RESUMO
A new sucrose ester, acretoside, has been isolated from the roots of the Greek endemic species Aristolochia cretica and identified as 6-O-p-coumaroyl-beta-D-fructofuranosyl-(2 --> 1)-alpha-D-glucopyranoside (1). In addition, a known sucrose ester, identified as arillatose B, two phenylpropanoid glucose esters, and five derivatives of aristolochic acids have been isolated. Their structures have been elucidated on the basis of MS and NMR data.
Assuntos
Aristolochia/química , Cumarínicos/isolamento & purificação , Ésteres/isolamento & purificação , Glicosídeos/isolamento & purificação , Sacarose/análogos & derivados , Cumarínicos/química , Ésteres/química , Glicosídeos/química , Grécia , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Raízes de Plantas/química , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Sacarose/química , Sacarose/isolamento & purificaçãoRESUMO
The chemical composition of the essential oils obtained from the aerial parts of Nepeta camphorata and Nepeta argolica ssp. dirphya were analysed by GC-MS. A total of 52 components were identified and significant differences (qualitative and quantitative) were observed between the two samples. 1,8-Cineol and two nepetalactones were found to be the major components of the oil of N. camphorata and N. argolica ssp. dirphya respectively. The in vitro activity, of the two oils and the three above mentioned isolated compounds, against 25 clinically isolated and commercial strains of Helicobacter pylori was investigated and some activity was found.
Assuntos
Helicobacter pylori/efeitos dos fármacos , Monoterpenos , Nepeta , Óleos Voláteis/farmacologia , Cicloexanóis/química , Cicloexanóis/isolamento & purificação , Cicloexanóis/farmacologia , Monoterpenos Ciclopentânicos , Ciclopentanos/química , Ciclopentanos/isolamento & purificação , Ciclopentanos/farmacologia , Eucaliptol , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis/análise , Óleos Voláteis/química , Estruturas Vegetais/química , Pironas/química , Pironas/isolamento & purificação , Pironas/farmacologia , Terpenos/química , Terpenos/isolamento & purificação , Terpenos/farmacologiaRESUMO
Thermic aromatic nucleophilic displacement of the methoxy group at C-6 of (+/-)-1-oxo-2-hydroxy-1,2-dihydroacronycine (2) by an amine is a reaction that gives a facile entry to acronycine derivatives bearing an amino substituent at this position. The introduction of the amino substituents was confirmed with a long-range 1H-15N correlation NMR spectrum at natural abundance. Under basic conditions, compound 2 can also be rearranged to the corresponding isopropylfuroacridone 12, in 80% yield.
Assuntos
Acronina/química , Acronina/síntese química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/síntese química , Acronina/análogos & derivados , Aminação , Animais , Indicadores e Reagentes , Leucemia L1210/tratamento farmacológico , Espectroscopia de Ressonância Magnética , Espectrometria de MassasRESUMO
The essential oils obtained from the aerial parts of Origanum scabrum and Origaum microphyllum, both endemic species in Greece, were analyzed by means of GC and GC-MS. Forty-eight constituents were identified, representing 98.59 and 98.66% of the oils, respectively. Carvacrol, terpinen-4-ol, linalool, sabinene, alpha-terpinene, and gamma-terpinene were found as the major components. Furthermore, both samples exhibited a very interesting antimicrobial profile after they were tested against six Gram-negative and -positive bacteria and three pathogenic fungi.
Assuntos
Cromatografia Gasosa/métodos , Lamiaceae/química , Óleos Voláteis/análise , Óleos Voláteis/farmacologia , Fungos/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacosRESUMO
In an effort to detect potential inhibitors of cdc25 phosphatase, nineteen flavonoids belonging to the quercetin and kaempferol series have been evaluated, using a colorimetric assay of recombinant human cdc25A tyrosine phosphatase as a cell cycle-specific target. Compounds bearing two benzyl or methyl groups in positions 7 and 4' and acetyl on the hydroxy groups of the sugar moiety showed the maximal activity.
Assuntos
Quinases Ciclina-Dependentes/antagonistas & inibidores , Flavonoides , Quempferóis , Magnoliopsida/química , Quercetina/farmacologia , Fosfatases cdc25/antagonistas & inibidores , Bioensaio , Divisão Celular , Células Cultivadas , Colorimetria , Quinases Ciclina-Dependentes/metabolismo , Escherichia coli/citologia , Humanos , Magnoliopsida/citologia , Fator Promotor de Maturação , Estrutura Molecular , Quercetina/análogos & derivados , Quercetina/química , Fosfatases cdc25/metabolismoRESUMO
A novel macrocyclic dimer lactone, named verbalactone, was isolated from the roots of Verbascum undulatum and exhibited interesting antibacterial activity. It is the first time that 1,7-dioxacyclododecane is reported as the ring system of a natural product. The structure and the absolute stereochemistry of the new compound were determined by spectral methods and chemical correlation.
Assuntos
Antibacterianos/isolamento & purificação , Lactonas/isolamento & purificação , Plantas Medicinais/química , Antibacterianos/química , Antibacterianos/farmacologia , Cromatografia em Camada Fina , Ácidos Decanoicos/química , Ácidos Decanoicos/farmacologia , Enterobacter aerogenes/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Grécia , Klebsiella pneumoniae/efeitos dos fármacos , Lacticaseibacillus casei/efeitos dos fármacos , Lactonas/química , Lactonas/farmacologia , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Conformação Molecular , Estrutura Molecular , Raízes de Plantas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Salmonella enteritidis/efeitos dos fármacos , Espectrofotometria Infravermelho , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacos , EstereoisomerismoRESUMO
The synthesis and antimicrobial activity of ten labdane-type diterpenes derived from ent-3-beta-hydroxy-13-epi-manoyl oxide (ribenol) is reported. The chloroethyl carbamidic ester 9 showed the strongest antimicrobial activity against all the tested gram (+), gram (-) bacteria and pathogenic fungi. Moreover, the glycoside 11 exhibited an interesting activity against the three tested fungi.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Terpenos/síntese química , Terpenos/farmacologia , Anidridos , Ácidos Carboxílicos/síntese química , Ácidos Carboxílicos/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus/efeitos dos fármacosRESUMO
Two alkaloids, furomegistine I (1) and furomegistine II (2), were isolated from the bark of Sarcomelicope megistophylla. Their structures have been elucidated on the basis of MS and NMR data. Both belong to the category of furanopyridine alkaloids and should be considered as oxidation products of a furo[2,3-b]quinoline precursor. The two alkaloids exhibited moderate cytotoxic activity.
Assuntos
Alcaloides/química , Alcaloides/isolamento & purificação , Furanos/química , Furanos/isolamento & purificação , Piridinas/química , Piridinas/isolamento & purificação , Quinolonas/química , Rosales/química , Alcaloides/farmacologia , Fatores Biológicos/química , Fatores Biológicos/isolamento & purificação , Fatores Biológicos/farmacologia , Neoplasias do Colo/tratamento farmacológico , Furanos/farmacologia , Humanos , Concentração Inibidora 50 , Neoplasias Pulmonares/tratamento farmacológico , Espectroscopia de Ressonância Magnética , Oxirredução , Caules de Planta/química , Piridinas/farmacologia , Árvores/química , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
The synthesis and cytotoxic activity of some new 2,2-dimethyl-2H-anthra[2,3-b]pyran-6,11-diones is described. Certain compounds possess interesting activity against murine leukemia L-1210 cells. Relationships between the biological activity and the pyrano-ring conformations are discussed.
Assuntos
Antraquinonas/farmacologia , Antineoplásicos/síntese química , Animais , Antracenos/síntese química , Antracenos/farmacologia , Antraquinonas/síntese química , Antineoplásicos/classificação , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Citometria de Fluxo , Concentração Inibidora 50 , Camundongos , Modelos Moleculares , Piranos/síntese química , Piranos/farmacologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas/efeitos dos fármacosRESUMO
The antimicrobial activity of fifteen semisynthetic labdane-type diterpenes derived from the two major natural compounds 3 and 4 of the resin "ladano" of Cistus creticus is reported. The chloroethyl carbamidic esters 15 and 20 showed the strongest antimicrobial activity against Gram(+), Gram(-) bacteria and pathogenic fungi.
Assuntos
Anti-Infecciosos/química , Bactérias/efeitos dos fármacos , Diterpenos/química , Fungos/efeitos dos fármacos , Rosales/química , Antibacterianos , Anti-Infecciosos/isolamento & purificação , Anti-Infecciosos/farmacologia , Antifúngicos/química , Antifúngicos/farmacologia , Diterpenos/isolamento & purificação , Diterpenos/farmacologia , Grécia , Testes de Sensibilidade Microbiana , Conformação Molecular , Estrutura Molecular , Naftóis/químicaRESUMO
The new flavonoid glycoside stachyspinoside (1), and the three iridoids, 7-O-acetyl-8-epi-loganic acid (2), ajugol (3) and harpagide (4) were isolated from Stachys spinosa. The structures of these compounds were established on the basis of mass spectrometry (ESMS and tandem MS), one- and two-dimensional nuclear magnetic resonance experiments (COSY, COSY LR, HMQC, TOCSY and HMBC) as well as simple chemical derivatization.
Assuntos
Antioxidantes/isolamento & purificação , Flavonoides/isolamento & purificação , Glucosídeos/isolamento & purificação , Glicosídeos/isolamento & purificação , Lamiaceae/química , Plantas Medicinais/química , Piranos/isolamento & purificação , Antioxidantes/química , Antioxidantes/farmacologia , Cromatografia Líquida , Flavonoides/química , Flavonoides/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Glicosídeos/química , Glicosídeos/farmacologia , Grécia , Hidrólise , Concentração Inibidora 50 , Glicosídeos Iridoides , Iridoides , Espectrometria de Massas , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Piranos/química , Piranos/farmacologia , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria UltravioletaRESUMO
A new theoretical method has been developed for recognition and classification of membrane proteins. The method is based on computation of a polar energy surface that can reveal characteristic interaction patterns for individual helices even if crystal or NMR structure coordinates are not available. A protein with N transmembrane helices is described as a set of N vectors that are derived from a Fourier analysis of this polar energy surface computed for each helix. We then derive a polarity difference score (PDS) for any two proteins computed as the root mean square deviation between the respective vector coordinate sets. The score was found to correlate with the degree of structural similarity between the following three protein families for which tertiary structures have been determined: bacteriorhodopsin, rhodopsin, and the cytochrome c oxidase III subunit.
Assuntos
Proteínas de Membrana/química , Algoritmos , Sequência de Aminoácidos , Animais , Bacteriorodopsinas/química , Complexo IV da Cadeia de Transporte de Elétrons/química , Humanos , Modelos Químicos , Modelos Moleculares , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas/química , Rodopsina/química , Alinhamento de Sequência/métodos , Eletricidade Estática , TermodinâmicaRESUMO
The antiviral activity of seven flavonoids, belonging to the kaempferol series, was evaluated against human cytomegalovirus (HCMV) by a rapid method of detection of the immediate-early (IE) antigen, induced by the virus in infected cells. Flavonoids bearing acyl substituents were found to be the most active compounds.
Assuntos
Antivirais/farmacologia , Citomegalovirus/efeitos dos fármacos , Flavonoides , Glicosídeos/farmacologia , Quempferóis , Quercetina/análogos & derivados , Estudos de Avaliação como Assunto , Humanos , Quercetina/química , Quercetina/farmacologiaRESUMO
Two new alkaloids, megistophylline I (1) and megistophylline II (2), were isolated from the bark of Sarcomelicope megistophylla. Their structures have been elucidated on the basis of MS and NMR data.
Assuntos
Alcaloides/isolamento & purificação , Árvores/química , Alcaloides/química , Estrutura Molecular , Análise EspectralRESUMO
The synthesis and pharmacological evaluation of 7-O-(4-O-acetyl-3-iodo-2,3,6-trideoxy-alpha-L-arabino-hexopyranosyl) daunomycinone and 7-O-(3-chloro-2,3,6-trideoxy-4-O-propanoyl-alpha-L-lyxo-hexopyrano syl) daunomycinone are described. Their cytotoxic activity was evaluated against normal and resistant cell lines. Both compounds exhibited activity against the adriamycin resistant cell line KB-A1. These results support the hypothesis that the increased lipophilicity of the sugar part of anthracyclines is associated with their ability to overcome multidrug resistance (MDR).
Assuntos
Antibióticos Antineoplásicos/síntese química , Daunorrubicina/análogos & derivados , Antibióticos Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Daunorrubicina/síntese química , Daunorrubicina/farmacologia , Doxorrubicina/farmacologia , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Genes MDR , Humanos , Espectroscopia de Ressonância Magnética , Células Tumorais CultivadasRESUMO
Two kaempferol coumaroyl glycosides (i.e. platanoside and tiliroside) isolated from the methanolic extract of Platanus orientalis L. buds, were examined for their in vitro cytotoxic activity against a panel of human leukaemic cell lines. Platanoside (1) exhibited cytotoxic activity against most of the cell lines tested, while tiliroside (2) was active against two of the nine tested cell lines. Compound 1, was examined for its effect on the uptake of [(3)H]thymidine as a marker of DNA synthesis. Kaempferol was used as a control. 2000 Academic Press@p$hr Copyright 2000 Academic Press.
RESUMO
Two new alkaloids, megistonine I (1) and megistonine II (2), were isolated from the bark of Sarcomelelicope megistophylla. Their structures, which are derived from the 3-methoxy-4-quinolone basic skeleton, were elucidated on the basis of MS and extensive NMR studies.
Assuntos
Quinolonas/isolamento & purificação , Rosales/química , Alcaloides/química , Alcaloides/isolamento & purificação , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Caules de Planta/química , Quinolonas/químicaRESUMO
We developed a method of predicting the tertiary structures of seven transmembrane helical proteins in triangle lattice models, assuming that the configuration of helices is stabilized by polar interactions. Triangle lattice models having 12 or 11 nearest neighbor pairs were used as general templates of a seven-helix system, then the orientation angles of all helices were varied at intervals of 15 degrees. The polar interaction energy for all possible positions of each helix was estimated using the calculated polar indices of transmembrane helices. An automated system was constructed and applied to bacteriorhodopsin, a typical membrane protein with seven transmembrane helices. The predicted optimal and actual structures were similar. The top 100 predicted helical configurations indicated that the helix-triangle, CFG, occurred at the highest frequency. In fact, this helix-triangle of bacteriorhodopsin forms an active proton-pumping site, suggesting that the present method can identify functionally important helices in membrane proteins. The possibility of studying the structure change of bacteriorhodopsin during the functional process by this method is discussed, and may serve to explain the experimental structures of photointermediate states.
Assuntos
Bacteriorodopsinas/química , Estrutura Secundária de Proteína , Algoritmos , Proteínas de Membrana/químicaRESUMO
Two kaempferol coumaroyl glycosides (i.e. platanoside and tiliroside) isolated from the methanolic extract of Platanus orientalis L. buds, were examined for their in vitro cytotoxic activity against a panel of human leukaemic cell lines. Platanoside (1) exhibited cytotoxic activity against most of the cell lines tested, while tiliroside (2) was active against two of the nine tested cell lines. Compound 1, was examined for its effect on the uptake of [(3)H]thymidine as a marker of DNA synthesis. Kaempferol was used as a control.