14959-92-3Relevant academic research and scientific papers
Photochemistry of Biliverdin IXδ as a Model for the Study of the Photoproducts from Natural Biliverdin IXγ (Pterobilin)
Bois-Choussy, Michele,Barbier, Michel
, p. 1098 - 1110 (1980)
The configurations of biliverdin-IXγ and -IXδ dimethyl esters 1 and 2 in solutions, have been studied using Nuclear-Overhauser-Effect (NOE) experiments.Irradiation (500-700 nm) of biliverdin IXδ gave syn-Z -> anti-E isomerization of the central methine bridge and in aerated polar solutions, four new cyclized pigments were isolated for which structures 3, 4, 5 and 6 are proposed.Neobiliverdin IXδ is also formed in degassed solution (Φ = 4E-5) but pigments 4, 5 and 6 arise from photo-oxidation with O2.Biliverdin IXδ appears to be a good model for the study of photo-reactions occurring on the vinyl groups of the natural biliverdin IXγ (pterobilin).
Derivatives of Natural Tetrapyrroles for Photodynamic Therapy, 3. Oxidative Degradation Studies on Porphyrins with Chromic Acid
Gauler, Rainer,Hesse, Ulrike,Risch, Nikolaus
, p. 2227 - 2230 (2007/10/03)
Until now the composition of the complex porphyrin mixtures of hematoporphyrin derivative (HPD) and Photofrin II could not be clarified in detail.We investigated the applicability of oxidative degradation to the structural assignment of HPD constituents.Therefore, some fundamental work concerning the characterization of the relevant degradation products had to be done.In this article we present the special and analytical data of monomeric and dimeric maleimides potentially arising from the corresponding constituents of HPD. - Keywords: Oxidative degradation; Chromic acid; Porphyrins; Maleimides; HPD; PDT
Structurel Analysis of Tetrapyrroles by Hydrogen Chemical Ionization Mass Spectrometry
Shaw, George J.,Eglinton, Geoffrey,Quirke, J. Martin E.
, p. 2014 - 2020 (2007/10/02)
The H2 chemical ionization mass spectra of several standard porphyrins have been determined.Fragmentation proceeds via hydrogenation yielding porphyrinogens, followed by cleavage at the meso (bridge) positions to produce mono-, di-, and tripyrrolic ions.Secondary fragmentation by cleavage of substituent groups attached to the pyrrole rings may then occur.Identification of these fragments and the corresponding molecular ions produces considerable structural information on the parent molecule.In certain cases these data are sufficient to distinguish porphyrin type (positional) isomers.In addition information of substituents at meso positions may be retained.
PETROPORPHYRINS - II. THE PRESENCE OF PORPHYRINS WITH EXTENDED ALKYL SUBSTITUENTS
Martin, J.,Quirke, E.,Shaw, George J.,Soper, Paul D.,Maxwell, James R.
, p. 3261 - 3268 (2007/10/02)
The vanadyl porphyrins from Boscan oil (Cretaceous, W.Venezuela) were isolated as 3 fractions, and degraded to maleimides (1H-pyrrole-2,5-diones) by chromic acid.Analysis of the products by GC-MS, using multiple ion detection to enhance sensitivity, revealed a major homologous series of 3-Me components with n-alkyl side chains extending to C11, and a minor series with branched alkyl side chains, the Me branch being at C-1.The origin of the extended alkyl groups is discussed.
