Isodesmic reactions, in which chemical bonds are redistributed between substrates and products, provide a general and powerful strategy for both biological and chemical synthesis. However, most isodesmic reactions involve either metathesis or functional-group transfer. Here, we serendipitously discovered a novel isodesmic reaction of indoles and anilines that proceeds intramolecularly under weakly acidic conditions.
View Article and Find Full Text PDFAnalyzing polysorbate 20 (PS20) composition and the impact of each component on stability and safety is crucial due to formulation variations and individual tolerance. The similar structures and polarities of PS20 components make accurate separation, identification, and quantification challenging. In this work, a high-resolution quantitative method was developed using single-dimensional high-performance liquid chromatography (HPLC) with charged aerosol detection (CAD) to separate 18 key components with multiple esters.
View Article and Find Full Text PDFOrganic molecules bearing chiral sulfur stereocenters exert a great impact on asymmetric catalysis and synthesis, chiral drugs, and chiral materials. Compared with acyclic ones, the catalytic asymmetric synthesis of thio-heterocycles has largely lagged behind due to the lack of efficient synthetic strategies. Here we establish the first modular platform to access chiral thio-oxazolidinones via Pd-catalyzed asymmetric [3+2] annulations of vinylethylene carbonates with sulfinylanilines.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
May 2023
Metal-polarized aza-ortho-quinone methides (aza-o-QMs) are a unique and efficient handle for azaheterocycle synthesis. Despite great achievements, the potential of these reactive intermediates has not yet been fully exploited, especially the new reaction modes. Herein, we disclosed an unprecedented dearomatization process of metal-polarized aza-o-QMs, affording transient dearomatized spiroaziridine intermediates.
View Article and Find Full Text PDFSearching for efficient strategies to access structurally novel aminoindolines is of great significance for drug discovery. However, catalytic asymmetric de novo construction of aminoindoline scaffolds with functionality primed for diversification still remains elusive. Here, we report a Cu-catalyzed asymmetric cyclization of ethynyl benzoxazinones with amines, producing chiral 3-aminoindolines in good yield and with high enantioselectivity (up to 97% yield and 98:2 er).
View Article and Find Full Text PDFObjective: The aim of this study is to investigate the clinical characteristics and prognostic effects of different subtypes of suprasellar arachnoid cysts (SAC) in children.
Methods: Fifty patients with primary SAC who had undergone endoscopic treatment in our department between January 2010 and December 2020 were studied retrospectively. All patients underwent endoscopic treatment after diagnosis, including ventriculocystostomy (VC) in 23 cases and ventriculocystocisternostomy (VCC) in 27 cases.
J Phys Condens Matter
June 2021
We have studied the valence effects on the stability of Stone-Wales (SW) defect in some typical two-dimensional honeycomb crystals containing group-IV, V, and VI elements employing density functional theory. The energetics involved in an in-plane formation process of SW defects in pristine and substitutionally doped materials is simulated. The SW defects are stable and have a rotation angle about 90 degree in the group-IV materials.
View Article and Find Full Text PDFMost human cancers develop from stem and progenitor cell populations through the sequential accumulation of various genetic and epigenetic alterations. Cancer stem cells have been identified from medulloblastoma (MB), but a comprehensive understanding of MB stemness, including the interactions between the tumor immune microenvironment and MB stemness, is lacking. Here, we employed a trained stemness index model based on an existent one-class logistic regression (OCLR) machine-learning method to score MB samples; we then obtained two stemness indices, a gene expression-based stemness index (mRNAsi) and a DNA methylation-based stemness index (mDNAsi), to perform an integrated analysis of MB stemness in a cohort of primary cancer samples (n = 763).
View Article and Find Full Text PDFShanghai Kou Qiang Yi Xue
October 2019
Purpose: To explore the methods and characteristics of removable denture restoration in children with congenital missing teeth.
Methods: From 1998 to 2018, 61 children aging 3 to 12 years old with congenital dental deficiency were treated with removable dentures. There were 59 males and 2 females.
: Population-based estimates of the incidence and prognosis of metastatic disease at the initial diagnosis of primary central nervous system (CNS) tumors are currently lacking. : A total of 43,455 patients diagnosed with a primary CNS tumor were enrolled to evaluate metastatic rates utilizing the data from the Surveillance, Epidemiology, and End Results (SEER) program. We used multivariate logistic regression to analyze the risk factors associated with the presence of metastasis at the first visit of patients with metastatic medulloblastoma (MB), atypical teratoid/rhabdoid tumor (ATRT), glioblastoma multiforme (GBM), or pilocytic astrocytoma (PA).
View Article and Find Full Text PDFCatalytic asymmetric cycloadditions via transition-metal-containing dipolar intermediates are a powerful tool for synthesizing chiral heterocycles. However, within the field of palladium catalysis, compared with the well-developed normal electron-demand cycloadditions with electrophilic dipolarophiles, a general strategy for inverse electron-demand ones with nucleophilic dipolarophiles remains elusive, due to the inherent linear selectivity in the key palladium-catalyzed intermolecular allylations. Herein, based on the switched regioselectivity of iridium-catalyzed allylations, we achieved two asymmetric [4+2] cycloadditions of vinyl aminoalcohols with aldehydes and β,γ-unsaturated ketones through synergetic iridium and amine catalysis.
View Article and Find Full Text PDFA copper-catalyzed Friedel-Crafts propargylation/hydroamination/aromatization sequence is described. In the presence of a catalytic amount of CuI, this sequential reaction can convert ethynyl benzoxazinanones and indoles into a diverse set of 3,3'-biindoles with high efficiency and selectivity. Moreover, the synthesis of other indole-heteroaryl molecules and the catalytic asymmetric formation of axially chiral 3,3'-biindoles are demonstrated.
View Article and Find Full Text PDFA novel copper-catalyzed decarboxylative cyclization of ethynyl benzoxazinanones with P(O)H compounds has been developed. This protocol leads to a series of 2-phosphorylmethyl indoles with high efficiency and selectivity (up to 99% yield) through tandem C-P/C-N bond formation under mild conditions.
View Article and Find Full Text PDFPolycyclic indolines are the common and core structural motif of many indole alkaloids that usually exhibit biological activities. Here, we describe two copper-catalyzed cascade reactions between propargylic carbamates and indoles. By doing so, one-step and divergent synthesis of structurally distinct polycyclic indolines, quinoline-fused indolines, C(3a)-indolyl furoindolines, and pyrroloindolines was achieved in high synthetic efficiency and selectivity.
View Article and Find Full Text PDFThe palladium-catalyzed branch- and enantioselective allylic amination of vinyl benzoxazinones was accomplished through controlling the hydrogen bond direction. This protocol provides a rapid and efficient route for synthesizing an important building block, chiral amino alkene, from widely available aliphatic amines in 64 → 99% yields with up to 99% ee. Furthermore, this transformation and the accompanying products were utilized to develop one-pot reactions through dual catalysis, affording chiral indolines with good synthetic efficiency and excellent enantiocontrol.
View Article and Find Full Text PDFMini Rev Med Chem
September 2017
Background: The widespread application of fluorine in drug design benefits from distinctive properties. Incorporation of fluorine can positively modulate certain pharmacokinetics properties, including lipophilicity, eletrophilicity, metabolic stability, chemical stability, et al., which were of interest to medicinal chemists.
View Article and Find Full Text PDFObjective: This overview seeked to bring together the microRNA (miRNA) researches on biogenesis and bio-function in these areas of clinical diagnosis and therapy for malignant glioma.
Data Sources: Using the keyword terms "glioma" and "miRNA," we performed the literature search in PubMed, Ovid, and web.metstr.
A series of bromophenol derivatives containing indolin-2-one moiety were designed and evaluated that for their anticancer activities against A549, Bel7402, HepG2, HeLa and HCT116 cancer cell lines using MTT assay in vitro. Among them, seven compounds (4g-4i, 5h, 6d, 7a, 7b) showed potent activity against the tested five human cancer cell lines. Wound-healing assay demonstrated that compound 4g can be used as a potent compound for inactivating invasion and metastasis by inhibiting the migration of cancer cells.
View Article and Find Full Text PDFAlthough decidualization is crucial for the establishment of successful pregnancy, the molecular mechanism underlying decidualization remains poorly understood. Crystallin αB (CryAB), a small heat shock protein (sHSP), is up-regulated and phosphorylated in mouse decidua. In mouse primary endometrial stromal cells, CryAB is induced upon progesterone treatment via HIF1α.
View Article and Find Full Text PDFTotal mRNA was extracted from lymphocytes separated from the peripheral blood of allergic patients, and then variable region of heavy chain (VH) and variable region of light chain (VL) cDNA library were constructed by RT-PCR. Human scFv templates for rabbit reticulocyte lysate ribosome display were assembled by primers and linker peptide (Gly4Ser)3. mRNA bound in antibody-ribosome-mRNA complexes was recovered using in-situ single primer RT-PCR, and three rounds of anti-IgE scFv DNA were enriched.
View Article and Find Full Text PDFAim: The risk factors mostly strongly associated with gastric cancer are gastric bacteria Helicobacter pylori and diet. Using a case-control study among residents in Jinan, we examined the association between the salt taste and gastric cancer according to H. pylori infection, smoking and histological type as well as tumor site.
View Article and Find Full Text PDFShanghai Kou Qiang Yi Xue
April 2012
Purpose: To study the bonding strength between the FCVA (filtered cathode vacuum arc) film and the titanium substrate.
Methods: According to the Engineer Manual of Germany (VDI3198), the indentation test was applied to evaluate the bonding strength between the FCVA film and the titanium substrate. The structure of the FCVA film and the interface between the film and the substrate were observed by means of scanning electron microscope(SEM).
Tumor-associated macrophages (TAMs) have been implicated in promoting tumor progression. Nowadays, adenocarcinoma has surpassed squamous cell carcinoma as the most frequent type of lung cancer, but in lung adenocarcinoma, the correlation of TAMs with lymphangiogenesis patients remains unclear. The aim of this study was to examine the relationship between TAMs and lymphangiogenesis and the lung adenocarcinoma patients' prognosis.
View Article and Find Full Text PDFObjective: To evaluate the effectiveness and safety of the combination chemotherapy of capecitabine (X) with fractionated administration of cisplatin (C) in Chinese patients with advanced gastric cancer (AGC).
Methods: 141 patients with AGC were enrolled between July 2002 and August 2004. All patients had measurable tumor according to the criteria of RECIST, Karnofsky performance status > or = 60, adequate bone marrow, renal and hepatic functions.
Bacterial Outer membrane (OM) proteins involved in antibiotic resistance have been reported. However, little is known about the OM proteins and their interaction network regulating streptomycin (SM) resistance. In the present study, a subproteomic approach was utilized to characterize OM proteins of Escherichia coli with SM resistance.
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