To further confirm the identity of the unidentified signal, we considered that the difference of 106.979 ± 0.0102 Da would equal the mass of a chemical moiety analogous to a dehydrated peptide residue. Thus, the mass was hydrated in silico, and the NIST chemical database () was searched for all compounds in the mass range of 124.99-125.03 Da. This search yielded 31 compounds consisting mostly of structural isomers and radical species.