Zenovia Moldovan

Objective: Based on our previous findings, we designed new molecules by extending functionalized pyrazole derivatives containing iodine atoms, which are linked via an amino bond to halogen-substituted phenyl groups. In addition, these newly developed pyrazole compounds exhibit anti-tumor, antibacterial, and anti-biofilm activities. Methods: Three new series of pyrazole compounds were designed. Fifteen novel pyrazole derivatives, distributed across three series (4a–d, 5a–d, and 6a–g), were synthesized and structurally characterized by ¹H-NMR, ¹³C-NMR, FTIR, UV-Vis spectroscopy, and elemental analysis. Results: Among them, compound 4c, which exhibited notable anti-tumor activity, crystallized in a monoclinic system and was further analyzed via single-crystal X-ray diffraction. All synthesized compounds were evaluated in vitro on NCTC normal fibroblast cells and HEp-2 tumor epithelial cells. Compound 4c demonstrated significant anti-tumor activity while displaying no cytotoxic effects on normal cells. The antibacterial and anti-biofilm activities of the compounds were also assessed against four bacterial strains. Compounds 5a and 5c exhibited the highest antibacterial activity against Staphylococcus aureus ATCC 25923, both with a minimum inhibitory concentration (MIC) of 0.023 μg/mL. Additionally, compounds 4a, 5a, 6a, 6e, and 6f showed the strongest anti-biofilm effects, each presenting a minimum biofilm inhibition concentration (MBIC) of 0.023 μg/mL. ADME and ADMET in silico predictions indicated that all compounds exhibit generally favorable, drug-like physicochemical properties. Conclusions: The study reinforces the applicability of these compounds as promising anticancer, antibacterial, and anti-biofilm drugs.

New haloaminopyrazole derivatives differing in the number of pyrazole nuclei 4a–f and 5a–e, respectively, were synthesized and characterized by ¹H-NMR, ¹³C-NMR, IR, UV-Vis, and elemental analysis. The single-crystal X-ray diffraction method was used to describe compounds 4a and 5d. When tested on normal NCTC fibroblasts in vitro, the newly synthesized derivatives were shown to be non-cytotoxic at a dosage of 25 μg/mL. Two compounds 4a and 5d showed a high degree of biocompatibility. From the two series of compounds tested on HEp-2 human cervical carcinoma cells, compound 5d showed a more pronounced antiproliferative effect. Gram-positive strains of Staphylococcus aureus ATCC25923, Enterococcus faecalis ATCC29212, Gram-negative strains of Pseudomonas aeruginosa ATCC27853, and strains of Escherichia coli ATCC25922 were used to test the newly synthesized compounds antibacterial and antibiofilm properties. Among the studied pyrazole compounds, 2 compounds 4a and 5a with fluorine content on the phenyl ring and 4 compounds 4b, 4e, 4f, and 5b with chlorine content on the phenyl ring were noted, which proved to be the most active compared with the two reference drugs, metronidazole and nitrofurantoin. The six compounds showed a broad spectrum of action against all four tested bacterial strains, the most active being compound 4b, with a chlorine atom in the “4” position of the phenyl nucleus and a MIC of 460 μg/mL. Compounds 4a and 5a showed the best antibiofilm activity against the bacterial strain Staphylococcus aureus ATCC25923, with an MBIC of 230 μg/mL.

The present study was focused on the preparation and characterization of different topical oil in water emulsions based on natural ingredients such as collagen hydrolysate and vegetable oils mixtures. As oil phases, mixtures of coconut, almond, jojoba, avocado oils (in different ratios) were used while the water phase consisted in lavender water. As emulsifier, a plant based product containing glyceryl stearate and potassium stearate was incorporated (in the concentration range 4–5 %), while as rheology modifier xanthan gum was used (in the concentration range 0.2–1 %). As preservatives, Cosgard (containing benzyl alcohol, salicylic acid, glycerol, ascorbic acid) and mixtures of two essential oils (lemon and lavender) were selected. The designed formulations were assessed by means of their physico-chemical properties (pH, viscosity, thixotropic behavior), optical microscopy analysis and sensorial characteristics. The obtained emulsions were found to present pseudoplastic and thixotropic behaviors, adequate for cosmetic skin care product formulations.

The paper describes the physicochemical studies made on the decorative plant, Rudbeckia triloba (Asteraceae). For this purpose, essential oil, infusion, decoction, and hydroalcoholic macerate obtained from different aerial parts of Rudbeckia triloba were analyzed. The main phytochemical constituents identified by GC-MS analysis were found to be α-pinene (in dried leaves (46.0%) and flowers (40.1%)) and β-phellandrene (in essential oil of dried inflorescences (26.09%)). The Folin–Ciocalteu and quercetin assays revealed different values of total phenolic and flavonoid contents of petals, leaves, and seeds as a function of the solvent used and extraction procedure. The hydroalcoholic macerate of petals was found to present the maximum phenolic and flavonoid contents (130.29 ± 5.58 mg gallic acid equivalent/g dry vegetable material and 30.72 ± 1.35 mg quercetin equivalent/g dry vegetable material, resp.) and also exhibits the lower value of EC50 (0.32% (v/v)), obtained by applying the DPPH⋅ assay. Comparing the extraction methods applied, the maceration was found to be the most effective for phenolic compounds, most likely due to the solvent (70% ethanol). The use of water-alcohol mixture leads to an improvement of the extraction yield of phenolic compounds (including those with higher molecular weights) than by using water as extractive solvent, in the case of infusions and decocts.

The aim of this research was to investigate the chemical composition of Coreopsis tinctoria Nutt. fruits extract, to highlight the potential of ultrasound assisted extraction in the fast preparation of extracts rich in polyphenols using different solvents (55%, 78% and 96% hydrous ethanol) and to evaluate the antioxidant potential of formulated extracts. LC-MS/MS was used to characterize the ethanolic extract from Coreopsis tinctoria Nutt. dried fruits. The extract contains different flavonoids (marein, flavanomarein, quercetagetin-7-O-glucoside, okanin aurone, leptosidin, luteolin, apigenin) and phenolic acids (chlorogenic acid, caffeic acid). Several parameters that could affect extraction efficiency were evaluated. Finally, this study focused on determination of plant extracts total phenolic content and their antioxidant capacity. The experimental results allowed the selection of the optimum operating parameters leading to the highest total polyphenolic content, expressed as gallic acid equivalents, and avoiding the degradation of phenolic compounds (ethanol 55%; extraction temperature 323.15 K, extraction time 30 min, liquid/solid ratio 20/1). A good relationship between total phenolic content and antioxidant capacity was obtained.

A novel simple, sensitive and rapid kinetic-spectrophotometric method for the determination of trace amounts of nitrite is proposed. The method is based on its catalytic effect on the oxidation of congo red (CR) by potassium bromate in acidic solution. The oxidation reaction is monitored spectrophotometrically by measuring the decrease in the absorbance of CR at a suitable λ_max= 570 nm for the first 10–40 s from the start of the reaction. Under the optimum experimental conditions (sulfuric acid, 0.3 M; CR, 0.75x10^-4 M; potassium bromate, 5x10^-4 M and 25 ^oC), nitrite can be determined in the range of 0.015–0.75 µg mL⁻¹ with the detection limit of 0.006 µg mL⁻¹. The relative standard deviation of five replicate determination of 0.25 µg mL⁻¹ nitrite was 2.5%. The proposed method was applied satisfactorily to the determination of nitrite in spiked drinking water samples. KEY WORDS: Nitrite, Catalytic effect, Congo red, Spectrophotometry, Drinking water Bull. Chem. Soc. Ethiop. 2012, 26(2), 159-169. DOI: http://dx.doi.org/10.4314/bcse.v26i2.1

A spectrophotometric method for the indirect determination of captopril (CP) in pharmaceutical formulations is proposed. The proposed procedure is based on the oxidation of captopril by potassium dichromate and the determination excess oxidant on the basis of its reaction with diphenylcarbazide (DPC). Under the optimum conditions, a good linear relationship (r = 0.9997) was obtained in the range of 0.08-3.5 µg mL-1. The assay limits of detection and quantitation were 0.024 and 0.08 µg mL-1, respectively. The results obtained for captopril determination in pharmaceuticals using the proposed method and those obtained with the US Pharmacopoeia method were in good agreement at the 95% confidence level