Quantitative analysis of multi-components by single marker method combined with UPLC-PAD fingerprint analysis based on saikosaponin for discrimination of Bupleuri Radix according to geographical origin.

Saikosaponins are regarded as one of the most likely antipyretic constituents of Bupleuri Radix, establishing a comprehensive method that can reflect both the proportion of all constituents and the content of each saikosaponin is critical for its quality evaluation. In this study, the combination method of quantitative analysis of multiple components with a single marker (QAMS) and fingerprint was firstly established for simultaneous determination of 7 kinds of saikosaponins in Bupleuri Radix by ultra-high performance liquid chromatography (UPLC). The results showed that saikosaponin d was identified as the optimum IR by evaluating the fluctuations and stability of the relative calibration factors (RCFs) under four different conditions.

A comprehensive review on traditional and modern research of the genus Bupleurum (Bupleurum L., Apiaceae) in recent 10 years.

Ethnopharmacological Relevance: The genus Bupleurum (family Apiaceae), comprising approximately 248 accepted species, is widely distributed and used in China, Japan, India, Central Asia, North Africa and some European countries as traditional herbal medicines. Certain species have been reported to have significant therapeutic effects in fever, inflammatory disorders, cancer, gastric ulcer, virus infection and other diseases.

Aim Of The Review: we performed a comprehensive review of the ten-year research progress in phytochemistry, pharmacology, toxicity, along with bibliometrics research of the genus Bupleurum, aiming to identify knowledge gaps for future research.

Free-electrodeposited anodic stripping voltammetry sensing of Cu(II) based on TiCT MXene/carbon black.

A proof-of-principle concept for free-electrodeposited anodic stripping voltammetry (ASV) sensing of Cu is proposed by using TiCT MXene/carbon black (TiCT@CB) nanohybrids as electrode materials. Owing to the high adsorption and reduction capability of TiCT towards Cu, TiCT MXene enables Cu to be immobilized and self-reduced directly to form Cu on the TiCT@CB electrode surface. As a result an oxidation peak current appears from the re-oxidation of Cu via differential pulse voltammetry.

Novel methodology for anodic stripping voltammetric sensing of heavy-metal ions using TiCT nanoribbons.

Conventional anodic stripping voltammetry (ASV) sensing of heavy-metal ions (HMIs) generally includes a two-step approach: (a) preconcentration via electrodeposition and (b) re-oxidation, while the requirement of the electrodeposition step makes the detection processes more complex. Herein, a novel methodology using self-reduction instead of electrodeposition was developed for the ASV sensing of HMIs (selecting Cd2+ as a representative analyte) by introducing Ti3C2Tx MXene nanoribbons (Ti3C2Tx NR) as a sensing element that can exhibit direct adsorption and reduction capabilities towards HMIs. Compared with conventional ASV technology, the proposed methodology is simpler and power-saving, and has a significant low detection limit (0.

Dual-Signal Electrochemical Enantiospecific Recognition System via Competitive Supramolecular Host-Guest Interactions: The Case of Phenylalanine.

For developing highly selective and sensitive electrochemical sensors for chiral recognition, taking advantage of the synthetical properties of β-cyclodextrin (β-CD, strong host-guest recognition) and carbon nanotubes wrapped with reduced graphene oxide (CNTs@rGO, excellent electrochemical property and large surface area), as well as the differences in binding affinity between β-CD and guest molecules, a dual signal electrochemical sensing strategy was proposed herein for the first time in chiral recognition based on the competitive host-guest interaction between probe and chiral isomers with β-CD/CNTs@rGO. As a model system, rhodamine B (RhB) and phenylalanine enantiomers (d- and l-Phe) were introduced as probe and target enantiomers, respectively. Due to the host-guest interactions, RhB can enter into the β-CD cavity, showing remarkable oxidation peak current of RhB.

Reactivity of (1-methoxycarbonylpentadienyl)iron(1+) cations with hydride, methyl, and nitrogen nucleophiles.

The reaction of tricarbonyl and (dicarbonyl)triphenylphosphine (1-methoxycarbonyl-pentadientyl)iron(1+) cations and with methyl lithium, NaBHCN, or potassium phthalimide affords (pentenediyl)iron complexes and , while reaction with dimethylcuprate, gave (,-diene)iron complexes and . Oxidatively induced-reductive elimination of gave vinylcyclopropanecarboxylates . The optically active vinylcyclopropane (+)-, prepared from (1)-, undergoes olefin cross-metathesis with excess (+)- to yield (+)-, a C9-C16 synthon for the antifungal agent ambruticin.

De Novo Asymmetric Synthesis of (+)-Monanchorin.

A de novo asymmetric total synthesis of the guanidine alkaloid natural product (+)-monanchorin has been achieved in nine steps from the commodity chemicals furan and caproic acid. The asymmetry of the route was introduced by a Noyori reduction of an acylfuran. In addition, this route relies upon an Achmatowicz rearrangement, a diastereoselective palladium catalyzed glycosylation, reductive amination, and an acid catalyzed bicyclic guanidine mixed acetal formation.

Identification and characterization of the first Escherichia coli strain carrying NDM-1 gene in China.

New Delhi metallo-β-lactamase-1 (NDM-1), an acquired class B carbapenemase, is a significant clinical threat due to its extended hydrolysis of β-lactams including carbapenems. In this study, we identified the first confirmed clinical isolate of Escherichia coli BJ01 harboring bla(NDM-1) in China. The isolate is highly resistant to all tested antimicrobials except polymyxin.

Cationic metal-corrole complexes: design, synthesis, and properties of guanine-quadruplex stabilizers.

A series of pyridinium and quaternary ammonium copper corroles has been designed and synthesized. All new compounds have been fully characterized by NMR spectroscopy, high-resolution mass spectrometry, UV/Vis spectrscopy, and elemental analysis. Biochemical studies have indicated that all of these corrole derivatives can stabilize G-quadruplex structures, with corrole 4 being the most effective according to the results of circular dichroism (CD) melting experiments, polymerase chain reaction (PCR) stop assays, and surface plasmon resonance (SPR) experiments.