A first report on the biological evaluation of a series of isomericall
y pure benzoporphyrin derivatives (cis- and trans-isomers) as methyl e
sters is described. In preliminary in vivo studies, the n-hexyl ether
analogues of both cis- and trans-isomers of benzoporphyrin derivatives
were found to be more active than the industrially prepared benzoporp
hyrin derivative, a mixture of monocarboxylic acids (BPDMA, Quadralogi
c Technologies, Vancouver). Further studies with 4-de-vinyl-4-(1-hexyl
oxyethyl) benzoporphyrin derivative showed that, like BPDMA, it had re
duced residual skin phototoxicity compared in mice with Photofrin(R).
The uptake and clearance characteristics of BPDMA were also compared w
ith the 4-(1-hexyloxyethyl)-derivative by in vivo reflection spectrosc
opy.