Li⁺‐ and Ag⁺‐cationized per‐O‐acetyl‐ and Per‐O‐benzyl‐α‐D‐thioglycosides: a collision‐induced decomposition study

Abstract

The collision-induced decompositions of the [ M + Lil+ and ( M + Agl+ ions of per-0-acetyl-and per-0-benzyla-D-thioglycosides having phenyl sulphide, phenyl sulphoxide and phenyl sulphone as the aglycone moieties were studied. The [ M + Li] + ion of the acetyl derivative of the phenylthioglucoside shows loss of AcOLi, whereas its [ M + Agj+ ion shows elimination of PhSAg. Their sulphoxide and sulphone derivatives lose the C(l) and C(2) substituents to form the glucal under both Li+ and Ag + cationization conditions. The corresponding benzyl derivatives do not show the loss of metal. The formation of glucal leads to ring fragmentation by retro-DielsAlder reaction in the ring-activated benzyl derivatives.

Tandem mass spectra of divalent metal ion adducts of glycosyl sulfides, sulfoxides and sulfones; distinction among stereoisomers

“…Anchimeric assistance of the sulfide could initiate dissociation of the doubly charged ion into two singly charged ions as shown in Scheme . Similar anchimeric assistance was invoked by us in the dissociation of lithiated adducts earlier 18. The MS/MS spectrum of the Sr 2+ adduct of 2 also showed [M + SrOAc] + at m / z 603.…”

“…Metal cationization of carbohydrates during ESI followed by tandem mass spectrometry (MS/MS) produces data that is rich in structural and stereochemical information 28–32. As a continuation of our earlier studies18, 19 on the collision‐induced dissociation mass spectra of S‐containing sugars, it was decided to study the ESI MS/MS spectra of divalent metal cationized 1,2‐ trans ‐glycosyl sulfides ( 1 , 4 and 7 ), sulfoxides ( 2 , 5 and 8 ) and sulfones ( 3 , 6 and 9 ), with an objective of achieving differentiation of diastereomers by MS/MS and comparing the effect of different metals. The structures of the compounds studied are shown in Fig.…”

“…There are a number of reviews and reports on the mass spectra of sulfur‐containing organic compounds 11–15. However, there are only a few reports on the mass spectra of S‐containing carbohydrates 16–19…”

Tandem mass spectra of ammonium ion, metal ion and ligated metal ion adducts of acyclic sugar derivatives

“…Elimination of LiOAc from the retro‐aldol fragment ion at m/z 279 leads to the ion at m/z 213. LiOAc elimination was reported earlier by several workers;39–41 it reflects lithium ion attachment to acetoxy groups. The peak at m/z 228 is produced by the concomitant elimination of LiOAc, CH 2 CO and H 2 O from the [M+Li] + ion.…”

Gas-Phase Reactivity of Glycosides and Methyl Glycosides with Cu+, Ag+ and Pb2+ Ions by Fast-Atom Bombardment and Tandem Mass Spectrometry

“…Several papers have also reported the gasphase mass spectrometric study of the complexation by glycosides of alkali, alkaline earth and transition metal cations. All these studies showed that gas-phase metal ion chemistry is a powerful tool in the linkage position determination [12][13][14][15][16] or stereochemical differentiation [17][18][19][20][21][22] of saccharides.…”