Structural elucidation studies of erythromycins by electrospray tandem mass spectrometry

Gates, Paul J.; Kearney, Gordon C.; Jones, Raymond C. F.; Leadlay, Peter F.; Staunton, James

doi:10.1002/(sici)1097-0231(19990228)13:4<242::aid-rcm447>3.0.co;2-b

Cited by 30 publications

(1 citation statement)

References 13 publications

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“…The erythromycin molecule, displayed in the inset in Figure , consists of a 14-membered macrocycle bearing two sugar units, namely, d -desosamine and l -mycarose. Tandem mass spectrometry of erythromycin has been reported using CID activation, − infrared multiphoton dissociation (IRMPD), and also electron-induced dissociation (EID) . The present CID data (Figure , top panel) are in agreement with the earlier reports.…”

Section: Resultssupporting

confidence: 91%

Extreme Ultraviolet Radiation: A Means of Ion Activation for Tandem Mass Spectrometry

2018

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Tandem mass spectrometry has long been established as a corner stone of analytical and structural chemistry. Fast radical-directed dissociation, produced by electron-transfer and electron-capture dissociation (ETD and ECD) has been shown to provide important complementary information to collision-induced dissociation (CID). We report the first application of extreme-ultraviolet (XUV) lamps to tandem mass spectrometry. These discharge lamps are versatile, robust, and low-cost sources of energetic photons (40-80 nm). The coupling of the discharge lamp with a Waters Synapt G2-Si Q-ToF mass spectrometer is achieved through a specific trapping scheme in the TriWave region of the instrument, allowing efficient irradiation of the precursor ions. Rich radical-directed dissociation was produced for a number of model compounds, providing unique, complementary information to existing dissociation techniques.

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Section: Resultssupporting

confidence: 91%

Extreme Ultraviolet Radiation: A Means of Ion Activation for Tandem Mass Spectrometry

2018

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Structural elucidation studies of erythromycins by electrospray tandem mass spectrometry II

Kearney

Gates

Leadlay

et al. 1999

Rapid Commun. Mass Spectrom.

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Erythromycin A (EryA), sec-butyl erythromycin B (SEryB), oleandomycin (Olean) and a synthetic derivative, roxithromycin (Rox), were used to investigate the fragmentation of polyketide macrolide antibiotics by collision induced dissociation (CID) tandem mass spectrometry (MS/MS). Analyses were performed with two commercially available mass spectrometers: a Q-TOF hybrid quadrupole time-of-flight instrument and a BioApex II (4.7 Tesla) Fourier transform ion cyclotron resonance (FTICR) instrument both equipped with electrospray ionisation (ESI) sources. One of the first fragmentation processes is the loss of an H(2)O molecule from the [M+H](+) ion. EryA has three hydroxyl groups on the polyketide ring and loses three H(2)O molecules during CID. This study indicates that these facts are not necessarily related. Deuterium exchange experiments were carried out in order to isotopically label free hydroxyl groups. (18)O-exchange experiments were also carried out in order to label the carbonyl group at the 9-position. In EryA and its analogue the first H(2)O loss shifts in mass from loss of 18 Da to loss of 20 Da in deuterated solvents. For both molecules the loss also shifts in mass from loss of 18 Da to loss of 20 Da during the (18)O-exchange experiments. This suggests that the first loss of H(2)O is from the 9-position carbonyl group, indicating that this, and not the nitrogen of the amino sugar, is the site of protonation of the activated MH(+) ions. For Rox the initial loss of H(2)O is replaced by loss of the 9-position oxime group, the rest of the fragmentation sequence being the same as for EryA. For Olean, there is no H(2)O loss from the parent ion. The results have allowed the proposal of a mechanism for the first loss of H(2)O in the EryA MS/MS fragmentation.

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Analysis of a commercial preparation of erythromycin estolates by tandem mass spectrometry and high performance liquid chromatography/electrospray ionization tandem mass spectrometry using an ion trap mass spectrometer

Lai

Tsai

et al. 2000

Rapid Commun. Mass Spectrom.

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Because of the lack of a UV chromophore and their much smaller abundances in comparison with the major component, the minor components in erythromycin estolate preparations are difficult to analyze by high performance liquid chromatography ultraviolet (HPLC-UV). Tentative assignment of the major and minor components can be achieved with the combination of full scan and ZoomScan using an ion trap mass spectrometer. Tandem mass spectrometry (MS/MS) provided an effective method to quickly identify most components without chromatographic separation, and all the related compounds, except the isobaric pair ECE and PdMeEA, could be identified in this way. The best result was obtained by using liquid chromatography/tandem mass spectrometry (LC/MS/MS) operated in selected reaction monitoring mode. The major compound, the estolate of erythromycin A (EAE), and seven other minor components, could be separated and identified, with semiquantitative estimates of relative concentrations.

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Structural elucidation studies of erythromycins by electrospray tandem mass spectrometry

Cited by 30 publications

References 13 publications

Extreme Ultraviolet Radiation: A Means of Ion Activation for Tandem Mass Spectrometry

Extreme Ultraviolet Radiation: A Means of Ion Activation for Tandem Mass Spectrometry

Structural elucidation studies of erythromycins by electrospray tandem mass spectrometry II

Analysis of a commercial preparation of erythromycin estolates by tandem mass spectrometry and high performance liquid chromatography/electrospray ionization tandem mass spectrometry using an ion trap mass spectrometer

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