Molecular Rotations of N^α-Acyl-L-lysines at Various pH Values

抄録

Molecular rotations of N^α-acyl-L-lysines were determined in water and in water containing various amounts of HCl or NaOH. The acyl groups were formyl, acetyl, propionyl, and butyryl. Each N^α-acyl-L-lysine exhibited more negative rotation in HCl or NaOH solution than in water. The plot of molecular rotation against amount of HCl or NaOH resembled that of a D-α-amino acid even though N^α-acyl-lysine was of L-form. The reason for this is discussed from the standpoint of steric factors. N^ε-Acyl-L-lysines corresponding to the N^α-acyl-L-lysines were synthesized as reference compounds. It was found that water-soluble N^ε-acyl-L-lysines can be easily prepared by acylation of the Cu complex solution of L-lysine hydrochloride in the presence of triethylamine. The molecular rotation plots for N^ε-acyl-L-lysines were typical of L-α-amino acids.