[Monomers containing 2'-o-alkoxymethyl groups as synthons for the synthesis of oligoribonucleotides by the phosphotriester method].

A general scheme for the synthesis of ribonucleotide monomers containing alkoxymethyl group in 2'-O-position for the solid-phase phosphotriester oligonucleotide synthesis using O-nucleophilic intramolecular catalysis has been developed. In particular, the monomers containing 2'-O-modifying 2-azidoethoxymethyl, propargyloxymethyl, or 3,4-cyclocarbonatebutoxymethyl groups has been prepared.

[An azidomethyl protective group in the synthesis of oligoribonucleotides by the phosphotriester method].

A rapid and effective method of an automatic oligoribonucleotide synthesis alternative to the phosphoroamidite one was developed based on the phosphotriester approach of internucleotide bond formation under intramolecular O-nucleophilic catalysis and the use of an azidomethyl group for protection of a nucleotide 2'-hydroxyl function.

On the synthesis of platelet-activating factor via acetylation of 1-alkyl-sn-glycero-3-phosphocholine. Formation of structural isomer of PAF in the presence of bases.

It has been shown that platelet-activating factor (PAF) specimens prepared via acetylation of 1-alkyl-sn-glycero-3-phosphocholine (lyso-PF) with acetic anhydride are heterogeneous. The contaminated compound was isolated and identified to be the structural isomer of PAF, 1-alkyl-3-acetyl-sn-glycero-2-phosphocholine (iso-PAF). It appeared, that iso-PAF is formed when performing the reaction in the presence of organic bases,but not under acid catalysis. The mechanism of iso-PAF formation is discussed.

[Synthesis of cholesterol-containing cationic amphiphiles with heterocyclic bases]. / Sintez kholesterinsoderzhashchikh kationnykh amfifilov s geterotsiklicheskimi osnovaniiami.

A number of cationic derivatives of cholesterol containing polar residues of N-methylimidazole, pyridine, N-methylmorpholine, and 4-N,N-dimethyaminopyridine were synthesized by the interaction of the corresponding heterocyclic bases with cholesterol 5-bromopentanoate followed by the treatment with methyl iodide in the case of tertiary amines. In addition, N-(4-cholesteryloxycarbonylbutyl)piperazine was obtained for the preparation of pH-sensitive liposomes.

[Formation of a structural isomer of platelet activating factor during acetylation of 1-alkyl-sn-glycero-3-phosphocholine]. / Obrazovanie strukturnogo izomera faktora aktivatsii trombotsitov pri atsetilirovanii 1-alkil-sn-glitsero-3-fosfokholina.

In studying acetylation of 1-alkyl-sn-glycero-3-phosphocholine (lyso PAF) with acetic anhydride, a key step of the platelet activating factor (PAF) synthesis, we have found that in the presence of triethylamine or 4-dimethylaminopyridine some 1-alkyl-3-acetyl-sn-glycero-2-phosphocholine as an admixture to PAF formed, whereas the acid catalysed reaction resulted in isomerically pure PAF. The mechanism of the reaction leading to the PAF structural isomer is discussed.

[The synthesis of cationic glycerolipid acetals containing aliphatic and heterocyclic bases]. / Sintez kationnykh glitserolipidov atsetal'nogo tipa s alifaticheskimi i geterotsiklicheskimi osnovaniiami.

1,3-Dioxolane series cationic lipids containing residues of aliphatic or heterocyclic nitrogenous bases were synthesized. The bases were attached to the glycerol backbone either directly (piperazine) or via a spacer group through a thioether bond.

[Neutral lipids as stimulators of natural unspecific immunity]. / Ispol'zovanie neitral nykh lipidov v kachestve stimuliatorov estestvennogo nespetsificheskogo immuniteta.

Neutral lipids (various monoglycerides and cholesterol derivatives) were used as stimulators of natural unspecific immunity. All the compounds studied exhibited the biological activity. Saturated monoglycerides (chimyl and batyl alcohols) and cholesterol derivatives possessed the highest activity. Unsaturated lipids with double bonds were less active.

Synthesis of RNA by the rapid phosphotriester method using azido-based 2'-O-protecting groups.

The azidomethyl and 2-(azidomethyl)benzoyl as 2'-OH protecting groups are reported for preparation of oligoribonucleotides by the phosphotriester solid-phase method using O-nucleophilic intramolecular catalysis. The procedures for the synthesis of the corresponding monomer synthons were developed and the usefulness of the application of 2'-O-azidomethyl and 2'-O-2-(azidomethyl)benzoyl groups was examined in the synthesis of different RNA fragments with a chain length of 15-22 nucleotides. The azidomethyl group was found to be more preferable for effective synthesis of oligoribonucleotides. Hybridization properties of RNAs toward their complementary oligonucleotides were examined before and after the removal of 2'-O-azidomethyl groups.