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1.
Angew Chem Int Ed Engl ; : e202404295, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38649323

RESUMEN

Homogeneous electrocatalysts can indirect oxidate the high overpotential substrates through single-electron transfer on the electrode surface, enabling efficient operation of organic electrosynthesis catalytic cycles. However, the problems of this chemistry still exist such as high dosage, difficult recovery, and low catalytic efficiency. Single-atom catalysts (SACs) exhibit high atom utilization and excellent catalytic activity, hold great promise in addressing the limitations of homogeneous catalysts. In view of this, we have employed Fe-SA@NC as an advanced redox mediator to try to change this situation. Fe-SA@NC was synthesized using an encapsulation-pyrolysis method, and it demonstrated remarkable performance as a redox mediator in a range of reported organic electrosynthesis reactions, and enabling the construction of various C-C/C-X bonds. Moreover, Fe-SA@NC demonstrated a great potential in exploring new synthetic method for organic electrosynthesis. We employed it to develop a new electro-oxidative ring-opening transformation of cyclopropyl amides. In this new reaction system, Fe-SA@NC showed good tolerance to drug molecules with complex structures, as well as enabling flow electrochemical syntheses and gram-scale transformations. This work highlights the great potential of SACs in organic electrosynthesis, thereby opening a new avenue in synthetic chemistry.

2.
J Org Chem ; 86(22): 16121-16127, 2021 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-33599123

RESUMEN

The study reported an electrochemically mediated method for the preparation of 2,1-benzoxazoles from o-nitrophenylacetylenes. Different from the traditional electrochemical reduction of nitro to nitroso, the nitro group directly underwent a cyclization reaction with the alkyne activated by selenium cation generated by the anodic oxidation of diphenyl diselenide and finally produced the desired products.


Asunto(s)
Benzoxazoles , Selenio , Catálisis , Ciclización , Oxidación-Reducción
3.
Nat Prod Res ; 34(18): 2689-2693, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30856009

RESUMEN

In this study, antitumor activity and composition analysis of the core of Camellia osmantha fruit were investigated. The cores were extracted by 80% ethanol to obtain the crude extract (TF), which was successively distributed by different concentrations of ethanol with MCI resin to obtain three different parts (Frs 1 to 3). Cytotoxicity activities showed that TF, Fr-2, and Fr-3 exhibited good inhibition against T-24 with IC50 values of 6.7 ± 1.3, 6.9 ± 0.9, and 6.7 ± 1.7 µg/mL, respectively. Fr-3 has a strong inhibitory activity on T-24 cells, mainly due to effectively increasing the release of intracellular calcium ions and reactive oxygen species. In addition, Fr-3 can inhibit T-24 cells migration and invasion. Further composition analysis on Fr-3 was detected by LC-Q-TOFMS implying the main components to be ellagic acid and its derivatives.


Asunto(s)
Antineoplásicos Fitogénicos/aislamiento & purificación , Camellia/química , Frutas/química , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Antineoplásicos Fitogénicos/farmacología , Calcio/metabolismo , Camellia/anatomía & histología , Línea Celular Tumoral , Ácido Elágico/análisis , Humanos , Invasividad Neoplásica/prevención & control , Extractos Vegetales/farmacología , Especies Reactivas de Oxígeno/metabolismo , Neoplasias de la Vejiga Urinaria/patología
4.
Fitoterapia ; 138: 104345, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31470063

RESUMEN

The present study reports the phytochemical investigation of n-butanol-soluble extracts of Glechoma longituba. Five new oleanane-type triterpenoid saponins with an 11α, 12α-epoxy unit, named glechomanosides A - E, were isolated from the n-butanol soluble fraction of G. longituba. Their chemical structures were established using HRESIMS, IR, 1D NMR, and 2D NMR techniques. The compounds were all evaluated for their antithrombus activities by monitoring thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), and antiplatelet aggregation assays. These results suggest that G. longituba might be a candidate plant source of an interesting antithrombotic activity.


Asunto(s)
Plaquetas/efectos de los fármacos , Lamiaceae/química , Ácido Oleanólico/análogos & derivados , Saponinas/farmacología , Animales , China , Femenino , Masculino , Ratones , Estructura Molecular , Ácido Oleanólico/aislamiento & purificación , Ácido Oleanólico/farmacología , Tiempo de Tromboplastina Parcial , Fitoquímicos/aislamiento & purificación , Fitoquímicos/farmacología , Agregación Plaquetaria , Tiempo de Protrombina , Conejos , Saponinas/aislamiento & purificación , Tiempo de Trombina
5.
J Asian Nat Prod Res ; 18(5): 429-35, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26757778

RESUMEN

A new cytisine-type alkaloid, (-)-N-hexanoylcytisine (1), and a new isoflavan, (3S, 4R)-4-hydroxy-7,4'-dimethoxyisoflavan 3'-O-ß-d-glucopyranoside (2), along with 10 known compounds, were isolated from the rhizomes of Sophora tonkinensis. Their structures were determined by spectroscopic methods, chemical evidence, and ECD data analysis. All of the isolates were evaluated for their cytotoxic activities against four human tumor cell lines.


Asunto(s)
Alcaloides/aislamiento & purificación , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Medicamentos Herbarios Chinos/aislamiento & purificación , Alcaloides/química , Antineoplásicos Fitogénicos/química , Azocinas , Ensayos de Selección de Medicamentos Antitumorales , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/farmacología , Flavonoides/química , Células Hep G2 , Humanos , Isoflavonas , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Raíces de Plantas/química , Quinolizinas , Rizoma/química , Sophora
6.
Zhongguo Zhong Yao Za Zhi ; 41(1): 96-100, 2016 Jan.
Artículo en Chino | MEDLINE | ID: mdl-28845648

RESUMEN

Thirteen compounds were isolated from the 95% aqueous EtOH extract of the rhizomes of Sophora tonkinensis by a combination of various chromatographic techniques including column chromatography over silica gel, Sphadex LH-20, MCI, ODS, and semi-preparative HPLC.Their structures were elucidated as 1-(6,7-dihydro-5H-pyrrolo[1,2-a]imidazol-3-yl)ethanone(1), cyclo(Pro-Pro)(2), nicotinic acid(3), p-hydroxybenzonic acid(4), p-methoxybenzonic acid(5), 4-hydroxymethyl-2,6-dimethoxyphenol-1-O-ß-D-glucopyranoside(6), coniferin(7), syringin(8),(-)-secoisolariciresinol-4-O-ß-D-glucopyranoside(9),(-)-syringaresinol-4-O-ß-D-glucopyranoside(10),(-)-syringaresinol-4,4'-di-O-ß-D-glucopyranoside(11),(-)-pinoresinol-4,4'-di-O-ß-D-glucopyranoside(12), and(6S,9R)-roseoside(13) by their physicochemical properties and spectroscopic data.Compound 1 was a new naturalproduct, and compounds 2,5,6,9,10,12 and 13 were obtained from the Sophora genus for the first time.Compound 1 possessed moderate cytotoxic activity against A549 human tumor cell [IC50(23.05 ± 0.46)µmol•L⁻¹].


Asunto(s)
Medicamentos Herbarios Chinos/química , Rizoma/química , Sophora/química , Cromatografía Líquida de Alta Presión , Medicamentos Herbarios Chinos/aislamiento & purificación , Estructura Molecular , Espectrometría de Masa por Ionización de Electrospray
7.
Bioorg Med Chem Lett ; 23(19): 5283-9, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23988357

RESUMEN

A series of novel α-aminophosphonate derivatives containing DHA structure were designed and synthesized as antitumor agents. In vitro antitumor activities of these compounds against the NCI-H460 (human lung cancer cell), A549 (human lung adenocarcinoma cell), HepG2 (human liver cancer cell) and SKOV3 (human ovarian cancer cell) human cancer cell lines were evaluated and compared with commercial anticancer drug 5-fluorouracil (5-FU), employing standard MTT assay. The pharmacological screening results revealed that many compounds exhibited moderate to high levels of antitumor activities against the tested cancer cell lines and that most demonstrated more potent inhibitory activities compared with the commercial anticancer drug 5-FU. The action mechanism of representative compound 7c was preliminarily investigated by acridine orange/ethidium bromide staining, Hoechst 33258 staining, JC-1 mitochondrial membrane potential staining and flow cytometry, which indicated that the compound can induce cell apoptosis in NCI-H460 cells. Cell cycle analysis showed that compound 7c mainly arrested NCI-H460 cells in G1 stage.


Asunto(s)
Abietanos/síntesis química , Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Organofosfonatos/síntesis química , Abietanos/química , Abietanos/farmacología , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Evaluación Preclínica de Medicamentos , Citometría de Flujo , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Organofosfonatos/química , Organofosfonatos/farmacología
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