RESUMO
A new zinc-based boron nitride (Zn-BNT) material was synthesized from boron nitride and zinc acetate in 95% yield. The morphological and spectroscopic properties of Zn-BNT were elucidated by SEM, XRD, BET, DSC-TGA, and FT-IR. Zn-BNT catalyzed the synthesis of benzimidazoles (3a-3h) through a reaction between o-phenylenediamine and different aromatic aldehydes under microwave conditions for 15 min. The compounds were purified by silica-gel chromatography. The synthesized compounds were characterized by FT-IR, 1H-NMR, 13C-NMR, and elemental analysis. Zn-BNT was reused eight times with only a 5% loss of catalytic activity. Furthermore, 2-(4-fluorophenyl)-1H-benzo[d]imidazole (3f) was selected for a computational study of the IR and NMR spectrum, which matched the experimentally generated spectra. The HOMO-LUMO gap was 4.48, and the Fukui function analysis showed high activity in the reactive sites.
RESUMO
Plant extracts continue gaining significant prominence in green synthesis of silver nanoparticles (AgNPs), due to their potential applications in nano-medicine and material engineering. This work reports on green synthesis of silver nanoparticles (AgNPs) from aqueous extracts of Iboza Riparia leaf and Ilex Mitis root bark with diterpenes (DTPs) and saponins (SPNs) as major components. After TEM, DLS, TGA/DSC, ATR, XRD and UV-Vis characterization, the relevant cytotoxicity studies were conducted with the MTT assay on human embryonic kidney cells (HEK293T) followed by antioxidant activity with ABTS. Overall, the AgNPs-DTPs (156nm) were found to be less toxic with 49.7% cell viability, while AgNPs-SPNs (50nm) and AgNPs-PVA (44nm) had cell viability of 40.8 and 28.0% respectively at 400µM. Based on the cytotoxicity and antioxidant activity, it is fair to report that these plant extracts have potential reducing and capping agents as they retain chemical properties on the surface of the nanoparticles.
