Functionalized diphenylchlorins and bacteriochlorins: their synthesis and bioconjugation for targeted photodynamic therapy and tumour cell imaging

Abstract
A range of 5,15-diphenylporphyrins with symmetric and unsymmetric substitution patterns were subjected to osmium tetroxide-mediated dihydroxylations. The resulting chlorins and bacteriochlorins present an important group of compounds for studying structure-activity relationships of photodynamic sensitizers. The regioselectivity of the dihydroxylation of various 5,15-diphenylporphyrins with unsymmetrical substitution patterns was also examined. Both diphenylchlorin diol (DPC) and diphenylbacteriochlorin tetrol (DPBC) examples were converted into reactive isothiocyanates and conjugated with bovine serum albumin (BSA).