Abstract
Porphyrins are vital macrocyclic molecules that exist naturally and are significant to the metabolic processes of living organisms. Some of the best-known examples include iron-containing porphyrins in heme and magnesium-containing porphyrins in chlorophyll. These compounds are substantial for life on Earth. Therefore, gaining a deep understanding of porphyrins and their properties is essential for understanding many biological processes.⁶⁹ This research investigates the synthesis, photochemical characterization, and applications of porphyrin derivatives, focusing on their potential in photodynamic therapy. Initially, the synthesis of non-water-soluble Dimethyl-amino-phenylporphyrin (DMAPP) and its transformation into water-soluble derivatives TAPPI₄ (Tetra-p-trimethyl-ammonium-phenyl-porphyrin-tetraiodide) and its metallo derivatives ZnTAPPI₄ (Tetra-(p-trimethyl-ammonium-phenyl) zinc (II)-porphyrin- tetraiodide) and CuTAPPI₄ (Tetra-(p-trimethyl-ammonium-phenyl) copper (II)-porphyrin- tetraiodide) were produced. Comprehensive photochemical analysis revealed unique absorption and emission abilities, aggregation behaviors, and fluorescence lifetimes, suggesting different photostability and reactivity under light exposure with lifetimes measured at 3.26 x 10⁻⁵ seconds for TAPPI₄, 1.49 x 10⁻¹¹ seconds for ZnTAPPI₄, and 3.66 x 10⁻⁹ seconds for CuTAPPI₄. These compounds were then tested in-vitro on tetrahymena thermophila, a unicellular eukaryote, and basal cell carcinoma cells (BCC) from the salivary gland and the lung with the following concentrations: 100 ppm, 50 ppm, 30 ppm, 15 ppm, three ppm, and 0 ppm. Results indicate no dark toxicity except for 100 ppm CuTAPPI₄ and studies showed 90% tetrahymena thermophila cell death within 12h of continuous red-light radiation in 50 ppm TAPPI₄ solutions. Furthermore, studies demonstrated 75% effectiveness on benign salivary gland BCC cells and 94% on malignant lung BCC cells at a concentration of 100ppm TAPPI₄ within 12h of continuous red-light radiation. Finally, Photochemical and photophysical studies included fluorescence quenching of TAPPI₄ with the following quinones: 2,6-dichloro-1,4-benzoquinone, Methyl-p-benzoquinone and Benzoquinone. The quenching constant was established for each quinone and is at kq= 1.36 x 10⁷ L mol⁻¹s⁻¹ for methyl-p-benzoquinone, at kq 3.37 x 10⁶ L mol⁻¹s⁻¹, 2,6-dichloro-1,4-benzoquinone and at kq = 7.41 x 10⁵ L mol⁻¹s⁻¹ for Methyl-p-benzoquinone. This research involves several analytical methods, including UV-Vis absorption spectroscopy, emission spectroscopy, and GC-MS analysis, to characterize reaction products and intermediates.