Spontaneous Assembly Formation of Cyclic Dimer of (beta)-Amino Acid in Water

A novel cyclic dimer composed of chiral L-(beta)-homoalanine was synthesized, and the formation of molecular assembly in water was investigated. The cyclic dimer was found to spontaneously form a spherical assembly with diameter of 40–100 nm in water. The cyclic dimer takes a boat conformation with cis-amide configuration, and forms intermolecular hydrogen bondings in the assembly. The assembling property of the cyclic dimer of (beta)-amino acid is distinct from that of (alpha)-amino acid.