Showing papers on "Protoporphyrins published in 1980"

Uptake of protoporphyrin IX by isolated rat liver mitochondria

Abstract: Rat liver mitochondria accumulate protoporphyrin IX from the suspending medium into the inner membrane in parallel with the magnitude of the transmembrane K+ gradient (K+in/K+out). Only protoporphyrin IX taken up in parallel with the transmembrane K+ gradient is available for haem synthesis. Coproporphyrins (isomers I and III) are not taken up by the mitochondria. The results support the suggestion by Elder & Evans [(1978) Biochem. J. 172, 345-347] that the prophyrin to be taken up by the inner mitochondrial membrane belongs to the protoporphyrin(ogen) IX series. Protoporphyrin IX at concentrations above 15 nmol/mg of protein has detrimental effects on the structural and functional integrity of the mitochondria. The relevance of these effects to the hepatic lesion in erythropoietic protoporphyria is discussed.

The chemistry of pyrrolic compounds. XLII. The synthesis of some diacetyldeuteroporphyrins as intermediates in the preparation of the isomeric protoporphyrins: a comparative spectroscopic study of the diacetyldeuteroporphyrins

Abstract: A range of isomeric diacetyldeuteroporphyrins has been synthesized by the oxidative cyclization of appropriately substituted bilenes-b, and the electronic and n.m.r. spectra of these porphyrins have been studied. As a result it has been shown that the relative position of the two acetyl groups influences the absorption pattern of the visible spectrum more precisely than was previously appreciated. In consequence, it is possible to recognize the 1,4, 2,3 and 2,4 relative distribution of the acetyl groups by an examination of the electronic spectrum. In addition, it is clear that the acetyl groups present in this series of porphyrins affect the chemical shift of all the methine protons and not only the one which is directly adjacent to the carbonyl function.

The chemistry of pyrrolic compounds. xlii. the synthesis of some diacetyldeuteroporphyrins as intermediates in the preparation of the isomeric protoporphyrins: a comparative spectroscopic study of the diacetyldeuteroporphyrins

Abstract: A range of isomeric diacetyldeuteroporphyrins has been synthesized by the oxidative cyclization of appropriately substituted bilenes-b, and the electronic and n.m.r. spectra of these porphyrins have been studied. As a result it has been shown that the relative position of the two acetyl groups influences the absorption pattern of the visible spectrum more precisely than was previously appreciated. In consequence, it is possible to recognize the 1,4, 2,3 and 2,4 relative distribution of the acetyl groups by an examination of the electronic spectrum. In addition, it is clear that the acetyl groups present in this series of porphyrins affect the chemical shift of all the methine protons and not only the one which is directly adjacent to the carbonyl function.