I. A. Nizova

Synthesis of ( 2S, 4S)-4-phenylamino-5-oxoproline derivatives.

Summary. The paper describes the synthesis of (2S,4S)-4-(N-Ts)- and (2S,4S)-4-(N-Boc)-phenylamino-5-oxoprolines (pyroglutamic acid). These derivatives have been shown to be useful for synthesis of their amides and peptides in spite of steric hindrances caused by bulky groups adjacent to the reaction centre. Under the conditions applied no lactam ring opening and no loss of stereochemical integrity of any of the chiral centres were observed, which has been confirmed by NMR techniques.

Synthesis and antimycobacterial activity of N-(2-aminopurin-6-yl) and N-(purin-6-yl) amino acids and dipeptides

Synthetic routes to novel N-(purin-6-yl)- and N-(2-aminopurin-6-yl) conjugates with amino acids and glycine-containing dipeptides were developed. In vitro testing of 42 new and known compounds made it possible to reveal a series of N-(purin-6-yl)- and N-(2-aminopurin-6-yl) conjugates exhibiting significant antimycobacterial activity against Mycobacterium tuberculosis H37Rv, Mycobacterium avium, Mycobacterium terrae, and multidrug-resistant M. tuberculosis strain isolated from tuberculosis patients in the Ural region (Russia). N-(2-Aminopurin-6-yl)- and N-(purin-6-yl)-glycyl-(S)-glutamic acids were the most active compounds.

Synthesis of stereoisomeric 4-(2-methylindolin-1-yl)- and 4-(2-methylindol-1-yl) derivatives of glutamic acid

The reaction of dimethyl (2S,4RS)-N-phthaloyl-4-bromoglutamate with 2-methylindoline afforded diastereomeric 4-(2-methylindolin-1-yl)-(S)-glutamic acid derivatives, whose oxidation gave rise to 4-(2-methylindol-1-yl)-(S)-glutamic acid derivatives.

Synthesis and piezoelectric properties of N -phthaloylglutamic acid derivatives

The (S,S)- and (R,R)-enantiomers of dimethyl 2,4-diphthalimidoglutarate were synthesized by nucleophilic substitution of bromine in dimethyl (2S,4RS)-4-bromo-N-phthaloyl-glutamate upon treatment with potassium phthalimide, followed by separation. The crystal structure of the obtained compounds was studied by X-ray diffraction. Crystals of enantiomerically pure dimethyl 4-hydroxy- and 4-phthalimido-N-phthaloylglutamates were found to possess a noticeable piezoelectric activity.

Synthesis of enantiomers of N-(2-aminopurin-6-yl)amino acids

Nonracemic N-(2-aminopurin-6-yl)-substituted amino acids were synthesized by nucleophilic substitution of chlorine atom in 2-acetamido-6-chloropurine upon treatment with amino acid tert-butyl esters and subsequent removal of protecting groups. Their enantiomeric composition was determined by HPLC on chiral stationary phases.

Lactam ring stability of stereoisomers of 4-amino-substituted pyroglutamic acids in acidic medium

The acid hydrolysis of the lactam ring of cis and trans stereoisomers of 4-(1-piperidyl)-, 4-dibenzylamino-, 4-[(methyl)(phenyl)amino]-, 4-phenylamino-, and 4-(4-methoxyphenyl)-aminopyroglutamic acids was studied. It was shown that the relative stability of the lactam ring of 4-amino-substituted pyroglutamic acids to acid hydrolysis depends both on the structure of a substituent in the position 4 and on the configuration of the compounds studied. Among these compounds, 4-amino-1-arylpyroglutamic acids were the most stable in acidic medium. The trans isomers are more stable than the corresponding cis isomers.

Nucleophilic substitution of halogen in 4-halo genated derivatives of glutamic acid: 2. Structural effects of arylamine as nucleophile

Kinetics of nucleophilic substitution of halogen in diastereomeric dimethyl 4-bromo- and 4-iodoglutamates withortho-, meta-, andpara-substituted anilines was studied by HPLC. Thethreo-diastereomers of the halogenated derivatives react 3–5 times faster than theerythro ones. The structure of the transition state is discussed.

Synthesis of derivatives of the RGD peptide with the residues of glutaric and adipic acids

A method of the synthesis of RGD peptide derivatives containing glutaric or adipic residues linked with α-amino group of L-arginine and allowing carrying out their coupling with other biomolecules and nanoparticles.Derivatives of the RGD peptide were prepared by the attachment of the residues of glutaric and adipinic acids to the α-amino group of L-arginine. This modification allowed condensation of these derivatives with other biomolecules or nanoparticles.