Antioxidant and antibacterial insights into the leaves, leaf tea and medicinal roots from Astragalus membranaceus (Fisch.) Bge.

Used as traditional Chinese medicine, Astragalus membranaceus (Fisch.) Bge. (A. membranaceus) roots are also used as tonic food material in a wide range of applications, while the leaves are left in the field, unused. Therefore, comprehensively exploring and utilizing the leaves will inevitably reduce the associated resource waste and environment pollution. In this study, the plant leaves were processed into tea using green tea processing technology. Bioactive components, antioxidant and antibacterial activities of the Leaf Tea (LT) and Dry Leaves (DL) were studied, and compared to that of the Dry Roots (DR). The results showed that the polysaccharides content (POL) in the DR (20.44%) was twice as high as the DL (10.18%) and LT (8.68%). However, the DL contained 36.85% more water-soluble extracts (WSE), 35.09% more ethanol-soluble extracts (ESE), 409.63% more total flavonoid content (TFC), 221.01% more total phenolic content (TPC) and 94.34% more proteins, and the LT contained 26.21% more WSE, 40.64% more ESE, 326.93% more TFC, 191.90% more TPC and 37.71% more proteins. The total amino acid (AA) content in the DR was 8.89%, while in that of the DL and LT were 24.18% and 28.96% respectively, nearly 3-times higher than that of the DR. The antioxidant activity of DR was much lower than those of DL and LT, both of which had antioxidant activity closer to that of Vitamin C (VC) and the antioxidant activities were even stronger when the optimal concentration was reached. Except for Aspergillus niger and Staphylococcus aureus, the DL and DR exhibited inhibition activities to Salmonella, Bacillus subtilis, Escherichia coli and yeast, while the LT had antimicrobial activities against all the strains except for A. niger. In summary, compared with the most commonly used DR, the DL and LT from A. membranaceus contained higher bioactive components, and stronger antioxidant and antimicrobial activities. Producing leaf tea may be an appropriate way to economically and reasonably utilize the plant leaves which are by-products.

Rapid and Large-Scale Synthesis of IRMOF-3 by Electrochemistry Method with Enhanced Fluorescence Detection Performance for TNP.

Rapid and large-scale synthesis of metal-organic frameworks (MOFs) materials is of great significance for their practical applications. For the first time, we have electrochemically synthesized IRMOF-3 at room temperature by applying a voltage to a zinc electrode immersed in electrolyte containing 2-aminoterephthalic acid (NH2-H2BDC). The reaction conditions, including the ratio of solvent (electrolyte), the applied voltage, and different reaction times, were investigated and optimized. The degree of crystallinity and nanomorphology of the synthesized IRMOF-3 can be controlled by changing the reaction conditions. More importantly, we demonstrated that the electrochemical synthesis strategy can rapidly obtain nanoscale IRMOF-3 with high crystallinity on a gram scale. In addition, in comparison with the product of solvothermal synthesis, the electrochemically synthesized nanoscale IRMOF-3 exhibits improved fluorescent detection ability to 2,4,6-trinitrophenol (TNP) with a detection limit of about 0.1 ppm.

Postsynthetic Modification of ZIF-90 for Potential Targeted Codelivery of Two Anticancer Drugs.

Combination therapy has been regarded as a promising strategy for cancer treatment due to the enhanced anticancer efficacy achieved by blocking multiple drug resistance pathways. In this work, a drug carrier based on nanoscale ZIF-90 for the codelivery of two anticancer drugs has been synthesized by covalently attaching doxorubicin (DOX) to the surface of ZIF-90 via Schiff base reaction of amino group in DOX and aldehyde group of imidazole-2-carboxaldehyde (ICA) ligand and encapsulating 5-fluorouracil (5-FU) into the pores of the framework. The results of drug loading measurements show that the loading amount of drugs was estimated as high as 36.35 and 11-13.5 wt % for 5-FU and DOX, respectively. Moreover, we demonstrated that the carrier had the potential of cancer-targeted delivery of drugs for the collapse of framework under the pH environment around cancer cells and subsequently releasing drugs. Drug release at pH 5.5, imitating the environment of tumor, can reach over 95%, and the release time is less 16 h, meaning a more effective and faster release of drugs around tumoral cells than that in a normal environment. This is the first report for cancer-targeted codelivery of two different chemical drugs based on nanoscale metal-organic frameworks (NMOFs).