Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Chaos ; 34(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38198679

RESUMO

We study the effect of relative phase on the characteristics of rogue waves and solitons described by rational solutions in the nonlinear Schrödinger Maxwell-Bloch system. We derived the rational rogue wave and soliton solutions with adjustable relative phase and present the parameter range of different types of rogue waves and solitons. Our findings show that the relative phase can alter the distribution of rational solitons and even change the type of rational solitons, leading to a rich array of rational soliton types by adjusting the relative phase. However, the relative phase does not affect the structure of the rogue wave, because the relative phase of the rogue wave changes during evolution. In particular, we confirm that the rational solitons with varying relative phases and the rogue waves at corresponding different evolution positions share the same distribution mode. This relationship holds true for rogue waves or breathers and their stable counterparts solitons or periodic waves in different nonlinear systems. The implications of our study are significant for exploring fundamental excitation elements in nonlinear systems.

2.
iScience ; 26(5): 106586, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37138780

RESUMO

Pulmonary fibrosis (PF) is a fatal and irreversible respiratory disease accompanied by excessive fibroblast activation. Previous studies have suggested that cAMP signaling pathway and cGMP-PKG signaling pathway are continuously down-regulated in lung fibrosis, whereas PDE10A has a specifically expression in fibroblasts/myofibroblasts in lung fibrosis. In this study, we demonstrated that overexpression of PDE10A induces myofibroblast differentiation, and papaverine, as a PDE10A inhibitor used for vasodilation, inhibits myofibroblast differentiation in human fibroblasts, Meanwhile, papaverine alleviated bleomycin-induced pulmonary fibrosis and amiodarone-induced oxidative stress, papaverine downregulated VASP/ß-catenin pathway to reduce the myofibroblast differentiation. Our results first demonstrated that papaverine inhibits TGFß1-induced myofibroblast differentiation and lung fibrosis by VASP/ß-catenin pathway.

3.
J Sep Sci ; 33(11): 1587-94, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20405484

RESUMO

A sensitive and reliable HPLC-diode-array detector method was developed for the first time to simultaneously determine nine nucleosides and nucleobases including uracil, cytidine, guanine, uridine, thymine, inosine, guanosine, thymidine and adenosine in 13 different Fritillaria species. The analysis was performed on a BaseLine C18 column with a gradient of acetonitrile in water at a flow rate of 0.8 mL/min. The diode-array detector wavelength was set at 260 nm for the UV detection of nucleosides and nucleobases. Satisfactory separation of these compounds was obtained in less than 40 min. The optimized method provided good linear relation (r(2)>0.9995 for all the investigated analytes), satisfactory precision (RSD <1.51%) and good recovery (from 97.64 to 101.16%). The established method was successfully applied to simultaneous determination of nine nucleosides and nucleobases in 61 batches of samples from 13 Fritillaria species collected from different habitats in China, which could be helpful to control the quality of Fritillaria bulbs.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Fritillaria/metabolismo , Nucleosídeos/química , Calibragem , Química , Técnicas de Química Analítica , China , Modelos Químicos , Nucleotídeos/química , Extratos Vegetais/química , Reprodutibilidade dos Testes , Solventes/química , Fatores de Tempo
4.
Yao Xue Xue Bao ; 42(8): 867-71, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17944237

RESUMO

The aim of this study was to look for the chemical constituents from the rhizomes of Dryopteris sublaeta. The fresh plant was extracted twice with boiling water, the extract was concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate and n-butanol. The fraction of ethyl acetate was repeatedly chromatographied over silica gel and Sephadex LH-20 columns. Structures of pure compounds were established on the basis of their physiochemical and spectral data. Nine compounds were obtained and identified as sublaetentin A (1), sublaetentin B (2), sublaetentin C (3), sublaetentin D (4), matteuorienate A (5), matteuorienate C (6), arbutin (7), 3-methoxy-4-hydroxyphenyl-1-O-beta-D-glucopyranoside (8) and 3,4-dimethoxyphenyl-1-O-beta-D-glucopyranoside (9). Compounds 1 - 4 are new compounds, the others were isolated from this plant for the first time.


Assuntos
Dryopteris/química , Flavanonas/isolamento & purificação , Glucosídeos/isolamento & purificação , Glicosídeos/química , Extratos Vegetais/química , Arbutina/química , Arbutina/isolamento & purificação , Flavanonas/química , Flavonoides/química , Flavonoides/isolamento & purificação , Glucosídeos/química , Estrutura Molecular , Plantas Medicinais/química , Rizoma/química
5.
Chem Pharm Bull (Tokyo) ; 55(6): 950-2, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17541202

RESUMO

Two new xanthones, 1,5,6-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,4)-2-(3-methylbut-2-enyl)xanthone (1) and 1,6,7-trihydroxy-6',6'-dimethyl-2H-pyrano(2',3':3,2)-4-(3-methylbut-2-enyl)xanthone (2), have been isolated from the stem bark of Garcinia lancilimba (Guttiferae), together with six known xanthones. Their structures were identified on the basis of extensive spectral evidence including detailed 2D NMR and HR-MS data. Two new compounds showed moderate inhibitory effect on human breast cancer MDA-MB-435S cell line.


Assuntos
Garcinia/química , Caules de Planta/química , Xantonas/isolamento & purificação , Linhagem Celular Tumoral , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Xantonas/química , Xantonas/farmacologia
6.
Chem Biodivers ; 4(5): 940-6, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17511007

RESUMO

Three new hydroxylated xanthones with prenyl or geranyl substituents, compounds 1-3, were isolated from the twig bark of Garcinia xanthochymus, along with the four known compounds 1,4,5,6-tetrahydroxy-7,8-diprenylxanthone (4), 1,3,5,6-tetrahydroxy-4,7,8-triprenylxanthone (5), garciniaxanthone E (6), and 6-prenylapigenin (7). Their structures were elucidated by extensive spectroscopic analysis, including 1D- and 2D-NMR as well as HR-MS experiments. All compounds showed moderate cytotoxicities against breast cancer (MDA-MB-435S) and lung adenocarcinoma (A549) cell lines, but lacked antifungal activity against Candida albicans.


Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Garcinia/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Antineoplásicos/isolamento & purificação , Benzimidazóis/isolamento & purificação , Benzimidazóis/farmacologia , Neoplasias da Mama/patologia , Candida albicans/efeitos dos fármacos , Ciclopentanos/isolamento & purificação , Ciclopentanos/farmacologia , Humanos , Neoplasias Pulmonares/patologia , Fenóis/isolamento & purificação , Fenóis/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Xantonas/isolamento & purificação , Xantonas/farmacologia
7.
Yao Xue Xue Bao ; 40(5): 443-6, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-16220790

RESUMO

AIM: To study the chemical constituents of Dryopteris sublaeta Ching et Hsu. METHODS: Fresh plant of Dryopteris sublaeta Ching et Hsu was extracted twice with boiling water, the extract was concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate, and n-butanol. The fraction of ether extract was chromatographed over silica gel column. The compounds were identified on the basis of their physiochemical and spectral data. RESULTS: Four compounds were obtained and identified as 2 (S)-5, 7, 3'-trihydroxy-6, 8-dimethyl-5'-methoxyflavanone (1), matteucinol (2), desmethoxymatteucinol (3) and 5, 7, 2'-trihydroxy-6, 8-dimethylflavanone (4). CONCLUSION: Compound 1 is a new one, the others were isolated from Dryopteris for the first time.


Assuntos
Dryopteris/química , Flavanonas/isolamento & purificação , Plantas Medicinais/química , Cromonas/química , Cromonas/isolamento & purificação , Flavanonas/química , Conformação Molecular , Estrutura Molecular
8.
Yao Xue Xue Bao ; 40(12): 1131-4, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16496679

RESUMO

AIM: To study the chemical constituents of Dryopteris sublaeta Ching et Hsu. METHODS: Fresh plant of Dryopteris sublaeta ching et hsu was extracted twice with boiling water, concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate, and n-butanol. The fraction of ethyl acetate extract was chromatographed over macroporous adsorption resin (Diaion HP-20) eluted with a mixture of H2O and MeOH in increasing MeOH content. Their fractions from resin were repeatedly chromatographed over Toyopearl HW-40, Sephadex LH-20 and silica gel column chromatography. The compounds were identified on the basis of their physiochemical and spectral data. RESULTS: Four compounds were obtained and identified as 3,5-dihydroxy-stilbene-3-O-neohesperidoside (1), 3,5-dihydroxy-stilbene-3-O-beta-D-glucoside (2), polydotin peceid (3) and 3,5,4'-trihydroxy-bibenzyl-3-O-beta-D-glucoside (4). CONCLUSION: Compound 1 is a new compound, the others were isolated from Dryopteris for the first time.


Assuntos
Dryopteris/química , Glicosídeos/isolamento & purificação , Plantas Medicinais/química , Estilbenos/isolamento & purificação , Glicosídeos/química , Estrutura Molecular , Estilbenos/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...