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1.
Science ; 376(6595): 857-860, 2022 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-35587979

RESUMO

In plants, many invading microbial pathogens are recognized by cell-surface pattern recognition receptors, which induce defense responses. Here, we show that the ceramide Phytophthora infestans-ceramide D (Pi-Cer D) from the plant pathogenic oomycete P. infestans triggers defense responses in Arabidopsis. Pi-Cer D is cleaved by an Arabidopsis apoplastic ceramidase, NEUTRAL CERAMIDASE 2 (NCER2), and the resulting 9-methyl-branched sphingoid base is recognized by a plasma membrane lectin receptor-like kinase, RESISTANT TO DFPM-INHIBITION OF ABSCISIC ACID SIGNALING 2 (RDA2). 9-Methyl-branched sphingoid base is specific to microbes and induces plant immune responses by physically interacting with RDA2. Loss of RDA2 or NCER2 function compromised Arabidopsis resistance against an oomycete pathogen. Thus, we elucidated the recognition mechanisms of pathogen-derived lipid molecules in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ceramidas , Interações Hospedeiro-Patógeno , Ceramidase Neutra , Phytophthora infestans , Doenças das Plantas , Arabidopsis/genética , Arabidopsis/imunologia , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Ceramidas/metabolismo , Ceramidase Neutra/genética , Ceramidase Neutra/metabolismo , Phytophthora infestans/patogenicidade , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Receptores Mitogênicos/genética , Receptores Mitogênicos/metabolismo
2.
FEBS Lett ; 250(2): 615-8, 1989 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-2546815

RESUMO

The tumor promoter okadaic acid binds specifically to a particulate as well as a cytosolic fraction of various mouse tissues, e.g., skin, brain, lung and colon. The KD value was 21.7 nM for receptors in the particulate fraction and 1.0 nM for those in the cytosolic fraction of mouse skin. The specific binding of [3H]okadaic acid to the particulate fraction of mouse skin was inhibited dose-dependently by okadaic acid, but not okadaic acid tetramethyl ether, an inactive compound, or by other tumor promoters, such as 12-O-tetradecanoylphorbol-13-acetate and teleocidin. The results suggest a new pathway of tumor promotion mediated through the okadaic acid receptor(s).


Assuntos
Carcinógenos/metabolismo , Éteres Cíclicos/metabolismo , Pele/metabolismo , Animais , Encéfalo/metabolismo , Cromatografia DEAE-Celulose , Colo/metabolismo , Citosol/metabolismo , Pulmão/metabolismo , Camundongos , Ácido Okadáico , Fosfoproteínas Fosfatases/metabolismo , Proteínas Quinases/metabolismo , Pele/enzimologia
3.
Cancer Lett ; 22(2): 151-5, 1984 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6704946

RESUMO

Hyperplastic nodules (HN) of the liver were induced in Charles River Sprague-Dawley rats (CD rats) and ACI rats fed a diet containing 30% bracken for 260 and 180 days, respectively. HN were also induced in high incidence in CD rats fed a diet containing the carcinogenic fractions of bracken extract.


Assuntos
Fígado/efeitos dos fármacos , Extratos Vegetais/toxicidade , Plantas Comestíveis , Animais , Feminino , Hiperplasia/induzido quimicamente , Fígado/patologia , Masculino , Ratos , Ratos Endogâmicos , Fatores Sexuais
4.
Cancer Lett ; 21(3): 239-46, 1984 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6692342

RESUMO

Isolation of the carcinogen in the boiling water extract of bracken fern was conducted by following the active principle with a carcinogenicity bioassay. Fractionation of the bracken extract was carried out using adsorption on resin (Amberlite XAD-2 and TOYOPEARL HW-40 (c] and organic solvent extraction. A diet containing each of the fractions was given to 7 female Charles River Sprague-Dawley rats (CD rats) of 4 weeks old, except for the second fraction. All 7 rats given the last carcinogenic fraction developed mammary and intestinal tumors and 5 rats had urinary bladder tumors. Ptaquiloside (PT) which induced mammary cancer in female CD rats and rho-hydroxystyrene glycosides were isolated from this fraction.


Assuntos
Carcinógenos/isolamento & purificação , Plantas Tóxicas/análise , Animais , Feminino , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Experimentais/induzido quimicamente , Ratos , Ratos Endogâmicos
5.
Toxicon ; 29(11): 1409-12, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1814017

RESUMO

The serologic activities of structurally related okadaic acid derivatives have been determined. Binding of [3H]okadaic acid to rabbit anti-okadaic acid is inhibited with equal effectiveness by okadaic acid, dinophysistoxin-1, acanthifolicin, okadaic acid tetramethyl ether, and okadaic acid spiroketal II. Okadaic acid spiroketal I, which lacks the F- and G-rings of okadaic acid, inhibits serologic binding about 60 times less effectively. The F- and G-rings of okadaic acid may comprise part of the epitopes recognized by some of the polyclonal antibodies.


Assuntos
Éteres Cíclicos/metabolismo , Animais , Especificidade de Anticorpos , Reações Antígeno-Anticorpo , Ligação Competitiva , Éteres Cíclicos/imunologia , Éteres Cíclicos/isolamento & purificação , Ácido Okadáico , Piranos/imunologia , Piranos/isolamento & purificação , Coelhos/imunologia , Radioimunoensaio , Compostos de Espiro/farmacologia
6.
Toxicon ; 26(12): 1123-8, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3266384

RESUMO

An okadaic acid immunogen, prepared by conjugation of okadaic acid to bovine albumin with carbodiimide, was used to immunize two rabbits. The rabbits responded by producing antibodies that neutralized okadaic acid's stimulation of arachidonic acid metabolism and this neutralization increased during the course of immunization. The immune sera bound 3H-okadaic acid and this binding also increased with repeated immunization. After absorption of the rabbit IgG with a goat anti-rabbit IgG, binding was reduced greater than 99%. The binding of okadaic acid to the antibodies in one antiserum was inhibited by as little as 0.2 pmoles of unlabelled okadaic acid. The apparent association constant for binding with this antiserum was 4.17 x 10(9) M-1 (35 degrees C). Maitotoxin, teleocidin, 12-O-tetradecanoylphorbol-13-acetate, aplysiatoxin, palytoxin and brevetoxin B when tested at 29, 228, 168, 169, 3.7 and 112 pmole levels, respectively, did not inhibit binding. The serologic and biological activities of okadaic acid after incubation for 60 min in 0.01 N HCl at 35 degrees C or at 100 degrees C at pH 7.2 were unaffected.


Assuntos
Éteres Cíclicos/análise , Imunoglobulina G/análise , Imunotoxinas/análise , 6-Cetoprostaglandina F1 alfa/biossíntese , 6-Cetoprostaglandina F1 alfa/metabolismo , Formação de Anticorpos , Éteres Cíclicos/imunologia , Éteres Cíclicos/toxicidade , Ácido Okadáico , Radioimunoensaio
7.
Mutat Res ; 143(1-2): 75-8, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-4000145

RESUMO

The genotoxicity of ptaquiloside (PT), recently isolated from bracken fern and shown to be carcinogenic, was examined by means of the hepatocyte primary culture/DNA-repair test. PT elicited clear unscheduled DNA synthesis with a dose-response effect. The result indicates that PT is a genotoxic carcinogen.


Assuntos
Carcinógenos/toxicidade , Reparo do DNA/efeitos dos fármacos , Indanos , Plantas Tóxicas/análise , Sesquiterpenos , Terpenos/toxicidade , Animais , Células Cultivadas , DNA/biossíntese , Relação Dose-Resposta a Droga , Fígado/metabolismo , Masculino , Testes de Mutagenicidade , Ratos , Ratos Endogâmicos ACI
8.
Carbohydr Res ; 197: 15-32, 1990 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-2346947

RESUMO

This study completes the spectroscopic basis for a novel oligosaccharide microanalytical method, wherein a derivatization sequence provides monosaccharide subunits bearing two types of exciton-coupling chromophore groups ("bichromophoric") for circular dichroic spectroscopy, namely 4-bromobenzoate (lambda max 245 nm) and 4-methoxycinnamate (lambda max 311 nm). The 24 possible derivatives of methyl alpha-D-mannopyranoside bearing two chromophore and two acetate groups have been prepared and their c.d. spectra recorded. These spectra have been used to calculate the c.d. curves of the 14 possible tetrachromophic derivatives according to the pairwise additivity rule. The accuracy of these calculations has been demonstrated for six representative derivatives. The c.d. curves obtained here, together with curves of the corresponding D-glucose and D-galactose derivatives, comprise a set of 42 unique and distinctive spectra which can be utilized to identify sugars and their linkage patterns, and thus represent the basis for an alternative to methylation analysis which does not rely upon synthetic standards.


Assuntos
Metilglicosídeos/análise , Metilmanosídeos/análise , Oligossacarídeos/análise , Bromobenzoatos , Configuração de Carboidratos , Cinamatos , Dicroísmo Circular , Microquímica , Padrões de Referência , Estereoisomerismo
9.
J Antibiot (Tokyo) ; 51(3): 275-81, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9589062

RESUMO

New bithiazole-type antibiotics, cystothiazoles A (C20H26N2O4S2) and B (C20H26N2O5S2), have been isolated from a culture broth of the myxobacterium, Cystobacter fuscus. The gross structures of these compounds were elucidated by spectroscopic analysis, and their absolute stereochemistry was determined by chemical degradation of cystothiazole A. Cystothiazole A inhibits fungi and human tumor cells, whereas it is inactive against bacteria. The antifungal activity appears to result from the inhibition of submitochondrial NADH oxidation. Although these compounds are structurally related to the known antibiotic myxothiazol, cystothiazole A was more active against fungi and less cytotoxic than myxothiazol.


Assuntos
Antibacterianos/isolamento & purificação , Myxococcales/metabolismo , Tiazóis/isolamento & purificação , Antibacterianos/química , Antibacterianos/farmacologia , Fermentação , Conformação Molecular , Tiazóis/química , Tiazóis/farmacologia
10.
J Antibiot (Tokyo) ; 54(1): 17-21, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11269710

RESUMO

Clavariopsins were isolated from the fermentation broth of Clavariopsis aquatica AJ 117363. Clavariopsins are cyclic depsipeptide antibiotics with the molecular weight of 1,153 and 1,139. Clavariopsins showed in vitro antifungal activity against not only Aspergillus fumigatus but also, although to a lesser extent, A. niger and Candida albicans.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Depsipeptídeos , Fungos Mitospóricos/metabolismo , Animais , Antibacterianos/química , Antifúngicos/química , Aspergillus niger/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Fermentação , Camundongos , Testes de Sensibilidade Microbiana , Fungos Mitospóricos/classificação , Estrutura Molecular , Peptídeos Cíclicos
11.
J Antibiot (Tokyo) ; 54(1): 22-8, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11269711

RESUMO

The structures of new cyclic decadepsipeptides, clavariopsins A and B, were determined to be cyclo[-(R)-2-hydroxyisovaleryl-L-pipecoyl-L-MeVal-L-Val-L-MeAsp-L-MeIle-L-MeIle-Gly L-MeVal-L-Tyr(OMe)-] and cyclo[-(R)-2-hydroxyisovaleryl-L-pipecolyl-L-Val-L-Val-L-MeAsp-L-Melle-L-MeIle-Gly-L-MeVal-L-Tyr(OMe)-], respectively, by spectroscopic analyses, especially using 2D NMR techniques. The absolute stereochemistry was elucidated by the advanced Marfey's method and chiral HPLC analysis.


Assuntos
Antibacterianos/química , Fungos Mitospóricos/metabolismo , Peptídeos , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Conformação Molecular , Estrutura Molecular
12.
J Vet Med Sci ; 55(6): 979-83, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8117827

RESUMO

The process of occurrence of bright blindness, progressive retinal degeneration (PRD), in sheep was observed using two Suffolk ram lambs fed on a diet containing bracken powder. The first sign of the bright blindness was detected 4 months after the start of experiment. Based on these preliminary results, the amount of bracken powder necessary to induce PRD was estimated (experiment I). In the following experiment, ptaquiloside (PT), a norsesquiterpene glucoside of the illudane type isolated from bracken, which is a bracken carcinogen and a causative principle of cattle bracken poisoning was administered to two Suffolk ram lambs. It was clearly demonstrated in this experiment (experiment II) that PT present in bracken is also a causative principle of PRD.


Assuntos
Ração Animal , Indanos , Intoxicação por Plantas/veterinária , Degeneração Retiniana/veterinária , Sesquiterpenos , Doenças dos Ovinos , Terpenos/toxicidade , Animais , Medula Óssea/patologia , Masculino , Células Fotorreceptoras/patologia , Intoxicação por Plantas/patologia , Retina/patologia , Degeneração Retiniana/etiologia , Degeneração Retiniana/patologia , Ovinos , Terpenos/administração & dosagem , Terpenos/isolamento & purificação
13.
Vet Rec ; 115(15): 375-8, 1984 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-6506412

RESUMO

Acute bracken fern toxicity in a calf was reproduced with ptaquiloside, a norsesquiterpene glucoside, isolated from the boiling water extract of bracken fern. Ptaquiloside was dissolved in 500 ml of saline and administered by drench at increasing dosages for six days out of every seven for the following periods: 400 mg/day for 24 days, 800 mg/day for 14 days and 1600 mg/day for four days. Neutrophilic granulocytes began to decrease markedly around 50 days after the start of the experiment, and granulocytopenia continued for a further 35 days until the autopsy, despite the discontinuance of ptaquiloside administration. Thrombocytes showed a relatively slow depression and reached 1 X 10(5)/mm3 at the lowest level. The calf was autopsied 86 days after the start of administration of ptaquiloside. Sternal bone marrow was found to be mostly replaced with fat marrow and only small foci of erythropoietic cells and a small number of megakaryocytes remained.


Assuntos
Doenças dos Bovinos/etiologia , Indanos , Extratos Vegetais/intoxicação , Intoxicação por Plantas/veterinária , Sesquiterpenos , Terpenos/intoxicação , Agranulocitose/etiologia , Agranulocitose/veterinária , Animais , Bovinos , Feminino , Hemorragia/etiologia , Hemorragia/veterinária , Contagem de Leucócitos/veterinária , Leucocitose/etiologia , Leucocitose/veterinária , Intoxicação por Plantas/etiologia , Trombocitopenia/etiologia , Trombocitopenia/veterinária
14.
Gan To Kagaku Ryoho ; 27(2): 251-5, 2000 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-10700896

RESUMO

In general, the root of a seaweed is poorly developed as compared with its thallus and is called the rhizoid or holdfast. In Laminaria, belonging to Phaeophyceae, although the thallus is used for food, the rhizoid is considered an unuseful natural resource. We attempted to detect anti-breast cancer substances from that resource. As a result, a substance having a weak absorptivity to aluminium oxide and Sephadex G-25 was found. According to analysis of the FAB-MS spectra and 1H NMR spectra, the substance was identified as tryptophan, an amino acid. Finally, it was concluded by a chiral column-HPLC method that the tryptophan was the L-form.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/patologia , Alga Marinha/química , Triptofano/isolamento & purificação , Triptofano/farmacologia , Humanos , Células Tumorais Cultivadas/efeitos dos fármacos
17.
Biosci Biotechnol Biochem ; 63(8): 1501-2, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10501010

RESUMO

A search for neuritogenic compounds in Chinese herbs resulted in the isolation of two known substances, ostruthin and (-)-bornyl ferulate, from Notopterygium incisum (and/or N. forbesii). Both compounds induced comparable neurite-like structures in 20% of rat PC12 cells at 2 micrograms/ml, and showed cytotoxicity at concentrations higher than 3 micrograms/ml.


Assuntos
Ácidos Cumáricos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Umbeliferonas/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Neuritos/efeitos dos fármacos , Células PC12 , Ratos
18.
Bioorg Med Chem ; 9(8): 2171-7, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11504654

RESUMO

Termitomycesphins E and F, novel cerebrosides that are hydroxylated around the middle of the long-chain base (LCB), have been isolated from the edible Chinese mushroom Termitomyces albuminosus (Berk.) Heim. ('Jizong' in Chinese) together with termitomycesphins A-D, and shown to induce neuronal differentiation in rat PC12 cells. Their stereostructures have been determined based on their chemical derivatization and spectroscopic analysis. The major cerebroside obtained from the same mushroom was not hydroxylated around the middle of the LCB and was inactive against PC12 cells, suggesting the importance of the extra hydroxyl group on LCB. The Di- and tetrahydroxylation of this inactive cerebroside resulted in the enhancement of its neuritogenic activity.


Assuntos
Agaricales/química , Cerebrosídeos/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Cerebrosídeos/química , Cerebrosídeos/isolamento & purificação , Hidroxilação , Neurônios/citologia , Neurônios/efeitos dos fármacos , Células PC12 , Ratos
20.
Bioorg Med Chem ; 9(1): 179-83, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11197338

RESUMO

Two novel tetrabrominated benzofuran derivatives, named iantherans A and B, were isolated from an Australian marine sponge of the genus lanthella. The unique structures comprised of 2,3-bis(sulfooxy)-1,3-butadiene and two brominated benzofuran moieties were determined by spectroscopic and chemical methods. Iantheran A has a (Z,Z)-1,3-butadiene moiety, whereas iantheran B is the geometric isomer possessing a (Z,E)-1,3-butadiene moiety. The inhibitory activities of the iantherans and their derivatives against Na,K-ATPase as well as the efficacy of iantheran A against other several enzymes were evaluated.


Assuntos
Benzofuranos/isolamento & purificação , Butadienos/isolamento & purificação , Inibidores Enzimáticos/isolamento & purificação , Fenóis/isolamento & purificação , Poríferos/química , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Animais , Benzofuranos/farmacologia , Butadienos/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Isomerismo , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Fenóis/farmacologia , Poríferos/metabolismo
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