Chemical ionization mass spectrometry of macrolide antibiotics. III—M-4365 and related compounds

Suzuki, Makoto; Harada, Kenichi; Takeda, Nobuhiro; Tatematsu, Akira

doi:10.1002/bms.1200080803

Cited by 16 publications

(2 citation statements)

References 17 publications

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“…Besides quasi-molecular ions at m/z 484 and 485, fragment ions due to aminoglycoside bond cleavages were also observed at m/z 324, 163, and 162 for kanamycin A and C, and m/z 324, 323,163,162, and 161 for kanamycin B. Precisely the same species are observed in emitter Cl (27) and secondary ion mass spectra, as shown in Figures 7 and 8. These spectra show that API gives less fragmentations and therefore seems to be a milder ionization method than emitter CL Generally, secondary ion mass spectra give structural information.…”

Section: Reproducibility Of Mass Chromatogram Peaksmentioning

confidence: 60%

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Characteristics of a liquid chromatograph/atmospheric pressure ionization mass spectrometer

Sakairi¹,

Kambara²

1988

Anal. Chem.

104

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The wide applicability and high sensitivity of a liquid chromatograph/atmospheric pressure Ionization mass spectrometer (LC/API-MS) using an Interface with direct heating nebulizer and vaporizer are reported. This system can produce molecular Ions of many nonvolatile compounds comprising amines, amino acids, peptides, antibiotics, nucleosides, nucleotide, steroids, sugars, lipids, vitamins, and alkaloids, which are difficult or Impossible to handle by gas chromatography/mass spectrometry. The detection limit of this system by selected Ion detection (SID) mode is 5 pg for some compounds such as theophylline and caffeine. In the API method, reduced fragmentation for some types of compounds provides Insufficient structural Information. However, a simple CID method operated at a relatively high pressure proves to be useful for producing fragment Ions which give structural Information.Recently, analysis of mixtures of nonvolatile compounds has become increasingly important. For this reason, a liquid chromatograph/atmospheric pressure ionization mass spectrometer (LC/MS) shows promise as a new analysis method in various fields. Many groups have reported various kinds of LC/MS systems including a thermospray method (1-5), a moving belt method (6, 7), a DLI method (8, 9), a vacuum nebulizing method (10,11), an atmospheric pressure ionization (API) method (12-20), and so on.Basically, an API method has a moderately high sensitivity. However, the sensitivities of the reported liquid chromatograph / atmospheric pressure ionization mass spectrometer (LC/API-MS) systems are not so high (12,(16)(17)(18). In a LC/API-MS system, the sensitivity strongly depends on the size of gas clusters produced by an interface. To obtain very small gas clusters, a nebulizer producing very small droplets is required in the interface. Previously, the authors used a nebulizer with an ultrasonic vibrator for this purpose (14,15). However, the lifetime of the vibrator was not long enough. Consequently, a direct heating nebulizer like a thermospray interface probe (1-3) is used here. This nebulizer is very simple and has a long life. Other problems in LC/API-MS system are formation of cluster ions (19,21,22) and reduced fragmentation resulting from mild ionization (19). These difficulties can be overcome by a collision-induced dissociation (CID) method in a relatively high pressure region of a mass spectrometer (21, 22). This paper reports the detail of this system and demonstrates the high performance and wide applicability of the system. EXPERIMENTAL SECTION Apparatus. A schematic diagram of the interface and the API ion source of the LC/API-MS system is shown in Figure 1. In this system, effluents from a LC are vaporized by the interface. The vaporized sample and solvent molecules are then ionized by corona discharge followed by ion/molecule reactions. The resulting ions are introduced into mass analyzing region of a sector type mass spectrometer through two apertures.LC. A Hitachi 655A high-performance liquid chromatograph (HPLC) with a loop in...

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Section: Reproducibility Of Mass Chromatogram Peaksmentioning

confidence: 60%

“…Antibiotics. Structural elucidation of antibiotics is one of the important research targets in mass spectrometry and Cl (23) and FAB and SIMS (24) methods have been used for this study. However, only a few papers on LC/MS with antibiotics were reported (25,26).…”

Section: Reproducibility Of Mass Chromatogram Peaksmentioning

confidence: 99%

Characteristics of a liquid chromatograph/atmospheric pressure ionization mass spectrometer

Sakairi¹,

Kambara²

1988

Anal. Chem.

104

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Sequence determination of permethylated oligosaccharides by chemical ionization mass spectrometry

Harada

Ito

Takeda

et al. 1983

Biol. Mass Spectrom.

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Chemical ionization mass spectra of several permethylated oligosaccharides were studied using isobutane and ammonia as reagent gases. In the molecular ion region, protonated molecule [MH]" or ammonium adduct ion [M-NHJ were observed. Fragmentations were mainly restricted to the cleavages of the glycosidic bonds between the glycosidic oxygen and the anomeric carbon atoms. Resulting fragment ions were classified into oxonium type ions and their counterpart ions with hydrogen or methyl transfer, which were very useful for determining the sequence of the constituent saccharide units. These ions were confirmed by shift techniques with pertrideuteromethyl derivatives, deuterated reagent gases, i-C,ZH,, and N'H,, and 15NH3. Finally, these results were applied successfully to the structural characterization of the unknown trisaccharides, viridotriose A (6), B (7) and C (8).

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Structural characterization of underivatized menthyl glycosides using chemical ionization mass spectrometry

Takeda

Harada

Suzuki

et al. 1983

Biol. Mass Spectrom.

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Mass spectra of a series of menthyl glycosides containing up to three sugar units produced by chemical ionization with isobutane and ammonia as reagent gases as well as (*H3) ammonia are reported. The applicability of this mass spectrometric method in structural characterization of the underivatized glycosides is discussed. All of the mass spectra are simple to interpret and afford useful diagnostic information about molecular weight and structural units in the molecules but little information for differentiation between the stereoisomers. The fragmentations producing the diagnostic ions have been confirmed with high resolution measurements and shift technique with ('H3)ammonia reagent gas.

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Chemical ionization mass spectrometry of macrolide antibiotics. III—M-4365 and related compounds

Cited by 16 publications

References 17 publications

Characteristics of a liquid chromatograph/atmospheric pressure ionization mass spectrometer

Characteristics of a liquid chromatograph/atmospheric pressure ionization mass spectrometer

Sequence determination of permethylated oligosaccharides by chemical ionization mass spectrometry

Structural characterization of underivatized menthyl glycosides using chemical ionization mass spectrometry

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