PURPOSE: To obtain the subject new peptide useful for treating allergic diseases by synthesizing a straight-chain peptide on a resin by a solid phase method using a protected amino acid, subjecting to ring closure with a side-chain carboxylic acid of C-end aspartic acid, cutting off the peptide from the resin.
CONSTITUTION: Aspartic acid containing a amino group protected with 9- fluorenylmethoxycarbonyl(Fmoc) group and β carboxyl group protected with benzyl group is linked through a carboxyl group to a resin, the resultant substance is treated with an organic base to remove Fmoc group, amino acids containing an α amino group and a side-chain functional group which are protected are successively bonded according to an amino acid sequence of a peptide to give a peptide resin. Then the peptide resin is treated with an alkali to remove benzyl group of Asp of the peptide resin, the resulting substance is treated with an organic chlorine to remove Fmoc group at an N end. The resultant substance is condensed.subjected to ring formation with a condensation agent, the peptide is removed from the resin by adding an acid, the protecting group is removed and a cyclic peptide of the formula for preventing and treating various kinds of allergic diseases is recovered from the liquid phase.
YAMAMOTO YASUO
NOGUCHI KEIICHI
