Circular dichroism induced by the helical conformations of acylated chitosan derivatives bearing cinnamate chromophores
Circular dichroism induced by the helical conformations of acylated chitosan derivatives bearing cinnamate chromophores
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带有肉桂酸发色团的酰化壳聚糖衍生物的螺旋构象诱导的圆二色性
DOI：
10.1002/polb.20420
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
K. Sakurai
中科院分区：
文献类型：
--
作者：
Yusong Wu;T. Seo;S. Maeda;Takashi Sasaki;S. Irie;K. Sakurai
通过区域选择性修饰，制备了取代度（DS）为0.8 ~ 2.0的O-肉桂酰基壳聚糖和不同脂肪酰基链长（C2 ~ C12）的N-脂肪酰基-O-二肉桂酰基壳聚糖，并利用圆二色谱（CD）研究了它们在稀溶液中的手性性质。两个相邻的肉桂酰基发色团附加到螺旋主链之间的激子耦合引起的双信号棉花效应（CE），这是用来推断在溶液中的扭曲结构的绝对意义。研究发现，绝对螺旋度随DS、脂肪链长度和溶剂性质而变化，但几乎与热刺激无关。讨论了自组装有序结构中可能涉及的分子间相互作用（氢键和疏水作用）。© 2005 Wiley Periodicals，Inc.聚合物科学杂志B部分：聚合物物理43：1354-1364，2005
Through regioselective modifications, some acylated chitosan derivatives, O-cinnamoyl chitosans with degree of substitution (DS) varying from 0.8 to 2.0 and N-fatty acyl-O-dicinnamoyl chitosans with different fatty acyl chain lengths (C2–C12), were prepared, and their chiroptical properties in dilute solutions were investigated by circular dichroism (CD). Exciton coupling between two vicinal cinnamoyl chromophores appended to the helical mainchains gave rise to bisignate Cotton effects (CEs), which were used to deduce the absolute sense of the twisting structures in solution phase. It was found that the absolute helicities vary with DS, length of the fatty chain, and solvent property, but are nearly independent of thermal stimulus. The molecular interactions (hydrogen bonding and hydrophobic interaction) involved possibly in the self-assembled ordered structures were discussed. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1354–1364, 2005