531-14-6Relevant academic research and scientific papers
Spectral and kinetic investigation on oxidation and reduction of water soluble porphyrin-manganese(III) complex
Giovannetti, Rita,Alibabaei, Leila,Pucciarelli, Filippo
, p. 1561 - 1567 (2010)
In this work the oxidation and reduction reactions of MnIII-Coproporphyrin-I (MnIII-CPI) have been studied and four forms of manganese-CPI complexes have been characterized. This complex was observed to be highly reactive (at basic pH) towards Mn(II), hypochlorite, hydrogen peroxide and oxone, forming [MnIV(O)CPI(OH)]- that was unstable and, after a short time, formed again [MnIIICPI(OH)2]-. With an excess of NaClO, a further oxidation of the complex [MnIV(O)CPI(OH)]-, provoked a significant spectral change for the [MnV(O)CPI(OH)] formation that showed, in the time, a partial polymerization. [MnIIICPI(OH)2]- was reduced by sodium dithionite to form the very unstable complex of [MnIICPI(OH)]- that successively degraded with Mn(II) release.
SYNTHESIS AND CHARACTERIZATION OF COPROBILIVERDIN III, A NEW MODEL CHROMOPHORE
Koest, H.-P.,Benedikt, E.,Cmiehl, E.,Schneider, S.
, p. 3975 - 3978 (1983)
The synthesis of coprobiliverdin III, a new bile pigment with four conjugated pyrrole nuclei and four carboxylic acid side chains, is described.Coprobiliverdin is structurally characterized by chromic acid degradation, mass spectroscopy, UV vis and NMR spectroscopy.
Abiotic formation of uroporphyrinogen and coproporphyrinogen from acyclic reactants
Lindsey, Jonathan S.,Chandrashaker, Vanampally,Taniguchi, Masahiko,Ptaszek, Marcin
supporting information; scheme or table, p. 65 - 75 (2011/04/14)
Tetrapyrrole macrocycles (e.g., porphyrins) have long been proposed as key ingredients in the emergence of life, yet plausible routes for forming their essential pyrrole precursor have previously not been identified. Here, the anaerobic reaction of δ-aminolevulinic acid (ALA, 5-240 mM) with 5-methoxy-3-(methoxyacetyl)levulinic acid (1-AcOH, 5-240 mM) in water (pH 5-7) at 25-85°C for a few hours to a few days affords uroporphyrinogen, which upon chemical oxidation gives uroporphyrin in overall yield of up to 10%. The key intermediate is the α-methoxymethyl-substituted analogue of the pyrrole porphobilinogen (PBG). Reaction of ALA and the decarboxy analogue of 1-AcOH (1-Me) gave coproporphyrinogen (without its biosynthetic precursor uroporphyrinogen as an intermediate); oxidation gave the corresponding coproporphyrin in yields comparable to those for uroporphyrin. In each case a mixture of porphyrin isomers was obtained, consistent with reversible oligopyrromethane formation. The route investigated here differs from the universal extant biosynthetic pathway to tetrapyrrole macrocycles, where uroporphyrinogen (isomer III) - nature's last common precursor to corrins, heme, and chlorophylls - is derived from eight molecules of ALA (via four molecules of PBG). The demonstration of the spontaneous self-organization of eight acyclic molecules to form the porphyrinogen under simple conditions may open the door to the development of a chemical model for the prebiogenesis of tetrapyrrole macrocycles. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2011.
Direct assay of enzymes in heme biosynthesis for the detection of porphyrias by tandem mass spectrometry. Uroporphyrinogen decarboxylase and coproporphyrinogen III oxidase
Wang, Yuesong,Gatti, Paula,Sadilek, Martin,Scott, C. Ronald,Turecek, Frantisek,Gelb, Michael H.
, p. 2599 - 2605 (2008/09/20)
We report new assays of enzymes uroporphyrinogen decarboxylase (UROD) and coproporphyrinogen III oxidase (CPO) in the heme biosynthetic pathway. The assays were developed for use in clinical diagnostics of inherited disorders porphyria cutanea tarda and hereditary coproporphyria, respectively. Electrospray ionization tandem mass spectrometry is used to monitor the decarboxylation of pentaporphyrinogen I or uroporphyrinogen III catalyzed by UROD and to determine the enzyme activity in human erythrocytes by measuring the production of coproporphyrinogen I or III. The Km value for pentaporphyrinogen I was measured as 0.17 ± 0.03 μM. A mass spectrometric assay was also developed for the two-step decarboxylative oxidation of coproporphyrinogen III to protoporphyrinogen IX catalyzed by CPO in mitochondria from human lymphocytes (Km = 0.066 ± 0.009 μM). The assays show good reproducibility, use simple workup by liquid-liquid extraction of enzymatic products, and employ commercially available substrates and internal standards.
Studies on the formation of porphyrinogens from monopyrroles in presence of the enzymes PBG deaminase and/or Uro'gen III synthase
Pichon-Santander, Clotilde,Ian Scott
, p. 8669 - 8672 (2007/10/03)
The substrate-specificities of two enzymes in the biosynthetic pathway to vitamin B12, PBG deaminase and Uro'gen III synthase, which are involved in the formation of Uro'gen III from the pyrrole PBG, are investigated for the preparation of Uroporphyrin analogs. Both enzymes display strong substrate-specificity. However, tetramerization of pyrroles with carboxylate β-substituents in mildly basic buffer represents the best and most rapid route to a family of Uro I analogs for enzymatic activity studies.
Protease mediated drug delivery system
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, (2008/06/13)
Lipophilic and amphiphilic therapeutic or diagnostic agents having water solubilizing groups attached thereto by bonds that can be cleaved readily by one or more of the various proteases that are active in the extracellular fluid or on the surfaces of cells in many types of malignant tissue may accumulate selectively in such malignant tissues. Protease mediated removal of the water solubilizing groups converts such drugs into lipophilic or amphiphilic forms which are more soluble in plasma membrane lipids and which therefore enter cells more readily. Since the extracellular fluid in most non-malignant tissues under normal circumstances has little such protease activity, removal of the water solubilizing groups takes place primarily within malignant tissues, with consequent preferential accumulation of the lipophilic or amphiphilic forms of the drug within malignant tissues. Certain lipophilic and amphiphilic porphyrins and chlorins may be modified by the addition of water solubilizing groups, such as alcohols, which are attached by short polypeptide chains, that are stable while in the circulation but are cleaved by proteases in malignant tissue to provide novel compounds useful for the photodynamic therapy of cancer.
Biosynthesis of Porphyrins and Related Macrocycles. Part 15. Chemical and Enzymic Formation of Uroporphyrinogen Isomers from Unrearranged Aminomethylpyrromethane: Separation of Isomeric Coproporphyrin Esters
Battersby, Alan R.,Buckley, Dennis G.,Johnson, Dawid W.,Mander, Lewis N.,McDonald, Edward,Williams, D. Clive
, p. 2779 - 2785 (2007/10/02)
The unrearranged pyrromethane (1) is transformed chemically mainly into uro'gen-I with a smaller amount of uro'gen-IV but only traces of uro'gen-III are formed.Uro'gen-I is produced via a tetrapyrrolic (bilane) intermediate and when the diaminase-cosynthetase enzyme system from Euglena gracilis is present, this intermediate is converted into uro'gen-III.The rearrangement step for this conversion has the same characteristics found earlier for the natural biosynthetic process from porphobilinogen.Pyrromethane (1) is not a direct biosynthetic precursor of uro'gen-III and reasons are advanced why this is understandable.Methods are developed based on high pressure liquid chromatography for the separation of all four isomeric coproporphyrin esters.
