title: Two-photon ionisation of the antitumor drug pazelliptine (BD40) by 355 nm laser photolysis.
abstract: The effect of 2 ns pulses of 355 nm laser light on aqueous solutions of pazelliptine (PZE) was investigated and biphotonic ionization was observed. The absorption spectrum corresponding to the pazelliptine radical cation (PZE+) and the hydrated electron simultaneously formed in this process was determined. In the absence of oxygen, eaq- reacted with unexcited PZE (k = 1.6 x 10(10) M-1 s-1) to give the pazelliptine radical anion (PZE-). This latter species was identified by separate pulse radiolysis experiments. The radicals cation and anion disappeared by recombination on the millisecond time range. In presence of oxygen, eaq- was scavenged by O2 leading to the formation of the superoxide radical (O2.-) in competition to the formation of the radical PZE.-.PZE+ reacted with O2.- to produce H2O2 (k = 9 x 10(9) M-1 s-1). The spectral analysis revealed that PZE triplet was also formed during the laser pulse. In the absence of oxygen, the triplet-triplet absorption decreased on the microsecond time scale (2k = 1.5 x 10(10) M-1 s-1). In oxygenated solutions, eaq- and the pazelliptine triplet decayed exponentially in the same time range.
authors.affiliation: Laboratoire de Photophysique Moléculaire, Université Paris-Sud, France.
authors.forename: M P
authors.initials: MP
authors.lastname: Fontaine-Aupart
authors.forename: M
authors.initials: M
authors.lastname: Frejacques
authors.forename: E
authors.initials: E
authors.lastname: Renault
authors.forename: C
authors.initials: C
authors.lastname: Ferradini
authors.forename: M
authors.initials: M
authors.lastname: Gardes-Albert
authors.forename: B
authors.initials: B
authors.lastname: Hickel
authors.forename: C
authors.initials: C
authors.lastname: Rivalle
authors.forename: E
authors.initials: E
authors.lastname: Bisagni
mesh_terms: D000970:Antineoplastic Agents / Q000528:radiation effects*; D007211:Indoles / Q000737:chemistry / Q000528:radiation effects*; D007546:Isoquinolines / Q000737:chemistry / Q000528:radiation effects*; D007834:Lasers; D015394:Molecular Structure; D010782:Photolysis; D012996:Solutions; D013053:Spectrophotometry
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D007546:Isoquinolines; D012996:Solutions; C024256:pazelliptine