Sargentodoxae Caulis was extracted with 80% ethanol and separated by macroporous resin, MCI, and ODS column chromatography and semi-preparative high performance liquid chromatography. The structures of the compounds were identified based on the NMR and MS data. A total of 19 compounds were identified as parabaroside D(1),(R)-2-(3,4-dihydroxyphenyl)-2-hydroxyethyl-O-β-D-glucopyranoside(2),(S)-2-(3,4-dihydroxyphenyl)-2-hydroxyethyl-O-β-D-glucopyranoside(3), protocatechin-3-O-β-D-glucoside(4), p-hydroxybenzoate-β-D-glucopyranoside(5), gentisic-5-O-β-D-glucopyranoside(6), vanillic acid 4-O-β-D-glucoside(7), syringic acid glucoside(8), uracil(9), uridine(10), neochlorogenic acid(11), chlorogenic acid(12), cryptochlorogenic acid(13), 3,4-dihydroxyphenylethanol glucoside(14), cuneataside A(15), cuneataside C(16), 4-hydroxy-3-methoxyacetophenone-4-O-β-D-apiose-(1→6)-β-D-glucopyranoside(17), proanthocyanidin B2(18), and baimantuoluoamide B(19).
View Article and Find Full Text PDFThe packing fashion of an organic molecule in the crystal plays a critical role in the global nonlinear optical (NLO) responses under ambient conditions. To better understand how the crystal packing affects the first hyperpolarizability (β) and achieve efficient NLO material, herein, the three positional isomers (regioisomers) through changing the substituted position of 3-carbazole-pyrazine-based isomers were performed. The phenyl groups with different positions (-, -, and -) of pyrazine, named , , and , are theoretically studied in gas, solvent, and solid states by using the polarizable continuum model and the combined quantum mechanics and molecular mechanics method, respectively.
View Article and Find Full Text PDFEpilepsy is a prevalent and disabling neurological condition characterized by recurrent seizures. Approximately 50% of adults with active epilepsy have at least one comorbidity and they are at a greater risk of premature death than the general population. Gentiopicroside (Gent) is a primary component of Pall.
View Article and Find Full Text PDF(-)-Cylindrocyclophane A is a 22-membered C-symmetric [7.7]paracyclophane that bears bis-resorcinol functionality and six stereocenters. We report a synthetic strategy for (-)-cylindrocyclophane A that uses 10 C-H functionalization reactions, resulting in a streamlined route with high enantioselectivity and efficiency (17 steps).
View Article and Find Full Text PDFMR imaging is currently the main imaging modality used for the diagnosis and post therapeutic assessment of glioblastomas. Recently, several innovative PET radioactive tracers have been investigated for the evaluation of glioblastomas (GBM). These radiotracers target several biochemical and pathophysiological processes seen in tumors.
View Article and Find Full Text PDFSalt stress severely affects the growth and yield of apples (Malus domestica Borkh). Although salt-tolerant genes have been extensively studied, documentation on the role of the ATP-dependent phosphofructokinase gene MdPFK5 in salt stress is limited. This study conducted an evolutionary tree and three-dimensional structure analysis of the PFK gene family in Arabidopsis thaliana and MdPFK (MD01G1037400), revealing a close phylogenetic relationship between MdPFK (MD01G1037400) and AtPFK5.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2024
Despite extensive efforts to develop γ-lactamization reactions for pyrrolidinone synthesis using either cyclometallation, C-H insertion, or radical C-H abstraction strategies, γ-lactamization reactions of aliphatic amides using practical catalysts and common protecting groups remain extremely rare. Herein we report copper-catalyzed γ-C(sp)-H lactamization and iminolactonization of tosyl-protected aliphatic amides using inexpensive Selectfluor as the sole oxidant. A switchable selectivity of γ-lactams or γ-iminolactones can be obtained by using two different sets of reaction conditions.
View Article and Find Full Text PDFDespite recent advances in ligand-enabled C(sp)-H functionalization of native substrates, controlling chemoselectivity in the presence of methyl and methylene C(sp)-H bonds remains a significant challenge. Herein, we report the first example of the Pd(II)-catalyzed chemoselective lactonization of γ-methyl and methylene C(sp)-H bonds of carboxylic acids. Exclusive chemoselectivity of methyl or methylene γ-lactonization was achieved by using two different classes of Quinoline-Pyridone ligands.
View Article and Find Full Text PDFNeuropathic pain, a multifaceted and incapacitating disorder, impacts a significant number of individuals globally. Despite thorough investigation, the development of efficacious remedies for neuropathic pain continues to be a formidable task. Recent research has revealed the potential of metabotropic glutamate receptor 5 (mGlu5) as a target for managing neuropathic pain.
View Article and Find Full Text PDFNon-natural chiral α,α-disubstituted α-amino acids (α,α-AAs) constitute an attractive α-aminoisobutyric acid (Aib) replacement for improving bioavailability of linear peptides as therapeutics due to the ability of these amino acids to induce the peptides to form helical structures. Enantioselective β-C(sp)-H arylation of Aib could potentially provide a versatile one-step strategy for accessing diverse α,α-AAs, but the installation and removal of external directing groups was found in our previously reported work to reduce the efficiency of this approach. Herein we report a Pd(ii)-catalyzed enantioselective C-H arylation of -phthalyl-protected Aib enabled by a -2,6-difluorobenzoyl aminoethyl phenyl thioether (MPAThio) ligand, affording α,α-AAs with up to 72% yield and 98% ee.
View Article and Find Full Text PDFThe transition metal-catalyzed -C-H functionalization of alcohols and their hydroxylamine derivatives remains underdeveloped. Herein, we report an efficient -C-H arylation of both phenylethyl and benzylic alcohols and their hydroxylamine derivatives using a readily removable oxime ether directing group. Using electronically activated 2-carbomethoxynorbornene as the transient mediator and 3-trifluoromethyl-2-pyridone as the enabling ligand, this reaction features a broad substrate scope and good functional group tolerance.
View Article and Find Full Text PDFIn recent years, the widespread application of growth regulators and nutrients to boost yield and quality of strawberry fruits has led to the rapid growth of strawberry industry globally. Although the effects of major nutrients on strawberry yield have been widely studied, investigations into the effect of trace elements such as boron remain limited. This study examined the effect of boron application on the yield and quality of "Benihoppe" strawberry fruits.
View Article and Find Full Text PDFBackground: Ground-glass nodule (GGN) is the most common manifestation of lung adenocarcinoma on computed tomography (CT). Clinically, the success rate of preoperative diagnosis of GGN by puncture biopsy and other means is still low. The aim of this study is to investigate the clinical and radiomics characteristics of lung adenocarcinoma presenting as GGN on CT images using radiomics analysis methods, establish a radiomics model, and predict the classification of pathological tissue and instability of GGN type lung adenocarcinoma.
View Article and Find Full Text PDFPd(II)-catalyzed enantioselective C-H activation has emerged as a versatile platform for constructing point, axial, and planar chirality. Herein, we present an unexpected discovery of a Pd-catalyzed enantioselective cascade β,γ-methylene C(sp)-H diarylation of free carboxylic acids using bidentate chiral mono-protected amino thioether ligands (MPAThio), enabling one-step synthesis of a complex chiral 9,10-dihydrophenanthrene scaffolds with high enantioselectivity. In this process, two methylene C(sp)-H bonds and three C(sp)-H bonds were activated, leading to the formation of four C-C bonds and three chiral centers in one pot.
View Article and Find Full Text PDFA 50-year-old woman was admitted due to a liver mass discovered by ultrasound in routine physical examination. MRI demonstrated a large hepatocellular carcinoma. It also discovered an abdominal mass simultaneously.
View Article and Find Full Text PDFA 60-year-old man with a history of end-stage renal disease received renal transplant and had decreasing renal function 4 months later. Nuclear medicine renal flow and functional study showed severely decreased blood flow and decreased function of the right renal allograft. There was focal increased radiotracer uptake at blood flow phase around the anastomosis of the renal allograft artery and the right external iliac artery.
View Article and Find Full Text PDFSite-selective C(sp)-H oxidation is of great importance in organic synthesis and drug discovery. γ-C(sp)-H lactonization of free carboxylic acids provides the most straightforward means to prepare biologically important lactone scaffolds from abundant and inexpensive carboxylic acids; however, a versatile catalyst for this transformation with a broad substrate scope remains elusive. Herein, we report a simple yet broadly applicable and scalable γ-lactonization reaction of free aliphatic acids enabled by a copper catalyst in combination with inexpensive Selectfluor as the oxidant.
View Article and Find Full Text PDFCancer, a chronic disease characterized by uncontrolled cell development, kills millions of people globally. The WHO reported over 10 million cancer deaths in 2020. Anticancer medications destroy healthy and malignant cells.
View Article and Find Full Text PDFStereoselective construction of γ- and δ-stereocenters in carbonyl compounds is a pivotal objective in asymmetric synthesis. Here, we report chiral bifunctional oxazoline-pyridone ligands that enable enantioselective palladium-catalyzed remote γ-C-H (hetero)arylations of free cycloalkane carboxylic acids, which are essential carbocyclic building blocks in organic synthesis. The reaction establishes γ-tertiary and α-quaternary stereocenters simultaneously in up to >99% enantiomeric excess, providing access to a wide range of cyclic chiral synthons and bioactive molecules.
View Article and Find Full Text PDFEthylene is a key hormone that regulates the maturation and quality formation of horticultural crops, but its effects on non-respiratory climacteric fruits such as strawberries are not yet clear. In this study, strawberry fruits were treated with exogenous ethephon (ETH) and 1-methylcyclopropene (1-MCP). It was found that ETH treatment increased the soluble solids and anthocyanin content of the fruits, reduced hardness, and decreased organic acid content, while 1-MCP treatment inhibited these processes.
View Article and Find Full Text PDFThe chemical composition of the aqueous part of the extract from Lindera aggregata was studied, which was separated and purified by the macroporous resin column chromatography, MCI medium pressure column chromatography, semi-preparative high-performance liquid phase and other methods. The structures of the compounds were identified according to physical and chemical properties and spectroscopic data. Thirteen compounds were isolated and identified from the aqueous extracts, which were identified as(1S,3R,5R,6R,8S,10S)-epi-lindenanolide H(1), tachioside(2), lindenanolide H(3), leonuriside A(4), 3,4-dihydroxyphenyl ethyl β-D-glucopyranoside(5), 3,4,5-trimethoxyphenol-1-O-6-α-L-rhamnose-(1→6)-O-β-D-glucoside(6), 5-hydroxymethylfurfural(7),(+)-lyoniresin-4-yl-β-D-glucopyranoside(8), lyoniside(9), norboldine(10), norisopordine(11), boldine(12), reticuline(13).
View Article and Find Full Text PDFDrought stress is one of the dominating challenges to the growth and productivity in crop plants. Elucidating the molecular mechanisms of plants responses to drought stress is fundamental to improve fruit quality. However, such molecular mechanisms are poorly understood in apple (Malus domestica Borkh.
View Article and Find Full Text PDFNon-structural protein 2 (nsp2) exists in all coronaviruses (CoVs), while its primary function in viral pathogenicity, is largely unclear. One such enteric CoV, porcine epidemic diarrhea virus (PEDV), causes high mortality in neonatal piglets worldwide. To determine the biological role of nsp2, we generated a PEDV mutant containing a complete deletion (rPEDV-Δnsp2) from a highly pathogenic strain by reverse genetics, showing that nsp2 was dispensable for PEDV infection, while its deficiency reduced viral replication .
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