title: Fast relaxation processes and structural changes in immunoactive biomolecules.
abstract: Based upon an analysis of the absorption spectra, the fluorescence and fluorescence excitation spectra, and the lifetime of the excited states of aqueous solutions (pH 7.4) of 2,3-dimethoxy-8-azagona-1,3,5(10),13-tetraene-12,17-dione, it is established that two centers of different type exist: one emits long-wave (L-centers) and the other short-wave (S-centers) fluorescence. Irradiation of solutions increases the number of L-centers and greatly decreases that of S-centers. Examination of the picosecond transient absorption spectra and their kinetics revealed that the initial photochemical stage is defined as the ionization of a considered molecule and the subsequent one, as the formation, most probably, of the dehydroderivative of a parent molecule.
authors.affiliation: Institute of Molecular & Atomic Physics, National Academy of Sciences of Belarus, 70 F. Skaryna Avenue, 220072 Minsk, Belarus.
authors.forename: N A
authors.initials: NA
authors.lastname: Borisevich
authors.forename: V L
authors.initials: VL
authors.lastname: Dubovsky
authors.forename: A L
authors.initials: AL
authors.lastname: Mikhalchuk
authors.forename: T F
authors.initials: TF
authors.lastname: Raichyonok
authors.forename: S A
authors.initials: SA
authors.lastname: Tikhomirov
authors.forename: G B
authors.initials: GB
authors.lastname: Tolstorozhev
mesh_terms: D001378:Azasteroids / Q000737:chemistry*; D001704:Biopolymers / Q000737:chemistry*; D004224:Diterpenes / Q000737:chemistry*; D005898:Glass; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007700:Kinetics; D007834:Lasers; D008027:Light; D008956:Models, Chemical; D011522:Protons; D013053:Spectrophotometry / Q000379:methods*; D013997:Time Factors
chemical_list: C487849:2,3-dimethoxy-8-azagona-1,3,5(10),13-tetraene-12,17-dione; D001378:Azasteroids; D001704:Biopolymers; D004224:Diterpenes; D007477:Ions; D011522:Protons