Characterization of the transient species generated by the photoionization of Berberine: a laser flash photolysis study.
Using 266 nm laser flash photolysis it has been demonstrated that Berberine (BBR) in aqueous solution is ionized via a mono-photonic process giving a hydrated electron, anion radical that formed by hydrated electron react with steady state of BBR, and neutral radical that formed from rapid deprotonation of the radical cation of BBR. The quantum yield of photoionization is determined to be 0.03 at room temperature with KI solution used as a reference. Furthermore utilizing pH changing method and the SO(4.)(-) radical oxidation method, the assignment of radical cation of BBR was further confirmed, the pK(a) value of it was calculated, and the related set up rate constant was also determined.
Cheng
Ling-Li
LL
School of Life Science and Technology, Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, PR China. chenglingli_6@hotmail.com
Wang
Mei
M
Zhu
Hui
H
Li
Kun
K
Zhu
Rong-Rong
RR
Sun
Xiao-Yu
XY
Yao
Si-De
SD
Wu
Qing-Sheng
QS
Wang
Shi-Long
SL
D001599:Berberine / Q000737:chemistry*; D004583:Electrons; D005609:Free Radicals; D007477:Ions / Q000737:chemistry; D007834:Lasers; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010782:Photolysis; D013056:Spectrophotometry, Ultraviolet; D013431:Sulfates / Q000737:chemistry; D014867:Water / Q000737:chemistry
D005609:Free Radicals; D007477:Ions; D013431:Sulfates; C069025:sulfate radical; D014867:Water; D001599:Berberine