dc.contributor.author
Dahlmann, Franziska
dc.contributor.author
Griesbach, Caleb E.
dc.contributor.author
Torres-Boy, América Y.
dc.contributor.author
Helden, Gert von
dc.contributor.author
Peczuh, Mark W.
dc.contributor.author
Pagel, Kevin
dc.contributor.author
Greis, Kim
dc.date.accessioned
2025-03-05T11:47:47Z
dc.date.available
2025-03-05T11:47:47Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/45813
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-45526
dc.description.abstract
Sialic acids are monosaccharide residues involved in several biological processes. Controlling the stereoselectivity of sialylation reactions is challenging and mechanistic studies on the structure of its intermediate, the sialyl cation, are scarce. Here it is shown that a sialyl cation can be generated and isolated from an ionized sialic acid precursor. This short-lived species is structurally characterized for the first time using cryogenic infrared spectroscopy. In combination with quantum chemical calculations, the results reveal that the positive charge at the anomeric carbon of the sialyl cation is stabilized by remote participation of the C5-NHAc group leading to the formation of a bridged structure. In this structure, the β-side is shielded from nucleophilic attack, potentially explaining the α-selectivity of this building block in SN1-type sialylation reactions. Other modes of participation are energetically unfavored and cannot be observed experimentally.
en
dc.format.extent
7 Seiten
dc.rights.uri
https://creativecommons.org/licenses/by/4.0/
dc.subject
glycosylation
en
dc.subject
infrared spectroscopy
en
dc.subject
mass spectrometry
en
dc.subject
carbohydrates
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
dc.title
Direct Experimental Characterization of a Sialyl Cation
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.articlenumber
e202403724
dcterms.bibliographicCitation.doi
10.1002/chem.202403724
dcterms.bibliographicCitation.journaltitle
Chemistry - A European Journal
dcterms.bibliographicCitation.number
7
dcterms.bibliographicCitation.volume
31
dcterms.bibliographicCitation.url
https://doi.org/10.1002/chem.202403724
refubium.affiliation
Biologie, Chemie, Pharmazie
refubium.affiliation.other
Institut für Chemie und Biochemie

refubium.funding
DEAL Wiley
refubium.note.author
Die Publikation wurde aus Open Access Publikationsgeldern der Freien Universität Berlin gefördert.
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
1521-3765