13554-17-1Relevant academic research and scientific papers
A New Method for Regiospecific Deuteration and Reduction of 5,10,15,20-Tetraphenylporphyrins: Nucleophilic Reaction of Borohydride Ion with 2-Nitro-5,10,15,20-tetraphenylporphyrins
Crossley, Maxwell J.,King, Lionel G.
, p. 4370 - 4375 (1993)
New methods for specific reduction and deuteration of 5,10,15,20-tetraarylporphyrins are reported.Free-base and metalated 2-nitroporphyrins are converted into the corresponding nitrochlorins (2,3-dihydro-2-nitro-5,10,15,20-tetraphenyl-22H,24H-porphyrins) by reaction with borohydride followed by aqueous workup.These nitrochlorins may be readily converted into the denitrated chlorin by treatment with tributyltin hydride or into the corresponding denitrated porphyrin by elimination of nitrous acid by heating or treatment with silica.Deuterium labeling studies show that the formation of nitrochlorin from nitroporphyrin involves attack by hydride at the β-pyrrolic carbon next to that bearing the nitro group followed by protonation of the resultant nitronate in aqueous workup.Specific deuteriation at the β-pyrrolic next to that previously occupied by a nitro group is readily achieved by borodeuteride ion reaction with a 2-nitroporphyrin (50 atom percent deuterium incorporation) or with a 2-methoxy-3-nitroporphyrin (100 atom percent deuterium incorporation).
Thien-2-yl substituted chlorins as photosensitizers for photodynamic therapy and photodynamic antimicrobial chemotherapy
Babu, Balaji,Mack, John,Nyokong, Tebello,Sindelo, Azole
, (2021)
The synthesis and characterization of meso-tetra(thien-2-yl)chlorin (1) and meso-tetra(5-bromothien-2-yl)chlorin (2) is reported. These dyes have red-shifted absorption maxima compared to those of the analogous meso-tetraphenylchlorin (3). 1 and 2 have Q bands at 660 and 664 nm, respectively, singlet oxygen quantum yields of 0.60 and 0.64 and exhibit good photostability. The triplet states were found to have lifetimes of 8.6 μs in N2 purged DMF. Time-dependent cellular uptake of chlorins reached a maximum in MCF-7 cancer cells after 12 h. Upon irradiation with a Thorlabs M660L3 LED (280 mW cm?2), 2 exhibited better photocytotoxicity with an IC50 value of 2.7 μM against MCF-7 cells. The 2?,7?-dichlorodihydrofluorescein diacetate (DCFDA) assay provided evidence for intracellular generation of reactive oxygen species. Photodynamic inactivation of bacteria by the chlorins was also studied. 2 exhibits better activity with log reduction values of 7.42 and 8.34 towards Staphylococcus aureus and Escherichia coli, respectively, under illumination for 60 min at 660 nm with a Thorlabs M660L3 LED (280 mW cm?2). These results demonstrate that 2 is a promising candidate for future in vivo experiments and merits further in-depth investigation.
Efficient one-pot regioselective synthesis of 2,3-dibromo-5,10,15,20- tetraarylporphyrins from 5,10,15,20-tetraarylchlorins
Li, Ke-Lai,Guo, Can-Cheng,Chen, Qing-Yun
, p. 2867 - 2871 (2009)
2,3-Dibromo-5,10,15,20-tetraarylporphyrins were prepared from easily available 5,10,15,20-tetraarylchlorins in one flask and two steps, namely regioselective dibromination and subsequent oxidation. An improvement in the synthesis of 2,3,12,13-tetrabromo-5
Controlled porphyrinogen oxidation for the selective synthesis of meso-tetraarylchlorins
Serra, Arménio C.,Rocha Gonsalves, António M.D'A.
, p. 4192 - 4194 (2010)
Chlorins have been synthesized through the reduction of the corresponding porphyrins although theoretically they can be obtained from reduced macrocycle forms as porphyrinogens. A new method for the oxidation of meso- tetraarylporphyrinogens was developed generating a substantial amount of chlorin relatively to porphyrin. The structure of the porphyrinogen, particularly the presence of substituents on the meso-phenyl groups, is decisive for the final yield of chlorin. In the case of meso-tetrakis(2,6-dichlorophenyl)porphyrinogen, 92% of the corresponding chlorin is obtained.
MnO2 instead of quinones as selective oxidant of tetrapyrrolic macrocycles
Nascimento, Bruno F.O.,Rocha Gonsalves, António M.d'A.,Pineiro, Marta
experimental part, p. 395 - 398 (2010/06/12)
Porphyrins and chlorins were generated through dehydrogenation of the corresponding porphyrinogen and bacteriochlorin precursors using activated manganese dioxide and focused microwave irradiation. The application of this inexpensive heterogeneous oxidant under microwave heating conditions, instead of the quinones usually employed in conventional methodologies, allowed short reaction times, simple overall work-ups and good yields.
SYNTHESIS AND PHOTOPHYSICS OF DIAZA-CROWN ETHER-BASED BISPORPHYRINS
Martensson, Jerker,Sandros, Kjell,Wennerstroem, Olof
, p. 534 - 544 (2007/10/02)
The bisporphyrin N,N'-bis-4,13-diaza-18-crown-6 and its mono- and dizinc derivatives were synthesized in 66percent, 46percent and 53percent yields, respectively, from 5-(4'-bromomethylphenyl)-10,15,20-triphenylporphyrin or its zinc derivative and 4,13-diaza-18-crown-6.The zinc-containing bisporphyrins form dimers in solution at low temperature or at high concentration.The unsymmetrical bisporphyrin; monozinc N,N'-bis-4,13-diaza-18-crown-6 shows singlet-singlet energy transfer from the zinc porphyrin moiety to the free base moiety in both the monomeric and the dimeric form.The energy transfer rates were determined using time-resolved fluorescence spectroscopy and were found to be 1.26x109 and 2.29x109 s-1 for the monomeric and dimeric form, respectively.The difference in energy transfer rates between the two forms can be rationalized by the difference in overlap between the donor fluorescence spectrum and acceptor absorption spectrum, donor-acceptor distance and donor-acceptor orientation.
