RESUMO
OBJECTIVE: To screen the fractions from guava leaf to ascertain the effective anti-diarrhea fraction and to establish the method of quality control. METHODS: A series of samples from guava leaf were prepared through extraction and separation by solvents progressively, and their effect on the mice diarrhea models induced by senna decoction were tested individually; and the constituent correlated with the effect of the samples on the models was determined by HPLC. RESULTS: The effect of the fractions with moderate-polar glucosides from guava leaf was better than that of the other fractions; the effect of the fractions with the glucosides was correlated with the content of the quercetin glucosides in the fractions. CONCLUSION: The fractions with the moderate-polar glucosides is the effective anti-diarrhea fraction of guava leaf; determination of the quercetin glucosides can be used for quality control of guava leaf and its extracts.
Assuntos
Antidiarreicos/farmacologia , Diarreia/patologia , Medicamentos de Ervas Chinesas/química , Folhas de Planta/química , Psidium/química , Quercetina/análise , Animais , Antidiarreicos/química , Antidiarreicos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Diarreia/induzido quimicamente , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Feminino , Masculino , Camundongos , Plantas Medicinais/química , Controle de Qualidade , Quercetina/químicaRESUMO
OBJECTIVE: To study the extraction of quercetin in guava leaf by microemulsion. METHODS: The optimal component proportion was obtained by investigating the ratio of oil, water, surfactant and cosurfactant. The extraction of quercetin in microemulsion was determined by HPLC which compared with the traditional method. RESULTS: The traditional solvent extraction methods were used to extract quercetin in guava leaf, and the content of quercetin extracted with methanol was the highest (4.72 microg/mL). But the contents of quercetin extracted by 72 percent of the microemulsions were higher than methanol, and the extraction by the optimum formulation of microemulsion which consisted of acetoacetate (oil phase) -30% avantin solution (water phase) -RH60 (surfactant) was 2 times as much as that was extracted by methanol (10.43 microg/mL). CONCLUSION: Compared with traditional solvent extraction methods, microemulsion method can effectively improve the extraction rate of quercetin in guava leaf.
