It is known that several kinds of pyrrolidine alkaloids with a bis-amide structure are isolated from extracts from leaves and roots of Meliaceae family plants. A fragment ion m/z 85 was found in common in mass spectra of all these compounds. The structure and fragmentation mechanism of the ion were elucidated through high-resolution mass spectra and B/E as well as B2/E linked scan spectra. The fragment ion was also found useful as an index for searching compounds having similar structures.
