ONH(S)NHNONH(S)NHONH(S)HOONH(S)OHONH(R)OONH(S)CH3CH3ONH(S)OONH(S)NHNHNH2NH-NHtBuNHNHHisTrpSerTyrD-SerLeuArgHNHOOCH3H3CCH3NH2ONH2O