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

Abstract

The tandem mass spectra of the divalent metal ion (Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Ni2+, Co2+ and Zn2+) adducts of acetylated 1,2-trans-glycosyl sulfides, sulfoxides and sulfones were examined using low energy collision-induced dissociation on a Quattro II quadrupole tandem mass spectrometer. Abundant doubly charged ions, such as [3M + Met]2+ and [2M + Met]2+, were observed with alkaline earth metal chlorides. The other ions observed were [M + MetCl]+, [M + MetOAc]+, [M + MetO2SPh]+ and [2M + MetCl]+. The deprotonated metal adducts [M + Met-H]+ were seen only in the sulfones. The divalent metal ion adducts showed characteristic fragmentation pathways for the glycosyl sulfides, sulfoxides and sulfones, depending on the site of metal attachment. The doubly charged metal ion adducts dissociate to two singly charged ions, [M + MetOAc]+ and [M - OAc]+, in the sulfides and sulfoxides. In the sulfones, the adducts dissociate to [M + MetO2SPh]+ and [M - O2SPh]+. In contrast to the alkaline earth metals, which attach to the acetoxy functions, the transition metals attach to the sulfide and sulfoxide functions. The metal chloride adducts display characteristic fragmentation for the sulfides, sulfoxides and sulfones. The glucosyl, mannosyl and galactosyl sulfides, sulfoxides and sulfones could be differentiated on the basis of the stereochemically controlled MS/MS fragmentations of the metal chloride adducts.

Diastereochemical differentiation of bicyclic diols using metal complexation and collision‐induced dissociation mass spectrometry

“…Some earlier studies also showed that simple metal‐cationized monomeric or dimeric compounds exhibit stereoisomeric distinction when subjected to CID 50–53. For example, Fe 2+ ions have been used to form regioselective and stereoselective transition metal complexes and characteristic product ions by CID for structural elucidation of carbohydrates 50, 51.…”

“…Some earlier studies also showed that simple metalcationized monomeric or dimeric compounds exhibit stereoisomeric distinction when subjected to CID. [50][51][52][53] For example, Fe 2þ ions have been used to form regioselective and stereoselective transition metal complexes and characteristic product ions by CID for structural elucidation of carbohydrates. 50,51 Stereoisomeric differentiation of glycosyl dithioacetals, sulfides, sulfoxides and sulfones has also been successful using different transition-metal ion adducts and tandem mass spectrometry.…”

“…50,51 Stereoisomeric differentiation of glycosyl dithioacetals, sulfides, sulfoxides and sulfones has also been successful using different transition-metal ion adducts and tandem mass spectrometry. 52,53 In the present study, we first investigated the complexation of di-exo-, di-endo-and trans-2,3-disubstituted trinorbornanediols, 2,5-disubstituted trinorbornanediols, and cis-2,3-disubstituted camphanediols with cobalt(II), copper(II), and nickel(II) in the form of chlorides, nitrates, and acetates (Scheme 1). One purpose was to generate metal complexes with two or more diol molecules attached to the metal ion by ESI.…”

Mass Spectrometry in India

“…330 Aggarwal and colleagues 331,332 have undertaken the preparation and characterization of 234 U and of working standards for 238 Pu. They have applied GC-MS for the determination of Pb in blood and urine, of Hg in blood and of Te (Te from the antitumor drug AS-101) in urine, using stable isotopes ( 196 Hg,120 Te, 204 Pb) derivatized with appropriate chelating reagents. [333][334][335][336] Geochronological studies 40 Ar- 39 Ar dating of Siberian basaltic volcanism; Sm-Nd dating of Archean metavolcanics of the Dharwar Craton; Sm-Nd and Rb-Sr dating and P-T history of the Archean Sittampundi and Bhavani layered meta-northosite complexes in the Cauvery shear zone.…”

“…The hexose units in Me-glucoside, mannoside and galactoside could also be identified accurately. [120][121][122] Analysis of proscribed chemicals A significant contribution of Vairamani and colleagues was the establishment of the Centre for the Analysis of Chemical Toxins (CACT) at IICT. This centre is one of the 18 laboratories globally designated by the Organization for the Prohibition of Chemical Weapons (OPCW) for the off-site analysis of scheduled chemicals, prohibited under the Chemical Weapons Convention (CWC).…”