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

Mogroside V, a component with high content and sweetness in mogrosides, has many pharmacological activities such as relieving cough, reducing sputum, anti-cancer, anti-oxidation, regulating blood sugar, making it a natural nonsugar sweetener with therapeutic functions, and showing a broad market prospect. However, the limited resources and high extraction costs have restricted its widespread use. The rapid development of synthetic biology has provided a new idea for the production of plant natural products. The low-cost and large-scale production will be realized through the construction of a microbial cell factory for mogroside V. Here, we briefly introduce the structure and pharmacological activity of mogroside V, and review progress in applying synthetic biology for its synthesis, and also discuss the challenges faced by the current research, to provide a reference for further studies on the biosynthesis of mogroside V.
Biological Products/chemistry* ; Sweetening Agents/chemical synthesis* ; Synthetic Biology ; Triterpenes/chemical synthesis*

It is of great significance to use biosynthesis to transform the inorganic substance formaldehyde into organic sugars. Most important in this process was to find a suitable catalyst combination to achieve the dimerization of formaldehyde. In a recent report, an engineered glycolaldehyde synthase was reported to catalyze this reaction. It could be combined with engineered D-fructose-6-phosphate aldolase, a "one-pot enzyme" method, to synthesize L-xylose using formaldehyde and the conversion rate could reach up to 64%. This process also provides a reference for the synthesis of other sugars. With the increasing consumption of non-renewable resources, it was of great significance to convert formaldehyde into sugar by biosynthesis.
Biocatalysis ; Formaldehyde ; chemistry ; Fructose-Bisphosphate Aldolase ; metabolism ; Xylose ; chemical synthesis

L-2-aminobutyric acid (L-ABA) is an important chemical raw material and chiral pharmaceutical intermediate. The aim of this study was to develop an efficient method for L-ABA production from L-threonine using a trienzyme cascade route with Threonine deaminase (TD) from Escherichia. coli, Leucine dehydrogenase (LDH) from Bacillus thuringiensis and Formate dehydrogenase (FDH) from Candida boidinii. In order to simplify the production process, the activity ratio of TD, LDH and FDH was 1:1:0.2 after combining different activity ratios in the system in vitro. The above ratio was achieved in the recombinant strain E. coli 3FT+L. Moreover, the transformation conditions were optimized. Finally, we achieved L-ABA production of 68.5 g/L with a conversion rate of 99.0% for 12 h in a 30-L bioreactor by whole-cell catalyst. The environmentally safe and efficient process route represents a promising strategy for large-scale L-ABA production in the future.
Aminobutyrates ; chemical synthesis ; Bacillus thuringiensis ; enzymology ; Candida ; enzymology ; Escherichia coli ; enzymology ; Formate Dehydrogenases ; metabolism ; Leucine Dehydrogenase ; metabolism ; Threonine ; metabolism ; Threonine Dehydratase ; metabolism

According to drug design flattening principle,a series of novel indole podophyllotoxin derivatives which were introduced different indole substituents in C-4 position on the basis of podophyllotoxin nucleus were synthesized with the starting material podophyllotoxin and 1 H-indole-5-carboxylic acid. Its anti-tumor activity in vitro was tested in order to screen for high-efficiency and low-toxic compounds. Six target compounds were synthesized,and were confirmed by~1 H-NMR,~(13)C-NMR,HR-ESI-MS and melting point determination analysis. All these target compounds were not reported by previous literature. Using etoposide as positive control drug,all the target compounds were screened for cytotoxicity against He La cells,K562 cells and K562/A02 cell in vitro by MTT method. The antitumor activity screening results showed that compounds 4 b,4 e,4 f exhibited higher inhibitory rate against He La cells and K562 cells than those of control drug VP-16. This route has the advantages on simple operation and reasonable design,provides some practical reference value for the further development on the structure modification of podophyllotoxin and study on anti-tumor activity.
Antineoplastic Agents ; chemical synthesis ; pharmacology ; Drug Screening Assays, Antitumor ; HeLa Cells ; Humans ; Indoles ; chemical synthesis ; pharmacology ; K562 Cells ; Podophyllotoxin ; chemical synthesis ; pharmacology ; Structure-Activity Relationship

Ginsenoside Rh_2,firstly isolated from red ginseng,is protopanaxadiol type of steroidal saponin. Rh_2 possessed variety of activities,but bioavailability of oral administration Rh_2 was extremely low due to poor absorption. Moreover,ginsenoside Rh_2 exhibited toxicity on human normal cells. Therefore,to improve stronger anti-tumor activity and attenuate toxicity,it was essential to design and optimize chemical structure of ginsenoside Rh_2. Through n-octanoylchloride modifications,a novel ester derivative of ginsenoside Rh_2 named caprylic acid monoester of Rh_2( C-Rh_2) was designed and synthesized. Structure of novel ginsenoside derivative was identified by1 D and 2 D NMR,as well as ESI-MS analyses. Anti-tumor effect of C-Rh_2 was tested on H22 tumor bearing mice. C-Rh_2 displayed certain anti-tumor activities and exhibited less toxicity than Rh_2. In the present study,C-Rh_2 as ester form of ginsenoside Rh_2 showed better anti-tumor activity and less toxicity,but the specific mechanism needs further investigation.
Animals ; Caprylates ; Ginsenosides ; chemical synthesis ; pharmacology ; Mice ; Molecular Structure ; Neoplasms, Experimental ; drug therapy ; Saponins

Positron emission tomography (PET) is a powerful non-invasive molecular imaging technique for the early detection, characterization, and "real-time" monitoring of disease, and for investigating the efficacy of drugs (Phelps, 2000; Ametamey et al., 2008). The development of molecular probes bearing short-lived positron-emitting radionuclides, such as ¹⁸F (half-life 110 min) or ¹¹C (half-life 20 min), is crucial for PET imaging to collect in vivo metabolic information in a time-efficient manner (Deng et al., 2019). In this regard, one of the main challenges is rapid synthesis of radiolabeled probes by introducing the radionuclides into pharmaceuticals as soon as possible before injection for a PET scan. Although many potential PET probes have been discovered, only a handful can satisfy the demand for a highly efficient synthesis procedure that achieves radiolabeling and delivery for imaging within 1-2 radioisotope half-lives. Only a few probes, such as 2-deoxy-2-[¹⁸F]fluoro-D-glucose (¹⁸F-FDG) and [¹⁸F]fluorodopa, are routinely produced on a commercial scale for daily clinical diagnosis (Grayson et al., 2018; Carollo et al., 2019).
Lab-On-A-Chip Devices ; Positron-Emission Tomography/methods* ; Radioisotopes/chemistry* ; Radiopharmaceuticals/chemical synthesis* ; Solid Phase Extraction

A magnetic metal organic framework (MMOF) was synthesized and used to separate Sr2+ in aqueous solution. The shape and structure of prepared Fe3O4@UiO-66-NH2 were characterized, and the absorbed concentration of strontium was determined through inductively coupled plasma mass spectrometry. The results indicated that Fe3O4 and UiO-66-NH2 combined through chemical bonding. The experimental adsorption results for separation of Sr2+ in aqueous solution indicated that the adsorption of Sr2+ to Fe3O4@UiO-66-NH2 increased drastically from pH 11 to pH 13. The adsorption isotherm model indicated that the adsorption of Sr2+ conformed to the Freundlich isotherm model (R2 = 0.9919). The MMOF thus inherited the superior qualities of magnetic composites and metal organic frameworks, and can easily be separated under an external magnetic field. This MMOF thus has potential applications as a magnetic adsorbent for low level radionuclide 90Sr.
Adsorption ; Ferrosoferric Oxide ; chemistry ; Hydrogen-Ion Concentration ; Metal-Organic Frameworks ; chemical synthesis ; chemistry ; Models, Theoretical ; Nanoparticles ; chemistry ; Strontium ; analysis ; Surface Properties ; Water Pollutants, Radioactive ; analysis ; Water Purification ; methods

Chemokine 12 (CXCL12), also known as stromal cell derived factor-1 (SDF-1) and a member of the CXC chemokine subfamily, is ubiquitously expressed in many tissues and cell types. It interacts specifically with the ligand for the transmembrane G protein-coupled receptors CXCR4 and CXCR7. The CXCL12/CXCR4 axis takes part in a series of physiological, biochemical, and pathological process, such as inflammation and leukocyte trafficking, cancer-induced bone pain, and postsurgical pain, and also is a key factor in the cross-talking between tumor cells and their microenvironment. Aberrant overexpression of CXCR4 is critical for tumor survival, proliferation, angiogenesis, homing and metastasis. In this review, we summarized the role of CXCL12/CXCR4 in cancer, CXCR4 inhibitors under clinical study, and natural product CXCR4 antagonists. In conclusion, the CXCL12/CXCR4 signaling is important for tumor development and targeting the pathway might represent an effective approach to developing novel therapy in cancer treatment.
Animals ; Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Biological Products ; chemistry ; pharmacology ; Chemokine CXCL12 ; genetics ; metabolism ; Humans ; Molecular Targeted Therapy ; Neoplasms ; drug therapy ; genetics ; metabolism ; Receptors, CXCR4 ; antagonists & inhibitors ; genetics ; metabolism

A series of new hybrids of dehydroandrographolide (TAD), a biologically active natural product, bearing nitric oxide (NO)-releasing moieties were synthesized and designated as NO-donor dehydroandrographolide. The biological activities of target compounds were studied in human erythroleukemia K562 cells and breast cancer MCF-7 cells. Biological evaluation indicated that the most active compound I-5 produced high levels of NO and inhibited the proliferation of K562 (IC 1.55 μmol·L) and MCF-7 (IC 2.91 μmol·L) cells, which were more potent than the lead compound TAD and attenuated by an NO scavenger. In conclusion, I-5 is a novel hybrid with potent antitumor activity and may become a promising candidate for future intensive study.
Antineoplastic Agents ; chemical synthesis ; chemistry ; Cell Proliferation ; drug effects ; Diterpenes ; chemistry ; pharmacology ; Drug Design ; Drug Screening Assays, Antitumor ; Humans ; K562 Cells ; MCF-7 Cells ; Nitric Oxide ; chemistry ; pharmacology ; Structure-Activity Relationship