Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Magn Reson Chem ; 62(2): 74-83, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38112483

RESUMO

In October 2003, 20 years ago, the open-source and open-content database NMRshiftDB was announced. Since then, the database, renamed as nmrshiftdb2 later, has been continuously available and is one of the longer-running projects in the field of open data in chemistry. After 20 years, we evaluate the success of the project and present lessons learnt for similar projects.

3.
J Nat Prod ; 72(10): 1905-7, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19795903

RESUMO

The isolation, biological characterization, and structure elucidation of xanthepinone, a novel antifungal metabolite isolated from the broth of submerged cultures of a soil fungus, are described. Xanthepinone inhibits the conidial germination of Magnaporthe grisea (2 microg/mL), Phytophthora infestans (5 microg/mL), and Botrytis cinerea (10 microg/mL) while showing only weak antibacterial activity; cytotoxicity was not observed up to 50 microg/mL. Molecular taxonomy revealed that the producing strain is close to species in the genus Phoma as well as to uncultured soil fungi and endophytes.


Assuntos
Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Ascomicetos/química , Compostos Heterocíclicos com 3 Anéis/isolamento & purificação , Compostos Heterocíclicos com 3 Anéis/farmacologia , Antifúngicos/química , Botrytis/efeitos dos fármacos , Cristalografia por Raios X , Células HeLa , Compostos Heterocíclicos com 3 Anéis/química , Humanos , Magnaporthe/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Conformação Molecular , Phytophthora infestans/efeitos dos fármacos
5.
Z Naturforsch C J Biosci ; 64(7-8): 521-5, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19791504

RESUMO

In our ongoing screening culture fluid extracts of Gloeoporus (Caloporus) dichrous strain 83065 inhibited the germination of Magnaporthe grisea and Fusarium graminearum spores. While isolating the active metabolites two new caloporosides, caloporoside G and caloporoside H, in addition to the known caloporoside derivatives F-16438G, caloporoside A, and 2-hydroxy-6-(16-hydroxyheptadecyl)benzoic acid were obtained.


Assuntos
Manose/análogos & derivados , Salicilatos/farmacologia , Esporos Fúngicos/fisiologia , Animais , Antifúngicos/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , Humanos , Células Jurkat/efeitos dos fármacos , Leucemia L1210/patologia , Espectroscopia de Ressonância Magnética , Manose/química , Manose/farmacologia , Camundongos , Salicilatos/química , Esporos Fúngicos/efeitos dos fármacos , Fosfolipases Tipo C/antagonistas & inibidores
6.
Molecules ; 14(2): 798-806, 2009 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-19223828

RESUMO

Phenacylmalononitrile 1 reacts with dimethylformamide dimethyl acetal to yield an enaminone which could be readily converted into a pyrrole or an aminopyridazine by treating with ammonium acetate and hydrazine hydrate, respectively. Compound 1 reacted with hydrazine hydrate in ethanol at room temperature to yield the dihydropyridazine 9 as a single product. In refluxing ethanol this product further reacted with hydrazine hydrate to yield the novel dihydropyrazolopyridazinamine 10.


Assuntos
Nitrilas/química , Piridazinas , Pirróis , Estrutura Molecular , Piridazinas/síntese química , Piridazinas/química , Pirróis/síntese química , Pirróis/química
8.
J Nat Prod ; 71(9): 1654-6, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18771321

RESUMO

Cultures of the ascomycete Dasyscyphus niveus have yielded two new tetracyclic dasyscyphin-type terpenoids (1 and 2), and their structures were elucidated by NMR spectroscopy and X-ray crystallography. The absolute configuration of dasyscyphin D (1) was determined by synthesis and NMR spectroscopy of diastereomeric MTPA esters. Both compounds inhibited the germination of conidia of Magnaporthe grisea at 25 microg/mL.


Assuntos
Antifúngicos/isolamento & purificação , Ascomicetos/química , Diterpenos/química , Diterpenos/isolamento & purificação , Antifúngicos/química , Antifúngicos/farmacologia , Cristalografia por Raios X , Diterpenos/farmacologia , Fagus/microbiologia , Feminino , Alemanha , Humanos , Magnaporthe/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Conformação Molecular , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular
9.
J Antibiot (Tokyo) ; 61(9): 563-7, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19160524

RESUMO

Four members of a new family of tetracyclic sesquiterenoids possessing the isolactarane skeleton have been isolated from mycelial cultures of Stereum sp. IBWF 01060. Their structure elucidation and their antifungal activity against several plant pathogens as well as other microorganisms are reported.


Assuntos
Antifúngicos/isolamento & purificação , Basidiomycota/metabolismo , Sesquiterpenos/isolamento & purificação , Antifúngicos/química , Antifúngicos/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Sesquiterpenos/química , Sesquiterpenos/farmacologia
10.
J Antibiot (Tokyo) ; 61(5): 285-90, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18653993

RESUMO

In a screening program for new metabolites from fungi inhibiting the IL-4 mediated signal transduction, a novel chlorinated macrocyclic lactone, designated as oxacyclododecindione, was isolated from fermentations of the imperfect fungus Exserohilum rostratum. The structure was determined by a combination of spectroscopic techniques. Oxacyclododecindione inhibits the IL-4 induced expression of the reporter gene secreted alkaline phosphatase (SEAP) in transiently transfected HepG2 cells with IC50 values of 20-25 ng/ml (54-67.5 nM). Studies on the mode of action of the compound revealed that the inhibition of the IL-4 dependent signaling pathway is caused by blocking the binding of the activated STAT6 transcription factors to the DNA binding site without inhibiting tyrosine phosphorylation. The compound has no antibacterial or antifungal activity.


Assuntos
Interleucina-4/antagonistas & inibidores , Interleucina-4/fisiologia , Compostos Macrocíclicos/química , Compostos Macrocíclicos/farmacologia , Fungos Mitospóricos/química , Western Blotting , Linhagem Celular Tumoral , Fermentação , Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-4/farmacologia , Espectroscopia de Ressonância Magnética , Fungos Mitospóricos/metabolismo , Fator de Transcrição STAT6/antagonistas & inibidores , Fator de Transcrição STAT6/fisiologia , Transdução de Sinais/efeitos dos fármacos , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade , Transfecção
12.
Planta Med ; 68(5): 435-9, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12058321

RESUMO

A new monoterpenoid indole alkaloid, 10-hydroxy- N(alpha)-demethyl-19,20-dehydroraumacline ( 1), was isolated as a mixture of E- and Z-isomers from hairy root culture of Rauvolfia serpentina Benth. ex Kurz (Apocynaceae) and the structure was determined by 1D and 2D NMR analyses. The new indole alkaloid represents the first naturally occurring alkaloid of the raumacline group and its putative biosynthetical pathway is discussed.


Assuntos
Alcaloides Indólicos , Raízes de Plantas/química , Rauwolfia , Alcaloides de Triptamina e Secologanina/química , Isótopos de Carbono , Células Cultivadas , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Alcaloides de Triptamina e Secologanina/isolamento & purificação , Estereoisomerismo
13.
J Nat Prod ; 65(7): 1006-10, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12141861

RESUMO

Three new monoterpenoid indole alkaloids, 19(S),20(R)-dihydroperaksine (1), 19(S),20(R)-dihydroperaksine-17-al (2), and 10-hydroxy-19(S),20(R)-dihydroperaksine (3), along with 16 known alkaloids 4-19 were isolated from hairy root culture of Rauvolfia serpentina, and their structures were elucidated by 1D and 2D NMR analyses. Taking into account the stereochemistry of the new alkaloids and results of preliminary enzymatical studies, the putative biosynthetical relationships between the novel alkaloids are discussed.


Assuntos
Alcaloides Indólicos/isolamento & purificação , Plantas Medicinais/química , Rauwolfia/química , Alcaloides de Triptamina e Secologanina/química , Alcaloides de Triptamina e Secologanina/isolamento & purificação , Cromatografia em Camada Fina , Alcaloides Indólicos/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Raízes de Plantas/química , Rhizobium/metabolismo , Estereoisomerismo
14.
Chemistry ; 10(2): 360-70, 2004 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-14735504

RESUMO

Four OPV series 1-4 (a-d) with a terminal dialkylamino group as electron donor were prepared by Wittig-Horner reactions. To study the influence of the push-pull effect on the long-wavelength absorption, three of the four series contained terminal acceptor groups (CN, CHO, NO(2)). The length of the chromophores strongly affects the intramolecular charge transfer (ICT)-an effect which superimposes upon the extension of the conjugation. Increasing numbers n of repeat units cause an overall bathochromic shift for the purely donor-substituted series 1 a-4 a and the series 1 b-4 b with CN as weak acceptor. The two effects annihilate each other in the series 1 c-4 c with terminal CHO groups, so that the absorption maxima are almost independent of the length of the chromophore. A hypsochromic shift is observed for the series 1 d-4 d, which contains the strong acceptor group NO(2). This anomaly disappears on protonation of the dialkylamino group because the push-pull effect disappears in the ammonium salts. The results can be explained by semiempirical quantum mechanics (AM1, INDO/S). The HOMO-LUMO transition, which is mainly responsible for the ICT, becomes less important in the electron transitions S(0)-->S(1) when the distance between donor and acceptor is increased. The commonly used VB model, which contains an electroneutral and a zwitterionic resonance structure, is contrasted with a MO model with dipole segments at both ends of the OPV chains. The latter model turned out to be more appropriate-at least for donor-acceptor-substituted OPVs with n >/= 2.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA