Fragmentation of deprotonated cyclic dipeptides by electrospray ionization mass spectrometry

Guo, Yating; Cao, Shuting; Wei, Donghui; Zong, Xiangkun; Yuan, X.; Tang, Mingsheng; Zhao, Yufen

doi:10.1002/jms.1595

Cited by 16 publications

(20 citation statements)

References 31 publications

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“…3. [23,27,31]. The lactam-deprotonated Species 5 is therefore consistent with literature considerations.…”

Section: Glyser Fragmentationsupporting

confidence: 82%

“…S1. Zhao and co-workers [31] reported analogous product ions from cyclic dipeptides containing alkyl side chains. The first mechanism proposed for the formation of Species 9 from GlySer began with the well-established loss of formaldehyde and formation of the alpha enolate ion.…”

Section: Glyser Fragmentationmentioning

confidence: 94%

“…Using 13 C labeling the study also demonstrated that oxygen migration was not involved in the loss of CH 2 O, meaning that two hydrogens must have been transferred to the carbonyl group of the CH 2 O. In a more recent study, Cao, Zhao, and co-workers [31] reported on the fragmentation of deprotonated cyclic dipeptides by electrospray ionization (ESI)-MS/MS using an ion trap mass spectrometer interfaced with an ESI source. Although they did not look specifically at cyclo-(GlyGly), for other cyclic dipeptides containing only alkyl groups they reported a major product ion that is a deprotonated 2-imidazoline-4(5)-one, which they suggest is formed by the consecutive elimination of a molecule of CO and a saturated substituent (R + H, which would be H 2 in the case of cyclo-(GlyGly)).…”

Section: Introductionmentioning

confidence: 93%

“…There have also been studies of the fragmentation of protonated [29] and deprotonated [30,31] cyclic dipeptides, which exist as 2,5-DKPs. Bowie and co-workers [29] used negative chemical ionization to examine the mass spectra of various 2,5-DKPs, including cyclo-(GlyGly).…”

Section: Introductionmentioning

confidence: 99%

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Formation of deprotonated 2-imidazoline-4(5)-one product ions in the collision-induced dissociation of some serine-containing dipeptides

Swan

Findeis

Hilton

et al. 2015

International Journal of Mass Spectrometry

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a b s t r a c tA deprotonated 2-imidazoline-4(5)-one product ion was observed as a major fragment in the collisioninduced dissociation (CID) of several dipeptides containing serine at the C-terminal and an amino acid with an alkyl substituent at the N-terminal. This fragment becomes predominant at high collision energies. The same type of product ion was seen in the CID of cyclo(GlyGly). Labeling GlySer with O-18 suggests that the fragmentation may proceed through a symmetrical intermediate such as a deprotonated diketopiperazine. Density functional theory calculations of GlySer provided a possible mechanism for the fragmentation.

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“…3. [23,27,31]. The lactam-deprotonated Species 5 is therefore consistent with literature considerations.…”

Section: Glyser Fragmentationsupporting

confidence: 82%

Section: Glyser Fragmentationmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Formation of deprotonated 2-imidazoline-4(5)-one product ions in the collision-induced dissociation of some serine-containing dipeptides

Swan

Findeis

Hilton

et al. 2015

International Journal of Mass Spectrometry

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“…Bowie and coworkers [57] proposed the formation of a deprotonated DKP from diglycine methyl ester in high-energy CID. There have also been reports of CID fragmentation of deprotonated DKPs, as well as theoretical calculations of fragmentation pathways [81,82]. A diketomorpholine (DKM) is the analogous leaving group for a deprotonated peptide acid.…”

Section: Proposed Dissociation Mechanismsmentioning

confidence: 99%

A Comparison of the Effects of Amide and Acid Groups at the C-Terminus on the Collision-Induced Dissociation of Deprotonated Peptides

Bokatzian-Johnson

Stover

Dixon

et al. 2012

J. Am. Soc. Mass Spectrom.

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The dissociative behavior of peptide amides and free acids was explored using low-energy collision-induced dissociation and high level computational theory. Both positive and negative ion modes were utilized, but the most profound differences were observed for the deprotonated species. Deprotonated peptide amides produce a characteristic c m-2 -product ion (where m is the number of residues in the peptide) that is either absent or in low abundance in the analogous peptide acid spectrum. Peptide acids show an enhanced formation of c m-3 -; however, this is not generally as pronounced as c m-2 -production from amides. The most notable occurrence of an amide-specific product ion is for laminin amide (YIGSR-NH 2 ) and this case was investigated using several modified peptides. Mechanisms involving 6-and 9-membered ring formation were proposed, and their energetic properties were investigated using G3(MP2) molecular orbital theory calculations. For example, with C-terminal deprotonation of pentaglycine amide, formation of c m-2 -and a 6-membered ring diketopiperazine neutral requires 931.6 kcal/mol, which is 26.1 kcal/mol less than the analogous process involving the peptide acid. The end group specific fragmentation of peptide amides in the negative ion mode may be useful for identifying such groups in proteomic applications.

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UPLC–ESI–Q‐TOF–MS/MS analysis of anticancer fractions from Ophiocordyceps xuefengensis and Ophiocordyceps sinensis

Qin

Zhou

Jin³

et al. 2020

Biomedical Chromatography

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Ophiocordyceps xuefengensis (O. xuefengensis), a new species of caterpillar fungus, has been identified as the sister taxon of Ophiocordyceps sinensis (O. sinensis). The aims of the present study are to evaluate the anticancer activity and to qualitatively analyze the potential bioactive chemical constituents of O. xuefengensis and O. sinensis, comparatively. An MTT assay was used to evaluate the in vitro anticancer activities of different fractions from O. xuefengensis and O. sinensis. The results show that ethyl acetate fractions of O. xuefengensis and O. sinensis have significant in vitro anticancer activity. These two bioactive fractions were analyzed by ultra‐performance liquid chromatography–electrospray ionization with quadrupole–time of flight tandem mass spectrometry technology. A total of 82 compounds and 101 compounds were identified or tentatively characterized in the bioactive fractions of O. xuefengensis and O. sinensis, respectively. Among these compounds, 68 existed in both O. xuefengensis and O. sinensis. A total of 67 compounds were reported in O. xuefengensis and 8 compounds were reported in caterpillar fungus for the first time. This is the first detailed comparative analysis of the in vitro anticancer activity and chemical ingredients between O. xuefengensis and O. sinensis. The application of this work will provide reliable fundamental pharmacological substances for the use of O. xuefengensis by Yao people.

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Fragmentation of deprotonated cyclic dipeptides by electrospray ionization mass spectrometry

Cited by 16 publications

References 31 publications

Formation of deprotonated 2-imidazoline-4(5)-one product ions in the collision-induced dissociation of some serine-containing dipeptides

Formation of deprotonated 2-imidazoline-4(5)-one product ions in the collision-induced dissociation of some serine-containing dipeptides

A Comparison of the Effects of Amide and Acid Groups at the C-Terminus on the Collision-Induced Dissociation of Deprotonated Peptides

UPLC–ESI–Q‐TOF–MS/MS analysis of anticancer fractions from Ophiocordyceps xuefengensis and Ophiocordyceps sinensis

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