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Structural elucidation studies of erythromycins by electrospray tandem mass spectrometry
Author(s) -
Gates Paul J.,
Kearney Gordon C.,
Jones Raymond,
Leadlay Peter F.,
Staunton James
Publication year - 1999
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(19990228)13:4<242::aid-rcm447>3.0.co;2-b
Subject(s) - chemistry , fragmentation (computing) , tandem mass spectrometry , electrospray , mass spectrometry , chromatography , deuterium , tandem , electrospray ionization , analytical chemistry (journal) , stereochemistry , materials science , computer science , composite material , operating system , physics , quantum mechanics
Erythromycin A (EryA) was studied by electrospray ionisation tandem mass spectrometry (ESI‐MS/MS) with the aim of developing a methodology for the structural elucidation of novel erythromycins developed by biological synthetic methods. Skimmer dissociation along with sequential mass spectrometry studies (up to MS 5 ) have been employed in this study. In the low‐resolution MS/MS analysis of the polyketides, there are several fragment ions that are easily assigned to various neutral losses. These have all been confirmed by accurate‐mass measurements. There is also a series of peaks due to ring opening and fragmentation that can only be assigned by high‐resolution MS n analysis. Further experiments were performed in deuterated media (D 2 O/CD 3 OD 50%) which, along with the high‐resolution MS n of erythromycin analogues, has enabled us to identify some of the steps in the ring fragmentation, particularly the loss of the polyketide starter acid. This is an essential step for determining structural alterations in the novel polyketides, but further labelling experiments and studies on more erythromycin analogues are required before the complete fragmentation pathway can be confirmed. Copyright © 1999 John Wiley & Sons, Ltd.