Enzymic hydrolysis of phenylpenicillins

Pharmaceutical Chemistry Journal -     

Study of alkaline hydrolysis of anilides of benzylpenicillin

To examine the stability of penicillin and its derivatives in an alkaline medium the hydrolysis of substituted anilides of benzylpenicillin was studied at pH 9.1 and temperatures of 25, 30, and 40°. The velocity constants of the reaction and the activation energy of the process were calculated; hydrolysis of the amide bond of the-lactam ring of anilides of benzylpenicillin under these conditions was shown to be a pseudomonomolecular reaction. A satisfactory correlation was found between the logarithms of the velocity constants of the reaction and the pK of the amine. Hammett's equation is applicable to this process. The low absolute values of=0.33 indicate that the reaction is only slightly sensitive to structural changes in the anilide molecule.Translated from Khimiko-Farmatsevticheskii Zhurnal, No. 2, pp. 17–21, February, 1967.     

Synthesis of low molecular weight poly(N-acryloylmorpholine) end-functionalized with primary amino groups,and its use as macromonomer for the preparation of poly(amidoamines)

Amphiphilic oligomers of poly(N-acryloylmorpholine) terminated at one end by primary amino groups have been prepared by free radical polymerization of the corresponding monomer, N-acryloylmorpholine, in the presence of cysteamine (2-mercaptoethylamine) as chain-transfer agent. The polymerization reaction was performed in aqueous media at acidic pH, in order to avoid any hydrogen-transfer addition reaction the the acrylic double bonds by the SH or NH₂ groups present in cysteamine. The chain-transfer constant of cysteamine towards N-acryloylmorpholine, under the conditions we used, was found to be very close to 1. The aminated poly(N-acryloylmorpholine) oligomers were found to behave as true macromonomers in polyaddition reactions with a diacrylamide, leading to new poly(amidoamines) carrying poly(N-acryloylmorpholine) chains as side substituents.     

Synthesis and Immunomodulant Properties of Copolymers of N-Vinylpyrrolidone and Vinyl Saccharides

Pharmaceutical Chemistry Journal -     

Development of multifunctional polymer-mineral composite materials for bone tissue engineering

The main goal of this article is the development of a novel approach to construct multifunctional composite scaffolds for bone tissue engineering. For this purpose, different kinds of mineral macroporous supports, water-soluble aldehyde-containing copolymers of N-vinylpyrrolidone, as well as different nonspecific and biospecific ligands governing cell adhesion and growth have been used. The composite materials were tested initially for cytotoxicity in cell culture experiments using a model cell line.     

Polymer complexes of dimethylbenzylalkylammonium chlorides

The interaction of cationic surfactants from the series of dimethylbenzylalkylammonium chlorides (DMBAAC, alk. = C_nH_2n+1 (n = 10, 12, 14)) with water-soluble copolymers of N-vinyl-2-pyrrolidones (VP) with methacrylic, acrylic, and crotonic acids in aqueous and aqueous-salt solutions was investigated by polarized luminescence. It was established that the main factors determining the stability of water-soluble DMBAAC complexes with carboxyl-containing VP copolymers include the composition and structure of the copolymer, the length of the alkyl group of DMBAAC, the ratio of the interacting components, the pH, and the ionic strength of the solution. The equilibrium dissociation constants of these complexes in aqueous solution were determined. Potentiometric titration, turbidimetry, and viscometry showed that the complexation features manifested by the interaction of individual DMBAAC's with carboxyl-containing VP copolymers are also characteristic of complexation processes occurring with participation of industrial DMBAAC, which is a mixture of individual DMBAAC's.