The chitosan derivatives containing antiradical fragments in the polymer side chain have been synthesized by interaction of the partially quaternized chitosan(QCH) with gallic acid (GA). The antioxidative activity of the chitosan derivatives — QCH‐GA was investigated by thiobarbituric method. Introduction of GA fragment in amount of 2. 0 mass % in the structure of QCH resulted in appearance of pronounced antioxidative activity of the polymeric system contrary to initial chitosan for which this activity was equal to zero. It was found that QCH‐GA was a markedly higher effective inhibitor in a peroxidase — catalyzed oxidation of the model amine than the low‐molecular antioxidant — GA. Targetted chitosan modification resulted in a substantial raize of the polymeric antimutagenic (at γ‐irradiation) efficiency, which for QCH‐GA was equal to 92% in comparison with the protective effect of the initial chitosan — 42% (plant test‐system, barley seeds, γ = 15 Gr).

A new approach to the problem of construction of efficient antimutagenic ( at y-irradiation ) systems has been developed on the basis of the models-synthetic cationjc polyelectrolytes-polyquatemary salts of diallyldimethylammonium type.Studies designed to reveal correlation between the structure and activity of polymers are of great importance for targetted synthesis of polymers capable to protect cells from y-radiation. From this point of view a positive contribution of the total charge 1 0 1998 Hiithig & 2 of the inacroion and antiiadical activity of polycations into their antiinutagenic effect were revealed. Taking into account the dependencies found, the niacromolecular design of super efficient antimutagenic systems on the basis of the natural biodegradable polycation-chitosan has been realized. The protective efficiency ( up to 93%) of the systems is achieved by combination of an adsorption ability of the polycation matrix and antiradical activity of a hydrophobic derivative of hindered phenol incorporated into the polymer structure. These systems are able to scavenge short-lived radicals formed in water and to soine extent to prevent the nienibiane lipid peroxidatioii processes responsible for genetic damage at *Iirradiation.

The adsorptive capacity on the model bilayer lipid membrane and antimutagenic activity of synthetic polycations of diallyldimethylammonium chloride (DADMACh) were studied. A correlation between the total positive charge of a macro-ion and the polymer efficiency as a bioprotector was found. A number of ternary copolymers (TCP) containing different amounts of di(tertbutyl)phenol (TBPh) in the side chain of a DADMACh and acrylic acid binary copolymer (30:70 mol%) were prepared. A correlation between the amount of the TBPh in the TCP(TBPh) structure and both the antiradical and the antimutagenic efficiencies was obtained. Taking into account the correlations found in model synthetic polycations, modification of chitosan was fulfilled. Chitosan derivatives containing quaternary ammonium groups and TBPh in the polymer side chain improved the antimutagenic efficiency of the polymer in a plant test-system from 48 to 93%.