The electron impact induced fragmentation of Aspergillus amstelodami alkaloids and derivatives.

The mass spectral data of four isoprenylated indole alkaloids containing a piperazinedione group, neoechinuline, cryptoechinuline C, and A and echinuline, isolated from Aspergillus amstelodami cultures, and of two derivatives obtained by catalytic hydrogenation of neoechinuline and echinuline, are reported and discussed. Their fragmentation patterns are strongly dependent upon the presence of a single or a double bond betueen C-8 and C-9.