RESUMO
The enzymatic glucose cleavage of palicoside revealed the biosynthetic pathway to akagerine, whereas the conversion of dolichantoside led to a new quaternary heteroyohimbine alkaloid named N(b)-methyl-21-beta-hydroxy-mayumbine. The hypothetical models of reactions occurring after the conversion of both substrates are proposed. Dolichantoside and palicoside, as well as Strychnos mellodora stem bark crude ethanol extract, exhibit significant antimycotic activity against human pathogens in presence of specific glucosidase.
Assuntos
Alcaloides/metabolismo , Glucosidases/metabolismo , Monossacarídeos/metabolismo , Aspergillus niger/metabolismo , Candida/metabolismo , Cinética , Análise EspectralRESUMO
Two new quaternary alkaloids, 9-methoxy-Nb-methylgeissoschizol and guiachrysine together with the known compounds C-alkaloid O, fluorocurine, mavacurine, macusine B and C-profluorocurine, were isolated from Strychnos guianensis stembark. The structures of the compounds were elucidated on the basis of spectroscopic studies.
Assuntos
Alcaloides/isolamento & purificação , Indóis/isolamento & purificação , Fármacos Neuromusculares/isolamento & purificação , Plantas Medicinais/química , Alcaloides/química , Alcaloides/toxicidade , Animais , Técnicas In Vitro , Indóis/química , Indóis/toxicidade , Potenciais da Membrana/efeitos dos fármacos , Camundongos , Fármacos Neuromusculares/química , Fármacos Neuromusculares/toxicidade , Junção Neuromuscular/efeitos dos fármacos , Junção Neuromuscular/fisiologia , Caules de Planta/química , Ranidae , América do SulRESUMO
Two new quaternary indole alkaloids 5',6'-dehydroguiachrysine (1) and 5',6'-dehydroguiaflavine (2) were isolated from Strychnos guianensis stem bark. Their structures were determined by analysis of spectral data. Their inhibitory effects on neuromuscular transmission are also reported and compared to that of other quaternary alkaloids.
Assuntos
Alcaloides/isolamento & purificação , Indóis/isolamento & purificação , Loganiaceae/química , Caules de Planta/química , Alcaloides/química , Indóis/química , Estrutura Molecular , Análise EspectralRESUMO
The reinvestigation of Strychnos nux-vomica resulted in the isolation of a colored monoquaternary bisindole alkaloid from the roots. The structure of this new orange substance, strychnochrysine (1), was defined by detailed spectroscopic methods.
RESUMO
A reinvestigation of Strychnos guianensis resulted in the isolation of a colored quaternary bisindole alkaloid from the stem bark. The structure of this new substance, guiaflavine (1), was defined by detailed spectroscopic methods and comparison with model compounds.
Assuntos
Indóis , Quinolizinas/isolamento & purificação , Estricnina/análogos & derivados , Árvores , Animais , Cromatografia em Camada Fina , Masculino , Camundongos , Extratos Vegetais/química , Quinolizinas/toxicidade , América do Sul , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Estricnina/isolamento & purificação , Estricnina/toxicidadeRESUMO
Reinvestigation of Strychnos usambarensis Gilg resulted in the isolation of a tertiary phenolic bisindole alkaloid, 10'-hydroxyusambarensine (1), which was identified by detailed spectroscopic methods. Compound 1 was moderately active against two strains of Plasmodium falciparum in vitro.
Assuntos
Alcaloides/farmacologia , Antimaláricos/farmacologia , Indóis/farmacologia , Plantas Medicinais/química , Alcaloides/química , Alcaloides/isolamento & purificação , Animais , Antimaláricos/química , Antimaláricos/isolamento & purificação , Humanos , Técnicas In Vitro , Indóis/química , Indóis/isolamento & purificação , Espectroscopia de Ressonância Magnética , Raízes de Plantas/química , Plasmodium falciparum/efeitos dos fármacos , Ruanda , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , TanzâniaRESUMO
Reinvestigation of Strychnos icaja Baillon resulted in the isolation of vomicine, isostrychnine and of three new sungucine derivatives, named isosungucine (8), 18-hydroxy-sungucine (9) and 18-hydroxy-isosungucine (10). They were identified by detailed spectroscopic methods. The complete 1H- and 13C-NMR study of sungucine was also realized. Some of these compounds were highly active against Plasmodium falciparum in vitro and more particularly against the chloroquine-resistant strain. Compound 10 showed a selective antiplasmodial activity, with > 100-fold greater toxicity towards Plasmodium falciparum, relative to cultured human cancer cells (KB and HeLa lines) or fibroblasts (WI38).
Assuntos
Alcaloides/isolamento & purificação , Antimaláricos/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Indóis/isolamento & purificação , Plantas Medicinais/química , Alcaloides/química , Alcaloides/farmacologia , Animais , Antimaláricos/química , Antimaláricos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Indóis/química , Indóis/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Células Tumorais CultivadasRESUMO
A reinvestigation of Strychnos icaja roots has resulted in the isolation of two tertiary quasi-symmetric bisindole alkaloids named strychnogucines A (1) and B (2). Their structures were identified by means of spectroscopic data interpretation. Compound 2 was highly active in vitro and compound 1 moderately active against four strains of Plasmodium falciparum. Strychnogucine B (2) was more active against a chloroquine-resistant strain than against a chloroquine-sensitive one (best CI(50), 80 nM against the W2 strain). In addition, this compound showed a selective antiplasmodial activity with 25-180 times greater toxicity toward P. falciparum, relative to cultured human cancer cells (KB) or human fibroblasts (WI38).