution, molecular total energy, the frontier molecular orbital energies, bond lengths and bond angles of the complexes are discussed. Moreover, The mode of interaction between [Cu2(C9H8Br2NO3)4]n·2nCH3OH·2nH2O,[Ni(phen)(C9H8Br2NO3)2]·2CH3OH·2H2O and CT-DNAis studied. The details of contents are as follow:(1) The metal binary complexes derived from3,5-dibromotrysine are synthesized. One single crystal is obtained. The crystal data show that the complex is a polymer compound which belongs to the Monoclinic crystal system, space group P21with cell parameters a=9.0057(8), b=24.598(2), c=13.0721(11) A,β=107.9410(10), V=2754.9(4) A3, Z=4,F(000)=1532, S=1.086,ρ=1.904g/cm3,μ=6.637mm-1, the final R1=0.0651and wR2=0.1449for7329observed reflections (Ⅰ>2σ(Ⅰ)). Two individual Cu(Ⅱ) coordination center together with two water molecules and two methanol molecules are located in an asymmetric unit. The Flack parameter is-0.005(18). Both of the two Cu(Ⅱ) ions adopt the six-coordination geometry. They are coordinated with two nitrogen and two oxygen atoms from3,5-dibromo-L-tyrosine in the basal plane in a cis-configuration, and two carboxyl oxygen atoms from the adjacent3,5-dibromo-L-tyrosine in the crystal lattice via relatively long axial Cu-O (carbonyl) bonds. All of the carboxylate groups adopt monodentate coordination modes, which bridge between two Cu(Ⅱ) ions to form an eight-membered ring (Cu-O-C-O-Cu-O-C-O). In addition, the benzene rings of the four ligands in the asymmetric unit have a different conformation. The possible chemical structure of other complexes are confirmed to be [M2(C9H8Br2NO3)4]·2CH3OH·2H2O (M=Ni(Ⅱ), Zn(Ⅱ), Cd(Ⅱ), Mn(Ⅱ), Pb(Ⅱ), Co(Ⅱ).(2) The metal ternary complexes derived from3,5-dibromotrysine are synthesized. One single crystal is obtained. The crystal crystallizes in the Orthorhombic system, space group P21212with a=12.9546A,b=14.9822A,c=9.9705A,V=1935.2A,Z=1, F(000)=1008,S=0.969, ρcalcd=1.742g·cm-3,μ=4.688mm-1,R1=0.0529and wR2=0.0738for3424observed reflections (I>2σ(I))). And the complex is coordinated by six atom, namely, two nitrogen atoms and two carboxylic oxygen atoms from3,5-dibromo-L-tyrosine, and two nitrogen atoms from1,10-phenanthroline, forming a neutral4N+2O complex. The possible chemical structure of other complexes are confirmed to be [M(phen)(C9H8Br2NO3)2]·2CH3OH·2H2O (M=Co(Ⅱ), Pb(Ⅱ), Cd(Ⅱ).(3) The metal complexes derived from Indole-3-carboxaldehyde are synthesized. The possible chemical structure of other complexes are confirmed to be [M(C16H12N2O3)2(H2O]·2H2O(M=Ni(Ⅱ), Cu(Ⅱ))、[M(C18H15N3O3)2(H2O)2]2H2O(M=Ni(Ⅱ), Cu(Ⅱ)、[Sm(Ci8Hi5N3O3)·2(NO3)H2O]·2H2O.(4) we obtained molecular total energy and frontier molecular orbital energies of the complex by (DFT) B3LYP/6-31+G*method. The total energy of the Cu complex is-3010.582a.u. The energies of HOMO, HOMO-1and HOMO-2are-0.21339,-0.25014,-0.25267a.u, respectively, the energies of LUMO, LUMO+1and LUMO+2are-0.19102,-0.05920,-0.05452a.u, respectively. Part of the negative charges has transferred from the3,5-dibromotrysine ligands to the metal ions, and frontier molecular orbital evenly distributes on the3,5-dibromotrysine ligands. The total energy of the Ni complex is-2050.86a.u. The energies of HOMO, HOMO-1and HOMO-2are-0.1941,-0.2281,-0.2351a.u, respectively, the energies of LUMO, LUMO+1and LUMO+2are-0.1090,-0.1040,-0.0700a.u, respectively. The frontier molecular orbital evenly distributes on the1,10-phenanthroline ligand. In addition, we have discussed the relationship between the energies of the frontier molecular orbital of the complex and the energies of the frontier molecular orbital of DNA base-pairs, and find that the complex may prone to interacts with DNA in an electrostatic binging mode.(5) The interaction between calf thymus DNA and the complex was investigated by electrochemical methods and UV absorption spectra. The result shows that the complex most likely interacts with DNA in an electrostatic binding mode. There may be other binding modes, such as hydrogen bonds.