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  • Open access
  • 26 Reads

Wnt/β-catenin signaling pathway is deregulated in colorectal carcinoma, and its central component β-catenin is the focus of many targeted anticancer therapies. In healthy cells, where the Wnt signaling pathway is not active, this protein is present in the peripheral part of the cytoplasm, bound to E-cadherin, thus forming a complex with a role in connecting neighboring cells, which reflects its importance in the epithelium tissue. If found free in the cytoplasm, it becomes immediately degraded by the APC complex. However, in cancer cells, the Wnt pathway is deregulated and if the APC is mutated or absent, β-catenin is not degraded. It becomes transported into nucleus where acts as transcription factor regulating cell proliferation, migration and invasion, thus formation of metastases. We examined the effect of the natural product, royal jelly (RJ) on β-catenin, since previous studies have shown that RJ has certain suppressive properties on cancer, as well as on its progression in terms of metastasis.

In this study, we examined the effects of two RJ concentrations after 24 h on gene expression of this marker using the qRT-PCR method, while the levels and localization of protein fractions in the nucleus and cytoplasm were evaluated by immunofluorescence technique.

The results showed that this natural treatment caused increase in β-catenin gene expression in a dose-dependent manner, compared to the level of the control housekeeping gene β-actin. However, regarding protein expression, RJ significantly decreased the level of nuclear β-catenin, while simultaneously increasing the values ​​of its cytoplasmic fraction. Immunofluorescence also showed its membrane localization, implying its involvement in intercellular connections. The results presented indicate that the treatment caused the export of β-catenin from the nucleus to the cytoplasm and migration to the membrane in order to bind to E-cadherin and restore intercellular connections, which is a significant result of our study.

  • Open access
  • 42 Reads
Catalytic [6+2] cycloaddition of N-substituted azepines as a key element in the direct construction of 9-azabicyclo[4.2.1]nonanes

The data obtained by the authors in the field of studying catalytic cycloaddition reactions of N-substituted azepines are summarized. Cobalt(I)-catalyzed [6π+2π]-cycloaddition of N-carboethoxy-, phenoxy-, and cholesteroxyazepines with 1,2-dienes, alkynes, and 1,3-diynes leads to the formation of a practically important class of heterocyclic compounds, 9-azabicyclo[4.2.1]nonadi(tri)enes. Data on the study of the antitumor properties of the synthesized azabi(tri)cycles are presented, among which samples with increased antitumor activity and a high selectivity index were identified.

  • Open access
  • 32 Reads
Structure-property influence on the amphiphilicity of phenolipids

Phenolipids are amphiphilic antioxidants having both hydrophilic phenolic moiety and hydrophobic molecules. Alkyl esters of phenolic acids are the main known phenolipids. These compounds can be considered as potential replacements for synthetic antioxidants such as butylated hydroxyanisole or butylated hydroxytoluene commonly used in the fat industry. Therefore, it is desirable to better understand of physicochemical properties of phenolic acid esters.

The aim of this work was the estimation of lipophilicity of some phenolipids, p-hydroxycinnamic acid derivatives, especially sinapic acid alkyl esters. The lipophilicity was expressed as partition coefficient (Log P) and measured by shaking-flask methods. Additionally, the obtained results were compared with calculated data in the ALOGPS 2.1.

The examination of the data allows concluding that the lipophilicity increases with the elongation of alkyl chain length of phenolipids. Significant increases in hydrophobic properties of the synthesized phenolic acid esters were observed in comparison with the parent compounds. Additionally, the effect of substitution in the aromatic ring of the phenolic acid was associated with Log P.

The lipophilic properties of phenolipids are crucial to applying them in the food, cosmetic, and pharmaceutical industries.

  • Open access
  • 32 Reads
Catalytic cycloaddition of diazo compounds based on pharmacologically significant and natural compounds to C60-fullerene

The data obtained by the authors in the field of carbon cluster chemistry, namely, the catalytic cycloaddition of diazo compounds of modern pharmacologically significant and natural compounds to C60-fullerene under the action of complex Pd-catalysts, are summarized. Cycloaddition reactions of diazoacetates, diazoamides, diazoketones with C60-fullerene, catalyzed by Pd(acac)2-PPh3-Et3Al, with selective formation of methano- and pyrazolinofullerenes, new and promising classes of biologically active derivatives of C60-fullerenes

  • Open access
  • 32 Reads
Phosphorylation of hyaluronic acid

Chemical phosphorylation of hyaluronic acid (HA) remains an unresolved problem for the chemistry of this unique polysaccharide, since convenient phosphorylating reagents are not reactive enough to obtain HA phosphates (HA-P) with a satisfactory degree of esterification of hydroxyl groups. The synthesis of phosphates of low molecular weight (43 kDa) and high molecular weight (0.5–0.7 MDa) HA was undertaken by us using such reagents as sodium trimetaphosphate Na3P3O9, H3PO4, NaH2PO4/Na2HPO4, and anhydride P2O5. Solid-phase HA esterification with P2O5 was found to be the most convenient and efficient method. The HA-P samples were characterized by XRF and NMR spectroscopy (31P and 1H-31P) and contained, depending on the HA/Р2О5 ratio, 0.30–6.25% P wt. in the form of disubstituted mono-, di- and polyphosphates.

  • Open access
  • 94 Reads
Activity of medium chain oxygen-containing aliphatic compounds against Bursaphelenchus spp.

The pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD), is a threat to Pinus forests in Asia and Europe. Bursaphelenchus mucronatus and B. fraudulentus are closely related to the PWN, sharing morphological traits and tree hosts. However, they are considered non-pathogenic when compared to the PWN. Pest management often includes the trunk injection of pesticides, yet, many formulations have been discontinued for presenting ecological and human health concerns. Furthermore, most pesticides are non-specific, affecting non-target organisms, including beneficial microbes. In the present work, four medium chain aliphatic alcohols (C10 to C13) were evaluated in direct contact bioassays against B. xylophilus, B. mucronatus and B. fraudulentus, to assess possible specificity in nematicidal activity. Compounds activity was determined from corrected mortality values obtained after 24-hour long bioassays using serial dilutions of each compound, with a dilution factor of two, from 1.0 to 0.0038 mg/mL. The compounds showed a high nematicidal activity against all Bursaphelenchus species tested. Moreover, the lowest half maximal effective concentrations (EC50) were determined for B. fraudulentus, suggesting a higher sensibility to these compounds. Based on EC50 values, the Bursaphelenchus species showed slightly different response patterns to the series of aliphatic alcohols used. Further bioassays will include compounds with different chain lengths and functional groups to explore the diversity in the activity of oxygen-containing aliphatic compounds for a more targeted sustainable control strategy for the PWN.

  • Open access
  • 31 Reads
Sulfur-containing homo- and methanofullerenes, synthesis and study of tribological properties

The data obtained by the authors in the field of carbon cluster chemistry, namely, the catalytic cycloaddition of sulfur-containing diazo compounds to C60-fullerene under the action of complex Pd-catalysts, are summarized. Cycloaddition reactions of diazoalkanes, diazoketones, diazothioates with C60- fullerene, catalyzed by Pd(acac)2-PPh3-Et3Al, with selective formation of new sulfur-containing methano- and homo-, and pyrazolinofullerenes, promising as modern nanosized additives to oils for highly loaded mechanisms.

  • Open access
  • 29 Reads
Synthesis of 6-(4-Chlorophenyl)-N-aryl-4-(trichloromethyl)-4H-1,3,5-oxadiazin-2-amines: Comparative Evaluation of Dehydrosulfurization Methods of Starting 4-Chloro-N-(2,2,2 -trichloro-1-(3-arylthioureido)ethyl)benzamides.

Derivatives of 1,3,5-oxadiazine are of interest to pharmacy, medicine, and agriculture as potential biologically active substances. These compounds have found wide application in organic synthesis and supramolecular chemistry. In this paper, we discuss and compare the effectiveness of two approaches to the dehydrosulfurization of 4-chloro-N-(2,2,2-trichloro-1-(3-arylthioureido)ethyl)benzamides resulting in the formation of 6-(4-chlorophenyl)-N-aryl-4-(trichloromethyl)-4H-1,3,5-oxadiazin-2-amines. Dicyclohexylcarbodiimide (DCC) or a mixture of iodine with triethylamine was used as a dehydrosulfurizing agent. It is shown that in the case of using DCC, the target products are predominantly formed in high yields. However, the use of the I2+Et3N mixture made it possible to obtain several new compounds of this class, which could not be obtained under the DCC action. The structure of all new compounds was confirmed by 1Н and 13С NMR spectroscopy data.

  • Open access
  • 32 Reads
Recent progress in the synthesis of promising bicyclo[4.3.1]decanes by the oxidative rearrangement reaction of bicyclo[4.2.2]decatetraenes

Data on the synthesis of practically important bicyclo[4.3.1]decatrienes based on oxidative transformations of bicyclo[4.2.2]deca-2,4,7,9-tetraenes are summarized. The authors have shown for the first time that the reactions of electrophilic activation of double bonds in bicyclo[4.2.2]deca-2,4,7,9-tetraenes under the action of m-chloroperbenzoic acid are accompanied by oxidative skeletal rearrangement with the formation of bicyclo[4.3.1]deca-2,4,8-triene-7,10-diols. A probable mechanism for the detected rearrangement is proposed. Data on the study of the antitumor properties of the resulting bicyclo[4.3.1]decatrienes are presented, among which samples with high antitumor activity were identified.

  • Open access
  • 23 Reads
Synthesis and chemosensory studies of a heterocyclic thiosemicarbazone as a new tributyltin optical chemosensor

Thiosemicarbazones are a versatile type of organic compounds known by their coordination ability with different types of analytes, due to the presence of sulfur and nitrogen heteroatoms. Therefore, the functionalization of thiosemicarbazones with heterocyclic moieties can be a promising route to develop new optical chemosensors. Tributyltin (TBT) is an antifouling component of paints which is acutely toxic to aquatic environments, being quickly absorbed by microorganisms and causing problems such as imposex. Herein, we report the synthesis of a novel heterocyclic thiosemicarbazone, functionalized with a quinoline moiety, in order to assess the potential of this recognition moiety for TBT optical chemosensing.

The new thiosemicarbazone was synthesized by a condensation reaction between quinoline aldehyde precursor and N-phenylhydrazinecarbothioamide, and the compound was then submitted to chemosensory studies in the presence of TBT in acetonitrile solution. A preliminary chemosensory study was performed showing that 50 equivalents of TBT were needed in order to induce a change of color from colorless to yellow. Spectrophotometric titration was performed to assess the concentration of TBT necessary for a maximum optical signal, revealing that 100 equivalents of TBT were necessary to reach maximum absorbance, although it was able to respond with a detectable color change to a TBT concentration as low as 10 uM.