A water-soluble N-protecting group,2-(4-sulfophenylsulfonyl)ethoxycarbonyl group,and its application to solid phase peptide synthesis in water

摘要

Solid phase peptide synthesis has many advantages compared with solution peptide synthesis,but it requires a large amount of organic solvents.Since safe organic solvent disposal is an important environmental problem,we aimed to perform peptide synthesis in water.To carry out peptide synthesis in water,water-soluble protected amino acids are needed.Various water-soluble N-protecting groups have been reported,including the methylsulfonylethoxycarbonyl goup described by Tesser and Balvert-Geers,and the 2-(triphenylphosphonio)ethoxycarbonyl,2-(triphenylphosphonio)isopropyloxycarbonyl,and 2(4-pyridyl)ethoxycarbonyl groups reported by Kunz et al..Kunz has prepared a tripeptide,2-(triphenylphosphonio)ethoxycarbonyl-Leu-Phe-Phe-OtBu by a solution method in water.Kunz also reported that the 2(methylthio)ethoxycarbonyl group could be removed under mild basic conditions after treatment with methyl iodide.We previously reported the preparation of water-soluble N-protected amino acids,2-[phenyl(methyl)sulfonio]ethyloxycarbonyl-amino acids(Pms-amino acids),and.their application to solid phase peptide synthesis in water.We also previously reported the preparation of a water-soluble active ester,4-sulfophenyl ester.Here,we have deigned a new water soluble N-protecting group,2-(4-sulfophenylsulfonyl)ethyloxy-carbonyl(Sps)group,based on this water-soluble active ester.Sps amino acids were prepared as shown in Fig.1.