RESUMEN
Six new tirucallane-type triterpenoid saponins, sapimukosides E-J (1-6) were isolated from the roots of Sapindus mukorossi GAERTN. Their structures were elucidated by a combination of spectral and chemical analysis.
Asunto(s)
Sapindus/química , Saponinas/química , Triterpenos/química , Espectroscopía de Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/normas , Conformación Molecular , Raíces de Plantas/química , Estándares de Referencia , Saponinas/aislamiento & purificación , Sensibilidad y Especificidad , Estereoisomerismo , Triterpenos/aislamiento & purificaciónRESUMEN
Two new tirucallane-type triterpenoid saponins, sapimukoside C (1) and sapimukoside D (2), have been isolated from the roots of Sapindus mukorossi Gaetn. Their structures have been determined, on the basis of spectral and chemical analysis, as 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L- arabinopyranosyl-(1-->3)]-beta-D-glucopyranosyl (21,23R)-epoxyl tirucalla-7,24-diene-(21S)-ethoxyl-3 beta-ol (1) and 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-arabinopyranosyl-(1-->3)]- beta-D-glucopyranosyl (21,23R)-epoxyl tirucall-7,24-diene-(21S)-methoxyl-3 beta-ol (2).
Asunto(s)
Fitoterapia , Extractos Vegetales/química , Sapindus , Saponinas/química , Triterpenos/química , Humanos , Espectroscopía de Resonancia Magnética , Raíces de PlantasRESUMEN
Different in vitro free radical generating systems were used to assess the antioxidative activity of aqueous extracts of the five herbal components of Wu-zi-yan-zong-wan, a traditional Chinese medicinal formula with a long history of use for tonic effects. Fructus Rubi [Rubus chingii (Rosaceae) fruits] was found to be the most potent. It was further investigated using the primary rat hepatocyte system. tert-Butyl hydroperoxide (t-BHP) was used to induce oxidative stress. Being a short chain analog of lipid hydroperoxide, t-BHP is metabolized into free radical intermediates by the cytochrome P450 system in hepatocytes, which in turn, initiate lipid peroxidation, glutathione depletion and cell damage. Pre-treatment of hepatocytes with Fructus Rubi extract (50 microg/ml to 200 microg/ml) for 24 h significantly reversed t-BHP-induced cell viability loss, lactate dehydrogenase leakage and the associated glutathione depletion and lipid peroxidation. The amount of reactive oxygen species formed was also decreased as visualized by the fluorescence probe 2',7'-dichlorofluorescin diacetate. These results suggested that Fructus Rubi was useful in protecting against t-BHP-induced oxidative damage and may also be capable of attenuating cytotoxicity of other oxidants.
