Datasheet1_Chiral Water-Soluble Molecular Capsules With Amphiphilic Interiors.pdf

We present the synthesis of new chiral water-soluble dimeric capsules by the multicomponent Mannich reaction between charged amino acids (glutamic acid or arginine), resorcinarene, and formaldehyde and by subsequent self-assembly. The zwitterionic character of the backbones enables electrostatic interactions between arms and induces self-assembly of dimeric capsules, namely, (L-ArgR)2 and (L-GluR)2, in water with a wide range of pH, as demonstrated by NMR, diffusion coefficient measurement, and circular dichroism. The assembly/disassembly processes are fast on the NMR timescale. This mode of dimerization leaves side chains available for additional interactions and creates chiral cavities of mixed hydrophobic/hydrophilic character. According to this characteristic, capsules do not bind fully nonpolar or fully polar guests but effectively encapsulate a variety of chiral molecules with mixed polar/apolar characters (aliphatic and aromatic aldehydes, epoxides, alcohols, carboxylic acids, amines, and amino acids) with moderate strength. We also demonstrate the formation of heterocapsules (GluR) (ArgR) (homo- and heterochiral) that utilize additional interactions between charged acidic and basic side chains and have better encapsulation properties than those of the homodimers.本研究报道了通过带电氨基酸（谷氨酸(glutamic acid)或精氨酸(arginine)）、间苯二酚芳烃(resorcinarene)与甲醛之间的多组分曼尼希反应(Mannich reaction)，经后续自组装过程合成新型手性水溶性二聚胶囊的方法。主链的两性离子特性可实现臂段间的静电相互作用，从而诱导二聚胶囊在宽pH范围的水溶液中自组装形成，具体为(L-ArgR)₂与(L-GluR)₂，该结论已通过核磁共振(NMR)、扩散系数测试与圆二色谱(circular dichroism)得以验证。该组装/解组装过程在核磁共振时间尺度上快速进行。此种二聚化方式可保留侧链以参与额外相互作用，并构建出兼具疏水/亲水特性的手性空腔。基于该特性，此类胶囊无法结合完全非极性或完全极性的客体分子，但可高效包合一系列兼具极性/非极性特性的手性分子（包括脂肪族与芳香族醛类、环氧化物、醇类、羧酸类、胺类以及氨基酸），结合强度适中。本研究还证实了异源胶囊(GluR)(ArgR)（包含同手性与异手性结构）的形成，这类胶囊借助带电酸性与碱性侧链间的额外相互作用，其包合性能优于同源二聚胶囊。