Design, synthesis and phototoxicity studies of novel iodinated amphiphilic porphyrins

International audience; In this study, we focus on is the enhancement of singlet oxygen generation, which can be promoted by the introduction of heavy atoms on the photosensitizer. Metalation of tetrapyrrole core by heavy atoms such as platinum or palladium is another option but these metals tend to aggravate the aggregation tendency of the macrocycle. Halogenation proved to be much more successful on photosensitizing phthalocyanine [1] and BOPDIPY [2]. Besides, our recent systematic study on monohalogenated trihydroxylated porphyrins [3] demonstrated that the effect of iodination on photoproperties is extremely positive, without significantly modifying the amphiphilicity of the molecules, another important parameter that directly affects cellular uptake. On another hand, we recently designed and demonstrated the efficiency of the amphiphilic porphyrin 1 which exhibited excellent phototoxicity [4]. To further enhance the PDT efficiency, we decided to introduce three iodine atoms on the structure of 1. The relevance of the design of resultant porphyrin 2 (Fig. 1) was assessed by determining its photoproperties and its in vitro phototoxicity [5].