Design, synthesis, and in vitro photodynamic activities of benzochloroporphyrin derivatives as tumor photosensitizers

Novel benzochloroporphyrin derivatives (BCPDs) were designed, synthesized, and characterized. In vitro dark cytotoxicity and photodynamic efficacy of BCPDs were evaluated by MTT assay on human hepatoma BEL-7402 cells. The experimental results showed that BCPDs 15, 16, 17, and 18 have strong long wavelength absorptions around 670 nm and exhibit significantly lower dark cytotoxicity than BPDMA and possess potent photocytotoxicity, IC50 values 1.32 μg/mL for 15, 0.26 μg/mL for 16, 0.47 μg/mL for 17 of 0.27 μg/mL for 18, and 0.23 μg/mL for BPDMA. Among them, BCPDs 16 and 18 are more effective and promising PDT photosensitizers based on the studies with BEL-7402 cells and show nearly the same photodynamic efficacy as BPDMA. MG-P staining qualitative analysis also indicated that PDT with BCPDs 16 can induce apoptosis in BEL7402 cells.