Mechanism of antioxidant reaction of vitamin E: charge transfer and tunneling effect in proton-transfer reaction

1992 ◽  
Vol 96 (6) ◽  
pp. 2754-2761 ◽  
Author(s):  
Shinichi Nagaoka ◽  
Aya Kuranaka ◽  
Hideki Tsuboi ◽  
Umpei Nagashima ◽  
Kazuo Mukai
Keyword(s):  
Charge Transfer ◽  
Vitamin E ◽  
Proton Transfer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Tunneling Effect

An abnormally slow proton transfer reaction in a simple HBO derivative due to ultrafast intramolecular-charge transfer events

2015 ◽  
Vol 17 (25) ◽  
pp. 16257-16269 ◽  
Author(s):  
Noemí Alarcos ◽  
Mario Gutierrez ◽  
Marta Liras ◽  
Félix Sánchez ◽  
Abderrazzak Douhal
Keyword(s):  
Charge Transfer ◽  
Proton Transfer ◽  
Transfer Reaction ◽  
Intramolecular Charge Transfer ◽  
Proton Transfer Reaction ◽  
Simple Derivative

Stepwise and coupled photoinduced ICT and ESIPT reactions in a simple derivative of HBO in solution.

Mechanism of prooxidant reaction of vitamin E: kinetic, spectroscopic, and ab initio study of proton-transfer reaction

1992 ◽  
Vol 96 (16) ◽  
pp. 6663-6668 ◽  
Author(s):  
Shinichi Nagaoka ◽  
Kouhei Sawada ◽  
Youji Fukumoto ◽  
Umpei Nagashima ◽  
Shunji Katsumata ◽  
...  
Keyword(s):  
Vitamin E ◽  
Proton Transfer ◽  
Ab Initio ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Ab Initio Study

scholarly journals Identifying volatile in vitro biomarkers for oral bacteria with proton-transfer-reaction mass spectrometry and gas chromatography–mass spectrometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kajsa Roslund ◽  
Markku Lehto ◽  
Pirkko Pussinen ◽  
Kari Hartonen ◽  
Per-Henrik Groop ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Proton Transfer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Oral Bacteria ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Analysis ◽  
Bacterial Volatiles

AbstractWe have measured the volatile fingerprints of four pathogenic oral bacteria connected to periodontal disease and dental abscess: Porphyromonas gingivalis (three separate strains), Prevotella intermedia, Prevotella nigrescens and Tannerella forsythia. Volatile fingerprints were measured in vitro from the headspace gas of the bacteria cultured on agar. Concrete identification of new and previously reported bacterial volatiles were performed by a combination of solid phase microextraction (SPME) and offline gas chromatography–mass spectrometry (GC–MS). We also studied the effect of the reduced electric field strength (E/N) on the fragmentation patterns of bacterial volatiles in online proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS). We aimed to discover possible new biomarkers for the studied oral bacteria, as well as to validate the combination of GC–MS and PTR-MS for volatile analysis. Some of the most promising compounds produced include: 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ), indole, and a cascade of sulphur compounds, such as methanethiol, dimethyl disulphide (DMDS) and dimethyl trisulphide (DMTS). We also found that several compounds, especially alcohols, aldehydes and esters, fragment significantly with the PTR-MS method, when high E/N values are used. We conclude that the studied oral bacteria can be separated by their volatile fingerprints in vitro, which could have importance in clinical and laboratory environments. In addition, using softer ionization conditions can improve the performance of the PTR-MS method in the volatile analysis of certain compounds.

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