Fig. 8

LC-Q-TOF mass spectrum (ESI⁺) of peptides and their proposed fragmentation patterns in positive-ion mode. A = Isoleucyl-Alanine, [M + H]⁺with m/z202) shows product ions with m/z185 by the loss of H₂O, which further dissociated to produce a fragment ion at m/z129 and 86 due to elimination of (C₃H₅O₂) ,(C₄H₆NO₃), respectively. B = L-isoleucyl-L-proline[M + H]⁺with m/z228), started the formation of a fragment ion at m/z210 by the loss of H₂O, which further dissociated to produce a fragment ion at m/z86 due to the loss of the(C₆H₈NO₃)