Nanoadsorbents preparing from oligoethylene glycol dendron and citric acid: Enhanced adsorption effect for the removal of heavy metal ions.

Poly(methacrylate oligoethylene glycol dendron-co-citric acid) (PGCA) that is based on citric acid and oligoethylene glycol (OEG) dendrons is utilized as a nanomaterial for the removal of heavy metal ions from aqueous solution. PGCA shows excellent solubility in aqueous solution and realizes satisfactory removal efficacy for Pb2+ ions; the removal rate exceeds 95 %. In addition, PGCA can be utilized in Chinese herbal decoctions; the removal rate of Pb2+ ions in the ligusticum wallichii decoction exceeds 90 %, meanwhile the concentration of the active ingredient, namely, ferulic acid, is maintained. In this nanoadsorbent, citric acid provides the active site for the chelation of heavy metal ions, and OEG dendron serves as a protective layer that reduces the opportunity for carboxyl groups to be occupied by other ingredients. In summary, nanomaterial PGCA is designed and synthesized successfully that can be applied as a nanoadsorbent for the removal of Pb2+ ions from aqueous solution, especially in Chinese herbal decoctions that have acidic compounds as active ingredients.

[Research progress on alkaloid monomer analgesic preparations].

Pain is one of the problems that seriously affect people's quality of life for thousands of years. The causes of pain are complex and varied,and long-term pain can also lead to depression. It has become a research hotspot to develop analgesic preparations with significant drug effects and small side effects. Recent studies have shown that certain alkaloid monomers have analgesic targets such as γ-aminobutyric acid,cannabinoids,and capsaicin. If their preparation is applied to the analgesic field,they can make up for the defects such as strong addiction and side effects of traditional opioid and non-steroidal analgesic drugs,but there is no relevant literature to summarize the research results in this field. This article first introduces the mechanism of pain production and the target of analgesia. Based on this,the application status of alkaloid monomer analgesic preparations approved by China Food and Drug Administration( CFDA)( number varieties,type of dosage form,drug description,analgesic mechanism and advantages) was analyzed,and the research dynamics of alkaloid monomer analgesic preparations( new formulation and new technology) were reviewed. Finally,some problems in this field were pointed out,such as imperfect medication information,inadequate transformation of research results,and too few kinds of analgesic components in developed alkaloids. The development direction was also pointed out for the above problems,with a view to provide reference for further development and in-depth research.

Nanoadsorbents Based on NIPAM and Citric Acid: Removal Efficacy of Heavy Metal Ions in Different Media.

Heavy metal ions in aqueous solutions are harmful to human health, but exploring and exploiting nanoadsorbents with a high adsorption capacity and low cost should be an effective method for overcoming this problem. In this study, a novel nanoadsorbent termed poly(N-isopropylacrylamide-co-citric acid) (PNCA) was designed and synthesized via free-radical polymerization. PNCA exhibits good solubility in aqueous solutions and can self-assemble into spherical nanoaggregates with a mean hydrodynamic diameter of approximately 723.1 nm. After freeze-drying, the solid powder of PNCA exhibited a loose porous structure. When PNCA is dissolved in water, the resulting copolymer solution exhibits high removal rates for Cu2+ and Pb2+ of over 80%; meanwhile, over 97% of the PNCA is precipitated with metal ions. The adsorption process of PNCA chelated with Cu2+ ions fit the Freundlich model. The adsorption capacity is independent of the media pH, but could be affected by the temperature. Except for herbal medicines with alkaloids as active ingredients, PNCA also presents good adsorption capacity for Cu2+ in herbal medicine decoctions, with a removal rate of over 80%. The cell cytotoxicity in vitro and system toxicity in vivo demonstrate the desirable biosafety of PNCA. These results suggest that PNCA with good biosafety can be utilized as a nanoadsorbent to remove the metal ions, especially Cu2+, in different media.