Sakowicz Arkadiusz Marek, Szumna Agnieszka
Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland.
Front Chem. 2022 Apr 14;10:883093. doi: 10.3389/fchem.2022.883093. eCollection 2022.
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-) and (L-), 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 () () (homo- and heterochiral) that utilize additional interactions between charged acidic and basic side chains and have better encapsulation properties than those of the homodimers.
我们通过带电氨基酸（谷氨酸或精氨酸）、间苯二酚芳烃和甲醛之间的多组分曼尼希反应以及随后的自组装，展示了新型手性水溶性二聚体胶囊的合成。主链的两性离子特性使臂之间能够发生静电相互作用，并诱导二聚体胶囊，即（L-）和（L-），在广泛的pH值范围内于水中自组装，这通过核磁共振（NMR）、扩散系数测量和圆二色性得到了证明。在NMR时间尺度上，组装/拆卸过程很快。这种二聚化模式使侧链可用于额外的相互作用，并产生具有混合疏水/亲水特性的手性空腔。根据这一特性，胶囊不会完全结合非极性或完全极性的客体，而是能以适度的强度有效包封各种具有混合极性/非极性特性的手性分子（脂肪族和芳香族醛、环氧化物、醇、羧酸、胺和氨基酸）。我们还展示了利用带电酸性和碱性侧链之间的额外相互作用形成的异质胶囊（）（）（同手性和异手性），其具有比同二聚体更好的包封性能
