Study On Recognition Of Biomolecules By Porphyrin And Metalloporphyrin

Chapter 1: In the chapter the progresses of porphyrin are reviewed in analytical chemistry. The history and development are introduced, especially in the application of analytical chemistry, including spectrophotometry, electrochemistry, molecular recognition, probe, and so on.Chapter 2: The development of hematoporphyrin and its ramifications are concluded in detail, including the importance of them in nature. Hematoporphyrin and its ramifications are used to treat tumor and cancer as photosentizer in PDT (photodynamic therapy). The studies of the damage of hematoporphyrin and its ramifications to cells are also described. The content and significance of the paper are reviewed.Chapter 3: Purines are one of hydrolysate of nucleic acid, In the chapter the interactions of purines with hematoporphyrin (HP) and metallohematoporphyrin (MHP) are studied in detail. The optimal conditions of recognition are selected. Recognition mechanism is discussed in detail by absorption spectra, fluorometry and NMR spectra. The results show that the fluorescence of purines are very strong in pH=11.0 buffer solution. When HP and MHP are added, the fluorescence of purines are quenched, and in according with equation of static quenching. Purines have strongly binding ability with HP and MHP, and can be recognized by porphyrins. Recognition is achieved by cooperative functions of four functional groups.Chapter 4: In this chapter the interactions of amino acids with hematoporphyrin and metallohematoporphyrin are studied. Amino acids are basic units of protein; The research of amino acids with MHP can further understand the interactions of protein with porphyrins. Recognition mechanism is discussed by absorption spectra and fluorometry. It shows that the influences of acidity are very obvious to fluorescence of amino acids. In pH=7.4 buffer solution amino acids can be recognized by hematoporphyrin and metallohematoporphyrin.Chapter 5: Serum albumin is one of important protein in body, which is as a matrix of many endogenous and extraneous substances transportation and ejection from body. Hematoporphyrin must be combined with serum albumin before it enters into body.So the binding constants can decide the efficacy of drug. The experiment results show that blood serum with MP and MHP have larger binding constants at physiological conditions. The binding constants of Bovine Serum Albumin with MP and MHP are larger than that of Human Serum Albumin with MP and MHP. The mechanisms are approved of static interactions. And porphyrins form complex with protein on external of protein, which don't change the conformations of tryptophan and tyrosine among protein.Chapter 6: Pyridine and purines are both hydrolysates of nucleic acid. In the chapter the ramification of pyridine-trimethoprim is studied. The intensity of trimethoprim is stronger in basic condition. It shows that a new complex is formed in pH=11.0 Kolthoff buffer solution. The binding constant of MHP with trimethoprim is smaller than that of HP with trimethoprim. The reason may that the core of porphyrin is distorted, which weaken the interaction of aromatic-ring stack. Recognition is achieved by cooperative functions of four functional groups: carboxyl groups, the hydroxy groups, aromatic-ring stack and metal ions.