RESUMO
From the rhizomes of Dioscorea cayenensis Lam.-Holl (Dioscoreaceae), the new 26- O- beta- D-glucopyranosyl-22-methoxy-3 beta,26-dihydroxy-25( R)-furost-5-en-3- O- alpha- L-rhamnopyranosyl-(1-->4)- alpha- L-rhamnopyranosyl-(1-->4)-[ alpha- L-rhamnopyranosyl-(1-->2)]- beta- D-glucopyranoside ( 1) was isolated together with the known dioscin ( 2) and diosgenin 3- O- alpha- L-rhamnopyranosyl-(1-->4)- alpha- L-rhamnopyranosyl-(1-->4)-[ alpha- L-rhamnopyranosyl-(1-->2)]- beta- D-glucopyranoside ( 3). Their structures were established on the basis of spectral data. Compound 2 exhibited antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis (MICs of 12.5, 12.5 and 25 micro g/mL, respectively) whereas 3 showed weak activity and 1 was inactive.
Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Dioscorea , Fitoterapia , Extratos Vegetais/farmacologia , Esteroides/farmacologia , Antifúngicos/administração & dosagem , Antifúngicos/química , Antifúngicos/uso terapêutico , Humanos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Raízes de Plantas , Esteroides/administração & dosagem , Esteroides/química , Esteroides/uso terapêuticoRESUMO
Fifteen new ursolic and betulinic triterpenoids, bearing various functionalities at C-3 and C-28 were synthesized as potential cytotoxic agents. All compounds were obtained by a hemisynthetic route via ursolic and betulinic acids. Preliminary screening of these compounds on human HT 29 colon cancer cells revealed inhibitory activity for three of them. Beta-D-Glucopyranosyl-3beta-hydroxyurs-12(13)-en-28-oate 1c, 3beta-3-(3-pyridyl)-prop-2-enoyloxyurs-12(13)-en-28-oic acid 1i and the potassium salt of 3beta-cinnamoyloxylup-20(29)-en-28-oic acid 2d demonstrated cytotoxic activity in the micromolar range: 8.0, 45.0 and 8.0 microM, respectively.
Assuntos
Antineoplásicos , Triterpenos , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células HT29 , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Triterpenos Pentacíclicos , Relação Estrutura-Atividade , Triterpenos/síntese química , Triterpenos/química , Triterpenos/farmacologia , Ácido Betulínico , Ácido UrsólicoRESUMO
The aim of this review is to update current knowledge on the betulinic, ursolic and echinocystic acids and their natural and semisynthetic analogs, focussing on their cytotoxic and anti-HIV activities. Then, the last results of the authors' team on unusual semisynthetic derivatives of these triterpenoids will be presented in order to establish structure/activity relationships.
Assuntos
Fármacos Anti-HIV/química , Fármacos Anti-HIV/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Ácido Oleanólico/análogos & derivados , HIV-1/efeitos dos fármacos , Células HT29 , Humanos , Estrutura Molecular , Ácido Oleanólico/química , Ácido Oleanólico/farmacologia , Triterpenos Pentacíclicos , Relação Estrutura-Atividade , Triterpenos/química , Triterpenos/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos , Ácido Betulínico , Ácido UrsólicoRESUMO
The antiplasmodial activity of twelve alkaloids with an aspidospermane skeleton was estimated in vitro on chloroquine-resistant and sensitive strains of Plasmodium falciparum. Seven tetracyclic alkaloids possessing a free ethyl chain such aspidospermine, showed IC50 after incubation for 72 h between 3.2 and 15.4 microM. Moreover, four pentacyclic alkaloids with ethyl chain included in a tetrahydrofuran, such haplocine, showed a reduced activity, with IC50, after 72 h, between 22.6 and 52.6 microM. According to these results, a chloroquine-potentiating experiment was also performed with two of the most active compounds. Isobolograms were obtained and demonstrated a synergic effect of N-formyl-aspidospermidine and aspidospermine when associated with chloroquine. The cytotoxicity and the selectivity index of some alkaloids were also estimated.
Assuntos
Antimaláricos/farmacologia , Aspidosperma , Alcaloides Indólicos/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Quinolinas , Alcaloides/farmacologia , Animais , Antimaláricos/química , Linhagem Celular , Cloroquina/farmacologia , Resistência a Medicamentos , Humanos , Hipoxantina/farmacologia , Alcaloides Indólicos/química , Indóis/farmacologia , Concentração Inibidora 50 , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Relação Estrutura-Atividade , Testes de ToxicidadeRESUMO
Bidentatoside II(1) and chikusetsusaponin V methyl ester (2) are two further triterpene saponins isolated from the roots of Achyranthes bidentata. Chemical and homo and heteronuclear two-dimensional (2D) NMR techniques have led to the structural elucidation of 1 which is a new seco-glycoside of oleanolic acid and the full 1H- and 13C-NMR assignments of 2. These compounds did not show any potentiation of the in vitro cytotoxicity of cisplatin in the HT 29 human colon cancer cell line.
Assuntos
Achyranthes/química , Saponinas/química , Triterpenos/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Células HT29/efeitos dos fármacos , Humanos , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Raízes de Plantas/química , Saponinas/isolamento & purificação , Saponinas/farmacologia , Triterpenos/isolamento & purificação , Triterpenos/farmacologiaRESUMO
The isolation of 14 known triterpenoids and phytosterols from the trunk bark of Maquira coriacea, and complete spectral data of a cardenolide, k-strophanthin-beta (1), are reported.
Assuntos
Cardenolídeos/química , Moraceae , Fitoterapia , Extratos Vegetais/química , Triterpenos/química , Humanos , Espectroscopia de Ressonância MagnéticaRESUMO
Bidentatoside I (1) is a new triterpene saponin bearing an unusual dioxopropionic acid unit, isolated from the roots of Achyranthes bidentata. Structural elucidation was performed mainly by chemical and homo- and heteronuclear 2D NMR techniques. This compound did not show any potentiation of the in vitro cytotoxicity of cisplatin in the HT 29 human colon cancer cell line.
