Synthesis, structure, electrochemical, DNA interaction and antimicrobial studies of fluorinated trans-dicationic pyridinium porphyrins

Abstract

A series of trans-pyridyl porphyrins, 5,15-di(pentafluorophenyl)-10,20-bis(2ꞌ/3ꞌ/4ꞌ-pyridyl)porphyrin (1−3), trans-dicationic pyridinium porphyrins, 5,15-di(pentafluorophenyl)-10,20-bis(2ꞌ/3ꞌ/4ꞌ-Nmethylpyridyl)porphyrins (4−6) and their copper(II) and zinc(II) derivatives were synthesized. These compounds were characterized using various spectroscopic methods, electrochemical and single crystal X-ray crystallographic studies. The trans-dicationic porphyrin derivatives exhibit red shifted absorption spectra over the simple pyridyl porphyrins. The reduction potentials of trans-pyridyl porphyrins are more positive than those of MTPPs. Crystal structure of 3c is forming networks of molecules through Zn-N coordination displaying large number of channels. The intermolecular interactions involving fluorine contributes considerably to the crystal packing in all the structures which was further confirmed by computational Hirshfeld surface analysis. The dicationic porphyrins were further explored for its DNA interaction abilities and antimicrobial activities. The UV-visible and fluorescence spectroscopic titrations indicate that the porphyrins bind with the calf thymus DNA by outside groove binding mode with or without self-stacking. The intrinsic binding constants K b of these dicationic porphyrins to DNA was found to be in the range of 10 5 −10 6 M −1 . The results reveal that among the three sets of porphyrins (4−6), the 3-/4-pyridyl derivatives display higher DNA binding activities compared to the 2-pyridyl analogues.The photocleavage experiments disclose that the porphyrins employ 1 O 2 -mediated mechanism in cleaving DNA and the freebase and zinc(II) derivatives show better photoinduced cleavage ability compared to its copper(II) analogues. The dicationic porphyrins also show significant antimicrobial activities than those of non-fluorinated analogues.Trans-dicationic pyridinium porphyrins: Synthesis, structure, electrochemical, DNA interaction and antimicrobial studies of fluorinated trans-pyridyl and trans-dicationic pyridinium porphyrins are reported and the studies indicate that they are superior artificial nucleases than its non-fluorinated analogues; bind with the calf thymus DNA by outside groove binding mode with or without self-stacking, also show significant antimicrobial activities than those of nonfluorinated analogues.

Synthesis, molecular structure, photophysical properties and spectroscopic characterization of new 1D-magnesium(II) porphyrin-based coordination polymer

“…Synthesis and functionalization of porphyrins and associating metal complexes have long been of great interest in the chemistry community because of their remarkable applications such as catalysis [1][2][3], solar cells [4], chemical sensors [5], building blocks of assemblies [6] and so forth. Porphyrins were reported to exhibit a variety of biological activities [7][8][9][10][11], notably several derivatives based on this molecule had been developed as excellent photosensitive agents of photodynamic therapy (PDT) in clinical applications [12][13][14]. During the past decade, numerous porphyrinic coordination polymers have been designed by using different methods [15][16][17][18][19], especially based on the axial coordination to the metal of a metalloporphyrin through the nitrogen atoms of a bidentate ligand [20].…”

Synthesis, spectroscopic/electrochemical characterization and DNA interaction study of novel ferrocenyl‐substituted porphyrins

“…To further clarify the DNA binding mode, the intrinsic binding constants ( K b ) of compounds 2 , 2a and 2b were calculated as described in Section 1 and the results are summarized in Table . The K b values are comparable to those of other non‐charged or charged porphyrins, indicating that ferrocenyl derivatives 2a and 2b can interact strongly with ct‐DNA, following the increasing binding constant order: 2 < 2a < 2b . The hypochromic effect for porphyrin 2a was three times higher than the corresponding C 6 F 5 precursor 2 .…”

A3B Porphyrins Bearing Thienyl/Pyridyl Moieties Obtained via Scrambling: Characterization, DNA interaction and Anticancer Studies

“…The mono cationic porphyrins showed a bathochromic shift of Soret band of 6–13 nm along with peak broadening and hypochromicity. Among the compounds, the Zn(II) derivatives ( S3c & S4c ) show a larger red shift of 13 nm when compared to our previously reported dicationic porphyrins (Table ). This may be due to the outside stacking between DNA and porphyrins.…”

“…For instance, reports reveal that the presence of strong electron‐withdrawing substituents on the phenyl ring of the dipyrromethane enhances scrambling . In continuous with our previous report on DNA interaction properties of trans ‐pyridyl porphyrins bearing fluoro substituents, we were interested to check the biological properties of trans ‐porphyrins bearing 2/3/4‐pyridyl as well as thienyl substituents. In this line, during the synthesis of trans ‐porphyrin with 3‐pyridyl substituents, we have isolated the scrambled product namely, 5‐(3′‐pyridyl)‐10,15,20‐tri(2/3‐thienyl)porphyrins ( S1a and S2a ) with reasonable yield (Figure ).…”