Asymmetric Synthesis of Functionalized α-Amino Acid Derivatives via the γ-Pyrone Carbaldimine-Based Organocatalytic Mannich Reaction.

A powerful synthetic strategy for the asymmetric synthesis of enantiomerically enriched γ-functionalized α-amino acid derivatives based on the highly stereoselective proline-catalyzed Mannich-type reaction of pre-prepared or -generated γ-pyrone-derived aldimines with carbonyl compounds and subsequent transformations of multifunctional reaction products has been developed. A significant positive nonlinear effect was detected for the key organocatalytic reaction. The developed strategy was applied for facile gram-scale preparation of ()-γ-oxonorvaline, used for site-specific modification of proteins, and both enantiomers of amycolatolide A recently isolated from the lichen-derived actinomycete sp.

Concise enantioselective synthesis of non-proteinogenic α-aminoacids an organocatalytic Mannich-type reaction.

A bifunctional tertiary amine-squaramide-catalyzed enantioselective Mannich-type addition of available allomaltol to -protected aldimines was developed. The resulted adducts were readily transformed into non-proteinogenic α-amino acids and their derivatives were not easily accessible by other methods oxidative fragmentation, esterification, amidation and deprotection reactions. The absolute ()-configuration of the thus obtained α-amino acids was established by comparison of the -Ts-PheGly optical rotation sign with the reported data.

Obtainment and Characterization of Metal-Coated Polyethylene Granules as a Basis for the Development of Heat Storage Systems.

The research studied the feasibility of using copper-coated polyethylene granules as a basis for creating efficient heat storage systems. A technology for imparting catalytic properties to a polymer surface by the joint processing of polymer granules and an activator metal in a ball mill with their subsequent metallization in a chemical reducing solution is proposed. The efficiency of copper-coating a polyethylene surface is shown to be largely determined by the activation stage and the assumption regarding the mechanism of interaction of the activator metal with the polymer surface is made.

The effect of resource-saving tillage technologies on the mobility, distribution and migration of trace elements in soil.

The influence of agricultural tillage technologies on the accumulation and distribution of trace elements in the soil is poorly studied. At the same time, intensive agriculture requires large amounts of fertilizers, growth stimulators, pesticides, and other substances, which can effect the ecological safety of the plant products and soil. This paper represents studying the effect of various agricultural techniques (including resource-saving technologies) on the mobility and profile distribution of Pb, Zn, and Cu in Haplic Chernozem.

Anti-inflammatory and antidiabetic effects of grape-derived stilbene concentrate in the experimental metabolic syndrome.

Aims: This study aimed to investigate the carbohydrate and lipid dynamics, associated inflammation markers and the effectiveness of a grape-derived stilbene concentrate (GDSC) treatment in experimental metabolic syndrome (MetS).

Methods: The study was carried out on 40 male 12-weeks of age Wistar rats. The MetS was induced using the fructose model (feeding with 60%-solid fructose diet for 24 weeks).