Unified schedule for multiple parallel solid-phase synthesis of so-called “difficult” peptides on polypropylene pins was developed. Increase in the efficiency of 9-fluorenyl(methoxycarbonyl) N-terminal amino-protecting group removal was shown to have a greater influence on the accuracy of the “difficult” peptide synthesis than the use of more efficient amino acid coupling reagents such as aminium salts. Hence the unified schedule for multiple parallel solid-phase synthesis of “difficult” peptides included the procedure for N-terminal amino group deprotection modified by applying a more efficient reagent for the deprotection and the standard procedure of amino acid coupling by carbodiimide method with an additional coupling using aminium salts, if necessary. Amino acid coupling with the help of carbodiimide allows to follow the completeness of the coupling via the bromophenol blue indication, thus providing the accuracy of the synthesis and preventing an overexpenditure of expensive reagents. About 100 biotinylated hepatitis C virus envelope protein fragments, most of which represented “difficult” peptides, were successfully obtained by synthesis on pins with the help of the developed unified schedule.

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The conditions for the preparation of a drug formulations based on the lipid derivative of sarcolysin embedded in phospholipid nanoparticles have been optimized. The drug is an ultra-thin emulsion with a light transmittance above 80% and a particle size of not more than 50 nm. It should be noted that 99% of the lipid derivative of sarcolysin are incorporated into phospholipid nanoparticles. Preservation of aggregation stability in the aquatic environment was observed for at least 2 days. In vitro experiments have shown that sarcolysin, introduced as a part of phospholipid nanoparticles, is distributed among lipoproteins and protein components of plasma. Moreover, the content of sarcolysin in all fractions involved in the transport of biologically active substances in the body, is significantly higher in case of prodrug administration (lipid derivative of sarcolysin) in the composition of phospholipid nanoparticles than, as compared with administration of a free form (pharmacological substances) to the incubation medium. The transformation of a prodrug into the drug sarcolysin occurs in the blood cells.

The amino acid profiles of the whole water-soluble fraction of some popular fish products (muscle and caviar) have been studied. The pike (Esox lucius) muscle and caviar contain more branched-chain amino acids than all the products being studied including some valuable sturgeon and salmon fish species, and pike muscle also contains the highest amount of phenylalanine and lysine. Pike caviar is also a leader in threonine content. The pike may be considered as one of the most nutritionally valuable fish species, especially if the full amino acid content from the water-soluble fraction of its edible tissues is compared.