scholarly journals Synthesis and structural investigation of a series of mannose-containing oligosaccharides using mass spectrometry

2018 ◽  
Vol 16 (2) ◽  
pp. 228-238
Author(s):  
S. Daikoku ◽  
R. Pendrill ◽  
Y. Kanie ◽  
Y. Ito ◽  
G. Widmalm ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Acid Hydrolysis ◽  
Gas Phase ◽  
Structural Investigation ◽  
Collision Induced Dissociation ◽  
Linkage Isomers ◽  
Hydrolysis Of ◽  
Reactivity Order

Gas-phase collision-induced dissociation and acid hydrolysis of mannose-containing oligosaccharides were performed, which revealed the reactivity order of linkage isomers.

Rapid Evaluation of Suitable Substrates with High Affinity to Artificial Caffeine Receptors by MS Based Techniques

2005 ◽  
Vol 60 (10) ◽  
pp. 1077-1082 ◽  
Author(s):  
Daniela Mirk ◽  
Heinrich Luftmann ◽  
Siegfried R. Waldvogel
Keyword(s):  
Mass Spectrometry ◽  
Gas Phase ◽  
Collision Induced Dissociation ◽  
Rapid Evaluation ◽  
Tandem Mass ◽  
Binding Affinities ◽  
Electrospray Tandem Mass Spectrometry ◽  
Relative Stabilities ◽  
Receptor Complexes ◽  
High Affinity

A modification of our triphenylene ketal based receptor facilitates electrospray tandem mass spectrometry investigations. Binding affinities of eleven potential substrates, e.g. caffeine and other xanthine alkaloids, are probed in the gas phase with collision induced dissociation. The relative stabilities of the substrate-receptor complexes are rapidly determined and the findings are correlated with the corresponding results in solution.

scholarly journals Photoproducts of the Photodynamic Therapy Agent Verteporfin Identified via Laser Interfaced Mass Spectrometry

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5280
Author(s):  
Chris Furlan ◽  
Jacob A. Berenbeim ◽  
Caroline E. H. Dessent
Keyword(s):  
Mass Spectrometry ◽  
Photodynamic Therapy ◽  
Macular Degeneration ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Red Light ◽  
Solution Phase ◽  
Collision Induced Dissociation ◽  
Free Base ◽  
New Information

Verteporfin, a free base benzoporphyrin derivative monoacid ring A, is a photosensitizing drug for photodynamic therapy (PDT) used in the treatment of the wet form of macular degeneration and activated by red light of 689 nm. Here, we present the first direct study of its photofragmentation channels in the gas phase, conducted using a laser interfaced mass spectrometer across a broad photoexcitation range from 250 to 790 nm. The photofragmentation channels are compared with the collision-induced dissociation (CID) products revealing similar dissociation pathways characterized by the loss of the carboxyl and ester groups. Complementary solution-phase photolysis experiments indicate that photobleaching occurs in verteporfin in acetonitrile; a notable conclusion, as photoinduced activity in Verteporfin was not thought to occur in homogenous solvent conditions. These results provide unique new information on the thermal break-down products and photoproducts of this light-triggered drug.

scholarly journals Conformational-dependent reaction mechanism: case of acid hydrolysis of N-benzoyl-9-azabicyclo[6.1.0]non-4-ene

2017 ◽  
Vol 95 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Djallila Missaoui ◽  
Ali Rahmouni ◽  
Okkacha Bensaid ◽  
Néji Besbes
Keyword(s):  
Sulfuric Acid ◽  
Reaction Mechanism ◽  
Acid Hydrolysis ◽  
Gas Phase ◽  
Quantum Chemical ◽  
Basis Sets ◽  
Stable Conformer ◽  
Chemical Studies ◽  
Quantum Chemical Studies ◽  
Hydrolysis Of

Quantum chemical studies of the acid hydrolysis of cis-cis-N-benzoyl-9-azabicyclo[6.1.0]non-4-ene in gas phase and sulfuric acid solution have been carried out. Conformational analysis of reactant and intermediates were done at DFT level of calculations, using different basis sets. Transition states were identified and IRC calculations were done at the same level. In the first step of the reaction, the protonation occurs preferentially on the nitrogen atom. Three products are obtained. The type of mechanism, stepwise or concerted, depends on the stable conformers and the cleaved N–C bond. The main conclusion is that the products of the reaction depend on the nature of the stable conformer of the reactant.

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