EVALUATION OF NEW BENZOPORPHYRIN DERIVATIVES WITH ENHANCED PDT EFFICACY*

Abstract— A first report on the biological evaluation of a series of isomerically pure benzoporphyrin derivatives ( cis- and frarcs-isomers) as methyl esters is described. In preliminary in vivo studies, the n- bexyl ether analogues of both cis- and trans -isomers of benzoporphyrin derivatives were found to be more active than the industrially prepared benzoporphyrin derivative, a mixture of monocarboxylic acids (BPDMA, Quadralogic Technologies, Vancouver). Further studies with 4-de-vinyl-4-(I-hexyloxyethyl) benzoporphyrin derivative showed that, like BPDMA, it had reduced residual skin phototoxicity compared in mice with Photofrin®. The uptake and clearance characteristics of BPDMA were also compared with the 4-(1-hexyloxyethyl)-derivative by in vivo reflection spectroscopy.