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Eur. J. Mass Spectrom.
9, 563–577 (2003)
DOI:
10.1255/ejms.589 |
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Unusual covalent bond-breaking reactions of β-cyclodextrin inclusion complexes of nucleobases/nucleosides and related guest
molecules |
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Ana K. Vrkic and Richard A.J. O’Hair*
School of Chemistry, University of Melbourne, Victoria, Australia 3010. E-mail:
rohair@unimelb.edu.au
Carlito B. Lebrilla
Department of Chemistry, University of California, Davis, California, 95616, USA |
| ABSTRACT: |
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Host–guest complexes
between nucleobases or nucleosides and β-cyclodextrin can be observed by electrospray ionization mass spectrometry (ESI-MS) and their relative abundances appear to
correlate with the condensed-phase binding order. Using Fourier transform ion cyclotron resonance mass spectrometry, the extent of the interactions between the host
oligosaccharide and guest species have also been examined for permethylated β-cyclodextrin : adenine/deoxyadenosine and permethylated maltoheptaose :
adenine/deoxyadenosine using gas-phase exchange reactions with the gaseous amines, n-propylamine and ethylenediamine. The ease of guest exchange in the gas-phase
follows the order : deoxyadenosine > adenine >> deoxycytidine > cytosine, which is in contrast to their relative binding order in solution. Collision-induced dissociation (CID) has
been used to probe the fragmentation behavior of oligosaccharide : nucleobase/nucleoside complexes. Under these conditions the inclusion complexes either (a) dissociate, (b)
result in cleavage of the host oligosaccharide or (c) result in cleavage of the guest molecule. This study has shown that the preferred dissociation pathway of these complexes
depends on the structures of both the cyclodextrin and guest molecule. |
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Keywords:
β-cyclodextrin, nucleobases, nucleotides, inclusion complexes, electrospray ionization, tandem
mass spectrometry, ion–molecule reactions, collision-induced dissociation, fragmentation |
