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Separation of cyclosporins by high‐performance liquid chromatography and mass spectrometric study of cyclosporin metabolites
Author(s) -
Tuominen J.,
Suortti T.,
Ishikawa K.,
Lundell J.,
Koga Y.
Publication year - 1998
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/(sici)1097-0231(19980831)12:16<1085::aid-rcm284>3.0.co;2-l
Subject(s) - chemistry , chromatography , cyclosporins , fast atom bombardment , mass spectrometry , tandem mass spectrometry , ion , isobaric process , analytical chemistry (journal) , organic chemistry , transplantation , medicine , physics , surgery , thermodynamics
A semi‐preparative (high‐performance liquid chromatography) method for separation of cyclosporin metabolites in a fungal fermentation sample was developed. By using the optimized chromatographic separation, 20 cyclosporin metabolites in a process sample were isolated, and their molecular masses measured by double focusing sector mass spectrometry. The structures of some of the cyclosporin congeners were investigated by tandem sector mass spectrometry using fast atom bombardment ionization. The isobaric cyclosporins D ([Val 2 ]CS) and G ([Nva 2 ]CS) were differentiated by significantly different relative intensities of a fragment ion at m/z 30 [CH 4 N] + from a precursor ion at m/z 72 [C 4 H 10 N] + . Otherwise the tandem mass spectrometry (MS/MS) spectra of the fragment ions of the two isomers are very similar. Cyclosporin A and iso‐cyclosporin A were also analysed by high energy MS/MS. No significant fragment ions were found to provide distinctions between them. Relatively good overviews of process samples containing very similar structures were achieved by combining LC separation, molecular ion recognition and MS/MS characterization. © 1998 John Wiley & Sons, Ltd.