Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Agric Food Chem ; 67(42): 11710-11717, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31600058

RESUMO

Lactuca sativa L. var. augustana has a basmati rice-like odor with a green note in the background. This typical odor is due to the release of 2-acetyl-1-pyrroline (2-AP) after heating, which is confirmed by volatile analysis. Recent metabolomic and genomic studies of different rice varieties highlighted that the presence of 2-AP was linked to the accumulation of γ-aminobutyraldehyde; genome-wide association studies also indicated that acyltransferases were involved. These results prompted us to analyze nonvolatile compound precursors in L. sativa L. var. augustana (celtuce) to search for compound derivatives with a 4,5-dioxohexan alkyl amine-like structure. Hypothetical synthetic compounds were prepared from a reductive amination between 4,5-dioxohexanal and glycine, alanine, aspartic acid, and glutamic acid to give 2-(2-acetylpyrrolidin-1-yl) alkanoic acid. We proved that 2-(2-acetylpyrrolidin-1-yl) propionic acid is present in L. sativa, which, when thermally treated, released 2-AP. Other 2-AP precursors occurring in this plant are discussed.


Assuntos
Lactuca/química , Extratos Vegetais/química , Pirróis/química , Genoma de Planta , Lactuca/genética , Espectrometria de Massas , Odorantes/análise
2.
J Org Chem ; 79(2): 599-607, 2014 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-24344740

RESUMO

Aphadilactones A-D (1-4), four diastereoisomers possessing an unprecedented carbon skeleton, were isolated from the Meliaceae plant Aphanamixis grandifolia. Their challenging structures and absolute configurations were determined by a combination of spectroscopic data, chemical degradation, fragment synthesis, experimental CD spectra, and ECD calculations. Aphadilactone C (3) with the 5S,11S,5'S,11'S configuration showed potent and selective inhibition against the diacylglycerol O-acyltransferase-1 (DGAT-1) enzyme (IC50 = 0.46 ± 0.09 µM, selectivity index > 217) and is the strongest natural DGAT-1 inhibitor discovered to date. In addition, compounds 1-4 showed significant antimalarial activities with IC50 values of 190 ± 60, 1350 ± 150, 170 ± 10, and 120 ± 50 nM, respectively.


Assuntos
Antimaláricos/farmacologia , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Diterpenos/farmacologia , Inibidores Enzimáticos/farmacologia , Meliaceae/química , Plasmodium falciparum/efeitos dos fármacos , Antimaláricos/química , Antimaláricos/isolamento & purificação , Diacilglicerol O-Aciltransferase/metabolismo , Dimerização , Diterpenos/química , Diterpenos/isolamento & purificação , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Humanos , Conformação Molecular , Testes de Sensibilidade Parasitária , Proteínas Recombinantes/metabolismo , Relação Estrutura-Atividade
3.
Yao Xue Xue Bao ; 47(7): 966-8, 2012 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-22993866

RESUMO

The paper is to report the establishment of three methods for determination of methyl salicylate-2-O-beta-D-galactopyranoside (1-4)-beta-D-glucopyranoside (MSG) by HPLC, UV or potentiometric titration. The results determined by the three methods turned out to be of no significant difference (P>0.05). The method was chosen according to MSG difference test demands.


Assuntos
Anti-Inflamatórios/análise , Cromatografia Líquida de Alta Pressão/métodos , Glicosídeos/análise , Potenciometria/métodos , Salicilatos/análise , Espectrofotometria Ultravioleta/métodos , Anti-Inflamatórios/química , Glicosídeos/química , Estrutura Molecular , Reprodutibilidade dos Testes , Salicilatos/química , Sensibilidade e Especificidade
4.
Planta Med ; 77(14): 1617-22, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21472647

RESUMO

Three new limonoids (toonaciliatins N-P, 1-3)and four new pimaradiene-type diterpenoids(toonacilidins A-D, 4-7) were isolated from the leaves and twigs of Toona ciliata Roem. var. yunnanensis.Their structures were elucidated on the basis of spectroscopic methods. Toonacilidin B(5)showed moderate inhibitory activity against H. pylori-SS1 with an MIC of 50 µg/mL.


Assuntos
Anti-Infecciosos/química , Diterpenos/química , Helicobacter pylori/efeitos dos fármacos , Limoninas/química , Meliaceae/química , Extratos Vegetais/química , Anti-Infecciosos/isolamento & purificação , Diterpenos/isolamento & purificação , Limoninas/isolamento & purificação , Testes de Sensibilidade Microbiana , Estrutura Molecular
5.
Bioorg Med Chem Lett ; 21(1): 125-9, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-21131198

RESUMO

Five new ring A-seco triterpenoids, dysoxyhainic acids F-J (1-5), along with a known ring A-seco triterpenoid koetjapic acid (6) were isolated from the twigs and leaves of Dysoxylum hainanense. Their structures were established on the basis of extensive spectroscopic analysis. Antimicrobial activity of all the compounds against fungi and bacteria were tested. Compounds 2-4 and 6 exhibited significant antimicrobial activity against Gram-positive bacteria, and the antibacterial SAR (structure-activity relationship) was also briefly discussed.


Assuntos
Antibacterianos/química , Meliaceae/química , Triterpenos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias Gram-Positivas/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Conformação Molecular , Folhas de Planta/química , Relação Estrutura-Atividade , Triterpenos/isolamento & purificação , Triterpenos/farmacologia
6.
J Nat Prod ; 73(8): 1344-9, 2010 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-20614901

RESUMO

Ten new limonoids, namely, mesendanins A-J (1-10), together with 14 known compounds, have been isolated from the leaves and twigs of Melia toosendan. Their structures were established on the basis of spectroscopic data analysis.


Assuntos
Medicamentos de Ervas Chinesas/isolamento & purificação , Limoninas/isolamento & purificação , Melia/química , Medicamentos de Ervas Chinesas/química , Limoninas/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Caules de Planta/química
7.
Org Lett ; 12(6): 1168-71, 2010 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-20148570

RESUMO

Three highly oxygenated new diterpenes, trigochinins A-C (1-3) were isolated from Trigonostemon chinensis. Their structures with the absolute configuration were determined by a spectroscopic method, X-ray crystallography, and CD analysis. This study suggested the revision of the C-6 stereochemistry of trigonothyrins A-C reported quite recently. Compound 3 showed significant inhibition against MET tyrosine kinase activity with a IC(50) value of 1.95 microM.


Assuntos
Diterpenos/química , Euphorbiaceae/química , Inibidores de Proteínas Quinases/química , Cristalografia por Raios X , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Modelos Moleculares , Conformação Molecular , Folhas de Planta/química , Caules de Planta/química , Inibidores de Proteínas Quinases/isolamento & purificação , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Estereoisomerismo
8.
J Nat Prod ; 73(1): 45-50, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20038159

RESUMO

Two new sesquiterpenes, sarcandralactones A (1) and B (2), and five new dimeric sesquiterpenoids, sarcandrolides A-E (3-7), along with 10 known compounds were isolated from the whole plants of Sarcandra glabra. Their structures were elucidated on the basis of spectroscopic analysis. Some of the new isolates exhibit significant cytotoxicities when tested against a small panel of tumor cell lines.


Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Medicamentos de Ervas Chinesas/isolamento & purificação , Magnoliaceae/química , Sesquiterpenos/isolamento & purificação , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Células HL-60 , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Sesquiterpenos/química , Sesquiterpenos/farmacologia
9.
Org Lett ; 11(18): 4080-3, 2009 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-19702252

RESUMO

Trigochilides A (1) and B (2), two highly modified daphnane-type diterpenoids with 12-carbon-containing polyketide appendages at C-16 forming a macro-lactone with C-3, were isolated from the twigs and leaves of Trigonostemon chinensis. Their structures were elucidated by spectroscopic analysis. Trigochilides A (1) showed modest cytotoxicity against two tumor cell lines.


Assuntos
Antineoplásicos/uso terapêutico , Diterpenos/uso terapêutico , Ensaios de Seleção de Medicamentos Antitumorais , Euphorbiaceae/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Diterpenos/classificação , Medicamentos de Ervas Chinesas/química , Células HeLa , Humanos , Células K562 , Lactonas/farmacologia , Folhas de Planta/química , Relação Estrutura-Atividade , Células Tumorais Cultivadas
10.
Org Lett ; 10(19): 4327-30, 2008 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-18771268

RESUMO

Two novel rearranged oleanane-type triterpenes, dysoxyhainanin A ( 1) possessing a unique 1,3- cyclo-2,3- seco A ring with a formamido-containing appendage and dysoxyhainanin B ( 2) featuring an unprecedented 1,2-dinor-3,10:9,10- bisseco skeleton, were isolated from Dysoxylum hainanense. Dysoxyhainanin A ( 1) exhibited significant antibacterial activity against Gram-positive bacteria.


Assuntos
Meliaceae/química , Triterpenos/química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Cristalografia por Raios X , Triterpenos/isolamento & purificação , Triterpenos/farmacologia
11.
Chem Asian J ; 3(10): 1824-9, 2008 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-18604820

RESUMO

Five new alkaloids, gelseganines A-D (1-4) and humantenine N(4)-oxide (5), were isolated from the stems and leaves of Gelsemium elegans. Compounds 1-4 represent a rare class of monoterpenoid indole alkaloids that bear an N(4)-iridoid unit. The structures of 1-5 were determined by spectroscopic analysis, single-crystal X-ray diffraction, and chemical correlation, and their absolute configurations were elucidated by CD analysis. A plausible biogenetic pathway for alkaloids 1-5 was also postulated.


Assuntos
Gelsemium/química , Iridoides/química , Alcaloides de Triptamina e Secologanina/química , Dicroísmo Circular , Iridoides/isolamento & purificação , Estrutura Molecular , Folhas de Planta/química , Caules de Planta/química , Plantas Medicinais/química , Alcaloides de Triptamina e Secologanina/isolamento & purificação
12.
Zhongguo Zhong Yao Za Zhi ; 31(1): 21-3, 2006 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-16548160

RESUMO

OBJECTIVE: To select a proper Ganoderma luciderm strain for the fruiting body production. METHOD: The strains were cultivated on the agar media and in the liquid media, respectively. Then the strains were inoculated onto the solid medium made from agricultural products (such as wheat bran, corn powder, wood meal, etc.) and cultured for a certain period. RESULT: Strains, which were easier to produce polyporic tissues at the vegetative growth stage, would be more quickly to form fruiting body with high quality and yield of the spores. CONCLUSION: Appearance of the polyporic tissues at the mycelium vegetative growth stage could be used as a marker for the strain selection for the G. luciderm substituted cultivation.


Assuntos
Carpóforos/crescimento & desenvolvimento , Ganoderma/crescimento & desenvolvimento , Micélio/crescimento & desenvolvimento , Reatores Biológicos , Meios de Cultura , Triticum , Zea mays
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...