3 research outputs found
Aminopyridyl/Pyrazinyl Spiro[indoline-3,4′-piperidine]-2-ones As Highly Selective and Efficacious c‑Met/ALK Inhibitors
A series
of novel aminopyridyl/pyrazinyl-substituted spiroÂ[indoline-3,4′-piperidine]-2-ones
were designed, synthesized, and tested in various in vitro/in vivo
pharmacological and antitumor assays. 6-[6-Amino-5-[(1<i>R</i>)-1-(2,6-dichloro-3-fluorophenyl)Âethoxy]-3-pyridyl]-1′-methylspiroÂ[indoline-3,4′-piperidine]-2-one
(compound <b>5b</b> or <b>SMU-B</b>) was identified as
a potent, highly selective, well-tolerated, and orally efficacious
c-Met/ALK dual inhibitor, which showed pharmacodynamics effect by
inhibiting c-Met phosphorylation in vivo and significant tumor growth
inhibitions (>50%) in GTL-16 human gastric carcinoma xenograft
models
Construction of a Tannase-Immobilized Magnetic Graphene Oxide/Polymer Nanobiocatalyst with Enhanced Enzyme Stability for High-Efficiency Transformation of Tannins
Highly efficient biotransformation of natural compounds
into sustainable
biochemical products has attracted great attention. The integration
of nanoscience and biotechnology provides attractive solutions for
this purpose. Herein, we report the fabrication of a nanobiocatalyst
employing a magnetic graphene oxide/polymer nanocomposite as a robust
carrier for immobilizing the tannase enzyme, which catalyzes the bioconversion
of tannin into gallic acid and glucose. Attributed to the covalent
immobilization and propitious interface properties of the coated polymers
comprising polyethylenimine and sodium hyaluronate, the nanobiocatalyst
is stable without compromising the enzymatic activity. The nanobiocatalyst
exhibits 91.8% activity of original tannase and a high enzyme bound
amount of 356.8 mg g–1. The stability tests at variable
temperatures (30–80 °C) and under pH conditions (4.0–9.0),
various inhibitors, and a long-term storage process (25 days) reveal
that the heterofunctional support and surface microenvironment facilitate
better stability, adaptability, and tolerance ability of the nanobiocatalyst
modified with a multicomponent polymer in comparison to the free enzyme
and the nanobiocatalyst modified with the monocomponent polyethylenimine.
The nanobiocatalyst maintains 94.2% of its initial activity after
10 consecutive uses and is 100% recoverable by applying an external
magnet. Moreover, the nanobiocatalyst is used to hydrolyze 96.5 and
95.1% tannins in extracts from Chinese Torreya grandis testa and cake,
respectively. These results establish the practicability of magnetic
graphene oxide-based supports for immobilizing tannase and the promising
application of immobilized tannase for efficient tannin hydrolysis
Magnetic-Encoded Fluorescent Multifunctional Nanospheres for Simultaneous Multicomponent Analysis
In this study, magnetic-encoded fluorescent
(CdTe/Fe<sub>3</sub>O<sub>4</sub>)@SiO<sub>2</sub> multifunctional
nanospheres were constructed
by adjusting the initial concentration of Fe<sub>3</sub>O<sub>4</sub> in a fabrication process based on reverse microemulsion. The resultant
multifunctional nanospheres were characterized by transmission electron
microscopy, X-ray diffraction measurements, fluorescence spectrophotometry,
and vibrating sample magnetometry. They showed good fluorescence properties,
gradient magnetic susceptibility (weak, moderate, and strong), and
easy biofunctionalization for biomolecules, such as immunoglobulin
G (IgG), protein, and antibody. Then the capture efficiency of the
(CdTe/Fe<sub>3</sub>O<sub>4</sub>)@SiO<sub>2</sub> nanospheres were
investigated by using the fluorophore-labeled IgG-conjugated nanospheres
as a model. Further studies demonstrated the ability of these (CdTe/Fe<sub>3</sub>O<sub>4</sub>)@SiO<sub>2</sub> multifunctional nanospheres
to accomplish sequentially magnetic separation, capture, and fluorescent
detection for each corresponding antigen of CA125, AFP, and CEA with
a detection limit of 20 KU/L, 10 ng/mL, and 5 ng/mL, respectively,
from a mixed sample under a certain external magnetic field within
a few minutes. The strategy of combining magnetic-encoding-based separation
and fluorescence-based detection proposed in this study shows great
potential to achieve easy, rapid, economical, and near-simultaneous
multicomponent separation and analysis for a variety of targets such
as drugs, biomarkers, pathogens, and so on