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Diagnostic Test with Targeted Therapy for Cancer: The Theranostic Nanomedicine
Published in Paula V. Messina, Luciano A. Benedini, Damián Placente, Tomorrow’s Healthcare by Nano-sized Approaches, 2020
Paula V. Messina, Luciano A. Benedini, Damián Placente
The agent frequently used, inherently fluorescent, is a non-toxic drug in the absence of the activating light or a dye. Porphyrins are one of the main photosensitizing agents used in this therapy. They have a porphine structure along with a side chain, which is usually metallic. Porphine is formed by tetrapyrrole backbone connected by bridges of methine in a cyclic configuration (O’Connor et al. 2009). Depending on the specific structure of these agents, the absorption bands are ranged from 600 to 800 nm (Abrahamse and Hamblin 2016). Other tetrapyrrole structures used as photosensitizers are the chlorins which are naturally derived from chlorophyll. Their activation wavelength is between 650 and 700 nm (red light). Examples of these compounds are tetrahydroxyphenylchlorin, benzoporphyrin derivatives and Radachlorin (Biswas et al. 2014, Chan et al. 2010, Wagner et al. 2015). Additionally, bacteriochlorins and phthalocyanines are other types of agents based on pyrrole structure. We can mention synthetic dyes used as a photosensitizer: Phenothiazinium salts, squaraines and others based on boron-dipyrromethene named Bodipy dyes among others (Abrahamse and Hamblin 2016).
Synthesis, crystal structure, computational studies, and antioxidant properties of dimethylformamide-bound magnesium tetraphenylporphyrin
Published in Journal of Coordination Chemistry, 2023
Abdul K Choudhury, Bishnu Prasad Borah, Karishma Devi Borah, Jagannath Bhuyan
In green leaves the pigment chlorophylls, which are magnesium-coordinated tetrapyrrolic molecules, absorb sunlight to begin the process of photosynthesis. Magnesium porphyrins are widely used as model compounds for mimicking chlorophyll of artificial photosynthesis [1]. There are, however, fewer reports of magnesium porphyrins when it comes to metalloporphyrins [2]. The crystal structure of the simplest magnesium porphyrin, MgTPP, was first reported by Timkovich and Tulinsky, where a water molecule was present as an axial ligand [3]. In recent work, the crystal structures of MgTPP with different axial ligands such as tetrahydrofuran (THF), PCl3, N3−, SCN−, OCN−, pyrazine (pyz), and HCO3− have been reported [4–6]. In the chloroplast, a water molecule is typically attached to molecules of chlorophyll [6]. Carbon dioxide/bicarbonate-bound chlorophyll initiates the light-harvesting process of photosynthesis [5]. In vitro, chlorophyll molecules undergo self-aggregation and adopt a nano spherical shape [7, 8]. We previously investigated the photophysical characteristics of MgTMPP (Figure 1) in combination with lipid cholesterol to better comprehend the aggregation that takes place in the native chlorophyll system. The fluorescence of porphyrin is enhanced with treatment with lipid cholesterol similar to the fluorescence of chlorophyll in vivo [9].