A. A. Zharov

Immobilization of trypsin on polysaccharides upon intense mechanical treatment

Immobilization of a ptoteolytic enzyme, trypsin, on chitosan and cellulose was accomplished in the solid state under pressure and shear strain. Trypsin immobilized in this way retains 70—80% of the catalytic activity and exhibits prolonged action. The mechanical treatment allows introduction of a much larger amount of the active protein into a polymer matrix than the equilibrium sorption from solution.

Synthesis of 5,4″-di-O-succinoylavermectin B1

A reaction of avermectin B1 with succinic anhydride at ultrahigh pressure (10 kbar) gave previously unavailable 5,4″-di-O-succinoylavermectin B1, which is of interest as potential antiparasitic agent.

Cotrimerization of mono- and dinitriles of perfluorocarboxylic acids under high pressures

Cotrimerization of mono- and dinitriles of perfluorocarboxylic acids under high pressures affords oligoperfluoroalkylenetriazines. These oligomers are highly efficient stabilizers of thermooxidative destruction of perfluoropolyethers, when they are contacting with metals at elevated temperatures.

Synthesis of amorphous homopolymer of perfluoropropyl vinyl ether at a high pressure

A high-molecular-weight amorphous homopolymer of perfluoropropyl vinyl ether was synthesized by radical polymerization at a pressure from 500 to 1200 MPa. The polymer properties were studied and reported.

Kinetics and mechanism for synthesis of iodo-containing telomeres and block copolymers at high pressures

Radical telomerization reactions of hexafluoropropylene, perfluoromethyl vinyl ether, and perfluoropropyl vinyl ether in the presence of alkyl iodides were studied at high pressures (1000 MPa). Iodo- and diiodo-containing telomeres were synthesized. Their preparation is almost impossible under usual conditions. The mechanism and kinetics of telomerization were studied. Block copolymers of different structures were synthesized from the obtained telomeres by the “living” radical telomerization method.

Synthesis of condensed pregnano[17,16-d]triazolines under high pressure

Condensed pregnano[17,16-d]triazolines were produced in 1,3-dipolar cycloaddition of 16-dehydropregnenolone acetate with organic azides at 10 kbar. The structure of the synthesized compounds was determined by using two-dimensional NMR spectroscopy (1H—1H COSY, NOESY, HSQC, and HMBC).

Reactions of nucleophilic substitution involving solid organic halogen compounds under shear deformation at high pressure

Under conditions of shear deformation and high pressures (SD+HP), reactions of nucleophilic substitution were studied: 1) the replacement of aliphatic halogen atom with alkaline metal halides (halo-substituted aliphatic carboxylic acids, 1-bromoadamantane); 2) the replacement of halogen atom in aromatic nucleus (halobenzoic acids, dihalobenzenes) with halogen of salt; 3) the replacement of aliphatic halogen with hydroxyl (hydrolysis in a solid phase); 4) the replacement of halogen with amino group under deformation of the samples of ammonium α-halocarboxylates to give the corresponding amino acids. It was found that the exchange of the halogen atoms bonded with aliphatic carbon is most intensive in the mixtures of alkaline metal iodides with bromo-substituted acetic and propionic acids: the exchange reaction in these mixtures is observed even during grinding in the mortar. Unlike the liquid phase, under conditions of SD+HP exchange of the halogen atom of the aromatic nucleus with alkaline metal halides, proceeds successfully, and the reactivity of halides increases in the series Na < K < Rb < Cs. Under SD+HP, 1-Br-adamantane reacts with water to form 1-adamantanol. A high reactivity of the water adsorbed by the reagents is observed.

Trimerization of perfluoroheptanonitrile at high pressures

ConclusionsA study was carried out on the trimerization of perfluoroheptanonitrile under high pressure conditions at 110 and 124°C. This reaction obeys zero-order kinetics relative to the monomer and first-order kinetics relative to the catalyst.