Figure 3

Mass spectra (electron impact, EI) for cyclic dipeptide 1 (1) for: S. virgatus (A), S. merriami (B), and the reference standard compound cyclo(L-Leu-Pro) (C). Mass spectra for cyclic dipeptide 2 (2) for: S. virgatus (D), S. merriami (E), and the reference standard compound cyclo(L-Pro-L-Pro) (F).