Purpurin 18 is a derivative of chlorophyll and is a type of dihydroporphyrin, which can be used to produce photosensitizers. It has potential application values in fields such as photodynamic therapy and photocatalysis. For example, in photodynamic therapy, it can generate reactive oxygen species such as singlet oxygen under the irradiation of light with a specific wavelength. This can then damage diseased cells, achieving the purpose of treating diseases. In the field of photocatalysis, its unique molecular structure may endow it with the ability to participate in certain catalytic reactions under light irradiation, showing potential for applications in environmental remediation, such as the degradation of pollutants.