Bioorganicheskaia khimiia最新文献

A new method for synthesizing 4-amino-3-methyl-1-phenyl-1H-5-substituted thieno[2,3-c]pyrazole was reported. The substituted groups at position 5 include carbonitrile, carboxamide, N-phenyl carboxamide, and benzoyl groups. The newly synthesized compounds and their derivatives were characterized by elemental analysis and spectroscopy (IR, 1H NMR, and mass spectra). Furthermore, some of these synthesized compounds were screened against various pathogenic bacterial and fungal strains. The results demonstrate that most of the synthesized compounds possess a significant antibacterial activity against gram-positive and gram-negative bacteria. In addition, most of these compounds showed a remarkable anti-fungal activity. On the other hand, some of the synthesized compounds possess high anti-inflammatory activity, which was demonstrated using the carrageenan-induced rat paw edema assay.

Screening of the genus Aspergillus micromycetes for secretion of extracellular proteolytic enzymes, capable of acting on human proteins of the hemostatic system, has been conducted. The ability of extracellular proteases of Aspergillus to cleave specific proteins of the hemostatic system chromogenic peptide substrates, as well as activate a series of proenzymes (protein C, factor X and prothrombin) has been found. The ability of extracellular proteases of micromycetes activate X factor of human blood plasma was first shown at the first time.

The expression of the total proteasome pool, immune proteasome subunits LMP2 and LMP7, TAP1 and TAP2 transporters, as well as RT1A molecule of MHC class I was investigated in the ascite Zajdela hepatoma at the 10th day after implantation into Brattleboro rats with the hereditary defect of hypothalamic arginine-vasopressin synthesis (AVP) and into WAG rats with normal AVP expression. In Zajdela hepatoma cells implanted into Brattleboro rats the 3-fold increase of the total proteasome pool and LMP2 level and 8-fold increase of the LMP7 level was detected by Western blotting as compared to those in WAG rats. Differences in the LMP2 and LMP7 expression suggest variations in their functions, namely the important role of LMP7 in anti-tumor immunity. The growth of Zajdela hepatoma in WAG rats was accompanied by the decreased level of total proteasome pool as well as immune proteasome expression as compared to those in Brattleboro rats during the regression of tumor. The analysis of TAP1 and TAP2 revealed the pronounced expression of these peptide transporters in Zajdela hepatoma cells implanted into Brattleboro and WAG rats. The expression level of RT1A molecule of MHC class I was increased 3 times in Zajdela hepatoma cells implanted into Brattleboro rats as compared to WAG rats. Moreover, flow cytometric analysis of CD4- and CD8-lymphocytes number in the spleen of Brattleboro and WAG rats was performed at the 10th day after implantation of Zajdela hepatoma. The increased number of CD4- and CD8-lymphocytes was observed in the spleen of Brattleboro as compared to WAG. The increased subpopulations of cytotoxic T-lymphocytes and T-helpers might promote the tumor regression in Brattleboro rats. The reduced populations of CD4- and CD8-lymphocytes in the spleen of WAG rats were accompanied by the splenomegaly and tumor progression. The data obtained suggest that AVP deficiency in Brattleboro rats leads to the increase of the immune proteasome and MHC class I expression in Zajdela hepatoma cells, resulting in tumor immunogenicity and its elimination by the adaptive immunity.

A key role in tumor progression play two processes--the destruction and angiogenesis. Matrix metalloproteases (MMPs) play a leading role during tissue degradation. Tissue collagenase--MMP-1 and MT1-MMP hydrolyze fibrillar collagens, which are the basis of connective tissue matrix, and ensure the development of an invasive process. Gelatinase A and B (MMP-2 and MMP-9) hydrolyze collagen type IV, which is the basis of the basal membrane, and facilitate the development of metastasis. Endogenous tissue inhibitors TIMP-1 and TIMP-2 are involved in the regulation of MMP expression and activity. It has been established that MMP-9 release vascular endothelial growth factor (VEGF) associated with the STM--the primary inductor angiogenesis. Angiotensin-converting enzyme (ACE) participates in the induction of VEGF synthesis. ACE--a key enzyme of the renin-angiotensin system, forms angiotensin II, which interactes with the receptor ATIR and induces VEGF synthesis, as well as stimulates endothelial cell proliferation. Our experimental studies devoted to the study of particularity expression of key enzymes of destruction and angiogenesis in squamous cell carcinoma of the cervix (SCC). It was studied: MMP-1, MT1-MMP, MMP-2 and MMP-9 and their endogenous regulators: TIMP-1, TIMP-2, and as well as ACE. Work was performed on clinical specimens containing the tumor tissue, taking into account the presence or absence of metastasis to regional lymph nodes and the specimens of adjacent morphologically normal tissue. It was shown that the increase of MMP-1, MT1-MMP and MMP-9 expression and low of TIMP-1 and TIMP-2 expression makes the main contribution to the destructive (invasive) potential of SCC. The change of MMP-2 expression is not so significant and it is less influenced to the destructive potential. It was shown dramatic increasing of MMP-1 and MMP-9 activity in metastasizing tumor tissue ACE activity in a tumor in most of the samples was higher than the activity in normal tissues. It was established that the expression of key enzymes degradation and angiogenesis occurs not only in tumor but also in normal tissues. Data are important for understanding the mechanisms of tumor progression and have prognostic value and may affect the therapeutic strategy for patients.

For the purpose of new detritylation agents search for microarray oligonucleotide synthesis we investigated applicability of [4-(4-methoxyphenyl)-2,6-dinitro-phenyl](phenyl)methyl 2,2,2-trichloroacetate for 4,4'-dimethoxytrityl group detritylation during oligonucleotide syntheses generating trichloroacetic acid at radiation by light with a length of wave of 405 nanometers. [4-(4-Methoxyphenyl)-2,6-dinitro-phenyl](phenyl)methyl 2,2,2-trichloroacetate has been successfully used for solid-phase oligonucleotide synthesis of desired oligonucleotides.

In continuation of our previous work, fused steroidal derivatives with pyrane, pyridine, pyrimidine moieties were synthesized and evaluated as androgenic-anabolic agents. Some of the newly synthesized compounds are exhibited pronounced androgenic-anabolic activities.

It is known that albumin is able to cut ester bonds in organophosphates (OPs). Amino acids responsible for esterase and pseudo-esterase activity of albumin towards OPs are still not determined. The purpose of this study is to identify the potential sites of esterase activity of albumin by the example of its interaction with soman using molecular modeling methods. The structures of the protein complexes with soman was determined by molecular docking procedure, the stability of the complexes were simulated using molecular dynamics method. It has been determined that productive sorption of soman near Tyr411 is possible only after deprotonation of the tyrosine. Tyr150 binds soman more efficiently than Tyr411; deprotonation of Tyr150 does not affect the binding efficiency, but affects on the stability of the complexes. The true esterase activity of albumin Tyr150 in relation to soman is proposed. It is shown that Ser193 can also be responsible for the esterase activity of albumin. We hypothesize that deprotonation of catalytic amino acid in one of the sites could be initiated by ligand binding in other sites (allosteric regulation).

A novel series of uracil derivatives with a 3,5-dimethylbenzyl group at the C-6 position were synthesized and evaluated as non-nucleoside HIV-1 reverse transcriptase inhibitors. Purity of the compounds has been confirmed by TLC. Structures of these compounds were established on the basis of elemental analyses and spectral studies. Some of the tested compounds showed moderate to potent activities against wild-type HIV-1, and N-1 alkylated derivatives were highly active.

Intracellular content of heat shock proteins of 70 kDa family (HSP70) possessing chaperone and cytoprotective functions depends on specialization and functional activity of the cells. The aim of this study was to analyze the dynamics of constitutive and inducible HSP70 levels evoked by heat shock in human neutrophils, the short-lived fraction of white blood cells providing non-specific defense against bacterial pathogens. Biphasic dynamics of the intracellular HSP70 level with an increase and following decrease in 15-30 min after the heat shock was revealed by flow cytometry. This dynamics was similar for constitutive and inducible forms of HSP70. Pre-incubation of neutrophils with cycloheximide, the inhibitor of protein synthesis, did not change the intracellular HSP70 dynamics registered by flow cytometry indicating that the increased HSP70 level detected immediately after the heat shock was not mediated by de novo protein synthesis. It was confirmed by Western blotting analysis of HSP70 intracellular content. It was suggested that the elevated HSP70 level was related to conformational HSP70 molecule changes and to increased availability of HSP70 epitopes for antibody binding. Using a panel of antibodies specific to the N-terminal ATP-binding or C-terminal substrate-binding domains of HSP70 it has been demonstrated by cell immunofluorescence and flow cytometry methods that the heat shock-associated increase of the intracellular HSP70 level was mediated by HSP70 interaction with antibodies recognizing HSP70 substrate-binding domain. It was demonstrated that the decrease of intracellular HSP70 level after heat treatment could be connected with a release of both inducible and constitutive HSP70 into extracellular space. Our data suggest that stress-induced release of HSP70 from neutrophils is regulated by ABC-transporters.

Liposomes are of great interest in biotechnology, as a drug delivery systems, due to their biocompatibility and low immunogenicity. However, low stability and tendency to aggregate still limits their application in medicine. Therefore, the actual problem is to obtain the effective stabilizing additives for the liposomes on the base of polymeric materials. In this paper we suggested to use the branched copolymers on the base of chitosan modified by polyethylene glycol (PEG-chitosan) as stabilizing additives for the liposomes. The method of copolymer synthesis of chitosan modified with PEG molecules by using mPEG-suc-NHS was developed and the PEG-chitosan copolymers of different modification degrees were obtained to investigate the influence of the complex formation of PEG-chitosan on the structure and stability of mixed anionic liposomes of dipalmitoylphosphatidylcholine (DPPC) and cardiolipin (CL) (80/20% w/w). It has been found by using FTIR spectroscopy and DLS methods that the PEG-chitosan co-polymers form a Complex of electrostatic nature by interaction with the anionic groups in liposomes. It was found that the main binding sites of the copolymer with liposomes are phosphate and carbonyl groups. Analysis of the IR spectra yields that the complex formation of liposomes with PEG-chitosan resulted to significant stabilization of liposomes against aggregation upon storage. This result is particularly important, taking into account the fact that the aggregation is one of the key factors limiting the use of liposomes in medicine. These results offer the prospect of the copolymer PEG-chitosan as an effective additive for stabilizing liposomes and hold promise for creating new drug delivery systems.