Effect of chitosan on the enantioselective bioavailability of the herbicide dichlorprop to Chlorella pyrenoidosa.
Effect of chitosan on the enantioselective bioavailability of the herbicide dichlorprop to Chlorella pyrenoidosa.
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DOI：
10.1021/es100507p
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发表时间：
2010-06
影响因子：
11.4
通讯作者：
Yuezhong Wen;Yu Yuan;Hui Chen;Dongmei Xu;Kunde Lin;Weiping Liu
中科院分区：
文献类型：
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作者：
Yuezhong Wen;Yu Yuan;Hui Chen;Dongmei Xu;Kunde Lin;Weiping Liu
壳聚糖是一种天然多糖，被广泛认为是一种具有生物相容性和潜在的控释药物载体。然而，壳聚糖对污染物环境行为的潜在影响尚不清楚，特别是对手性化学物质的影响。研究了壳聚糖对手性除草剂二氯丙对小球藻生物利用度的影响。(S)-对映体在不含壳聚糖的核核小球藻培养基中的消散速度快于具有除草活性的(R)-对映体，而在添加壳聚糖的培养基中，(R)-对映体的消散速度快于(S)-对映体。在不含壳聚糖的情况下，(R)-对映体对小球藻的毒性比(S)-对映体更强。相反，在壳聚糖的存在下，(R)-对映体的毒性小于(S)-对映体。这些观察结果清楚地表明壳聚糖改变了二氯丙的对体选择性生物利用度。荧光光谱分析表明，壳聚糖与二氯丙烷对映体的相互作用在很大程度上取决于二氯丙烷的空间结构，这可能解释了壳聚糖的加入改变了核核小球藻对二氯丙烷的对映选择性耗散的原因。这项工作表明，当与其他手性受体共存时，手性化合物在环境中的对映选择行为可能会发生改变。
Chitosan, a natural polysaccharide, is widely regarded as a biocompatible and potential carrier for controlled-release drug formulations. However, the potential effect of chitosan on the environmental behavior of contaminants is poorly understood, especially on chiral chemicals. In this study, the changes in bioavailability of the chiral herbicide dichlorprop to Chlorella pyrenoidosa by chitosan were investigated. The dissipation of (S)-enantiomer in Chlorella pyrenoidosa culture media without chitosan was faster than that of the herbicidally active (R)-enantiomer, whereas it was inversed to (R)-enantiomer being faster than (S)-enantiomer when chitosan was added into the media. In the absence of chitosan, the toxicity of (R)-enantiomer to Chlorella pyrenoidosa was more potent than that of the (S)-enantiomer. On the contrary, in the presence of chitosan, (R)-enantiomer was less toxic than (S)-enantiomer. These observations clearly suggest that chitosan changed the enantioselective bioavailability of dichlorprop. Fluorescence spectroscopic analysis showed that the interaction between chitosan and dichlorprop enantiomers depended greatly on the steric structure of dichlorprop, which offers a possible explanation as to why the addition of chitosan changed the enantioselective dissipation of dichlorprop by Chlorella pyrenoidosa. This work suggests that the enantioselective behaviors of chiral compounds in the environment might be shifted when interactions with other chiral receptors coexist.