Derivatization of porphyrins for DNA and metal ion binding, especially by employing secondary sulfonamide links

<div> <p align="justify"> <font size="3" face="Times">Porphyrins are of exceptional importance in nature, science and technology: For instance, as ligands for metals in supramolecular synthesis, as photosenstizers in photodynamic therapy (PDT), and as building blocks for electronic devices. In addition to their application in cancer therapy, porphyrin species also exhibit antiviral activity. New <i>meso</i>-tetraarylporphyrins (TArP, Ar = -C₆H₄-) of the general formula, T(R¹R²NSO₂Ar)P, with R¹ = N-py-n-CH₂ (n = 2, 3 or 4) or SO₃^- and R² = H or CH₃ were synthesized. These groups were linked to the 4-position of the phenylene group of the porphyrin by a secondary (SO₂NHR) or tertiary (SO₂NR₂) sulfonamide group. The sulfonamide group was found to be a versatile way of expanding the porphyrin. The presence of a tertiary sulfonamide group instead of a dissociable proton improved the solubility of the new class of porphyrin compounds synthesized.</font></p> <p align="justify"> <font size="3" face="Times">Adducts having four methylcobaloxime unit (CH₃Co(DH)₂) bound to the pyridyl nitrogens of T(<i>N</i>-py-4-CH₂(CH₃)NSO₂Ar)P or TpyP(4) were synthesized for the first time and their solution properties studied by ¹H NMR spectroscopy. The ¹H NMR signal of the axial methyl of CH₃Co(DH)₂L complexes shifts upfield with increasing L basicity, but the signal of the equatorial methyl is insensitive to L basicity. The axial methyl signal was used to examine the effect of coordination of the CH₃Co(DH)₂ moiety to the N-pyridyl group of the TpyP(4) and of the newly synthesized porphyrin, T(<i>N</i>-py-4-CH₂(CH₃)NSO₂Ar)P. </font></p> <p align="justify"> <font size="3" face="Times">A new class of water-soluble porphyrins <i>mes</i>o-tetraarylporphyrins and some metal derivatives were synthesized from the above class of compounds by simple alkylation and metallation with copper and zinc salt. Interactions of selected porphyrins and metalloporphyrins (Cu(II), Zn(II)) with calf thymus DNA were investigated by visiblr circular dichroism, absorption, and fluorescence spectroscopies. The main aim of studying this class of compounds was to assess whether <i>N</i>-methylpyridinium (<i>N</i>-Mepy) groups must be directly attached to the porphyrin core in order for intercalative binding to DNA to occur.</font></p> <p><font size="3" face="Times New Roman"> Porphyrins have been known for some years to show antiviral activity against human immunodeficiency virus (HIV) infection in assays that measured inhibition of virus replication. One promising approach receiving increasing attention is the development of microbicides which, when applied topically, can prevent viral infection. These compounds could directly interact with HIV virions to decrease or prevent infectivity, thus providing a defense against sexual transmission of the virus. Sulfonated derivatives of tetraarylporphyrin have also been shown to exhibit activity HIV. A new class of porphyrins containing sulfonamide links was synthesized and characterized by ¹H NMR spectroscopy and mass spectrometry.</font></p> </div> </div></body></html>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

Chemistry

Year dc:date.available

2009

Author dc:creator

• Manono, Janet

• Methylcobaloximes
• Tertiary sulfonamide links
• Cationic porphyrins

Statement dc:rights

• restricted
• Student has submitted appropriate documentation to restrict access to LSU for 365 days after which the document will be released for worldwide access.

Identifier

etd-04142009-133745
https://repository.lsu.edu/gradschool_dissertations/153

OAI identifier oai:identifier

oai:repository.lsu.edu:gradschool_dissertations-1152