Chemistry Journal of Moldova

https:/doi.org/10.19261/cjm.2022.946   

 

Abstract (PDF)
Graphical Abstract: The composition of the lipophilic and hydrophilic extracts from the Feteasca Neagra ground seeds, grown in three different vineyards, was studied. The physicochemical indicators of the seeds, the oil quality indicators and the total content of polyphenols and flavonoids in the extracts were determined.  Some phenolic and flavanol constituents were identified and quantified using reversed-phase HPLC by gradient-elution. The Trolox equivalent antioxidant capacity assay proved the increased antioxidant activity of the hydrophilic extracts, with the highest DPPH• scavenging effect of almost 91.70 and 93.81%, an equivalent of 281.66 and 288.27 µM/L Trolox. It was concluded that the seeds recovered from Feteasca Neagra by-products are a rich source of functional compounds, with significant antioxidant properties. 


 

https://doi.org/10.19261/cjm.2022.892   

Abstract (PDF)
Supplementary Material (PDF)  

Graphical Abstract: Herein, an efficient one-pot synthesis is described, of substituted benzimidazole derivatives (3a-j) from a condensation of various o-phenylenediamine (1a-j) aromatic aldehyde (2a-j) using ZnFe₂O₄ as a nano-catalyst under ultrasonic irradiation conditions. All forms of aldehydes with an electron releasing or electron –withdrawing substituent have a significant yield. The catalyst can easily be recovered after completion of the reaction and reused without affecting its activity. Prepared benzimidazole derivatives showed moderate to good anti-tuberculosis results.


 

 

 

Abstract (PDF)
Graphical Abstract: This paper presents a study of the hydrochemical composition and physicochemical properties of natural water samples from various sources in the Voronezh and Moscow regions. Two model systems are proposed for assessing the state of the aquatic environment: UV spectroscopy with spectrum decomposition by the Gauss method and spontaneous aggregation of lecithin in a polar medium. Based on the performed investigation, it was determined that the size of lecithin aggregates decreases, and the value of their zeta potential increases with an increase in the content of hydrophobic compounds in natural water.


 

Abstract (PDF)
Graphical Abstract: The aim of the work was to study the isomerization of limonene on zeolite-containing biporous acid catalysts based on kaolin (from Ukraine). Results of this study show that at 160°C, the maximum isomer yield was 60–65% with an 80–90% conversion. The studied samples do not have a significant accumulation of carbonaceous deposits because limonene has high solubility, which helps to remove intermediate products of transformation from the surface of the samples. 


 

 

Abstract (PDF)
Graphical Abstract: Two coordinating compounds of zinc(II) (1) [Zn₂(DAnH₂)₂(1,3-bdc)₂(DMSO)₄] and nickel(II) (2) [Ni(DAnH₂)(1,4-bdc)(DMF)₂]_n were obtained based on dianilineglyoxime (DAnH₂), 1,3-benzenedicarboxylic acid (1,3-bdcH₂) and 1,4-benzenedicarboxylic acid (1,4-bdcH₂), where DMSO is dimethylsulfoxide and DMF is dimethylformamide. The molecular and crystalline structure of reported compounds were established by infrared spectroscopy and single crystal X-ray diffraction, and for 1, additionally, the ¹H and ¹³C NMR spectroscopy was used. According to data, the Zn(II) molecular complex is a binuclear and the Ni(II) is a 1D polymer compound. 


 

 

Abstract (PDF)
Graphical Abstract: The work was aimed at preparing the CA+A300 composite consisting of caffeic acid (CA) and fumed silica (A300) and at comparing the properties of CA in the solution and in the composite. The results showed that the solution and the composite are effective antioxidant/antimicrobial agents and that inclusion of CA in the CA+A300 composite provides its gradual release into solutions and reaction mixtures, thus ensuring a prolonged action of the compound.


 

 

Abstract (PDF)
Supplementary Material (PDF)
Graphical Abstract: 6-Chloro-2-ferrocenyl-1H-benzimidazole and (E)-((4-chloro-2-hydroxyphenylimino)methyl)ferrocene ligands and their Fe(III), Co(II), Cu(II), Zn(II) and Pd(II) complexes were synthesized. The structure of ligands and metal complexes has been investigated by different methods. In addition, magnetic moment, molar conductivity measurements and antibacterial activity of the ligands and the complexes were investigated.


 

Abstract (PDF) 

Graphical Abstract. In this work new methods to obtain complexes from β-cyclodextrin and dehydroabietic acid with chromenol-triazol hybrid with the sizes limits of approximately 0.1-250 μm are reported. Kneading, co-evaporation and co-precipitation for the resolution of racemic 2-tert-butyl-3-(1H-1,2,4-triazol-1-yl)-2H-chromen-2-ol for obtaining micro- and nanoparticles have been optimized. In vitro dissolution studies of the synthesized compounds in phosphate buffer (pH 6.8) showed an improved dissolution rate of chromenol-triazol hybrid in the inclusion complexes compared to the free form. The obtained β-complexes of β-cyclodextrin loaded with dehydroabietitoic acid and chromenol hybrid showed good antibacterial activity with MIC and MBC values ranging from 0.72 to 44.45 μM.


 

https://doi.org/10.19261/cjm.2022.927   

 

Abstract (PDF)
Graphical Abstract: The paper presents original results on the of nitric acid concentrations effect on structure, morphology, protolytic properties and the activity of low-temperature carbon monoxide oxidation catalysts based on acid-modified phlogopite (Н-Phl-1) and K2PdCl4, Cu(NO3)2, KBr base components. The obtained samples were characterized by XRD, SEM, FT-IR spectroscopy and pH metric method. The obtained catalyst Pd(II)-Cu(II)/8H-Phl-1 can be recommended for use in respiratory devices. 

https://doi.org/10.19261/cjm.2021.912   

 

Abstract (PDF)
Graphical Abstract: The effect of halide ions (X= Cl⁻, Br⁻, I−) on the kinetics of ozone decomposition by compositions supported on the natural bentonite of the Dashukovske deposit in Ukraine (N-Bent(D)) has been studied. The obtained results have shown that the activity of the KX/N-Bent(D) composition in the ozone decomposition reaction increases in the row KCl << KBr < KI, which correlates with an increase in their reducing properties (the redox potential of the Х₂/2Х⁻ pair decreases). Such catalyst compositions can be recommended for applying in personal protective equipment for the respiratory system.