Publications by authors named "Qingjiang Li"

Aims: Obesity always leads to profound perturbation of metabolome. Metabolome studies enrich the knowledge on associations between endogenous metabolites and obesity, potentially providing innovative strategies for the development of novel anti-obesity pharmacotherapy. This study aims to identify an endogenous metabolite that regulates energy expenditure and to explore its application for obesity treatment.

View Article and Find Full Text PDF

The geometrical control of atom transfer radical addition (ATRA) reactions to alkynes poses significant challenges. Herein, we present a uniform solution by developing a stereodivergent synthetic method for both isomers of the resulting alkene products, starting from the same materials. The synthesis of the thermodynamically more stable isomer utilizes the strategy of uphill catalysis while the accumulation of the less stable isomer is facilitated by a manganese-catalyzed iodo-abstraction/radical rebound process, taking advantage of its reversibility.

View Article and Find Full Text PDF
Article Synopsis
  • * The method utilizes tryptamine-derived isocyanides and involves an innovative cascade sequence that includes oxidative trifluorination and halogenative cyclization, resulting in effective formation of the desired compounds.
  • * This process is characterized by mild reaction conditions, good yields, and high selectivities, and it allows the resulting products to be further modified for creating diverse N-CF-pyrroloindolines.
View Article and Find Full Text PDF

GSLs are the major glycolipids in vertebrates and mediate many key biological processes from intercellular recognition to regulation of signal transduction. The fast-expanding field of glycobiology has led to a growing demand for diverse and structurally defined GSLs, and enzymatic GSL synthesis is developing rapidly in accordance. This article provides an overview of natural GSL biosynthetic pathways and surveys the bacterial enzymes applied to GSL synthesis and recent progress in synthesis strategies.

View Article and Find Full Text PDF
Article Synopsis
  • The study examines cerebrospinal fluid (CSF) circulation and its importance for waste clearance in the brain, specifically focusing on how CSF flow velocity relates to the glymphatic system in rats.
  • Using phase-contrast MRI, researchers measured CSF flow velocity in the brain aqueduct of rats, looking at various factors such as age, gender, strain, anesthetics, and the presence of Alzheimer’s disease.
  • Results showed that healthy young male Wistar rats had an average CSF flow velocity of 5.16 mm/s, while older rats and those with Alzheimer's experienced significantly reduced flow velocities.
View Article and Find Full Text PDF

The discovery of effective and safe antiobesity agents remains a challenging yet promising field. Our previous studies identified Bouchardatine derivatives as potential antiobesity agents. However, the 8a-aldehyde moiety rendered them unsuitable for drug development.

View Article and Find Full Text PDF

The first total synthesis of the repeating units of the -antigens of ATCC 27577, O10, and O19 was achieved via a linear glycosylation strategy. This also represents the first synthesis of an oligosaccharide containing an α-linked -acetyl-l-galactosaminuronic acid (l-GalNAcA) unit. All of the glycosyl linkages, including three challenging 1,2--glycosidic bonds of amino sugars, were effectively constructed with high to exclusive stereoselectivity, while orthogonal protection tactics were employed to facilitate regioselective glycosylations and the introduction of a variety of functionalities.

View Article and Find Full Text PDF

In order to increase the precision and effectiveness of power system analysis and fault diagnosis, this study aims to assess the power systems in the energy sector while utilizing artificial intelligence (AI) and environmental social governance (ESG). First, the ESG framework is presented in this study to fully account for the effects of the power system on the environment, society, and governance. Second, to coordinate the operation of various components and guarantee the balance and security of the power system, the CNN-BiLSTM power load demand forecasting model is built by merging convolutional neural network (CNN) and bidirectional long short-term memory (BiLSTM).

View Article and Find Full Text PDF

The glymphatic system suggests the convective bulk flow of cerebrospinal fluid (CSF) through perivascular spaces and the interstitial spaces of the brain parenchyma for the rapid removal of toxic waste solutes from the brain. However, the presence of convective bulk flow within the brain interstitial spaces is still under debate. We first addressed this argument to determine the involvement of the glymphatic system in brain waste clearance utilizing contrast-enhanced 3D T1-weighted imaging (T1WI), diffusion tensor imaging (DTI), and confocal microscopy imaging.

View Article and Find Full Text PDF

In this study, we developed a novel type of dibenzocyclooctyne (DBCO)-functionalized microbubbles (MBs) and validated their attachment to azide-labelled sialoglycans on human pluripotent stem cells (hPSCs) generated by metabolic glycoengineering (MGE). This enabled the application of mechanical forces to sialoglycans on hPSCs through molecularly specific acoustic tweezing cytometry (mATC), that is, displacing sialoglycan-anchored MBs using ultrasound (US). It was shown that subjected to the acoustic radiation forces of US pulses, sialoglycan-anchored MBs exhibited significantly larger displacements and faster, more complete recovery after each pulse than integrin-anchored MBs, indicating that sialoglycans are more stretchable and elastic than integrins on hPSCs in response to mechanical force.

View Article and Find Full Text PDF

The synthesis of allenyl boronates is an important yet challenging topic in organic synthesis. Reported herein is an NHC-gold-catalyzed 1,3-H shift toward allenyl boronates synthesis from simple propargylic B(MIDA)s. Mechanistic studies suggest dual roles of the boryl moiety in the reaction: to activate the substrate for isomerization and at the same time, to prevent the allene product from further isomerization.

View Article and Find Full Text PDF

The glymphatic system has recently been shown to be important in neurological diseases, including diabetes. However, little is known about how the progressive onset of diabetes affects the glymphatic system. The aim of this study is to investigate the glymphatic system response to the progressive onset of diabetes in a rat model of type 2 diabetic mellitus.

View Article and Find Full Text PDF

The introduction of trifluoromethyl groups into organic molecules is of paramount importance in modern synthetic chemistry and medicinal chemistry. While methods for constructing C(sp )-CF bonds have been well established, the advancement of practical and comprehensive approaches for forming C(sp )-CF bonds remains considerably restricted. In this work, we describe an efficient and site-specific deaminative trifluoromethylation reaction of aliphatic primary amines to afford the corresponding alkyl trifluoromethyl compounds.

View Article and Find Full Text PDF

Background: The glymphatic system actively exchanges cerebrospinal fluid (CSF) and interstitial fluid (ISF) to eliminate toxic interstitial waste solutes from the brain parenchyma. Impairment of the glymphatic system has been linked to several neurological conditions. Glioblastoma, also known as Glioblastoma multiforme (GBM) is a highly aggressive form of malignant brain cancer within the glioma category.

View Article and Find Full Text PDF

The glymphatic system suggests the convective bulk flow of cerebrospinal fluid (CSF) through perivascular spaces and the interstitial spaces of the brain parenchyma for the rapid removal of toxic waste solutes from the brain. However, the presence of convective bulk flow within the brain interstitial spaces is still under debate. We first addressed this argument to determine the involvement of the glymphatic system in brain waste clearance utilizing contrast-enhanced 3D T1-weighted imaging (T1WI), diffusion tensor imaging (DTI), and confocal microscopy imaging.

View Article and Find Full Text PDF

Geminal-difluoroalkanes featuring intriguing steric and electronic properties are of great significance in medicinal chemistry, and great progresses have been achieved for their synthesis. In recent years, iodine(III) reagent-mediated migratory gem-difluorination of alkenes has proved to be an efficient and powerful strategy to access to diverse gem-difluoroalkanes, especially those bearing a readily transformable functionality (TF), which are important for rapid assembly of complex gem-difluorinated molecules in a modular and diverse manner. In this review, we systematically summarize the recent development of iodine(III)-mediated migratory gem-difluorination reactions for the synthesis of gem-difluoroalkanes bearing a synthetically versatile TF at the β position.

View Article and Find Full Text PDF

Electrophilic addition reaction to alkynes is of fundamental importance in organic chemistry, yet the regiocontrol when reacting with unsymmetrical 1,2-dialkyl substituted alkynes is often problematic. Herein, it is demonstrated that the rarely recognized β-boron effect can confer a high level of site-selectivity in several alkyne electrophilic addition reactions. A broad range of highly functionalized and complex organoborons are thus formed under simple reaction conditions starting from propargylic MIDA (N-methyliminodiacetic acid) boronates.

View Article and Find Full Text PDF
Article Synopsis
  • Pituitary tumors can cause cognitive deficits by impairing glymphatic waste clearance in the brain, but how this process is affected by the tumors is not well understood.
  • In this study, researchers used MRI and mathematical modeling to examine glymphatic transport in rats with and without spontaneous pituitary tumors.
  • Findings showed that rats with tumors had significantly impaired glymphatic function, evidenced by lower rates of tracer infusion and clearance in brain regions, indicating that the tumors hinder the brain's waste removal system.
View Article and Find Full Text PDF

Organofluorine compounds have been widely used in pharmaceutical, agrochemical, and material sciences. Reported herein are divergent fluorination reactions of vinylcyclopropanes with different electrophiles, which allow the facile synthesis of homoallylic monofluorides and vicinal-difluorides through ring-opening 1,5-hydrofluorination and ring-retaining 1,2-difluorination, respectively. Both protocols feature mild conditions, simple operations, good functional group tolerance, and generally good yields.

View Article and Find Full Text PDF

Metabolic reprogramming is a crucial hallmark of tumorigenesis. Modulating the reprogrammed energy metabolism is an attractive anticancer therapeutic strategy. We previously found a natural product, , modulated aerobic metabolism and inhibited proliferation in the colorectal cancer cell (CRC).

View Article and Find Full Text PDF

The facile synthesis of stereo-defined and transformable functionality-enriched building blocks is of great importance in modern organic chemistry, as it allows the rapid and divergent assembly of complex molecules. Herein a halogen electrophile (N-bromosuccinimide and N-iodosuccinimide) initiated semipinacol rearrangement reaction of B(MIDA)-propargylic alcohols (MIDA=N-methyliminodiacetyl) by aryl migration towards the synthesis of amphoteric α-haloalkenyl boronates in moderate to good yields with excellent stereoselectivities is reported. The value of the products is evidenced by their ability to undergo divergent conversions to polysubstituted alkenes through manipulation of the C-B and C-X (X=Br, I) bonds and the carbonyl group.

View Article and Find Full Text PDF

Electrophilic addition to alkenes is a textbook-taught reaction, yet it is not always possible to control the regioselectivity of addition to unsymmetrical 1,2-disubstituted substrates. We report the observation and applications of the β-boron effect that accounts for high regioselectivity in electrophilic addition reactions to allylic MIDA (-methyliminodiacetic acid) boronates. While the well-established β-silicon effect bears partial resemblance to the observed reactivity, the silyl group is typically lost during functionalization.

View Article and Find Full Text PDF

The primary amino group has been seldom utilized as a transformable functionality in organic synthesis. Reported herein is a deaminative halogenation of primary amines using -anomeric amide as the nitrogen-deletion reagent. Both aliphatic and aromatic amines are competent substrates for direct halogenations.

View Article and Find Full Text PDF

α-Boryl ketones are traditionally challenging targets in organic synthesis. Reported herein is a mild and metal-free synthesis of α-boryl ketones via the hydration or oxidation of -methyliminodiacetyl boronate (B(MIDA))-decorated alkynes. A new hydration system comprised of AcCl and HO in HFIP allows the hydration of arylethynyl B(MIDA)s at room temperature with decent functional group tolerance.

View Article and Find Full Text PDF

Neuromorphic machines are intriguing for building energy-efficient intelligent systems, where spiking neurons are pivotal components. Recently, memristive neurons with promising bio-plausibility have been developed, but with limited reliability, bulky capacitors or additional reset circuits. Here, we propose an anti-ferroelectric field-effect transistor neuron based on the inherent polarization and depolarization of HfZrO anti-ferroelectric film to meet these challenges.

View Article and Find Full Text PDF