187 results match your criteria: "Lanzhou University. Lanzhou 730000[Affiliation]"

Substantial advancements have been achieved in the field of photocatalytic borylation utilizing 4c-7e Lewis base-boryl radicals. However, the utilization of 3c-5e neutral boryl radicals for C-B bond formation remains relatively underexplored due to their inherent instability. In this study, we successfully demonstrated the direct construction of C-B bonds using sodium tetraarylborate as a key reagent.

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Strong electronic interaction enhanced electrocatalysis of copper phthalocyanine decorated Co-MOF-74 toward highly efficient oxygen evolution reaction.

RSC Adv

December 2024

State Key Laboratory of Applied Organic Chemistry, Laboratory of Special Function Materials and Structure Design of the Ministry of Education, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 China.

Metal-organic frameworks (MOFs) have been identified as promising electrocatalysts for the oxygen evolution reaction (OER). However, most of the reported MOFs have low electrical conductivity and poor stability, and therefore addressing these problems is crucial for achieving higher electrocatalytic performance. Meanwhile, direct observations of the electrocatalytic behavior, which is of great significance to the understanding of the electrocatalytic mechanism, remain highly challenging.

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This study aims to decipher the mechanism of the broth of Codonopsis Radix fermented with Lactobacillus plantarum(FCR) on the gastric mucosa in the rat model of acute gastric ulcer. A total of 64 SD rats were randomized into 8 groups: control, model, positive control(omeprazole), probiotic, unfermented Codonopsis Radix, and low-, medium-and high-dose FCR, with 8 rats in each group. The rat model of acute gastric ulcer was established by gavage with anhydrous ethanol.

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CuBr-mediated surface-initiated controlled radical polymerization in air.

Chem Sci

November 2024

State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 P. R. China

Herein, we present a straightforward CuBr-mediated surface-initiated controlled radical polymerization (SI-CRP) method for fabricating polymer brushes using microliter volumes of reaction solution in air and at room temperature. The key advantage of this method is its ability to rapidly grow polymer brushes with oxygen tolerance, driven by the controlled disproportionation of Cu into Cu and Cu by CuBr and ligand. We demonstrate the successful preparation of homo-, block, patterned, and wafer-scale polymer brushes.

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Pancreatic cancer (PC) has poor prognosis. PRKAA1 (AMPK-α1) is the catalytic subunit of 5'-adenylate-activated protein kinase (AMPK), which plays a critical role in multiple stages of tumorigenesis and development. However, the biological mechanisms of PRKAA1 in the tumor microenvironment have not been well studied.

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Article Synopsis
  • Pyruvate kinase M2 (PKM2) is an important enzyme that is often overexpressed in cancer cells, making it a target for cancer treatments aimed at blocking glycolysis.
  • The study identifies plumbagin, a compound from a plant, as a novel inhibitor of PKM2, which decreases its activity and leads to reduced expression of related downstream genes in HepG2 cancer cells.
  • Plumbagin also induces oxidative stress and mitochondrial damage, resulting in increased apoptosis, while simultaneously decreasing cell migration and proliferation, highlighting its potential as an anticancer therapeutic.
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Intermolecular sulfur atom transfer cascade enabled late-stage introduction of sulfilimines into peptides.

Chem Sci

September 2024

Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences & Research Unit of Peptide Science, Chinese Academy of Medical Sciences, 2019RU066, Lanzhou University Lanzhou 730000 China

Sulfilimines, a privileged class of -S(iv)[double bond, length as m-dash]N- functional groups found in nature, have been exploited as valuable building blocks in organic synthesis and as pharmacophores in drug discovery, and have aroused significant interest in the chemical community. Nevertheless, strategies for late-stage introduction of sulfilimines into peptides and proteins have still met with limited success. Herein, we have developed a method of introducing biological sulfilimine fragments into peptides by an intermolecular sulfur atom transfer cascade reaction, utilizing hydroxylamine condensed with the acid moieties of peptides and varied diaryl disulfides.

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An unusual cascade C-H activation, vinylation and 6π-electrocyclization of 2-pyridyl aldimines with vinyl bromides/triflates was achieved using catalysis with a unique CCC pincer NHC-Ru(iii) complex (Cat B). This reaction was found to enable a rapid and diverse synthesis of polycyclic 4-pyrido[1,2-]pyrimidine derivatives in mostly good to high yields, and with a broad substrate scope. A mechanistic study suggested the formation of a semi-opened Ru(iii) intermediate chelating/activating the aldimine, and the occurrence of single-electron transfer (SET) to generate a vinyl radical, followed by vinylation and then an intramolecular 6π-electrocyclization of 1,3-hexatrene to form the product.

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Controllable β-carbon elimination to extrude norbornene remains a long-standing challenge in palladium and norbornene chemistry. Herein, this manuscript describes a switchable synthesis of biologically active C4-ethylaminoindole and C7-aminoindoline scaffolds by controlling β-carbon elimination, utilizing aziridine as a C-H ethylamination reagent through a C-N bond cleavage reaction. Furthermore, the protecting groups of the product can be easily removed, offering an unusual method for the synthesis of dopamine receptor agonists.

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Article Synopsis
  • * The resulting compounds displayed a wide range of structural characteristics, from 0D dimers to 3D and 2D interpenetrated frameworks.
  • * The compounds were tested as heterogeneous catalysts in the Knoevenagel reaction, showing high yields and potential for catalyst recycling, demonstrating Haipa's versatility in creating functional materials.
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Transition-metal-catalyzed hydroarylation of unactivated alkenes metal hydride hydrogen atom transfer (MHAT) is an attractive approach for the construction of C(sp)-C(sp) bonds. However, this kind of reaction focuses mainly on using reductive hydrosilane as a hydrogen donor. Here, a novel photoinduced Co/Ni-cocatalyzed Markovnikov hydroarylation of unactivated alkenes with aryl bromides using protons as a hydrogen source has been developed.

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The radical-mediated difunctionalization of 1,3-enynes facilitates rapid access to structurally diverse allenes and dienes. Whereas, owing to the existence of multiple active sites in conjugated 1,3-enynes, regulating selectivity in difunctionalized addition a single transition-metal-catalyzed radical tandem process remains elusive. Herein, we disclose an intriguing protocol of substrate-controlled nickel-catalyzed regiodivergent sulfonylarylation of 1,3-enynes with the assistance of sulfonyl chlorides and arylboronic acids.

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Enhanced photoelectrochemical water splitting performance of α-FeO photoanodes through Co-modification with Co single atoms and g-CN.

Chem Sci

August 2024

Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 P. R. China

Article Synopsis
  • - The study addresses the challenges of using α-FeO in water splitting due to issues with charge recombination and slow water oxidation by developing a CoSAs-g-CN/FeO photoanode.
  • - The combination of g-CN and α-FeO creates a heterojunction that enhances efficiency by reducing charge recombination and improving water oxidation kinetics through a built-in electric field.
  • - The incorporation of cobalt single atoms (CoSAs) in the g-CN framework increases the available active sites, leading to better surface hole extraction and improved overall performance and stability in photoelectrochemical water splitting.
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Cyclic peptides represent invaluable scaffolds in biological affinity, providing diverse collections for discovering functional molecules targeting challenging biological entities and protein-protein interactions. The field increasingly focuses on developing cyclization strategies and chemically modified combinatorial libraries in conjunction with M13 phage display, to identify macrocyclic peptide inhibitors for traditionally challenging targets. Here, we introduce a cyclization strategy utilizing -phthalaldehyde (OPA) for the discovery of active macrocycles characterized by asymmetric scaffolds with side-chain cyclization.

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[Chemical constituents from Cinnamomi Ramulus decoction].

Zhongguo Zhong Yao Za Zhi

June 2024

Department of Chemical and Pharmaceutical Engineering, College of Chemical Engineering, Huaqiao University Xiamen 361021, China.

Six compounds were isolated from the ethyl acetate extracts of Cinnamomi Ramulus decoction by RP-18, silica gel, Sephadex LH-20 column chromatography, together with prep-HPLC methods. Based on HR-ESI-MS, MS, 1D and 2D NMR spectral analyses, the structures of the six compounds were identified as 4,5,10,11-tetrahydroxybisabol-7-ene(1), 4,5,10,11-tetrahydroxybisabolin(2), 1-phenyl-1,2,3-glycerol(3),(+)-lyoniresinol(4), benzoic acid(5), and decumbic acid(6). Compound 1 was a new bisabolene-type sesquiterpene, and compounds 2 and 3 were isolated from the Cinnamomi Ramulus for the first time.

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Late-stage modification of peptides could potentially endow peptides with significant bioactivity and physicochemical properties, and thereby provide novel opportunities for peptide pharmaceutical studies. Since tryptophan (Trp) bears a unique indole ring residue and plays various critical functional roles in peptides, the modification methods for tryptophan were preliminarily developed with considerable progress transition-metal mediated C-H activation. Herein, we report an unprecedented tertiary amine catalyzed peptide allylation the S2'-S2' pathway between the N1 position of the indole ring of Trp and Morita-Baylis-Hillman (MBH) carbonates.

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At present, mainstream room-temperature phosphorescence (RTP) emission relies on organic materials with long-range charge-transfer effects; therefore, exploring new forms of charge transfer to generate RTP is worth studying. In this work, indole-carbazole was used as the core to ensure the narrowband fluorescence emission of the material based on its characteristic short-range charge-transfer effect. In addition, halogenated carbazoles were introduced into the periphery to construct long-range charge transfer, resulting in VTCzNL-Cl and VTCzNL-Br.

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Efficient separation of uranium from seawater stands as a pivotal challenge. This study unveils an approach focusing on the ingenious design of biomimetic two-dimensional (2D) membranes tailored explicitly for this purpose. Leveraging the unique interplay of DNA strands housing U aptamers, pH-responsive i-motifs, and poly A segments ingeniously embedded within graphene oxide membranes, a distinctive biomimetic 2D channel is engineered.

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Employing racemization strategies to simultaneously enhance the quantum yield, lifetime, and water stability of room-temperature phosphorescent materials.

Chem Sci

May 2024

Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 P. R. China

Room temperature phosphorescence (RTP) materials are increasingly recognized for their superior luminescent properties, which are pivotal in applications such as anti-counterfeiting, information storage, and optoelectronics. Despite this, the sensitivity of most RTP systems to humidity presents a significant challenge in achieving durable RTP performance in aqueous environments. This study proposes a strategy to enhance organic room-temperature phosphorescence through racemization.

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Electrocatalytic nitrate (NO) reduction reaction (eNORR) to ammonia under ambient conditions is deemed a sustainable route for wastewater treatment and a promising alternative to the Haber-Bosch process. However, there is still a lack of efficient electrocatalysts to achieve high NH production performance at wastewater-relevant low NO concentrations. Herein, we report a PdRu bimetallic nanocrystal (NC) electrocatalyst capable of exhibiting an average NH FE of ∼100% over a wide potential window from 0.

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The field of metal-organic frameworks (MOFs) includes a vast number of hybrid organic and inorganic porous materials with wide-ranging applications. In particular, the Cu(i) ion exhibits rich coordination chemistry in MOFs and can exist in two-, three-, and four-coordinate environments, which gives rise to many structural motifs and potential applications. Direct characterization of the structurally and chemically important Cu(i) local environments is essential for understanding the sources of specific MOF properties.

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Site selective functionalization of inert remote C(sp)-H bonds to increase molecular complexity offers vital potential for chemical synthesis and new drug development, thus it has been attracting ongoing research interest. In particular, typical β-C(sp)-H arylation methods using chelation-assisted metal catalysis or metal-catalyzed oxidative/photochemical generated allyl C(sp)-H bond processes have been well developed. However, radical-mediated direct β-C(sp)-H arylation of carbonyls remains elusive.

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Near-infrared red (NIR) fluorescence imaging guide phototherapeutic therapy (PDT) has the advantages of deep tissue penetration, real-time monitoring of drug treatment and disease, little damage to normal tissue, low cytotoxicity and almost no side effects, and thus, it is attracting increasing research attention and is expected to show promising potential for clinical tumor treatment. The photosensitizer (PS), light source and oxygen are the three basic and important factors to construct PDT technology, and highly efficient PSs are still being passionately pursued because they determine the PDT efficiency. Ideal PSs should have properties such as good biocompatibility, deep tissue penetration, and highly efficient reactive oxygen species (ROS) generation despite the hypoxic environment.

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Fluorine-functionalized magnetic amino microporous organic network for enrichment of perfluoroalkyl substances.

J Chromatogr A

May 2024

State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China. Electronic address:

Perfluoroalkyl substances (PFAS) are persistent organic pollutants that pose significant risks to human health and the environment. Efficient and selective enrichment of these compounds was crucial for their accurate detection and quantification in complex matrices. Herein, we report a novel magnetic solid-phase extraction (MSPE) method using fluorine-functionalized magnetic amino-microporous organic network (FeO@MONNH@F) adsorbent for the efficient enrichment of PFAS from aqueous samples.

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