Abstract: The structural characteristics of N-phosphorylated branched peptides 2-5 in solution have been studied by NMR. Diastereotopic phenomena, the interaction of hydrogen bonds and no regular secondary structures have been observed. It has been shown that participation of phosphoryl group only affects amino acid, which was bond on the phosphoryl group. Due to the formation of peptide planes and the increase of the effect of hydrogen bond between inter or intra-molecules, the position of P=O group relating with C_β=O group in compounds 2 5 was changed from trans into gauche conformation as compared with that in Dipp-Ala of compound 1. The phosphoryl group was still lain on trans position with N-C_α group. It suggests that there is not any polar groups on the side chain of the amino acid. These structural characteristics will provide some evidence for their studies.

Key words: N-phosphorylated branched peptide, NMR Conformation analysis