MassBank, https://massbank.eu/
License: CC BY 4.0
Have an unknown? Upload it and match against SPIRO(CYCLOHEXANE-1,4'-((6'S)-6'-METHOXYCARBONYL-2'-METHYLPERHYDROPYRROLO(3,4-C)PYRROLE-1',3'-DIONE)) and thousands more references with HQI scoring.