Two-photon ionisation of the antitumor drug pazelliptine (BD40) by 355 nm laser photolysis.
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.
Fontaine-Aupart
M P
MP
Laboratoire de Photophysique Moléculaire, Université Paris-Sud, France.
Frejacques
M
M
Renault
E
E
Ferradini
C
C
Gardes-Albert
M
M
Hickel
B
B
Rivalle
C
C
Bisagni
E
E
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
D000970:Antineoplastic Agents; D007211:Indoles; D007546:Isoquinolines; D012996:Solutions; C024256:pazelliptine