Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Más filtros

Bases de datos
Tipo del documento
Asunto de la revista
País de afiliación
Intervalo de año de publicación
1.
J Am Chem Soc ; 146(33): 22913-22917, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39110062

RESUMEN

The magneto-optical response of chiral materials holds significant potential for applications in physics, chemistry, and biology. However, exploration of the near-infrared (NIR) magneto-optical response remains limited. Herein, we report the synthesis and strong NIR-II magneto-optical activity of three pairs of chiral 3d-4f clusters of R/S-Ln15Cu54 (Ln = Sm, Gd, and Dy). Structural analysis reveals that R/S-Ln15Cu54 features a triangular prism cage with C3 symmetry. Interestingly, magnetic circular dichroism (MCD) spectra exhibit remarkable magneto-optical response in the NIR-II region, driven by the f-f transition. The maximum g-factor of R/S-Sm15Cu54 reaches 5.5 × 10-3 T-1 around 1300-1450 nm, surpassing values associated with DyIII and CuII ions. This remarkable NIR-II magneto-optical activity may be attributed to strong magnetic-dipole-allowed f-f transitions and helix chirality of the structure. This work not only presents the largest Ln-Cu clusters to date but also demonstrate the key role of magnetic-dipole-allowed transitions on magneto-optical activity.

2.
Inorg Chem ; 61(9): 4121-4129, 2022 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-35201748

RESUMEN

Metal clusters with well-defined crystal structures are extremely useful for studying the synergistic catalytic effects and associated catalytic mechanisms. In this study, two pairs of chiral lanthanide-transition metal clusters (R)/(S)-Co3Ln2 (Ln = Tb or Dy) were synthesized using Schiff-base ligands [(R)- or (S)-H3L] with multiple Lewis base sites (O sites). The as-prepared (R)/(S)-Co3Ln2 chiral metal clusters exhibited good catalytic functionality in the asymmetric synthesis of chiral cyanohydrins, with high conversions of up to 99% and medium-to-high enantiomeric excess values of up to 78%. The catalysis process followed a mechanism in which the bifunctional metal clusters of (R)/(S)-Co3Ln2, containing Lewis acid sites and Lewis base sites, simultaneously activated the aldehydes and trimethylsilyl cyanide, respectively. Consequently, synergistic catalysis was realized. The enantioselectivity of the different aldehydes and stereochemical configuration of the resulting products are attributed to the formation of a steric chiral pocket via the external chiral ligands on the clusters. In addition, heterogeneous asymmetric cyanosilylation using (R)/(S)-Co3Ln2 chiral metal clusters achieved high chemoselectivity and regioselectivity under mild conditions.

3.
Molecules ; 22(7)2017 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-28714918

RESUMEN

In this study, the cytotoxicities and anti-inflammatory activities of five resveratrol derivatives-vitisinol A, (+)-ε-viniferin, (+)-vitisin A, (-)-vitisin B, and (+)-hopeaphenol-isolated from Ampelopsis brevipedunculata var. hancei were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lipopolysaccharide (LPS)-stimulated RAW264.7 cells, respectively. The result from MTT assay analysis indicated that vitisinol A has lower cytotoxicity than the other four well-known oligostilbenes. In the presence of vitisinol A (5 µM), the significant reduction of inflammation product (nitric oxide, NO) in LPS-induced RAW264.7 cells was measured using Griess reaction assay. In addition, the under-expressed inflammation factors cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in LPS-induced RAW264.7 cells monitored by Western blotting simultaneously suggested that vitisinol A has higher anti-inflammatory effect compared with other resveratrol derivatives. Finally, the anti-inflammatory effect of vitisinol A was further demonstrated on 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced ear edema in mice. As a preliminary functional evaluation of natural product, the anti-inflammatory effect of vitisinol A is the first to be examined and reported by this study.


Asunto(s)
Ampelopsis/química , Antiinflamatorios/química , Biflavonoides/química , Catequina/química , Extractos Vegetales/química , Proantocianidinas/química , Estilbenos/química , Animales , Antiinflamatorios/farmacología , Biflavonoides/farmacología , Biomarcadores , Catequina/farmacología , Ciclooxigenasa 2/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Masculino , Ratones , Estructura Molecular , Óxido Nítrico/metabolismo , Extractos Vegetales/farmacología , Proantocianidinas/farmacología , Células RAW 264.7 , Estilbenos/farmacología
4.
Am J Clin Oncol ; 46(5): 193-198, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36991528

RESUMEN

OBJECTIVES: Investigate the survival of patients with stage III colorectal cancer (CRC) treated with immediate postoperative intraperitoneal chemotherapy. METHODS: The clinical data of 195 patients with stage III CRC admitted to The First Affiliated Hospital of Wenzhou Medical University from June 2017 to June 2018 were retrospectively analyzed. The patients were divided into an observation group and a control group, both groups were treated with the routine laparoscopic radical operation, on the basis of which, the patients in the observation group were treated with intraperitoneal perfusion chemotherapy during the operation. The local recurrence, abdominal cavity metastasis, and liver metastasis were followed up, and the time of disease recurrence and total survival were recorded. RESULTS: The survival analysis showed that there was a significant difference in progression-free survival (χ 2 = 5.416, P = 0.020) and overall survival (χ 2 = 4.673, P = 0.031) between the observation group and the control group. CONCLUSIONS: During laparoscopic radical resection of CRC, the use of intraperitoneal chemotherapy with raltitrexed can achieve satisfactory results and improve the survival rate of patients with stage III CRC, perioperative use of raltitrexed has been shown to be beneficial in terms of overall survival and progression-free survival.


Asunto(s)
Neoplasias Colorrectales , Recurrencia Local de Neoplasia , Humanos , Estudios Retrospectivos , Estadificación de Neoplasias , Recurrencia Local de Neoplasia/patología , Neoplasias Colorrectales/patología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA