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SOD-like activity studies of functional surfactants - containing copper (II) complexes
332
Abstracts
L072
SOD-LIKE
ACTIVITY
STUDIES
OF F U N C T I O N A L
SURFACTANTS
- CONTAINING
COPPER (II) COMPLEXES, Lu Chun-Su and Xiang Yang, School of Pharmaceutical Sciences, Beijing Medical University, Beijing 100083,PRC Eight functional surfactants, CI2-X (X=GIy, Ala, Val, Tyr, His) and Cl2-His-X (X=GIy, Ala, Leu) have been synthesized and the structure has been identified by IHNMR and MS. Its SOD-like activity was assayed as inhibition of cytochrome-c reduction(l). These complexes display a relatively high SOD-like activity, which is higher than their corresponding non-functional surfactants. The difference in behavior can be explained by the fact of micellar catalysis. SOD-like activity of all complexes varies with their initial concentration, showing a typical feature of enzyme kinetics. An activity enhancement of complexes has been observed in the presence of CTAB micelles. (i) Lu Chun-Su, et al., J. Beij. Med. Univ., 2~0, 451 (1988).
L073
MODEL COMPLEXES FOR Cu, Zn-SUPEROXIDE DISMUTASE. W. X. Tang, D. Chen, A . B . Dai, Nanjing University, Nanjing, P . R .
China. In order to find out the influence of ligand environments of Cu bound at the active site of Cu, Zn-SOD upon the enzymic activity, a series of imidazolate bridged heterobinuclear and heteropolynuclear complexes with different geometries were synthesized and characterized. The catalytic activities of the complexes in O{ disproportionation were measured. The results indicate that the central Cu with N4 and N202 square planar or N40 square pyramidal coordination in which there is a weak bond H20 on axial position has comparatively higher activity, but that with N5 square pyramidal having a strong bond axial ligand has almost no activity. Thus the results imply a possible formation of Cu-O~- intermediate adduct in the catalytic process by Cu, Zn-SOD.
L074
CONTRIBUTION
TO
THE
UNDERSTANDING
OF
THE
PROPERTIES
OF
TYPE
III
COPPER SITES. A. Benzekri, C. Cartier, + P. Dubourdeaux, J.M. Latour, J. Laugier, x P. Rey and+ M. Verdaguer. + DRF/LCH and XDRF/SP~, CENG 38041 Grenoble Cedex, and LURE, 91405 Orsay Cedex, France. The structural properties of two series of dinuclear copper complexes of new binucleating ligands have been investigated through x-ray crystallography and EXAFS and XANES techniques. They will serve as a basis for discussing the spectroscopic, redox and magnetic properties of these compounds. These properties (strong antiferromagnetic interactions, high Cu(I)/Cu(II) potentials) match those of the biological sites. A comparison of the latter and various existing models will be provided.
Abstracts
L072
SOD-LIKE
ACTIVITY
STUDIES
OF F U N C T I O N A L
SURFACTANTS
- CONTAINING
COPPER (II) COMPLEXES, Lu Chun-Su and Xiang Yang, School of Pharmaceutical Sciences, Beijing Medical University, Beijing 100083,PRC Eight functional surfactants, CI2-X (X=GIy, Ala, Val, Tyr, His) and Cl2-His-X (X=GIy, Ala, Leu) have been synthesized and the structure has been identified by IHNMR and MS. Its SOD-like activity was assayed as inhibition of cytochrome-c reduction(l). These complexes display a relatively high SOD-like activity, which is higher than their corresponding non-functional surfactants. The difference in behavior can be explained by the fact of micellar catalysis. SOD-like activity of all complexes varies with their initial concentration, showing a typical feature of enzyme kinetics. An activity enhancement of complexes has been observed in the presence of CTAB micelles. (i) Lu Chun-Su, et al., J. Beij. Med. Univ., 2~0, 451 (1988).
L073
MODEL COMPLEXES FOR Cu, Zn-SUPEROXIDE DISMUTASE. W. X. Tang, D. Chen, A . B . Dai, Nanjing University, Nanjing, P . R .
China. In order to find out the influence of ligand environments of Cu bound at the active site of Cu, Zn-SOD upon the enzymic activity, a series of imidazolate bridged heterobinuclear and heteropolynuclear complexes with different geometries were synthesized and characterized. The catalytic activities of the complexes in O{ disproportionation were measured. The results indicate that the central Cu with N4 and N202 square planar or N40 square pyramidal coordination in which there is a weak bond H20 on axial position has comparatively higher activity, but that with N5 square pyramidal having a strong bond axial ligand has almost no activity. Thus the results imply a possible formation of Cu-O~- intermediate adduct in the catalytic process by Cu, Zn-SOD.
L074
CONTRIBUTION
TO
THE
UNDERSTANDING
OF
THE
PROPERTIES
OF
TYPE
III
COPPER SITES. A. Benzekri, C. Cartier, + P. Dubourdeaux, J.M. Latour, J. Laugier, x P. Rey and+ M. Verdaguer. + DRF/LCH and XDRF/SP~, CENG 38041 Grenoble Cedex, and LURE, 91405 Orsay Cedex, France. The structural properties of two series of dinuclear copper complexes of new binucleating ligands have been investigated through x-ray crystallography and EXAFS and XANES techniques. They will serve as a basis for discussing the spectroscopic, redox and magnetic properties of these compounds. These properties (strong antiferromagnetic interactions, high Cu(I)/Cu(II) potentials) match those of the biological sites. A comparison of the latter and various existing models will be provided.