Solubility and Aggregation Behavior of Octanoyl Amino Acids Magnesium Complexes

Abstract

Using L-octanoyl alanine and L-octanoyl phenylalanine as precursors, they are reacted with magnesium hydroxide to prepare two low-molecular complexes Mg(oct-L-ala)2 and Mg(oct-L-phe)2. The composition and structure of the two complexes are characterized by elemental analysis, nuclear magnetic resonance spectroscopy and moisture analyzer, with the solubility and aggregation behavior of the complexes studied. A comparison of the two complexes shows that the Mg(oct-L-ala)2 complex exhibits better solubility and is easier to aggregate in the mixed solution. In addition, the aggregated solid formed by the aggregation of these two complexes in the solution has optically heterogeneous properties. After further heating and cooling treatment, the Mg(oct-L-phe)2 complex still retains the optically anisotropic state (liquid crystal state), while the Mg(oct-L-ala)2 complex forms an optically homogeneous morphology (glass state). This may be affected by the benzene ring functional group in the Mg(oct-L-phe)2 complex.