Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (05): 1054-1062.doi: 10.3866/PKU.WHXB201202222

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

Synthesis of Tailed Porphyrin Modified with Nicotinic Acid and Interactions with Human Serum Albumin

PENG Yu-Ling, WANG Shu-Jun, FU Li, ZHANG Cheng-Gen, LIU Xin-Gang   

  1. College of Chemistry & Material Science, Langfang Teachers College, Langfang 065000, Hebei Province, P. R. China
  • Received:2011-11-29 Revised:2012-02-01 Published:2012-04-26
  • Contact: WANG Shu-Jun E-mail:d022036@mail.nankai.edu.cn
  • Supported by:

    The project was supported by the Natural Science Foundation of Hebei Province, China (B2010001803) and Specialized Research Fund for the Program of Langfang Teachers College, China (LSZZ201003).

Abstract: Free porphyrins, namely o-(niacin)C2O-T(3p-OCH3)PP and p-(niacin)C2O-T(3p-OCH3)PP, their complexes, o-(niacin)C2O-T(3p-OCH3)PPZn and p-(niacin)C2O-T(3p-OCH3)PPZn modified with nicotinic acid, were designed, synthesized, and characterized by elementary analysis, and UV-Vis, 1H nuclear magnetic responance (1H NMR), and infrared (IR) spectroscopies. The conformations of the Zn porphyrins were calculated using a quantum- chemical method. The experimental results showed the following. It was found that the nicotinic acid group was on the porphyrin plane in o-(niacin)C2O-T(3p-OCH3)PPZn and Zn― N intramolecular coordination interactions which existed between the N atom of the nicotinic acid group in the side-chain and the Zn2+ in the porphyrin plane. The nicotinic acid group was far from the porphyrin plane in p-(niacin)C2O-T(3p-OCH3)PPZn and Zn ― N intermolecular coordination interactions which existed between the N atom of the nicotinic acid group in one Zn porphyrin and the Zn2+ in the other porphyrin plane. The fluorescence properties of the interactions between Zn porphyrins and human serum albumin (HSA) were studied using fluorescence spectroscopy. There is a large quenching interaction between the Zn porphyrins and human serum albumin. The mechanism of the combination reaction is hydrogen bonding or van der Waals interactions between the Zn porphyrins and human serum albumin. The fluorescence quenching data were analyzed using the Stem-Volmer equation and a double-reciprocal equation, and the quenching constant, binding constant, and thermodynamic parameters were obtained.

Key words: Nicotinic acid, Zn porphyrin, Human serum albumin, Fluorescence quenching, Thermodynamic parameter

MSC2000: 

  • O641