Researchers studied how cyclodipeptides break apart in mass spectrometry. They found that most cyclodipeptides break down in similar ways. When cyclodipeptides have large side chains, they first lose the side chain group and then break down further. For example, cycloglycylglycine produced ions at m/z 86 [M-CO] and m/z 71 [M-NHCO] in the mass spectrum. The most abundant ion at m/z 30 was formed from the ion at m/z 86.