STUDIA CHEMIA - Issue no.4 / 2023 - Table of contents

A novel chalcone containing (hetero)aromatic units was obtained by the Claisen-Schmidt condensation of phenothiazinyl-3-carbaldehyde with 4-hydroxy-acetophenone under three experimental approaches based on classical, mechanochemical and ultrasound-assisted procedures. A comparison between the experimental outcomes emphasizes shorter reaction time and lower energy usage in the case of mechanochemical and ultrasound-assisted procedures, recommending these methods as more environmentally friendly synthetic options. Moreover, the use of the sonochemical method resulted in the formation of the reaction product in crystalline state thus simplifying the purification process. The optical properties of the new chalcone were assessed by UV-vis spectroscopy. (E)-1-(4-hydroxyphenyl)-3-(10-methyl-10H-phenothiazin-3-yl)prop-2-en-1-one exhibited an intense absorption in the UV region (λmax=408 nm) and low intensity fluorescence emission in DMSO solution (λem=560 nm, Stokes shift 7558 cm-1). The X-ray diffraction on monocrystal technique which was employed to ascertain the solid-state structure of the new chalcone revealed strong O-H···O hydrogen bonds and weak dispersive van der Waals interactions such as π···π and C-H···π contacts ensuring its supramolecular architecture, crystal cohesion and stability.

Keywords: Phenothiazine; Chalcone; Sonochemistry; Mechanochemistry, UV-vis spectroscopy, XRD

Two convenient alternatives for the synthesis of metal(II) 2,9,16,23-tetranitrophthalocyanines (TNPc) were applied in the synthesis of the novel Strontium(II)TNPc and its Zinc(II)TNPc, Copper(II)TNPc and Cobalt(II)TNPc analogues. The thermal activation required for the tetramerization of the phthalic acid derivatives used as substrates (4-nitrophthalimide or 4-nitrophthalodinitrile) was provided by convective heating in solution or solvent free conditions. The optical properties of the synthesized metal(II)TNPc were compared by means of UV-vis spectroscopy. In solution, the novel Sr(II)TNPc was characterized by absorption bands with maxima situated around 690 nm (similar to Cu(II)TNPc), while its fluorescence emission maxima lays close to Zn(II)TNPc (710 nm), with a three times longer fluorescence emission life time in solid state (3.04 ns).

Keywords: phthalocyanine; strontium-complex; UV-vis spectroscopy; fluorescence emission life time

Different preparation methods of Ag-doped hydroxyapatite were compared and an efficient solid-state reaction-based method was developed for the synthesis of silver doped-hydroxyapatite using AgNO3 as silver source. The obtained nanomaterial was characterized by SEM, EDS and XRD measurements. By this method 10% silver was detected in the structure of the hydroxyapatite.

Keywords: hydroxyapatite, silver, silver-doped hydroxyapatite, wet precipitation method, solid state method

This paper shows the results of thermal and catalytic pyrolysis of conditioned lignosulfonate from the sulfite process, with a specific focus on the analysis of bio-oil and biochar. The conditioning of lignosulfonate was made by drying and grinding in a planetary ball mill. Thermal and catalytic pyrolysis of conditioned lignosulfonate were carried out under the same temperature and flow conditions. The use of two different catalysts produced via the impregnation method has shown distinctive effects, influencing both bio-oil yield and chemical composition. The resulting biochar exhibits characteristics comparable to non-activated carbonaceous materials, with variations in its specific surface area and pore size depending on the catalyst.

Keywords: catalytic pyrolysis, lignosulfonate, sulfite process, bimetallic catalyst

Ferrous particles are usually found in atmospheric particulate matters due to the cars chassis oxidation. These particles are able forming conglomerates with the other mineral particles. Thus, the investigated carwash slurry (CS) reveals a high mineralized composition dominated by Quartz, Calcite and clay minerals with significant amount of iron hydroxides. We found some unusual bigger particles of ferrous conglomerate (FC) into the CS sample. XRD and mineralogical microscopy (MOM) reveal that FC sample is formed by a nanostructured mixture of 56 wt.% Calcite and 44 wt.% Goethite. SEM images and EDS spectra reveal submicron particles within the FC structure with a dense mixture of Ca and Fe. FTIR investigation reveal strong absorption bands for goethite and very weak ones for Lepidocrocite within the FC sample. The results indicates that the conglomerate weas formed on the car chassis rust by wet partial dissolution of calcite that locally forms Ca(OH)2 which further is re-crystallized as calcite due to the CO2 from the combustion gases. Fine crystallites of iron hydroxides are embedded into the re-crystallized calcite. In conclusion, the magnetic selection is recommended for the ferrous conglomerate particles removal from CS to be used as natural coverage for of urban dump sites rehabilitation.

Keywords: Particulate Matters, ferrous conglomerate, environment

The present work aims to evaluate the antioxidant, cytotoxic, enzyme inhibitory, and anti-inflammatory properties of Cotinus coggygria Scop. The leaf extract was analyzed using LC-MS/MS and antioxidant activity was also investigated via several in vitro models (DPPH●, ABTS●+, FRAP, metal chelating, inhibition of β-carotene bleaching, and lipid peroxidation). Enzyme inhibition activity was evaluated on alpha-amylase and alpha-glucosidase. Molecular docking studies were performed to assess the binding efficiency of the identified compounds with alpha-glucosidase. The toxicity of the extract was studied using two breast cancer cell lines as well as healthy fibroblast cell lines (L929). Using LPS induced macrophage cell line model, the anti-inflammatory activity was examined by determining NO, IL-1β, IL-6, IL-10, and TNF-α levels. The methanol extract significantly affected the alpha-glucosidase enzyme, which also exhibited antioxidant activity. Galloyl hexose and methyl trigallate were found to have the highest binding contact energies for the alpha-glucosidase enzyme, according to docking analyses. Even at a 31.25 μg/mL concentration, the extract caused 43.46% inhibition in MDA-MB 231, and 48.09% in MCF-7 cell lines. Significant effects on TNF-α and IL-6 cytokine levels also proved anti-inflammatory activity. These findings suggest that C. coggygria may serve as an efficient alpha-glucosidase inhibitor and anti-inflammatory agent.

Keywords: Cotinus coggygria, enzyme inhibition, docking, anti-inflammatory, antioxidant, cytotoxicity

The eggplant is a vegetable that has been used more in recent years thanks to the low calories versus high content of phenolic compounds. This study aimed to determine total phenolic, flavonoid, proanthocyanidin, and saponin content using spectrophotometric assays and antioxidant activity using 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2’-azinobis(3-ethylbenzothiazol-6sulpho-nate (ABTS), total reducing power (TRP), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC) assassin peel and pulp of eggplant cultivars Robi, Tudela, Vernal, Aragon, and Rosa Bianca. The average total saponin content (TSC) in peel was 116.34 μg DSGE mg-1 DW (diosgenin equivalents per mg of extract’s dry weight), whereas in pulp was slightly lower (107.86 μg DSGE mg-1 DW). A similar trend was observed for total phenolic content (TPC) (24.54 μg GAE mg-1 DW (gallic acid equivalents per mg of extract’s dry weight) in peel and 15.88 μg GAE mg-1 DW in pulp); total proanthocyanidin (TP) (2.74 μg CE mg-1 DW (catechin equivalents per mg of extract’s dry weight) in peel and 1.24 μg CE mg-1 DW in pulp) and total flavonoid content (TFC) (0,05 μg RE mg-1 DW (rutin equivalents per mg of extract’s dry weight) in peel and 0.02 μg RE mg-1 DW in pulp). Principal component analysis (PCA) and cluster analysis (CA) methods were applied on the antioxidant activity (ABTS, DPPH, TRP, FRAP, and CUPRAC) and total bioactive compounds content (TSC, TPC, TP and TFC) parameters in order to reveal the relationships between analyzed samples. As a result of these approaches, analyzed samples were grouped into two groups.

Keywords: Eggplant, Solanum Melongena, Antioxidants, Chemometric analysis

In this study, a new series of chiral benzimidazole-glycosyl thiourea derivatives (5-10) were synthesized and evaluated for their inhibitory effects against hCA I, hCA II, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The structures of the benzimidazole-glycosyl thiourea compounds were determined by FTIR, 1H-NMR, 13C-NMR and elemental analysis. The KI values for the CA isoenzymes of the synthesized materials ranged from 6.03 to 42.98 nM. KI values for cholinesterase enzymes were shown to be between 5.32 and 39.14 nM. It was observed that compound 10 is the best hCA I inhibitor (KI:6.03 nM), compund 9 is the best hCAII inhibitor (KI:17.29 nM) and compound 8 is the best AChE (KI:5.32 nM) and the best BChE (KI:18.73 nM) inhibitor.

Keywords: Benzimidazole; amino acid; glycosyl thiourea; carbonic anhydrase; cholinesterase

An apparent molar volume ϕv of 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol in dilute aqueous solution has been particular for density measurements at 298.15 K. A restrictive apparent molar volumes ϕv˚ at infinite dilution of these compounds were investigated based on Masson’s equation. Based on the Jone-Dole equation, A and B viscosity constants for four alcohols have been identified. This liquid offers resilient solute-solvent interaction. The modified Jone-Dole equation has also been employed with the experimental consequences using four liquids as solutes in dilute aqueous solutions.

Keywords: Alcohols, Apparent molar volume, Modified Jone-Dole equation

The current study investigates the potential of the supramolecular complex between the antifungal agent Ketoconazole (KTZ) and PAMAM dendrimer G5 generation to be used as a topically applied antimycotic drug. The new drug-dendrimer formulation was confirmed by combining XRPD, FT-IR and DSC analytical techniques, and presents improved aqueous solubility and delayed in vitro release profile compare to pure KTZ. The biological assays data showed the biocompatibility of the supramolecular complex and improved delivery of the encapsulated KTZ into the superficial layers of skin and mucosa at the mycotic infections site, leading to a better outcome of the infection.

Keywords: Ketoconazole, PAMAM dendrimer, Drug-dendrimer complex, Solubility, Cell viability, Mouse ear sensitization test