International Journal of Peptide and Protein Reseach 1990-06-01

Thiolysis of the 3-nitro-2-pyridinesulfenyl (Npys) protecting group. An approach towards a general deprotection scheme in peptide synthesis.

O Rosen, S Rubinraut, M Fridkin

Index: Int. J. Pept. Protein Res. 35(6) , 545-9, (1990)

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Abstract

The hydroxylic side-chain functional groups of serine, threonine, hydroxproline and tyrosine, the alpha and epsilon-amino moieties of lysine and the thiol group of cysteine were masked by the 3-nitro-2-pyridinesulfenyl (Npys) protecting group. Deprotection was mildly affected by thiolysis with either 2-mercaptopyridine and 2-mercaptomethyl imidazole (O- and N-Npys) or with 3-mercaptoacetic acid and 2-mercaptoethanol (S-Npys). Thiolysis was monitored spectrophotometrically and was completed in a rather short time. Incorporation of the Npys group into a whole and single thiolyzable deprotection scheme is suggested.