A new approach that uses a hybrid Q-FTICR instrument and combines quadrupole collision-induced dissociation, hydrogen-deuterium exchange, and infrared multiphoton dissociation (QCID-HDX-IRMPD) has been shown to effectively separate and differentiate isomeric fragment ion structures present at the same m/z. This method was used to study protonated YAGFL-OH (free acid), YAGFL-NH(2) (amide), cyclic YAGFL, and YAGFL-OCH(3) (methyl ester). QCID-HDX of m/z 552.28 (C(29)H(38)N(5)O(6)) from YAGFL-OH reveals at least two distributions of ions corresponding to the b(5) ion and a non-C-terminal water loss ion structure. Subsequent IRMPD fragmentation of each population shows distinct fragmentation patterns, reflecting the different structures from which they arise. This contrasts with data for YAGFL-NH(2) and YAGFL-OCH(3), which do not show two distinct H/D exchange populations for the C(29)H(38)N(5)O(6) structure formed by NH(3) and HOCH(3) loss, respectively. Relative extents of exchange for C(29)H(38)N(5)O(6) ions from six sequence isomers (YAGFL, AGFLY, GFLYA, FLYAG, LYAGF, and LFGAY) show a sequence dependence of relative isomer abundance. Supporting action IRMPD spectroscopy data are also presented herein and also show that multiple structures are present for the C(29)H(38)N(5)O(6) species from YAGFL-OH.
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http://dx.doi.org/10.1016/j.jasms.2010.03.036 | DOI Listing |
J Am Soc Mass Spectrom
January 2025
Department of Chemistry, Dalhousie University, 1459 Oxford Street, P.O. Box 15000, Halifax, NS B3H 4R2, Canada.
We extend our previous work on the energetics and mechanisms of fragmentation in the mass spectrometry of triacylglycerols (TAGs). Previously, we proposed viable mechanisms for the collision-induced fragmentation of lithiated tripropionylglycerol using triple-quadrupole mass spectrometry. In this work, we used a QqLIT mass spectrometer to study both double- and triple-stage spectra from a range of TAGs having acid chains of types AAA (identical acid chains), AAB, ABA, and ABC, with chain lengths of 6-18 carbon atoms; we also studied some TAGs having a single double bond in the Δ-9 position.
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March 2025
Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Canada.
Rationale: In electrospray ionization and atmospheric pressure chemical ionization, the protonation site directly guides the ion's dissociation. But what if the site of protonation is ambiguous? In this study, we explored the unimolecular reactions of protonated α- and β-pinene ions with a combination of tandem mass spectrometry and theory. Each has multiple potential protonation sites that influence their chemistry.
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February 2025
College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Background: Analysis of the phytocannabinoids holds significant importance because of their various pharmacological properties and potential therapeutic applications. Tandem mass spectrometry (MS/MS) coupled with electrospray ionization in positive ion mode is employed in this study to describe the collision-induced dissociation (CID) behavior of a series of common phytocannabinoids with the aim of establishing a generalized MS/MS fingerprint.
Materials And Methods: Eight phytocannabinoids, namely, ∆-tetrahydrocannabinol (THC), cannabidiol (CBD), cannabichromene (CBC), cannabigerol (CBG), tetrahydrocannabivarin (THCV), 11-hydroxy-Δ-tetrahydrocannabinol (11-OH-THC), 6-hydroxy-cannabidiol (6-OH-CBD), and 7-hydroxy-cannabidiol (7-OH-CBD), were studied.
Rapid Commun Mass Spectrom
February 2025
Department of Medicine, Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Brigham Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
Rationale: ADP-ribosylation is a posttranslational modification whose higher-energy collisional dissociation (HCD) products are dominated by complete or partial modification losses, complicating peptide sequencing and acceptor site localization efforts. We tested whether in-source collision-induced dissociation (CID) performed on a quadrupole-Orbitrap could convert ADPr to the smaller phosphoribose-HO derivative to facilitate HCD-dependent peptide sequencing.
Methods: ADP-ribosyl (ADPr) peptides derived from the human macrophage-like cell line THP-1 were analyzed on a quadrupole-Orbitrap.
Rapid Commun Mass Spectrom
February 2025
Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania, USA.
Rationale: These experiments were conducted to measure the diversity of organo-U (IV) and U (III) ions created using multiple-stage tandem MS and collision-induced dissociation of halogen-substituted UO-phenide complexes [UO(CHFX)], X = Cl, Br, or I.
Methods: Samples of UO(OC-CHFX) were prepared by digesting UO with appropriate halogen-substituted carboxylic acids in deionized water. Solutions for ESI were created by diluting the digested sample in 50:50 HO/CHOH.
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