{"knowledge_schema": {"broad_category": "Chemistry \u2192 Organic Chemistry \u2192 Spectroscopy and Isomerism", "refinement": "This problem involves analyzing the NMR spectrum and mass spectrometry data of a synthesized peptidic compound to understand the nature of observed peaks.", "specific_scope": "The focus is on interpreting the presence of duplicate peaks in the 1H NMR spectrum and LC-MS analysis, which suggest the existence of different forms of the compound.", "goal": "Identify the most plausible explanation for the observed spectral data and peaks in the context of isomerism or contamination."}, "summary": "In this problem, we analyze the 1H NMR spectrum and LC-MS data of a synthesized peptidic compound that shows duplicate peaks for the same alpha-proton. The peaks have similar chemical shifts and integrals, and the LC-MS analysis reveals two peaks of equal intensity with the same mass spectrum. The most likely explanation for these observations is that the crude compound exists as a mixture of diastereoisomers, as this would account for the duplicate peaks without involving contamination or enantiomeric forms."}