title: Characterization of the transient species generated by the photoionization of Berberine: a laser flash photolysis study.
abstract: 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.
authors.affiliation: School of Life Science and Technology, Department of Chemistry, Tongji University, Siping Road 1239, Shanghai 200092, PR China. chenglingli_6@hotmail.com
authors.forename: Ling-Li
authors.initials: LL
authors.lastname: Cheng
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
authors.forename: Kun
authors.initials: K
authors.lastname: Li
authors.forename: Rong-Rong
authors.initials: RR
authors.lastname: Zhu
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Sun
authors.forename: Si-De
authors.initials: SD
authors.lastname: Yao
authors.forename: Qing-Sheng
authors.initials: QS
authors.lastname: Wu
authors.forename: Shi-Long
authors.initials: SL
authors.lastname: Wang
mesh_terms: 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
chemical_list: D005609:Free Radicals; D007477:Ions; D013431:Sulfates; C069025:sulfate radical; D014867:Water; D001599:Berberine