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首页> 外文期刊>Spectrochimica acta, Part A. Molecular and biomolecular spectroscopy >Interaction of meso-tetrakis(4-sulphonatophenyl)porphine with chitosan in aqueous solutions
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Interaction of meso-tetrakis(4-sulphonatophenyl)porphine with chitosan in aqueous solutions

机译：介孔四（4-磺酰基苯基）卟啉与壳聚糖在水溶液中的相互作用

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Interaction of meso-tetrakis(4-sulphonatophenyl)porphine (TPPS4) with chitosan (M-r similar to 400kDa, N-acetyls similar to 20mol.%) was studied in aqueous solutions. UV-vis absorption and circular dichroism (CD) spectroscopic titration of 10 mu mol l(-1) TPPS4 with chitosan demonstrated that an addition of the polysaccharide at appropriate concentrations and pH values induce and support self-aggregation of the macrocycles. The mode of aggregation was strongly dependent on pH: stacking (H-type) aggregates predominated at weak acidic conditions (pH 4.8-6.8) and tilted (J-type) aggregates at pH 2.5. At the intermediate pH value (3.6) both types of TPPS4 aggregates were detected. High amount of chitosan (> 0.05 mmol l(-1) of GlcN) disrupts H-aggregates forming monomeric porphyrin-chitosan complexes (pH 3.6-6.8), while J-aggregates (pH 2.5) are stable even at very high chitosan concentrations. CD titration experiments confirmed the formation of optically active species of TPPS4 in the presence of chitosan. The complex nature of CD bands assigned to both types of porphyrin aggregates indicated the occurrence of several chiral macrocyclic species dependently on pH value and chitosan concentration. (c) 2006 Elsevier B.V. All rights reserved.
机译：在水溶液中研究了介孔四（4-磺酰基苯基）卟啉（TPPS4）与壳聚糖的相互作用（M-r类似于400kDa，N-乙酰基类似于20mol。％）。紫外可见吸收和圆二色性（CD）光谱滴定与壳聚糖的10μmol l（-1）TPPS4表明，在适当的浓度和pH值下添加多糖诱导并支持大环的自聚集。聚集的模式强烈依赖于pH：在弱酸性条件下（pH 4.8-6.8）占主导地位的堆积（H型）聚集体和在pH 2.5时倾斜的（J型）聚集体。在中等pH值（3.6）下，检测到两种类型的TPPS4聚集体。大量的壳聚糖（> 0.05 mmol l（-1）的GlcN）会破坏H聚集体，形成单体卟啉-壳聚糖复合物（pH 3.6-6.8），而J聚集体（pH 2.5）即使在很高的壳聚糖浓度下也很稳定。 CD滴定实验证实了在壳聚糖存在下TPPS4光学活性物种的形成。分配给两种卟啉聚集体的CD条带的复杂性表明，取决于pH值和壳聚糖浓度，出现了几种手性大环物种。 （c）2006 Elsevier B.V.保留所有权利。

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