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Fragmentation of diketopiperazines from Aspergillus fumigatus by electrospray ionization tandem mass spectrometry (ESI-MS/MS)

Authors :
José Carlos Tomaz
Sérgio E. Galembeck
Antônio Eduardo Miller Crotti
Ricardo Vessecchi
Jairo Kenupp Bastos
Norberto Peporine Lopes
Niege Araçari Jacometti Cardoso Furtado
Source :
Journal of mass spectrometry : JMS. 42(10)
Publication Year :
2007

Abstract

Diketopiperazines (DKPs) corresponding to cyclic dipeptides have been reported to exhibit antimicrobial, antitumor, antimutagenic and antiviral properties. These compounds are commonly isolated from microorganisms and sponges and from a variety of tissues and body fluids. In this work, we used electrospray ionization tandem mass spectrometry (ESI-MS/MS) to investigate the fragmentation of a series of DKPs previously isolated from Aspergillus fumigatus, which exhibit the same structural core. Loss of CO directly from the protonated molecule was found to be a fragmentation process common to all the compounds analyzed. However, our results revealed a series of ions that are diagnostic for the substituents at C(4) and C(9). In order to rationalize the differences in the fragmentation pathways of substituted and nonsubstituted DKPs, the relative Gibbs energies (1G) of the product ions and intermediate ions were estimated using the B3LYP/6‐31++G(d,p) model. The data reported here can be used for the structural elucidation of DKPs from low sample amounts, as an alternative to NMR. Copyright  2007 John Wiley & Sons, Ltd.

Details

ISSN :
10765174
Volume :
42
Issue :
10
Database :
OpenAIRE
Journal :
Journal of mass spectrometry : JMS
Accession number :
edsair.doi.dedup.....4970f2ad7febab9a27f6ed77b480c533