Absorption spectrum characteristic of chorophyll derivatives photosensitizer CPD3

Absorption spectrum of CPD3 is determined. There are two absorption bands all in absorption spectrum, the maximal absorption of band B is at 395nm in 0.9% NaCl solution and TE buffer solution, the band Q is locating at 677nm and 651nm respectively in solvents above. The order of magnitude of extinction coefficient is 104 in both solvents. the absorption peak of CPD3-DNA mix solution have 6nm and 23nm red shift for band B and band Q respectively compared with pure CPD3 in 0.9% NaCl solution, this indicates that interaction between photosensitizer and DNA occurring. Time series data of absorption for CPD3-DNA mix solution supports the interaction viewpoint further, and the full action time is about 90mins. The type of interaction needs a further investigating. Stronger absorption in red region and the interaction with DNA suggests that CPD3 will have a bright future in photodynamic therapy.