两性反应的

Two kinds of water-soluble biomimetic chitosan derivatives with a phosphoramide linkage between glucosamine and choline were prepared through Atherton-Todd reaction under the mild conditions, including zwitterionic phosphorylcholine bound chitosan and acetyl-phosphorylcholine bound chitosan with positive charge. The interaction between chitosan derivatives and calf thymus DNA were inversigated by UV alsorption spectra and circular dichroism spectra.

采用Antherton-Todd反应制备了两种水溶性的磷酰化壳聚糖仿生衍生物：两性的N-磷酸胆碱磷酰化壳聚糖和带正电荷的N-乙基磷酸胆碱磷酰化壳聚糖，并用紫外吸收光谱和圆二色光谱研究了两种胆碱磷酰化壳聚糖衍生物与小牛胸腺DNA的相互作用。

In the meantime, we proposed a mechanism for this catalytic reaction. According to the possible formation of intermediate B, we designed a disubstituted ketene of more function to re-capture the zwitterion.

在同位素标记基础上，我们推测了这个N-甲基咪唑催化的二组分反应可能的机理，并根据此机理设计用一个二取代的烯酮来捕捉N-甲基咪唑和DMAD形成的两性离子。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。