The peptide compound represented by the formula: ##STR1## which is useful as a germicide or disinfectant, is produced by reducing a compound of the formula: ##STR2## wherein Y is amino group which may optionally be protected; R.sup.1 is hydrogen or protective group; and R.sup.2 is hydrogen or protective group; and subjecting the reduction product compound to deprotection reaction when required. A compound of the formula: ##STR3## wherein Z is amino group which may optionally be protected; R.sup.1 is hydrogen or protective group; and R.sup.2 is hydrogen or protective group, is a useful as intermediate for production of the first-mentioned compound.