RESUMEN
The aim of the present work is to isolate a series of triterpene derivatives with rhamnosyl linking acetyl groups from Glechoma longituba according to the structural characteristics of previously described triterpene saponins. The extract ion chromatography spectrum of the crude extract of G.â longituba was detected and analyzed by HPLC-HR-ESI-MS to determine possible components, and these metabolites were traced and separated by combining high-resolution mass spectrometry and predicted liquid chromatography retention time. Three 11α, 12α-epoxypentacyclic oleanolic acid triterpene saponins (glechomanosidesâ H-J) and one ursane triterpene aldehyde saponin with a C-28 aldehyde group were isolated from G.â longituba. The structure of these compounds was confirmed by NMR and compared with those of previously characterized compounds. The strategy described in this report enables a rapid, reliable, and complete analysis of glycoside compounds containing different numbers of acetyl groups at different positions on the sugar.
Asunto(s)
Lamiaceae/química , Extractos Vegetales/análisis , Ramnosa/análisis , Saponinas/análisis , Triterpenos/análisis , Acetilación , Cromatografía Líquida de Alta Presión , Conformación Molecular , Extractos Vegetales/metabolismo , Ramnosa/metabolismo , Saponinas/metabolismo , Espectrometría de Masas en Tándem , Triterpenos/metabolismoRESUMEN
Two novel binaphthyl compounds have been synthesized for the selective fluorescent recognition of Ca(2+) or Pb(2+). By introducing different terminal groups to the receptor unit, the fluorescence signals of the receptors are significantly changed: 1 is fluorescence enhancement for Ca(2+), 2 is fluorescence quenching for Pb(2+). The binding properties for metal ions were examined by the absorption and fluorescence spectra. The fluorescence intensity enhancement was ascribed to the complex formation between Ca(2+) and 1 which blocked the photo-induced electron transfer process.
