A theoretical and mass spectrometry study of the novel mechanism of N-glycosidic bond cleavage in nucleoside

Liu, Jihong; Cao, Shuting; Jia, Bin; Wei, Donghui; Liao, Xincheng; Lu, Jike; Zhao, Yufen

doi:10.1016/j.ijms.2009.01.003

Cited by 13 publications

(10 citation statements)

References 31 publications

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“…Negatively charged ions exhibit two major fragmentation pathways, deglycosylation to release the negatively charged nucleobase and phenyl radical loss to afford the distonic ion with m/z 281 (Scheme (a)). A mechanistic proposal for sugar loss involves nucleophilic attack by the oxyanion of the 5′‐OH group on C1′, elongation of the glycosidic bond with accommodation of partial negative charge on the imidazole‐ring nitrogen atoms, and eventual formation of the negatively charged nucleobase and the neutral sugar containing a 5′‐O‐C1′ bond . Following sugar elimination both 2,4,6‐TCP‐O‐G − and PCP‐O‐G − showed losses of HCl (‐36) and isocyanic acid (‐43) from the guanine component.…”

Section: Resultsmentioning

confidence: 99%

“…A mechanistic proposal for sugar loss involves nucleophilic attack by the oxyanion of the 5′-OH group on C1′, elongation of the glycosidic bond with accommodation of partial negative charge on the imidazole-ring nitrogen atoms, and eventual formation of the negatively charged nucleobase and the neutral sugar containing a 5′-O-C1′ bond. [34] Following sugar elimination both 2,4,6-TCP-O-G À and PCP-O-G À showed losses of HCl (-36) and isocyanic acid (-43) from the guanine component. In contrast, protonated ions of all investigated O-linked C8-dG adducts dissociated exclusively by elimination of the sugar moiety (Scheme 1(b)).…”

Section: Fragmentation Pathwaysmentioning

confidence: 98%

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Chlorine substitution promotes phenyl radical loss from C8-phenoxy-2′-deoxyguanosine adducts: implications for biomarker identification from chlorophenol exposure

et al. 2015

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Chlorophenols are persistent organic pollutants, which undergo peroxidase-mediated oxidation to afford phenolic radical intermediates that react at the C8-site of 2'-deoxyguanosine (dG) to generate oxygen-linked C8-dG adducts. Such adducts are expected to contribute to chlorophenol toxicity and serve as effective dose biomarkers for chlorophenol exposure. Electrospray ionization mass spectrometry (ESI-MS) was employed to study collision induced dissociation (CID) for a family of such phenolic O-linked C8-dG adducts. Fragmentation of the deprotonated nucleosides demonstrates that an unexpected homolytic cleavage of the ether linkage to release phenyl radicals and a nucleoside distonic ion with m/z 281 competes effectively with commonly observed breakage of the glycosidic bond to release the deprotonated nucleobase. Increased chlorination of the phenyl ring enhances phenyl radical loss. Density functional theory calculations demonstrate that Cl-substitution decreases phenyl radical stability but promotes homolytic breakage of the C8-phenyl bond in the C8-dG adduct. The calculations suggest that phenyl radical loss is driven by destabilizing steric (electrostatic repulsion) interactions between the ether oxygen atom and ortho-chlorines on the phenyl ring. The distonic ion at m/z 281 represents a unique dissociation product for deprotonated O-linked C8-dG adducts and may prove useful for selective detection of relevant biomarkers for chlorophenol exposure by tandem mass spectrometry using selective reaction monitoring.

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Section: Resultsmentioning

confidence: 99%

Section: Fragmentation Pathwaysmentioning

confidence: 98%

Chlorine substitution promotes phenyl radical loss from C8-phenoxy-2′-deoxyguanosine adducts: implications for biomarker identification from chlorophenol exposure

et al. 2015

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“…Negative-mode electrospray mass spectrometry (ESI-) detected [{Pt(ox)( n L) 2 }–H] − molecular peaks of 1 – 5 , and the peaks of deprotonated n L ligands, [ n L–H] − , were also observed in the case of 3 – 5 (Figure 2). Next one intensive peak was found in the ESI- MS spectra of the studied complexes, whose mass corresponds to [{Pt(ox)( n L)( n L')}–H] − (Figure 2), where n L' symbolizes the appropriate adenine derivative without ribose [19].…”

Section: Resultsmentioning

confidence: 99%

Platinum(II) Oxalato Complexes Involving Adenosine-Based N-Donor Ligands: Synthesis, Characterization and Cytotoxicity Evaluation

2014

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“…Formation of this ion can be explained by a 'H' migration from the active β-methylene group to the -NCO [40,42,45,46] -ions of all these isomeric peptides display an abundant m/z 125 ion corresponding to thymine anion [58,59].…”

Section: Coh − Hnco]mentioning

confidence: 99%

Differentiation of Positional Isomers of Hybrid Peptides Containing Repeats of β-Nucleoside Derived Amino Acid (β-Nda-) and L-Amino Acids by Positive and Negative Ion Electrospray Ionization Tandem Mass Spectrometry (ESI-MSⁿ)

Raju

Ramesh

Srinivas

et al. 2011

J. Am. Soc. Mass Spectrom.

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A new class of positional isomeric pairs of -Boc protected oligopeptides comprised of alternating nucleoside derived β-amino acid (β-Nda-) and L-amino acid residues (alanine, valine, and phenylalanine) have been differentiated by both positive and negative ion electrospray ionization ion-trap tandem mass spectrometry (ESI-MS n ). The protonated dipeptide positional isomers with β-Nda-at the N-terminus lose CH 3 OH, NH 3 , and C 2 H 4 O 2 , whereas these processes are absent for the peptides with L-amino acids at the N-terminus. Instead, the presence of L-amino acids at the N-terminus results in characteristic retro-Mannich reaction involving elimination of imine. A good correlation has been observed between the conformational structure of the peptides and the abundance of y n + and b n + ions in MS n spectra. In the case of tetrapeptide isomers that are reported to form helical structures in solution phase, no y n + and b n + ions are observed when the corresponding amide -NH-participates in the helical structures. In contrast, significant y n + and b n + ions are formed when the amide -NH-is not involved in the H-bonding. In the case of tetra-and hexapeptides, it is observed that abundant b n + ions are formed, presumably with stable oxazolone structures when the C-terminus of the b n + ions possessed L-amino acid and the β-Nda-at the C-terminus appears to prevent the cyclization process leading to the absence of corresponding b n + ions.

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A theoretical and mass spectrometry study of the novel mechanism of N-glycosidic bond cleavage in nucleoside

Cited by 13 publications

References 31 publications

Chlorine substitution promotes phenyl radical loss from C8-phenoxy-2′-deoxyguanosine adducts: implications for biomarker identification from chlorophenol exposure

Chlorine substitution promotes phenyl radical loss from C8-phenoxy-2′-deoxyguanosine adducts: implications for biomarker identification from chlorophenol exposure

Platinum(II) Oxalato Complexes Involving Adenosine-Based N-Donor Ligands: Synthesis, Characterization and Cytotoxicity Evaluation

Differentiation of Positional Isomers of Hybrid Peptides Containing Repeats of β-Nucleoside Derived Amino Acid (β-Nda-) and L-Amino Acids by Positive and Negative Ion Electrospray Ionization Tandem Mass Spectrometry (ESI-MSⁿ)

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A theoretical and mass spectrometry study of the novel mechanism of N-glycosidic bond cleavage in nucleoside

Cited by 13 publications

References 31 publications

Chlorine substitution promotes phenyl radical loss from C8-phenoxy-2′-deoxyguanosine adducts: implications for biomarker identification from chlorophenol exposure

Chlorine substitution promotes phenyl radical loss from C8-phenoxy-2′-deoxyguanosine adducts: implications for biomarker identification from chlorophenol exposure

Platinum(II) Oxalato Complexes Involving Adenosine-Based N-Donor Ligands: Synthesis, Characterization and Cytotoxicity Evaluation

Differentiation of Positional Isomers of Hybrid Peptides Containing Repeats of β-Nucleoside Derived Amino Acid (β-Nda-) and L-Amino Acids by Positive and Negative Ion Electrospray Ionization Tandem Mass Spectrometry (ESI-MSn)

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Differentiation of Positional Isomers of Hybrid Peptides Containing Repeats of β-Nucleoside Derived Amino Acid (β-Nda-) and L-Amino Acids by Positive and Negative Ion Electrospray Ionization Tandem Mass Spectrometry (ESI-MSⁿ)