[Potentially dangerous photosensitizers among drugs and medicinal plant extracts].

The review deals with photosensitizing properties of drugs and plant extracts. Some compounds are able to cause side effects such as phototoxicity and photoallergy. Revealing and study of harmful photosensitizers is actual problem in connection with changing photoecological situation.

Photoprotector and antioxidant properties of histamine-containing peptidomimetics in the photooxidation of glycyltryptophan.

The natural imidazole-containing dipeptide carnosine in vitro exhibits several antioxidant properties; however, in vivo its activity is limited due to enzymatic hydrolysis. A family of original histamine-containing peptidomimetics, i.e.

[Antioxidant properties of plant extracts].

Investigation of antioxidant properties of some plants was carried out. A group of plants exhibited antimicrobial activity was studied in detail. Efficiency of plants as antioxidants was tested by the influence of their extracts on the yield of photochemiluminescence of Gly-Trp solutions.

[Phenothiazine drugs as photosensitizers and photoprotectors].

The photosensitizing properties of eight N-alkylated phenothiazine neuroleptic drugs were studied. The experiments were carried out in a model system based on photooxidative chemiluminescence of Gly-Trp peptide in aqueous solution. Under irradiation with light longer than 280 nm, all the studied phenothiazine derivatives decrease the chemiluminescence intensity at low concentrations and enhance it at high concentrations.

[Photosensitizing and photoprotective properties of extracts from groups of medicinal plants].

Investigation of photosensitization and photoprotection induced by plant extracts was carried out. A group of plants affected human central nervous system was studied in detail. Efficiency of plants as photoprotectors and photosensitizers was tested in the frame of the influence of their extracts on the yield of photochemiluminescence of Gly-Trp solutions.

[Antioxidant properties of a series of extracts from medicinal plants].

Investigation of antioxidant properties of some plants was carried out. A group of plants affected human central nervous system was studied in detail. Efficiency of plants as antioxidants was tested by the influence of their extracts on the yield of photochemiluminescence of Gly-Trp solutions.

[Photosensitizing properties and antioxidant activity of furagin--an antimicrobial drug that is a derivative of nitrofuran].

Photosensitizing effect of antimicrobial drug nitrofuran derivative--furagin N-(5-nitro-2-furil)-allylidencamino-hydantoin) under irradiation with light longer than 280 nm was found. The method of investigation is based on photochemiluminescence of Gly-Trp peptide in aqueous solution. Maximum photosensitizing efficiency was observed at the furagin concentration 0.

[Ozone holes: prognosis of human photo-ecology. Protection and sensitization].

Photoecological consequence of ozone holes are considered. Analysis of the total UV-radiation intensity and the short-wave edge of atmospheric transmittance depending on ozone content is presented. Characteristic times of some photodamages to skin and eyes have been estimated under ozone content reducing.

[Comparative effectiveness of some medicinal substances as acceptors of superoxide radicals].

The effect of about 30 medicines and some other compounds on the yield of the riboflavin sensitized glycyltryptophan photochemiluminescence occurring at the participation of superoxide and glycyltryptophan peroxide free radicals in solution has been studied. Some of the investigated compounds decrease the chemiluminescence yield as a result of their reactions with superoxide and gly-try peroxide radicals. The concentrations of compounds decreasing the chemiluminescence yield by 2 times were obtained.

[The kinetics of the chemical modification of DNA radiation transformations in multicomponent systems. An analytical review].

Most probable ways of chemical protection and sensitization of DNA macromolecules under the effect of ionizing radiation in aqueous solutions have been investigated. A kinetic model in proposed, based on the experimental data available, that consists of 25 reactions involving DNA (D), protein (P), glutathione (G), oxygen (O2), various protectors and sensitizers (A), active products of water radiolysis (O, e (H)), free and peroxide radicals of DNA and other components, and peroxides. General and partial rates of radiation transformations of DNA, depending on D, P, G, O2 and A concentrations are expressed in analytical terms.

[Superoxide dismutase activity and photosensitizing properties of 2,5-dihydroxybenzolsulfonate].

2,5-dihydroxybenzolsulphonate was shown to actively interact with the superoxide radical O2-. formed under UV-radiation of glycyltryptophan aqueous solutions or under visible light illumination of glycyltryptophan and riboflavine. The constant of the rate of reaction of 2,5-dihydroxybenzolsulphonate with O2-.

[Protection and latent and patent sensitization by nucleotides of radiation-induced transformations of gylcyltryptophan and serum albumin].

A study was made of the influence of nucleotides (AMP, GMP, UMP, and CMP) on x-ray chemiluminescence of glycyltryptophan and serum albumin solutions in humans. The coefficient of modification of radiation transformations of peptide (10(-4) M) and protein (1.47.

[Formal kinetic treatment of the possible role of proteins in DNA radiation tolerance, protection and sensitization].

The formal-kinetic calculations have been made of the postirradiation behaviour of a "protein-DNA" water system with marked variations in protein and DNA concentrations. Protein is a strong competitive acceptor of active products of radiolysis of water and free radicals of DNA. The radioresistance of DNA in such a system and the influence of mercaptoethylamine, sensitizers and oxygen on DNA injury are discussed.

[Modifying effect of alcohols on the radiation transformations of serum albumin].

The method of roentgenochemoluminescence was used to study the reactions of alcohol radicals with tryptophanyl residues of protein. These radicals exhibited a high reactivity. In a series of alcohol radicals and 3-oxy-pyridine derivatives, a positive correlation was revealed between the rate of the reaction of radicals with the macromolecule and the hydrophobic character of free radicals.

[Influence of superoxide dismutase on photo- and x-ray chemoluminescence of serum albumin and glycyltryptophan solutions].

Enzyme superoxide dismutase is shown to decrease photo- and X-ray chemoluminescence when added both before and after irradiation. The relationship was established between chemoluminescence yield and the enzyme concentration. Chemoluminescence is supposed to be initiated by the reaction of free radicals of the peptide (protein) with superoxide anion-radicals: O2-.

[Comparative study of the radiation oxidation and x-ray chemiluminescence of globular proteins].

Regularities of radiation oxidation (oxygen absorption for irradiation) and X-ray chemoluminescence of human serum albumin solutions have been studied. The oxidative rate was shown to be proportional to chemoluminescence intensity under various experimental conditions. the yield values for radiation oxidation of natural amino acids, glycyl-tryptophane and some other proteins were obtained.

[Retinal sensitized photochemiluminescence of trypsin solutions and the effect of 3-hydroxypyridines].

A study of retinal sensibilized photochemiluminescence of trypsin is carried out. A kinetic scheme of processes responsible for the luminescence appearance according to which chemiluminescence depends on protein groups reaction with singlet oxygen is suggested. The values of a number of kinetic parameters of these processes are determined.

[Photochemiluminescence arising during sensitized photooxidation of trypsin solutions].

Kinetic study of eosin-sensitized photochemoluminescence (PCL) in tripsin solutions was carried out. Kinetics of luminescence increase and decrease, connection between sensitized PCL with triptophane photodissociation in protein were investigated. Effect of the concentrations of protein and oxygen in solution on the parameters of eosin-sensitized PCL was studied in order to establish the succession of processes resulting in the formation of free radicals.

[Effect of different substances on the x-ray chemiluminescence of solutions of serum albumin and glycyltryptophan].

Effect of different substances, such as known radioprotectors, inhibitors of free radical processes from the class of 3-oxipyridines and methanol on the characteristics of X-chemoluminescence of human serum albumin solutions and glycyl-triptophane is studied. Possible causes of various effects of added substances on X-chemoluminescence are considered: reactions of the additives with hydroxyl radicals, with primary free radicals and peroxid radicals of protein and peptide. In most substances studied protection is partially concerned with their reactions with hydroxyl radicals and partially with the reaction between additives and free radicals of peptide and protein.

[Photooxidation and photochemiluminescence of different proteins].

Information has been obtained concerning photooxidation rate of 18 proteins, blood plasma, glycyl triptophane and some amino acids under UV-irradiation. It has been shown that the majority of the objects studied have the quantum yields of oxygen absorption in the range 0.2--0.

[Intensification of the x-ray chemiluminescence of serum albumin solutions by the addition of dyes].

Effect of dyes of different classes on characteristics of X-chemoluminescence of human serum albumin solutions is studied. Intensification of lumininescence by the addition of uranin, eosin, tetrachlorfluorescein and erythrozan was found. The process of luminescence intensification with the addition of uranine was thoroughly studied (kinetic regularities, spectra, concentration relationships).

[Photochemiluminescence of tryptophan-containing peptides and proteins during photooxidation. VII. Mechanism of sensitization by eosin of the photochemiluminescence of human serum albumin solutions].

Dependence of photochemoluminescence (PCL) intensity of serum albumin solutions with eosine initiated under light illumination with the wave length of 546 nm on oxygen concentration in solution has been studied. The luminescence intensity was shown to increase gradually with the increase of oxygen concentration. The relationship obtained is described by an empyric formula.

[Photochemoluminescence of tryptophan-containing peptides and proteins during photooxidation. VI. Kinetic patterns of eosin sensitized photochemoluminescence of solutions of human serum albumin].

Regulariteis of sensitized photochemoluminescence of serum albumine solutions have been studied. The dependence of luminescence intensity on the dye cancentration is of an extremal character; at low concentrations it is determined by the Lambert--Beer law; at high concentrations quenching processes proceed. The shape of kinetic curves of after-luminescence and rise of luminescence is studied.