6533b7d1fe1ef96bd125c128

RESEARCH PRODUCT

Extraktionschromatographische trennung der freien porphyrine auf tri-n-butylphosphat-s?ulen im pH-gradienten

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Abstract The method described allows the separation of the free porphyrins on a tri-n-butyl phosphate (TBP) column by elution with a pH gradient. The prophyrins are eluted from the column at discrete pH values (xD) according to the number of carboxyl groups in the side chains. Separation of isomers could not be observed under the conditions used. The xD values indicate the centre of the pH-interval, in which the dissociation of the carboxyl groups occurs. This finding could be confirmed by spectro-photometric measurements. By combining the method proposed with the method of separation by extraction chromatography in the TBP/IN HCl partition system and the thin-layer technique in the 2,6-lutidine-water system, a very complex porphyrin mixture isolated from the urine of a patient with a hyporegenerative anaemia could be resolved. The 27 fractions obtained by these separations made clear that not only porphyrins of the reaction chain of the haem synthesis are present in the mixture, but also compounds which differ from the normal porphyrins by their substituents. However, further investigations are still necessary to elucidate the structure and determine the assumed substituents of the single fractions. In contrast to an earlier assumption it seems that porphyrins, not only of the isometric types I and III but also of types II and/or IV, are occurring in the urine sample studied.