PMID- 35052513
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20220128
IS  - 2076-3921 (Print)
IS  - 2076-3921 (Electronic)
IS  - 2076-3921 (Linking)
VI  - 11
IP  - 1
DP  - 2021 Dec 22
TI  - Electrochemical and Mechanistic Study of Reactivities of alpha-, beta-, gamma-, and 
      delta-Tocopherol toward Electrogenerated Superoxide in N,N-Dimethylformamide through 
      Proton-Coupled Electron Transfer.
LID - 10.3390/antiox11010009 [doi]
LID - 9
AB  - Scavenging of superoxide radical anion (O(2)(*-)) by tocopherols (TOH) and 
      related compounds was investigated on the basis of cyclic voltammetry and in situ 
      electrolytic electron spin resonance spectrum in N,N-dimethylformamide (DMF) with 
      the aid of density functional theory (DFT) calculations. Quasi-reversible 
      dioxygen/O(2)(*-) redox was modified by the presence of TOH, suggesting that the 
      electrogenerated O(2)(*-) was scavenged by alpha-, beta-, gamma-TOH through proton-coupled 
      electron transfer (PCET), but not by delta-TOH. The reactivities of alpha-, beta-, gamma-, and 
      delta-TOH toward O(2)(*-) characterized by the methyl group on the 6-chromanol ring 
      was experimentally confirmed, where the methyl group promotes the PCET mechanism. 
      Furthermore, comparative analyses using some related compounds suggested that the 
      para-oxygen-atom in the 6-chromanol ring is required for a successful electron 
      transfer (ET) to O(2)(*-) through the PCET. The electrochemical and DFT results 
      in dehydrated DMF suggested that the PCET mechanism involves the preceding proton 
      transfer (PT) forming a hydroperoxyl radical, followed by a PCET (intermolecular 
      ET-PT). The O(2)(*-) scavenging by TOH proceeds efficiently along the PCET 
      mechanism involving one ET and two PTs.
FAU - Nakayama, Tatsushi
AU  - Nakayama T
AUID- ORCID: 0000-0002-0346-2089
AD  - Department of Pharmacy, Gifu Pharmaceutical University, Daigaku-nishi, Gifu 
      501-1196, Japan.
FAU - Honda, Ryo
AU  - Honda R
AD  - United Graduate School of Drug Discovery and Medical Information Sciences, Gifu 
      University, 1-1 Yanagido, Gifu 501-1193, Japan.
FAU - Kuwata, Kazuo
AU  - Kuwata K
AD  - United Graduate School of Drug Discovery and Medical Information Sciences, Gifu 
      University, 1-1 Yanagido, Gifu 501-1193, Japan.
FAU - Usui, Shigeyuki
AU  - Usui S
AD  - Department of Pharmacy, Gifu Pharmaceutical University, Daigaku-nishi, Gifu 
      501-1196, Japan.
FAU - Uno, Bunji
AU  - Uno B
AD  - Faculty of Pharmacy, Gifu University of Medical Science, 4-3-3 Nijigaoka, Kani, 
      Gifu 509-0923, Japan.
LA  - eng
GR  - 19K16338/Japan Society for the Promotion of Science/
PT  - Journal Article
DEP - 20211222
PL  - Switzerland
TA  - Antioxidants (Basel)
JT  - Antioxidants (Basel, Switzerland)
JID - 101668981
PMC - PMC8773314
OTO - NOTNLM
OT  - antioxidants
OT  - cyclic voltammetry
OT  - electron spin resonance spectrum
OT  - proton-coupled electron transfer
OT  - superoxide radical anion
OT  - tocopherol
COIS- The authors declare no conflict of interest.
EDAT- 2022/01/22 06:00
MHDA- 2022/01/22 06:01
PMCR- 2021/12/22
CRDT- 2022/01/21 01:03
PHST- 2021/12/02 00:00 [received]
PHST- 2021/12/19 00:00 [revised]
PHST- 2021/12/20 00:00 [accepted]
PHST- 2022/01/21 01:03 [entrez]
PHST- 2022/01/22 06:00 [pubmed]
PHST- 2022/01/22 06:01 [medline]
PHST- 2021/12/22 00:00 [pmc-release]
AID - antiox11010009 [pii]
AID - antioxidants-11-00009 [pii]
AID - 10.3390/antiox11010009 [doi]
PST - epublish
SO  - Antioxidants (Basel). 2021 Dec 22;11(1):9. doi: 10.3390/antiox11010009.