Synthesis of Novel <i>Meso</i>-Tetraphenyltetrabenzoporphyrins and Evaluation of Their Photodynamic Anticancer Activities

To discover a potential anticancer photosensitizer drug, a series of <i>meso</i>-tetraphenyltetrabenzoporphyrins (<i>m</i>-Ph₄TBPs) with four carboxyl groups were afforded through a multistep reaction starting from cyclohexene. These new <i>m</i>-Ph₄TBPs demonstrated favorable antiaggregation properties and exhibited obvious absorption in the phototherapeutic window (600-800 nm). Additionally, <i>m</i>-Ph₄TBPs 1-5 displayed notable reactive oxygen species generation ability and obvious photodamage effectiveness against Eca-109 cells. Furthermore, <i>m</i>-Ph₄TBP 4 was able to inhibit tumor growth in mice bearing Eca-109 cells and demonstrated superior biosafety toward the kidney and liver both <i>in vitro</i> and <i>in vivo</i>. These results indicated that compound 4 could be considered a promising candidate for further studies in photodynamic therapy.