Silver decorated on cobalt ferrite nanoparticles as a reusable multifunctional catalyst for water treatment applications in non-radiation conditions.

In this investigation, cobalt ferrite nanoparticles (CFO NPs) were synthesized using a hydrothermal method. Then, silver nanoparticles (Ag NPs) were decorated on CFO NPs to form Ag/CFO NPs using jasmine extract as a reducing agent of Ag+ ions. The properties of Ag/CFO NPs were characterized by X-ray powder diffraction, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, vibrating sample magnetometry, and catalytic tests in non-radiation conditions. The catalytic results indicated that the Ag/CFO NPs could activate peroxymonosulfate to generate sulfate radicals for the decomposition of different dyes such as methylene blue, methyl orange, and rhodamine B. For the Ag/CFO sample, Ag NPs validated the roles in dye adsorption, reduction of 4-nitrophenol, and improvement of antibacterial behavior. The growth inhibition activity of Ag/CFO NPs was observed against Pseudomonas aeruginosa (18.18 ± 2.48 mm) and Staphylococcus aureus (10.14 ± 0.72 mm). Furthermore, Ag/CFO NPs displayed good reusability after three consecutive runs. Therefore, Ag/CFO material is shown to be a potential multifunctional catalyst in wastewater treatment.

Biologically Active Metabolites from the Marine Sediment-Derived Fungus Aspergillus flocculosus.

Four new compounds were isolated from the Vietnamese marine sediment-derived fungus Aspergillus flocculosus, one aspyrone-related polyketide aspilactonol G (2), one meroterpenoid 12-epi-aspertetranone D (4), two drimane derivatives (7,9), together with five known metabolites (1,3,5,6,8,10). The structures of compounds 1-10 were established by NMR and MS techniques. The absolute stereoconfigurations of compounds 1 and 2 were determined by a modified Mosher's method. The absolute configurations of compounds 4 and 7 were established by a combination of analysis of ROESY data and coupling constants as well as biogenetic considerations. Compounds 7 and 8 exhibited cytotoxic activity toward human prostate cancer 22Rv1, human breast cancer MCF-7, and murine neuroblastoma Neuro-2a cells.

Efficient click chemistry towards novel 1H-1,2,3-triazole-tethered 4H-chromene-d-glucose conjugates: Design, synthesis and evaluation of in vitro antibacterial, MRSA and antifungal activities.

The series of 2-amino-7-propargyloxy-4H-chromene-3-carbonitriles 5a-t were synthesized from corresponding 2-amino-7-phydroxy-4H-chromene-3-carbonitriles 4a-t and propargyl bromide. Two procedures were used in these syntheses: K2CO3/acetone and NaH/DMF procedures with yields of 65-89% and 80-96%, respectively. 1H-1,2,3-Triazole-tethered 4H-chromene-d-glucose conjugates 7a-t were synthesized using click chemistry of propargyl ethers 5a-t and tetra-O-acetyl-ß-d-glucopyranosyl azide. Cu@MOF-5 was the optimal catalyst for this chemistry. The yields of 1H-1,2,3-triazoles were 80-97.8%. All triazoles 7a-t were evaluated in vitro for anti-microorganism activities. Among tested compounds with MIC values of 1.56-6.25 µM, there were four compounds against B. subtilis, four compounds against S. aureus, and four compounds against S. epidermidis; five compounds against E. coli, four compounds against K. pneumoniae, five compounds against P. aeruginosa, and six compounds against S. typhimurium. Compounds 7c,7d,7f,7h, and 7r had MIC values of 1.56-6.25 µM for three clinical MRSA isolates. Some compounds had inhibitory activities against four fungi, including A. niger, A. flavus, C. albicans, and S. cerevisiae, with MIC values of 1.56-6.25 µM. Some 1H-1,2,3-triazoles had comparatively low toxicity against RAW 264.7 cells.