RESUMO
Steroidal glycoalkaloids of many Solanum species have recognized biological activities, especially those containing the glycosyl moiety alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->4)]-D-glucopyranose (chacotriose) whose peracetate is here synthesized and characterized by complete 1H and 13C NMR assignment.
Assuntos
Ácido Peracético/síntese química , Solanina/análogos & derivados , Tropanos/síntese química , Configuração de Carboidratos , Sequência de Carboidratos , Dados de Sequência Molecular , Extratos Vegetais/síntese química , Alcaloides de Solanáceas/química , Solanina/química , Solanum tuberosum/químicaRESUMO
The crystal structure of the title compound, C30H48O3, a triterpene extracted from the resin of Protium crenatum Sandwith, is reported. The aliphatic acidic side chain is attached to the tirucallene four-ring system on its alpha-face and is extended by 7.248 (5) A in the 'left-hand' orientation.
Assuntos
Árvores/química , Triterpenos/química , Cristalografia por Raios X , Ligação de Hidrogênio , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Extratos Vegetais/química , Plantas Medicinais/químicaRESUMO
The glycoalkaloids alpha-chaconine, alpha-solamargine, alpha-solanine, solasonine, sycophantine, and tomatine, as well as the aglycones demissidine, solanidine, solanocapsine, solasodine, tomatidine, and veratrine were tested as growth inhibitors of Trypanosoma cruzi, strain EP, in LIT medium. Their activity was compared with the antifungal ketoconazole. Glycoalkaloids containing alpha-chacotriose showed trypanolytic activity against the epimastigote form and trypanocidal activity against the bloodstream and metacyclic trypomastigote form of Trypanosoma cruzi in culture medium in micromolar concentrations. Ketoconazole showed a lower activity, at the same concentrations of alpha-chaconine and alpha-solamargine. The observations indicate that the initial target of the compound is at the membrane level with a concomitant change in the parasite morphology. Moreover, internal compartments of the parasites were observed to be affected by the drugs, revealing the dissolution of some organelles as mitocondrias and glycosomes.
Assuntos
Alcaloides/farmacologia , Cetoconazol/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Alcaloides/química , Animais , Sequência de Carboidratos , Camundongos , Dados de Sequência Molecular , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
This study consists of the synthesis, separation, and stereochemical analysis of oximino ethers, followed by a preliminary pharmacological evaluation for neuromuscular blockade. Synthesis of the compounds began with the double oximation of progesterone, which yielded EE and ZE dioximes as major products. Both stereoisomers were separated and purified by chromatography followed by crystallization. The diether of each dioxime was prepared by O-alkylation with 2-dimethylaminoethyl chloride hydrochloride, using a mixture of potassium tert-butoxide and sodium hydride as base. The diethers were separated from the monoethers by vacuum chromatography. Configurational assignments of all compounds were based on 1HNMR and 13CNMR spectroscopy. Quaternization with methyl bromide yielded the salts which were purified via fractional crystallization. A preliminary pharmacological evaluation was conducted by using mice on a treadmill apparatus. Structure-activity relationships are discussed on the basis of similarities to succinylcholine.