Investigation On Syntheses And Biological Activities Of Porphyrins Bearing Nitrogen Heterocyclic Substituents

In order to synthesize new more effective anticancer drugs, three series of porphyrin compounds bearing nitrogen heterocyclic substituents were designed and synthesized. The anticancer activities of some nitrogen heterocyclic porphyrins were investigated in vitro using the 3-(4,5-dimethylthiazo-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. We also investigated the interaction of nitrogen heterocyclic porphyrins with Bovine Serum Albumin (BSA) and DNA by fluorescence spectra and UV/Vis spectra. The main contents of this thesis include following:1. Porphyrin synthesisEight porphyrin compounds, OTeso-5,10,15,20-Tetra[4-aminophenyl]porphine (TAPPH2, 1), meo-5,10,15,20-Tetra[4-(N-pyrrolidinyl)phenyl]porphine (TBPPH2, 2), meso-5,10,15,20-Tetra[4-(4 '-ethylpiperazinyl)pheny l]porphine (TEPPH2, 3), meso-5, 0,15,20-Tetra[4-(4'-butylpiperazinyl)phenyl]porphine (TUPPH2, 4), meso-5,10,15,20-Tetra[4-(4'-heptylpiperazinyl)phenyl]porphine (THPPH2, 5), 5-[4-(4'-ethylpiperazinyl)phenyl]-10,15,20-triphenylporphine (MEPPH2 , 6), 5-[4-(4'-buthylpiperazinyl)phenyl]-10,15,20-triphenylporphine (MUPPH2 , 7) and N,N'-di(/wo-5,10,15,20-tetraphenylporphinato)piperazine (DiPPH2, 8) have been designed and synthesized. These porphyrins are never reported except TAPPH2. Six nitrogen heterocyclic substituted benzenes and six corresponding substituted benzaldehydes have been synthesized too, among which N,N'-di(4-formylphenyl)piperazine is a new compound. The structures of these porphyrin compounds and intermediates have been characterized by 'H NMR, MS, IR, UV/Vis and elemental analysis. The main contents of this section include following: 1) The synthetic strategy of porphyrinAn improved Adler method was used for preparing TAPPH2. TAPPH2 wassynthesized in high yield by direct condensation of pyrrole with 4-aminobenzaldehyde in refluxing propanoic acid with the presence of vitamin C. This new synthetic strategy for preparing TAPPH2 can greatly extend synthetic methods for porphyrins containing amino groups. The symmetric and asymmetric nitrogen heterocyclic porphyrin monomers were synthesized by Adler's method. The piperazine-bridged porphyrin dimer was obtained according to Lindsey's method. 2) The synthetic strategy of intermediatesN-phenylpyrrolidine, N,N'~diphenylpiperazine and N-alkyl-N'-phenylpiperazine were synthesized by nucleophilic substitution or condensation reaction. Treatment of these nitrogen heterocyclic substituted benzene with Vilsmeier reagents afforded the corresponding substituted benzaldehyde.2. Preliminary anticancer activities investigationIn order to study the biological activities of these synthetic porphyrins, TAPPH2, TEPPH2 ^ DiPPH2 and N-ethyl-N'-phenylpiperazine were selected and their anticancer activity to be tested in vitro against three human tumor cell lines, Bel-7404, a liver cancer cells, MCG, a stomach cancer cells, and HNE1, a nasopharyngeal darcinoma cancer cells using the MTT assay. The results of these pre-screenings indicated that TEPPH2 or DiPPH2 exhibit more satisfactory activity than that of TAPPH2 or N-ethyl-N'-phenylpiperazine and TEPPH2 exhibited more excellent activities comparing to cis-Platinum (cis-Pt) or 5-Fluorouracil (5-Fu).3. The interaction of nitrogen heterocyclic porphyrins with biomoleculesTo explore the origination of the biological activities of these nitrogen heterocyclic porphyrins, we investigated the interaction of nitrogen heterocyclic porphyrins with Bovine Serum Albumin (BSA) and calf thymus DNA by fluorescence spectra and UV/Vis spectra. This can provide some valuable messages for further studying the anticancer mechanism of nitrogen heterocyclic porphyrins. 1) The interactions of nitrogen heterocyclic porphyrins with BSAExperimental results show that these porphyrins can enter into the hydrophobiccavity of BSA by the "hydrophobic fOrce" to form a stable complex, which mightchange the protein's secondary structure. It is also shown that, with the sterichindrance of substituents increasing, the binding constant of BSA...