[Show abstract][Hide abstract] ABSTRACT: The new complexes tetra-platinum(II)-thiopyridylporphyrin 3 and tetra-platinum(II)-thiopyridylporphyrinato Zn(II) 4 were obtained by coordination of the peripheral thiopyridyl units of the free-base 5,10,15,20-tetrakis[2,3,5,6-tetrafluoro-4-(4-pyridylsulfanyl)phenyl]porphyrin 1 or their corresponding zinc complex 2, respectively, with four chloro(2,2’-bipyridine)platinum(II) [Pt(bpy)Cl]+ units. Both compounds were characterized by several spectroscopic techniques demonstrating a particular behaviour in the emission spectra due to the absence or presence of zinc. The tetra-platinum(II)-thiopyridylporphyrins exhibited an increase of the emission quantum yield when compared with the starting thiopyridylporphyrins 1 and 2. Spectroscopic studies of both platinum derivatives reveal the ability to interact unequivocally with DNA from calf thymus and DNA of low molecular weight from salmon sperm, and also with the most abundant protein in human blood plasma – human serum albumin (HSA). Herein, both tetra-platinum(II)-thiopyridylporphyrins 3 and 4 exhibit electrostatic surface binding with the negative phosphate groups of DNA. Remarkably to cationic-anionic binding with DNA, tetra-platinum(II)-thiopyridylporphyrinato zinc(II) demonstrates a particular binding intercalation mode with DNA. Photophysical studies demonstrated that both porphyrins are photostable and able to generate singlet oxygen (1O2) after light irradiation. Exposure of pMT123 plasmid DNA to tetra-platinum(II)-thiopyridylporphyrins and irradiated with light leads to single-strand break formation as determined by the conversion of the supercoiled form of the plasmid (form I) into the nicked circular form (form II). The tetra-platinum(II)-thiopyridylporphyrinato Zn(II) demonstrates a particular intercalation binding mode with DNA and high ability to cleavage DNA after photo-excitation.
[Show abstract][Hide abstract] ABSTRACT: Three phthalocyanines (Pcs) conjugated with α-, β- and γ-cyclodextrins (CDs) were prepared and their application as photosensitizer (PS) agents was assessed by photophysical, photochemical and in vitro photobiological studies. The photoactivity of and ensures their potential as PDT drugs against UM-UC-3 human bladder cancer cells.
Chemical communications (Cambridge, England). 06/2014;
[Show abstract][Hide abstract] ABSTRACT: The asymmetric unit of the title compound, C(44)H(38)N(8) (2+)·4I(-)·4H(2)O, comprises two halves of non-equivalent cations of 5,10,15,20-tetra-kis-(1-methyl-pyridinium)porphyrin (with the full mol-ecule of each completed by the application of inversion symmetry), four charge balancing iodide anions and four water mol-ecules of crystallization (two water mol-ecules are fully occupied and four mol-ecules have a site occupancy of 50%). The porphyrin cations are arranged into supramolecular columns parallel to the b axis, mediated by π-π [centroid-centroid distance = 3.762 (4) Å] and C-H⋯π supra-molecular inter-actions [C⋯centroid distance = 3.522 (7) Å, C-H⋯centroid = 128°], leading to the formation of columns parallel to the b axis. The close packing leads to the presence of a one-dimensional channel filled with partially occupied water mol-ecules engaged in O-H⋯O and O-H⋯I hydrogen bonds.