Objective: To develop effective alternatives to natural enzymes, it is crucial to develop nanozymes that are economical, resource efficient, and environmentally conscious. Carbon nanomaterials that have enzyme-like activities have been extensively developed as substitutes for traditional enzymes. Methods: Carbide-derived carbons (CDCs) were directly synthesized via a one-step electrochemical method from a MAX precursor using an ammonium bifluoride electrolyte at ambient conditions. The CDCs were characterized by systematic techniques. Results: CDCs showed bienzyme-like activities similar to that of peroxidase and superoxide dismutase. We systematically studied the dependence of CDC enzyme-like activity on different electrolytes and electrolysis times to confirm activity dependence on CDC content. Additionally, the synthesis mechanism and CDC applicability were elaborated and demonstrated, respectively. Conclusion The demonstrated synthesis strategy eliminates tedious intercalation and delamination centrifugation steps and avoids using high concentrations of HF, high temperatures, and halogen gases. This study paves the way for designing two-dimensional material-based nanocatalysts for nanoenzyme and other applications.
Ammonium Compounds/chemical synthesis* ; Carbon/chemistry* ; Electrochemical Techniques ; Enzymes ; Fluorides/chemical synthesis* ; Humans ; Nanostructures ; Oxidation-Reduction

The goal of treatment of metabolic syndrome is the prevention of diabetes and cardiovascular events. A series of novel tetrahydrocoptisine quaternary ammonium compounds were prepared to evaluate their action of hypoglycemia and hypolipidemia for finding the therapeutic agents of metabolic syndrome. Starting from the coptisine hydrochloride (2), fifteen target compounds were synthesized by reduction and substitution of the 7-N position. All of the target compounds were characterized by 1H NMR and HR-MS. Their hypoglycemic activities were evaluated in HepG2 cell and hypolipidemic activities of compounds with better hypoglycemic activity were tested further in vivo. Results indicated that compounds 5, 7, 8 and 9 exhibited better hypoglycemic activities in vitro and compounds 5 and 8 exhibited good hypolipidemic activities in high-fat-diet (HFD) induced hyperlipidemia mice and (or) hamsters. However, the activity is not as good as simvastatin.
Animals ; Berberine Alkaloids ; chemical synthesis ; chemistry ; pharmacology ; Cholesterol ; blood ; Glucose ; metabolism ; Hep G2 Cells ; Humans ; Hyperlipidemias ; blood ; Hypoglycemic Agents ; chemical synthesis ; chemistry ; pharmacology ; Hypolipidemic Agents ; chemical synthesis ; chemistry ; pharmacology ; Mesocricetus ; Mice ; Molecular Structure ; Quaternary Ammonium Compounds ; chemical synthesis ; chemistry ; pharmacology ; Structure-Activity Relationship ; Triglycerides ; blood

The membrane of sodium cellulose sulphate ( NaCS)-poly dimethyldiallylammonium chloride (PDMDAAC) microcapsule is compact and has low molecular weight cut-off, which would delay the mass transfer and affect the cell growth immobilized in the capsule. Macroporous NaCS-PDMDAAC microcapsules were prepared using the degradation of the starch by amylase in the membrane of the capsules. The pore size and the permeability in the membrane were improved obviously. As model cells, the Candida krusei CK1 and E. coli EC1 immobilized in the capsules were cultured in the shake flask and bubble column respectively. It was shown that the cell density immobilized in the microcapsules cultured in the bubble column was higher than that cultured in the shaking flask. It implied that the limiting factor of the cell growth in the capsule lied in the diffusion of the oxygen. Since the rate of the oxygen transporting across the membrane was greatly enhanced due to the enlarged pore size, the maximum cell density in the macroporous capsules was 20%-110% over than that in the standard capsules in the bubble column. However, the extent of E. coli cell density increasing was higher than that of the yeast, which may be due to the difference of the oxygen requirement between the two microbes.
Amylases ; metabolism ; Bioreactors ; Candida ; growth & development ; Capsules ; chemical synthesis ; chemistry ; Cell Culture Techniques ; methods ; Cells, Immobilized ; Cellulose ; analogs & derivatives ; chemical synthesis ; chemistry ; Escherichia coli ; growth & development ; Membranes, Artificial ; Polyethylenes ; chemical synthesis ; chemistry ; Porosity ; Quaternary Ammonium Compounds ; chemical synthesis ; chemistry ; Sodium ; Surface Properties ; Temperature ; Time Factors