Chemistry Journal of Moldova

 

DOI: https://doi.org/10.19261/cjm.2020.717   

 

Abstract (PDF)
Supplementary Material (PDF)

Graphical Abstract: This paper tackles the potential uses of agricultural wastes (sawdust, sunflower seed shells, pumpkin seed shells, cherry pits, walnut shells, and green walnut shells) for the production of pellets. Combustion heat was determined for these wastes and their thermal decomposition in an air atmosphere was analysed. Five types of mini-pellets were made from different combinations of available wastes and their thermal behaviour was analysed by the microscale combustion calorimetry method.
 

 

DOI: https://doi.org/10.19261/cjm.2020.672   

 

Abstract (PDF)
Graphical Abstract: The level, composition, and distribution of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) residues were determined by GC-ECD technique in soil samples from the Soroca district, Republic of Moldova. The concentrations of DDTs and HCHs were up to 1100 and 640 mg/kg, respectively. The high concentration and the degradation rates of the pesticides in soil suggest that the contaminated sites are acting as continuous sources of pollution for the environment. Thus, remediation measures are required to reduce the level of the contaminants in soil.


 

DOI: https://doi.org/10.19261/cjm.2020.694

Abstract (PDF)
Supplementary Material (PDF)

Graphical Abstract: The most common phenolic components of sixteen orchid extracts were identified using high performance liquid chromatography and laser desorption/ionization mass spectrometry. The interaction between these compounds and silica silanol groups was studied using quantum chemical calculations. Results show that the strength of the interaction of phenols with silica increased in the following order: ferullic, feruloylquinic and fertaric acids <kaempferol, apingenin <<сhlorogenic and caffeic acids, rhamnetin, quercetin, luteolin, epicatechin gallate. The common feature of compounds characterized by the strongest interaction with silanol groups is the presence of phenol ring with two neighbouring hydroxyl groups.


 

DOI: https://doi.org/10.19261/cjm.2020.669   

 

Abstract (PDF)
Graphical Abstract: A new, rapid and selective, HPLC method for simultaneous quantitative estimation of lisinopril and hydrochlorothiazide residues and sampling procedures from pharmaceutical manufacturing equipment surfaces were developed and validated. The sampling procedures have a good recovery (>80%). The limit of quantitation of the HPLC method - 0.155 µg/mL and 0.025 µg/mL for lisinopril and hydrochlorothiazide, respectively. 


 

DOI: https://doi.org/10.19261/cjm.2020.701   

 

Abstract (PDF)
Graphical Abstract: The concentrations of the accumulated heavy metals such as cadmium, lead, copper, mercury, zinc, and chromium have been determined in the muscles, gills and liver of the fish species of Clupea pallasii, Macolor niger and Pristipomoides filamentosus collected from the waters of the South Pacific Ocean around Lautoka in Fiji. Overall, the contents of heavy metals in all the samples were below the permissible limits, except for chromium that is slightly higher than the limit set by Food and Agriculture Organization of the United Nations and World Health Organization regulations, respectively. As anticipated, the muscles are still near the lowest concentration of all metal concentration. Significant variations in heavy metal concentrations were found between different tissues within each species of fish.


 

DOI: https://doi.org/10.19261/cjm.2020.664   

 

Abstract (PDF)
Graphical Abstract: Gismondine, laumontite and levyne type zeolites have been synthesized based on the natural minerals of Nakhchivan and the optimal crystallization conditions have been established. The initial components and the reaction products have been examined by X-ray diffraction, thermogravimetric and elemental analysis. It was found that changes in the temperature, alkalinity, ratio of starting components and time of processing of the reaction have different effects on the rate of formation of products, on their degree of crystallinity and on the phase purity of the obtained zeolite.


 

DOI: https://doi.org/10.19261/cjm.2019.650   

Abstract (PDF)
Supplementary Material (PDF)

Graphical Abstract: The aim of this paper is to evaluate an integrated multidisciplinary strategy for the characterization of mining waste, their possible recycling and reuse. The use of Fe-Mn rich wastes in arsenic removal and phosphorus recovery from water and the phytoextraction potential of metals and their possible recovery from biomass are evaluated.


 

DOI: https://doi.org/10.19261/cjm.2019.675   

 

Abstract (PDF)
Graphical Abstract: This paper reports on the synthesis and structure re-refinement of bis(lidocaine) diaquatetrathiocyanatonickelate(II). The compound with the formula (LidH)₂[Ni(NCS)₄(H2O)₂], where Lid is (2-(diethylamino)-N-(2,6-dimethylphenyl)acetamide, crystallizes in the monoclinic space group P2₁/c with a= 18.3509(5), b= 7.6532(2), c= 14.9585(4) Å, β= 109.964 (2)°, V= 1974.57 (9) ų, and Z= 2. Coordination of the Ni²⁺ ion with thiocyanate ions and water molecules generates slightly distorted octahedral anion [Ni(NCS)₄(H2O)₂]^2–  with N-bonded thiocyanate groups, while two protonated cations LidH⁺ remain in an outer coordination field. 


 

DOI: https://doi.org/10.19261/cjm.2019.657   

Abstract (PDF)
Graphical Abstract: This study describes the preparation of two bicyclo[3.3.3]nonane-steroid derivatives from either estradiol or estrone using some reactions such as etherification, addition, nucleophilic substitution and cyclization. The chemical structure was evaluated through NMR spectroscopic analysis. The results showed higher yield for 11 compared with 12. It is noteworthy that the reagents used in this investigation are not expensive and do not require special conditions for handling.


 

DOI: https://doi.org/10.19261/cjm.2019.647   

Abstract (PDF) 

Graphical Abstract: A series of novel isolated β-lactams 3a-c and thiazolidinone derivatives 4a-c were successfully synthesized from reactions of new Schiff's bases 2a-c with chloroacetyl chloride and thioglycolic acid. The antimicrobial activity of the obtained compounds was assessed in vitro against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria and Aspergillus flavus and Candida albicans fungi. Furthermore, a molecular docking study was carried out and the results indicated that compounds 3b and 4b displayed comparable binding affinity scores as that of glutamate. These two compounds are promising candidates as antibacterial and antifungal agents that would deserve further investigations.