Chemistry Journal of Moldova

DOI: http://dx.doi.org/10.19261/cjm.2019.637   

 

Abstract (PDF)
Graphical Abstract: This paper focuses on the study of the effect of extraction solvent choice on phenolic compounds contents and antioxidant activity of Bassia muricata. In this study, five different solvents namely: water, acetone, ethanol, methanol and hexane, and three extraction techniques were used to extract phenolic compounds: microwave-assisted extraction, Soxhlet and maceration. Total phenolics, total flavonoids and condensed tannins contents were determined. The results showed that different solvents with different polarity had a major effect on polyphenolic contents and antioxidant activity. Microwave-assisted extraction was the best suited for the extraction of antioxidant molecules when compared to Soxhlet and maceration.


 

 

Abstract (PDF)
Graphical Abstract: Four chalcone derivatives were synthesized and pre-evaluated as broad-spectrum UV protector. Chalcones 1-4 showed a wide range of UV absorbance values and moderate molar absorptivity values. Chalcones 3 and 4 showed better photostability than chalcones 1 and 2 because the lowering of their absorbance was smaller and slower under UVB irradiation. A combination of the spectra of chalcone derivatives 1-4 indicated that a formulation containing all four will provide a broad-spectrum sunscreen protecting the skin from UVA and UVB. 


 

Abstract (PDF)
Graphical Abstract: In this study, novel pyrazole, imidazole, pyrimidine derivatives bearing imidazo[4,5-b]indol moiety were successfully synthesized and their chemical structures were identified and confirmed by different spectral techniques. All the synthesized compounds were tested against four bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) and two fungi (Aspergillus flavus and Candida albicans). The obtained results show that the synthesized compounds could find fruitful applications as antibacterial and antifungal agents in pharmaceutical chemistry.


 

DOI: http://dx.doi.org/10.19261/cjm.2019.584   

 

Abstract (PDF)
Graphical Abstract: A total of 5206 samples from twenty-one different vegetables and fruits were collected. Residues of pesticides in concentrations exceeding the maximum residue levels were found in 22.9% of analysed samples. Thirteen insecticides, four fungicides, two acaricides and one herbicide were detected in the analysed samples. The highest value of hazard index was calculated for diazinon – 0.15. The obtained results show that the long-term consumption of vegetables and fruits could pose a health risk for the population of the Republic of Moldova.


 

DOI: http://dx.doi.org/10.19261/cjm.2019.636   

 

Abstract (PDF)
Graphical Abstract: Silver nanoparticles colloids were prepared using the extract from the leaves of Vitex agnus-castus. The effect of temperature on the reduction of silver ions and on the growth of silver nanoparticles was followed by measuring the intensity of the surface plasmon resonance band in the UV spectra. It was found that fast reduction of silver ions occurs even at 40°C, while effective synthesis of silver nanoparticles requires elevated temperatures of 60-80°C.


 

DOI: http://dx.doi.org/10.19261/cjm.2019.639   

Abstract (PDF) 

Graphical Abstract: 4-(Dimethylamino)pyridine was found to be an efficient homogenous catalyst for one-pot multi-component reactions between hydrazine monohydrate, ethyl cyanoacetate, ketone, and malononitrile for the synthesis of 1,6-diamino-2-oxo-1,2,3,4-tetrahydropyridine-3,5-dicarbonitrile derivatives using ultrasonication at room temperature in ethanol solution within 35-50 min with yields of over 90%.
 

DOI: http://dx.doi.org/10.19261/cjm.2019.616   

 

Abstract (PDF)
Graphical Abstract: This review presents last decade and some past especially relevant studies in the field of (+)-3-carene synthetic transformations. This paper discusses exclusively the transformations of (+)-3-carene, proceeding with the retention of the native bicyclic carbon skeleton. The data concerning the features of epoxidation and oxidation reactions of (+)-3-carene, the synthesis of sulphur- and selenium-containing derivatives and their use in asymmetric synthesis are given. It also describes methods for producing amino derivatives of (+)-3-carene, substituted heterocycles based on it, reactions for the preparation of aziridines, azido-alcohols and azidoamines, as well as chiral phosphites as bidentate ligands.


 

DOI: http://dx.doi.org/10.19261/cjm.2019.609   

 

Abstract (PDF)
Graphical Abstract: TThe present paper reports the synthesis of new hybrid terpeno-heterocyclic compounds belonging to di- and tri-norlabdane series. Starting from natural labdane diterpenoide (-)-sclareol, via its intermediates 8α-hydroxy-15,16-dinorlabd-13-one and sclareolide, two di-norlabdane and three tri-norlabdane, previously unreported compounds possessing 2-amino-1,3-thiazole structural units were obtained in three and four steps, respectively, with acceptable to good overall yields. The structures of newly obtained compounds were confirmed by means of spectral IR, ¹H and ¹³C NMR analyses.


 

DOI: http://dx.doi.org/10.19261/cjm.2019.607   

 

Abstract (PDF)
Graphical Abstract: A simple, precise and accurate UV-Vis spectrophotometric method has been developed and validated for the estimation of ciprofloxacin hydrochloride from combination ear drops with basil oil (Ocimum basilicum). The results of the validation of the method demonstrate that the developed method is simple, rapid, accurate and robust over the concentration range 2-10 μg/mL of ciprofloxacin hydrochloride in combination with volatile basil oil.


 

 

DOI: http://dx.doi.org/10.19261/cjm.2019.617   

 

Abstract (PDF)
Graphical Abstract: Heterobranchs are a fascinating group of marine mollusks that are recognized as an important source of bioactive natural products. Often, these molecules, which are either selected from the diet or de novo biosynthesized by the mollusks, play a fundamental role for their survival being utilized as defensive chemicals against predators. A summary of the studies carried out, in the last decade, on heterobranchs is presented here. A number of new compounds exhibiting different molecular architectures were chemically characterized.