In this study, a novel photosensitizer meso-tetra (3-pyrrolidinomethyl-4-methoxyphenyl) chlorin (TPMC) was reported. It displays a characteristic long wavelength absorption peak at 656 nm and it shows a singlet oxygen quantum yield of 0.48. After light irradiation with 650 nm laser, it can kill Eca-109 and SMMC-7721 cells in vitro (25mW/cm², 1.2 to 3.6 J/cm²) and destroy Eca-109 tumor in nude mice (50mW/cm², 90 J/cm²). It has the perspective to be developed as a new anti-tumor drug in photodynamic therapy (PDT) photodiagnosis, and deserves further investigation.

Photodynamic therapy (PDT) represents a promising method for treatment of cancerous tumors. The chemical and physical properties of used photosensitizer (PS) play key roles in the treatment e±cacy. In this study, a novel PS, 5,10,15,20-tetrakis((5-dipropylamino)pentyl)-chlorin (TDPC) which displayed a characteristic long wavelength absorption peak at 650 nm were synthesized. It also shows a singlet oxygen generation rate of 4.257 min^-1. Generally, TDPC is localized in mitochondria and nucleus of cell. After light irradiation with 650 nm laser, it can kill many types of cell, in addition, TDPC–PDT can destroy ECA-109 tumor in nude mice and a necrotic scab was formed eventually. The expression levels of many genes which regulated cell growth and apoptosis were determined by RT-PCR following TDPC–PDT. The results showed that it either increased or decreased, among which, the expression level of TNFSF13, a member of tumor necrosis factor superfamily, increased significantly. In general, TDPC is an effective antitumor PS in vitro and in vivo and is worthy of further study as a new drug candidate. TNFSF13 will be an important molecular target for the discovery of new PSs.