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Cadmium sulfide (CdS) quantum dots (QDs) were homogeneously embedded into chitosan (CTS), denoted as CdS@CTS, via an in situ hydrothermal method. The intact structure of the synthesized materials was preserved using freeze-drying. The materials were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy, transmission electron microscopy, high-resolution TEM, scanning TEM, dispersive energy X-ray (EDX) for elemental analysis and mapping, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption isotherms, thermogravimetric analysis, UV–vis spectroscopy, and diffuse reflectance spectroscopy (DRS). The synthesis procedure offered CdS QDs of 1–7 nm (average particle size of 3.2 nm). The functional groups of CTS modulate the in situ growth of CdS QDs and prevent the agglomeration of CdS QDs, offering homogenous distribution inside CTS. CdS@CTS QDs can also be used for naked-eye detection of heavy metals with high selectivity toward copper (Cu 2+ ) ions. The mechanism of interactions between Cu 2+ ions and CdS@CTS QDs were further studied.

Harmine 1 was extracted from the seeds of Peganum harmala. From this natural molecule, a new series of isoxazole derivatives with complete regiospecificity were prepared using 1,3-dipolar cycloaddition reactions with various arylnitrile oxides. Harmine and its derivatives were characterized by (1)H NMR, (13)C NMR and HRMS. The evaluation of their anti-acetylcholinesterase (AChE), anti-5-lipoxygenase (5-LOX), anti-xanthine oxidase (XOD) and anticancer activities were studied in vitro against AChE, 5-LOX and XOD enzymes, respectively, and in HTC-116, MCF7 and OVCAR-3 cancer cell lines. The prepared derivatives were shown to be inactive against the XOD enzyme (0-38.3 ± 1.9% at 100 µM). Compound 2 exhibited the best anti-AChE activity (IC50=1.9 ± 1.5 µM). Derivatives 3a, 3b and 3d had moderate cytotoxic activities (IC50=5.0 ± 0.3 µM (3a) and IC50=6.3 ± 0.4 µM (3b) against HCT 116 cells, IC50=5.0 ± 1.0 µM (3d) against MCF7 cells).

Context To date, there are no reports to validate the Tunisian traditional and folklore claims of Eruca vesicaria (L) Cav. subsp. longirostris (Brassicaceae) for the treatment of disease. Objective Investigation of the chemical composition antimicrobial and antioxidant activity of essential oils from Eruca longirostris leaves, stems, roots and fruits. Materials and methods The essential oils of E. longirostris from leaves, stems, roots and fruits were obtained after 4 h of hydrodistillation. Chemical compositions were determined using a combination of GC/FID and GC/MS. The in vitro antimicrobial activity of the volatile constituents of E. longirostris was performed in sterile 96-well microplates against three Gram-positive, four Gram-negative bacteria and one strain as yeast. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration values were reported. Furthermore, the antioxidant activity was evaluated by DPPH and ABTS assays. Results The main compound for fruits, stems and roots was the erucin (96.6%, 85.3% and 83.7%, respectively), while b-elemene (35.7%), hexahydrofarnesylacetone (23.9%), (E)-b-damascone (15.4%), erucin (10.6%) and a-longipinene (9.6%) constituted the major compounds in the essential oil of the leaves. The experimental results showed that in all tests, essential oil of fruits showed the better antioxidant activity than the others. On the other hand, the oils of stems, fruits and roots showed significant antimicrobial activity with MIC values ranging from 0.125 to 0.31 mg/mL against Candida species, Gram-positive and Gram-negative bacteria, mainly Salmonella enterica. Conclusions The present results indicate that essential oils of E. longirostris can be used as a source of erucin. ARTICLE HISTORY