| Widespread interest in the synthesis of porphyrazine derivatives has taken a central role in bioorganic chemistry, due to their applications in many areas such as liquid crystals1, chemical sensors 2, and nonlinear optics.3 The emerging field of photodynamic cancer therapy has prompted an interest in porphyrazine derivatives as potential target molecules for treating cancer and HIV.4 Tetracationic porphyrazines (Pcs), both metallated and unmetallated have also attracted much attention as photosentsitizers for photodynamic cancer therapy. 5-9; The synthesis of phthalocyanines from phthalonitrile containing metal centers and non-metal centers with organic bases is well known.10-13 We have recently reported the synthesis and characterization of a porphyrazine and a series of tetracationic porphyrazines, unmetallated and metallated.14 These porphyrazines are tetrapyridino porphyrazine.; The unmetallated porphyrazines is tetraethanoltetrapyridino porphyrazinium iodide and the metallated porphyrazines are, (Mn, Zn, Cu, Co) = M, M-tetraethanoltetrapyridino porphyrazinium iodide. The porphyrazine and the tetracationic porphyrazines, unmetallated and metallated, were characterized by elemental analysis, ESI-MS, 1H-NMR, MALDI-MS, FTIR and UV-VIS. The interaction of porphyrazines, tetraethanolpyridino porphyrazines (H2TEPPI), and its MnTEPPI, CoTEPPI, CoTEPPI, and ZnTEPPI derivatives with several nucleic acids have been investigated. In order to understand if porphyrazines bind to DNA oligonucleotides, a series of binding studies were conducted using competitive dialysis, scanning probe microscopy and uv/vis titrations. Also, our interest has focused on the screening of porphyrazines as potential inhibitors of reverse transcriptase of the HIV virus. Our findings indicate that porphyrazines have low binding affinities for single, followed by even lower affinities for double stranded DNA and much greater binding affinities for quadruplex forming oligomers such as T4G4, G4T4G4, T 4G4T, G2T2G2TGTG2T 2G2. Our findings also indicate that (H2TEPPI), (CuTEPPI), (ZnTEPPI), and (TEPPCl) inhibit the reverse transcriptase enzyme in the HIV virus. |
