Metalloporphyrins—Applications and clinical significance

Abstract

The fascinating structures of naturally occurring porphyrins and metalloporphyrins have been perfected by nature to give functional dyes par excellence. The important roles these tetrapyrrolic macrocycles play in vital biological processes, in particular photosynthesis (chlorophyll), oxygen transport (hemoglobin), oxygen activation (cytochrome), have led to their characterization as 'pigments of life'. Because porphyrins possess extended n-electron systems and exhibit stability, they are finding use, to an increasing extent, in advanced materials, as components in organic metals, molecular wires, and other devices. In medicine, porphyrins are experiencing a renaissance due to the acivent of photodynamic therapy of great promise in the treatment of cancer and dermatological diseases. The interdisciplinary interest porphyrins thus generate has provided the impetus to develop Novel-porphyrin like molecules anticipated to exhibit special properties, by structural variation of the tetrapyrrolic macrocycle, while maintaining a (4n+2)~ main conjugation pathway.In addition to their esoteric application in science, porphyrins have been shown to have profound implications for therapeutic purposes. Their photosensitizing properties have led to their utilization in photodynamic therapy. Certain metalloporphyrins such as SnPP are being tested as drugs for the treatment of neonatal jaundice. Metailoporphyrins are serving as SOD mimetics to combat oxidative stress and a range of metalloporphyrin complexes have been proposed as contrast agents for magnetic resonance imaging

Characterization of blue light irradiation effects on pathogenic and nonpathogenic Escherichia coli

“…The aromatic rings within electron donors and carriers absorb photons from light, which makes them ideal endogenous PSs (Herzfeld, 1940). Flavins have absorption peaks at 380 and 450 nm, porphyrins around 400 nm, while ubiquinones have various peaks in the 230-500 nm range (Chandra et al, 2000;Land, Simic, & Swallow, 1971;Yagi, Ozawa, & Harada, 1959;Zenichowski, Gothe, & Saalfrank, 2007).…”

Serum metabolomics study of patients with allergic rhinitis

“…Porphyrins are macrocyclic tetra pyrroles of profound importance in biology. They are found at the heart of the oxygen‐carrying proteins such as hemoglobin and in a variety of vital enzymes, especially those involved in biological oxidation and reduction (Chandra et al, ). The bilirubin is one of the products of the porphyrin metabolism, which is higher in patients with AR than in healthy volunteers.…”

Branched porphyrins as functional scaffolds for multisite bioconjugation

“…In the metal‐free form, the porphyrins are fluorescent with unique photophysical properties . Furthermore, several metalloporphyrins, especially Mn III –porphyrins, have recently been proposed as Magnetic Resonace Imaging (MRI) contrast agents . Therefore, the porphyrin moiety of the proposed thrombin‐targeting agents will allow the application of different detection techniques to reveal the interaction with thrombin, thus allowing thrombi imaging.…”

“…Besides this biological importance, the porphyrin macrocycle presents several features that make it extremely suitable as building block for the design of larger molecular architecture . In particular, the porphyrin ring has some key properties: (1) it is exceptionally resistant to thermal and chemical denaturation and to enzymatic degradation; (2) it is cell permeable both in the metalated and apo forms, with well documented pharmacokinetic properties; (3) it has several distinct functionalization sites: the meso , the β positions, and the inner nitrogens; (4) its rigidity allows the design of preorganized structures, with the anchored groups displaying geometrically defined orientations; (5) its unique spectroscopic properties allow the detection of small changes upon interaction with other molecules, by using a plethora of spectroscopies, such as UV–visible (Vis), circular dichroism, nuclear magnetic resonance (NMR), fluorescence, and Raman; (6) its complexes with paramagnetic or radioactive metal ions are valuable for diagnostic purposes; and (7) its metallated forms can also function as catalytic center, and henceforth the porphyrin can function as reporter .…”