Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Org Lett ; 26(7): 1489-1494, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38358098

RESUMEN

A novel approach using aromatic amines and chiral phosphoric acids in a synergistic catalytic cascade reaction of 2-alkynylnaphthols with aldehydes has been established. This method offers a direct route to preparing flavanone analogues with excellent stereoselectivity. Mechanistic studies reveal a sequential process involving addition, elimination, cyclization, and hydrolysis in which aromatic amines and chiral phosphoric acids play key roles via imine-enamine and hydrogen bonding models.

2.
J Colloid Interface Sci ; 657: 91-101, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38035423

RESUMEN

Layered double hydroxides (LDHs) with unique layered structure have excellent theoretical capacitance. Nevertheless, the constrained availability of electrically active sites and cationic species curtails their feasibility for practical implementation within supercapacitors. Most of the reported materials are bimetallic hydroxides, and fewer studies are on trimetallic hydroxides. In here, the hollow dodecahedron NiCoZn-LDH is synthesized using CoZn metal-organic frameworks (CoZn-MOFs) as template. Its morphology and composition are studied in detail. Concurrently, the effect of the amount of third component on the resulting structure of NiCoZn-LDH is also researched. Benefiting from its favorable structural and compositional attributes to efficient transfer of ions and electrons, NiCoZn-LDH-200 demonstrates outstanding specific capacitance of 1003.3F g-1 at 0.5 A/g. Furthermore, flexible asymmetric supercapacitor utilizing NiCoZn-LDH-200 as the positive electrode and activated carbon (AC) as the negative electrode reveals favorable electrochemical performances, including a notable specific capacitance of 184.7F g-1 at 0.5 A/g, a power density of 368.21 W kg-1 at a high energy density of 65.66 Wh kg-1, an energy density of 31.78 Wh kg-1 at a high power density of 3985.97 W kg-1, a capacitance retention of 92 % after 8000 cycles at 5 A/g, and a good capacitance retention of 90 % after 500 cycles of bending. The template method presented herein can effectively solve the problem of easy accumulation and improve the electrochemical properties of the materials, which exhibits a broad research prospect.

3.
J Colloid Interface Sci ; 658: 889-902, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38157613

RESUMEN

In contemporary times, electromagnetic radiation poses a significant threat to both human health and the normal functioning of electronic devices. Developing composites as adsorption materials possess exceptional electromagnetic wave absorption performances can efficient address this critical issue. Herein, hollow core-shell NiCo2O4@polypyrrole nanofibers/reduced graphene oxide (NiCo-HFPR) composites are fabricated by the combination of electrostatic spinning, air calcination, in-situ polymerization, freeze-drying and hydrazine vapor reduction. As anticipated, NiCo-HFPR-0.2 exhibits noteworthy properties, with the minimum reflection loss (RLmin) of -61.20 dB at 14.26 GHz and 1.56 mm, as well as the effective absorption bandwidth (EAB) of 4.90 GHz at 1.57 mm. Additionally, the simulation procedure is employed to determine the radar cross-section (RCS) attenuation. In comparison to a singular perfect electrically conductive (PEC) layer, the PEC layer coated with NiCo-HFPR-0.2 consistently yields an RCS value below -10 dB m2 within the range of -60° < θ < 60°. The RCS attenuation value of the NiCo-HFPR-0.2 coating achieves an outstanding 31.0 dB m2 at θ = 0°, strongly affirming the ability to effectively attenuate electromagnetic wave in real-world applications. The employed experimental methodology, the meticulously crafted composite, and the simulation outcomes presented in this study bear great promise for the progressive advancement of both theoretical investigations and practical applications within the domain of electromagnetic wave absorption.

4.
Langmuir ; 39(29): 10098-10111, 2023 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-37432980

RESUMEN

Adsorption materials have demonstrated huge potential in treating sewage; however, it is a great challenge to fabricate an adsorbent effectively adsorbing multiple dyestuffs and heavy metal ions simultaneously. Here, a magnetic core@shell Fe3O4@polypyrrole@sodium dodecyl sulfate (Fe3O4@PPy@SDS) composite is prepared through the combination of a hydrothermal method, an in situ polymerization method, and modification, exhibiting enhanced selective removal of five dyestuffs (methylene blue (MB), malachite green (MG), rhodamine B (RhB), Congo red (CR), acid red 1 (AR1)), and heavy metal ions (Mn(VII)). The effects of adsorbent type, time, initial concentration of the adsorbate, and temperature on adsorption performances are investigated in detail. Kinetics and isotherm studies indicate that all adsorption processes are more in line with the pseudo-second-order kinetic model and the Langmuir model, the diffusion behavior is controlled by intraparticle diffusion and liquid film diffusion, and research of thermodynamics reveals a spontaneous endothermic behavior. The removal efficiency after five desorption-adsorption cycles can still reach more than 90%. The prepared Fe3O4@PPy@SDS composite is an efficient and promising renewable adsorbent for the treatment of dyestuffs and Mn(VII), exhibiting a wide range of applications in the field of adsorption.

5.
Drug Dev Res ; 81(5): 585-592, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32163191

RESUMEN

To improve water solubility, reduce phototoxicity and increase the tumor-targeting ability of hematoporphyrin (Hp) as a sonosensitizer for sonodynamic therapy under ultrasonic conditions, a novel folate receptor (FR)-targeted, folate-conjugated ethylenediamine-ß-cyclodextrin (FA-EN-ß-CD) containing Hp (FA-EN-ß-CD-Hp) was constructed. ß-Cyclodextrin containing Hp (ß-CD-Hp) was also established as a nontargeted control. The inclusion efficiencies of Hp in FA-EN-ß-CD-Hp and ß-CD-Hp were determined to be 90.4 ± 2.7% (wt/wt) and 92.5 ± 3.4% (wt/wt), respectively. Growth inhibition rates in HepG-2 cells in vitro were assessed upon ultrasound exposure. The results indicated that the growth inhibition rates of FA-EN-ß-CD-Hp, ß-CD-Hp, and F-Hp (Hp: 150 µg/ml) reached 96.4 ± 3.6%, 53.4 ± 3.4%, and 48.2 ± 2.8%, respectively. These results indicated that FA-EN-ß-CD-Hp is a promising drug delivery system in the field of sonodynamic cancer therapy.


Asunto(s)
Antineoplásicos/administración & dosificación , Etilenodiaminas/administración & dosificación , Receptores de Folato Anclados a GPI/metabolismo , Ácido Fólico/administración & dosificación , Hematoporfirinas/administración & dosificación , Terapia por Ultrasonido , beta-Ciclodextrinas/administración & dosificación , Células A549 , Antineoplásicos/química , Supervivencia Celular/efectos de los fármacos , Liberación de Fármacos , Endocitosis , Etilenodiaminas/química , Ácido Fólico/química , Hematoporfirinas/química , Células Hep G2 , Humanos , beta-Ciclodextrinas/química
6.
J Drug Target ; 27(10): 1076-1083, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-30836772

RESUMEN

To facilitate targeting drug delivery and combined therapy, we constructed a novel drug carrier, in which oridonin-liposome containing microbubbles (LUMO) are covalently adhered to folic acid-conjugated multiwalled carbon nanotubes loaded with protohemin (FMTP) to form a novel conjugate (FMTP-LUMO). Oridonin (ORI) is used as a chemotherapeutic drug for chemotherapy (CHT), whereas protohemin (Ph) is applied in the field of sonodynamic therapy (SDT) as a sonosensitizer. In vitro release properties, cellular uptake and cytotoxicity in HepG-2 cells as well as in vivo antitumour effects in HepG-2 cell tumour-bearing mice submitted to chemo-sonodynamic therapy, SDT alone and CHT alone were evaluated upon ultrasound exposure. The results showed that the growth inhibition rates on FMTP-LUMO, FMTP, and LUMO were 95.4 ± 5.9%, 63.9 ± 7.4%, and 42.3 ± 2.9% in vitro, respectively. FMTP-LUMO exhibited strong binding to HepG-2 cells than MTP-LUMO. The chemo-sonodynamic therapy demonstrated a cooperative effect, resulting in significantly higher therapeutic efficacy for liver cancer. After treatment for 10 d, the tumour inhibition ratio for FMTP-LUMO exceeded to 90%, clearly higher than that of FMTP (42.8%) and LUMO (32.5%). Thus, FMTP-LUMO could serve as a highly effective drug carrier for chemo-sonodynamic therapy.


Asunto(s)
Diterpenos de Tipo Kaurano/química , Ácido Fólico/metabolismo , Hemina/química , Liposomas/química , Microburbujas/uso terapéutico , Nanotubos de Carbono/química , Células 3T3 , Animales , Línea Celular , Línea Celular Tumoral , Diterpenos de Tipo Kaurano/farmacología , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Hemina/farmacología , Células Hep G2 , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Ratones
7.
J Drug Target ; 25(1): 83-91, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27282800

RESUMEN

In this study, folate receptor (FR) targeted liposome microbubbles loaded with oridonin (ORI) (F-LMB-ORI), liposome loaded with ORI (L-ORI) and liposome microbubbles loaded with ORI (LMB-ORI) were prepared. In vitro release properties, cellular uptake and cytotoxicity in HepG-2 cells as well as in vivo antitumor effects in HepG-2 cells tumor-bearing mice of F-LMB-ORI, L-ORI and LMB-ORI were evaluated upon ultrasound exposure. Results showed cytotoxicity assay on F-LMB-ORI gave IC50 of 0.508 ± 0.018 µmol/mL on HepG-2 cells and LMB-ORI; L-ORI gave IC50 of 2.424 ± 0.116 µmol/mL, 3.031 ± 0.122 µmol/mL in vitro, respectively. These drug delivery carriers were able to control the release of ORI. F-LMB-ORI exhibited higher binding to HepG-2 cells in comparison to LMB-ORI and L-ORI. F-LMB-ORI improved antitumor activity of ORI obviously in comparison to L-ORI, LMB-ORI under in vivo ultrasound. After the treatment for 14 d, the tumor inhibition ratio for F-LMB-ORI (the dose of ORI: 1.5 × 10-2 g·kg-1, once a day) was 87.6%, obviously higher than that of LMB-ORI group, L-ORI group and free ORI (the dose of ORI: 1.5 × 10-2 g·kg-1, once a day) which were 71.5%, 64.3% and 43.4%, respectively.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Diterpenos de Tipo Kaurano/administración & dosificación , Portadores de Fármacos/química , Ácido Fólico/química , Microburbujas , Fonoforesis , Animales , Antineoplásicos Fitogénicos/uso terapéutico , Supervivencia Celular/efectos de los fármacos , Diterpenos de Tipo Kaurano/uso terapéutico , Liberación de Fármacos , Receptores de Folato Anclados a GPI/metabolismo , Células Hep G2 , Humanos , Ratones Endogámicos BALB C , Ratones Desnudos , Ensayos Antitumor por Modelo de Xenoinjerto
8.
J Pharm Pharmacol ; 69(2): 213-221, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28028809

RESUMEN

OBJECTIVES: To study the antitumour activity of a novel derivative of oridonin named geridonin in vitro and in vivo. METHODS: MTT and colony formation assay were used to test the cytotoxicity of geridonin; apoptosis, cell cycle arrest and the levels of reactive oxygen species were measured by flow cytometry; JC-1 staining assay was used to examine the mitochondrial membrane potential; the MGC 803 xenograft model was established to evaluate the antitumour effect of geridonin in vivo; H&E staining was performed for the histological analysis. KEY FINDINGS: In vitro, geridonin remarkably inhibited proliferation of gastrointestinal cancer cells including oesophageal, gastric, liver and colon cancers. On oesophageal, gastric cancer cells, geridonin displayed strong cytotoxicity than that of oridonin. In gastric cancer MGC 803 cells, geridonin triggered apoptosis through the mitochondrial pathway depending on caspase. In addition, geridonin sharply reduced the formation of cell colony, increased the intracellular levels of ROS and induced cell cycle arrest at G2/M phase. In vivo, geridonin delayed the growth of MGC 803 xenograft in athymic mice without obvious loss of bodyweight. CONCLUSIONS: The novel derivative of oridonin, geridonin, inhibited the growth of human gastric cancer cells MGC 803 both in vitro and in vivo mainly via triggering apoptosis depending on elevating intracellular level of ROS.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Diterpenos de Tipo Kaurano/farmacología , Especies Reactivas de Oxígeno/metabolismo , Animales , Apoptosis/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Ensayo de Tumor de Célula Madre , Ensayos Antitumor por Modelo de Xenoinjerto
9.
Drug Dev Res ; 77(3): 152-8, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-27029561

RESUMEN

Preclinical Research Sonodynamic therapy (SDT) is a cutting edge approach to treating cancer that involves necrosis and/or apoptosis. Multiwalled carbon nanotubes functionalized with carboxylic groups (MWCNTs-COOH) due their physicochemical structure represent a novel drug delivery system in the field of nanomedicine. The purpose of the research reported in this paper was to increase the antitumor potency and reduce the potential side effects of protohemin (Ph), a sonosensitizer for SDT, which was noncovalently encapsulated into MWCNTs-COOH (MWCNTs-Ph). The Ph loading efficiency in MWCNTs-COOH carrier was determined as approximately 68.8% (w/w). The growth inhibition rate of MWCNTs-Ph (Ph: 180 µg/mL) was approximately 95 ± 8.5%, whereas Ph-F (Ph: 180 µg/mL) inhibited 58 ± 4.5% of tumor cell. Ph (Ph: 180 µg/mL) alone had no antitumor effect in HepG-2 cells using ultrasound treatment at 1.0 MHz and 0.5 W/cm(2) for 100 s. Assessment of the antitumor effects of MWCNTs-Ph and Ph-F at day 11 after SDT showed that he tumor inhibition ratio for MWCNTs-Ph (6.18 × 10(-2) g·kg(-1) ·d(-1) ) was 82.8%, twice that of Ph-F (6.18 × 10(-2) g·kg(-1) ·d(-1) ) ay 41.8%. In conclusion, MWCNTs-Ph had increased antitumor efficiency and also decreased potential side effects. Drug Dev Res 77 : 152-158, 2016. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Ácidos Carboxílicos/química , Hemina/farmacología , Sonicación/métodos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Hemina/química , Células Hep G2 , Humanos , Nanotubos de Carbono
10.
PDA J Pharm Sci Technol ; 63(5): 409-16, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20158047

RESUMEN

High-purity oridonin was isolated and identified from Rabdosia rubescens hemsl by preparative high-performance liquid chromatography (HPLC). Stealth liposomes of oridonin were prepared by thin-film ultrasonic dispersion using polyethylene glycol-distearoylphosphatidyleth-anolamine(PEG2000-DSPE) as the surface-coating material. A reversed-phase HPLC method was developed and validated to determine the concentrations of oridonin in the serum and tissues of mice. The tissue distribution and pharmacokinetics of oridonin stealth liposomes and oridonin solution in mice were investigated. The results showed that the distribution and pharmacokinetics of oridonin stealth liposomes in mice were changed as compared to the distribution and pharmacokinetics of oridonin solution. The levels of stealth liposomal oridonin in the heart tissues were reduced, while the levels of stealth liposomal oridonin in the blood were increased. The stealth liposomes were very effective at inhibiting the rate of solid tumor growth. The PEG2000-DSPE of liposomes prolonged the circulation time of oridonin in mouse blood, reduced accumulation in the reticuloendothelial system and increased the anti-tumor activity of oridonin.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Diterpenos de Tipo Kaurano/administración & dosificación , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Animales , Antineoplásicos Fitogénicos/farmacocinética , Antineoplásicos Fitogénicos/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Cromatografía Líquida de Alta Presión/métodos , Diterpenos de Tipo Kaurano/farmacocinética , Diterpenos de Tipo Kaurano/farmacología , Portadores de Fármacos/química , Ensayos de Selección de Medicamentos Antitumorales , Femenino , Isodon/química , Liposomas , Neoplasias Hepáticas Experimentales/patología , Masculino , Ratones , Sistema Mononuclear Fagocítico/metabolismo , Miocardio/metabolismo , Fosfatidiletanolaminas/química , Polietilenglicoles , Distribución Tisular
11.
Chem Biodivers ; 4(3): 458-67, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17372948

RESUMEN

Endomorphin-2 (1; H-Tyr-Pro-Phe-Phe-NH2; EM2) and its novel cyclic asparagine (cycloAsn) analogues, H-Tyr-cAsn(CHPh)-Phe-Phe-NH2 (2) and H-Tyr-cAsn(CHMe2)-Phe-Phe-NH2 (3), were synthesized via liquid-phase synthesis. The structures of the products and intermediates were characterized by IR, 1H-NMR, MS, and HR-MS analyses. The antinociceptive activity of EM2 and its cyclic asparagine analogues were assessed in AcOH-induced abdominal constriction tests in mice with i.p. injection. The results show that the antinociceptive activities of EM2 and its cyclic asparagine analogue 2 were higher than those of aspirine and meperidine. Analogue 2 was observed to be a stronger analgesic with dose-dependence than EM2. The test mice did not show any tendency to be addicted while administrated of analogue 2 repeatedly and regularly.


Asunto(s)
Analgésicos Opioides/síntesis química , Analgésicos Opioides/farmacología , Oligopéptidos/síntesis química , Oligopéptidos/farmacología , Animales , Asparagina/análogos & derivados , Asparagina/síntesis química , Asparagina/farmacología , Relación Dosis-Respuesta a Droga , Femenino , Masculino , Ratones , Dimensión del Dolor/efectos de los fármacos , Receptores Opioides/agonistas , Receptores Opioides/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...