SYNTHESES AND PHOTOSENSITIZING ACTIVITY OF PORPHYRINS JOINED WITH ESTER LINKAGES

  • 15 April 1989
    • journal article
    • research article
    • Vol. 49  (8) , 2042-2047
Abstract
In order to investigate the structure of hematoporphyrin derivative and its purified version, Photofrin-II, porphyrin dimers with ester linkage were synthesized. 2,4-Diacetyldeuteroporphyrin dimethyl ester and protoporphyrin IX dimethyl ester were used as starting materials. The methyl esters were replaced by trimethylsilylethyl esters to protect the carboxylic groups. Deprotection using tetra-n-butylammonium fluoride in tetrahydrofuran regenerated the carboxylic functions. Reversed phase high performance liquid chromatography was used to compare the synthetic dimers with components of Photofrin-II. Our data indicate that these dimers are not components of Photofrin-II. During the synthesis of a 13C-labeled dimer with an ester linkage, a small amount of trimer was also isolated. The structures of these compounds were confirmed by nuclear magnetic resonance and mass spectroscopy. Using a standard screening system with DBA/2 mice bearing transplanted SMT-F tumors, these dimers were found not to be as active as Photofrin-II.