A novel amphiphilic 2-taurine substituted hypocrellin B (THB) and its photodynamic activity

A novel 2-taurine substituted hypocrellin B (THB) was designed and synthesized in this work. Both the light absorbance in the phototherapeutic window (600–900 nm) and the amphiphilicity (a compromise between the lipophilicity and hydrophilicity) were greatly improved. The semiquinone anion radical (THB˙−), superoxide anion (O2˙−), hydroxyl radical (˙OH) (Type I mechanism) and singlet oxygen (1O2) (Type II mechanism) could be generated via the photosensitization of THB, confirming its photosensitization activity. In this work, it was also found that the cytochrome c reduction method is not the exclusive one for detecting O2˙− in photosensitization systems.