Bioorganičeskaâ himiâ

A new approach to the synthesis of Anti-Reverse Cap Analog (ARCA) of the classical structure – dimethylated guanosine dinucleotide ^2mGpppG is proposed. The classical approach to obtaining consists in condensation of activated 5′-diphosphate of 7,3′-O-dimethylguanosine with 5′-guanosine monophosphate. We suggest to use a commercially available 3′-O-methylguanosine for the synthesis of 5′-monophosphate of dimethylated guanosine only, and to use an activated 5′-guanosine diphosphate in the condensation. The conditions of 3′-O-methylguanosine phosphorylation were determined to avoid the formation of a side product 3′-O-methyl-5′-deoxy-5′-chloroguanosine-3′-phosphate. ARCA was synthesized with a high yield (89% at the condensation stage). Our approach to the synthesis is easily scaled and can be used for a preparative synthesis of ARCA (several grams).

The aim of the study was to study the role of transcription factor CREB1 in regulating the expression of the gene encoding the mitochondrial form of malate dehydrogenase (MDH, EC 1.1.1.37) in the liver of rats with experimental diabetes. An increase in the rate of work of NAD-dependent malate dehydrogenase in rat liver cells during the development of experimental diabetes was shown, associated with the activation of the Mdh1 and Mdh2 genes encoding this enzyme. The analysis of the promoters of these genes showed that only in the Mdh2 gene there is a specific binding site with the transcription factor CREB1. It was found that in the liver of rats with pathology, there is an increase in the rate of expression of the gene encoding this transcription factor, which correlates with the expression of the Mdh2 gene. Thus, the data obtained by us confirm the possibility of positive regulation of the rate of the Mdh2 gene by the transcription factor CREB1.

A method for the synthesis of ketosteroid oxime conjugates with a fluorescein (6-FAM) derivative connected via a short bifunctional aminooxypropyl linker is proposed. The conjugates were used as tracers for fluorescence polarization immunoassay (FPIA) with monoclonal antibodies. Stereoisomers by the oxime group were separated by preparative RP TLC and HPLC and tested in the FPIA method. Binding parameters of of tracers with monoclonal antibodies (mAbs) to progesterone were studied. Tracers showed high efficiency in the analysis of steroid hormones, the detection limit of progesterone being lower than that for a previously described analog. The Z-isomer was found to be more sensitive in the FPIA analysis compared to the E-isomer.

We report a series of 3-aminocoumaranones possess significant chemiluminescence under various conditions. The introduce of the electron-donor groups in the coumaranone moiety and increasing of the conjugated π-system of coumaranones allow to shift 30–40 nm of the chemiluminescence maxima to the long-wavelength region. We showed that some 3-aminocoumaranones can be used for detecting of the urease and hydrogen peroxide.

We report about a series of arylidene-rhodanines and their acyclic analogues. The fluorescent properties of these substances were studied. We showed that the derivatives containing a 2,5-dimethoxybenzylidene fragment or similar groups are characterized by a noticeable variation in the fluorescence quantum yield depending on the properties of the medium. We discovered that two of the synthesized compounds – dimethoxy-benzylidene-rhodanine and dimethoxy-benzylidene-malononitrile – can be used as selective fluorogenic dyes for lipid droplets (adiposomes) of living cells for labeling under fluorescent microscopy conditions.