A Photoprotective Effect by Cation-π-Interaction? Quenching of Singlet Oxygen by an Indole Cation-π Model System.

ABSTRACT: We investigated the effect of the cation-π interaction on the susceptibility of a tryptophan model system toward interaction with singlet oxygen, that is, type II photooxidation. The model system consists of two indole units linked to a lariat crown ether to measure the total rate of removal of singlet oxygen by the indole units in the presence of sodium cations (i.e. indole units subject to a cation-π interaction) and in the absence of this interaction. We found that the cation-π interaction significantly decreases the total rate of removal of singlet oxygen (k_T ) for the model system, that is, (k_T  = 2.4 ± 0.2) × 10⁸  m^-1  s^-1 without sodium cation vs (k_T  = 6.9 ± 0.9) × 10⁷  m^-1  s^-1 upon

SUBMITTER: Arevalo GE 

PROVIDER: S-EPMC7704691 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature