{"knowledge_schema": {"broad_category": "Chemistry \u2192 Structural Analysis \u2192 NMR Spectroscopy", "refinement": "This problem involves interpreting NMR spectral data and mass spectrometry results to understand the structural characteristics of a peptide.", "specific_scope": "The focus is on the observation of two sets of peaks for beta-protons in the NMR spectrum and the presence of two peaks in LC-MS analysis, indicating structural diversity in the peptide.", "goal": "Identify the structural explanation for the observed spectral data, particularly regarding the presence of diastereoisomers."}, "summary": "In this scenario, the observations from the 1H NMR spectrum and LC-MS analysis suggest that the peptide exists as a mixture of diastereoisomers. The presence of two sets of peaks for beta-protons, each integrating to 1H, indicates that there are two distinct environments for these protons, which is characteristic of diastereoisomers. Additionally, the equal intensity of the two peaks in the LC-MS analysis supports the idea of structural diversity without indicating contamination or racemization, as both diastereoisomers would have the same mass but different spatial arrangements."}