RESUMO
This paper shows the influence of benzenic groups on the chitosan surface for the separation of bioactive biflavonoids from Rheedia gardneriana leaves The yield of the biflavonoids using chitin modified with benzaldehyde (CH-Bz) as adsorbent in column chromatography was higher than that achieved with silica gel and chitosan. The presence of benzenic groups decreases the polarity of chitosan and consequently the interaction of hydrogen bonding between phenolic hydroxyl (OH) of biflavonoids and amine groups of the adsorbent. Therefore, the separation of these compounds appears to be the result of hydrophobicity and pi-pi interaction among electrons from the aromatic ring in sorbent and biflavonoid molecules.
Assuntos
Biflavonoides/química , Garcinia/química , Benzaldeídos , Biflavonoides/isolamento & purificação , Brasil , Quitosana , Indicadores e Reagentes , Estrutura Molecular , Extratos Vegetais/químicaRESUMO
Heptaldehyde-modified chitosan (heptyl-chitosan, CH-Hp) was investigated as adsorbent for chromatograhic separation of the flavonoids from A. moluccana. The amount of 2"-O-rhamnosylswertisin isolated (30.0 mg) was approx. twice as high as swertisin (17.5 mg). The improved surface hydrophobicity effected by the heptyl groups promoted the separation of flavonoids. From the results obtained, CH-Hp seems to be more suitable for separation of glycosylated flavonoids than other flavonoids. Thus, modified chitosan described here can be used for hydrophobic interaction chromatography as sucessfully illustrated with flavonoids.
Assuntos
Aleurites/química , Flavonoides/química , Oligossacarídeos/química , Folhas de Planta/química , Acetilação , Aldeídos , Sequência de Carboidratos , Quitosana , Cromatografia/métodos , Flavonoides/isolamento & purificação , Indicadores e Reagentes , Dados de Sequência Molecular , Oligossacarídeos/isolamento & purificação , Espectrofotometria Infravermelho/métodosRESUMO
This paper describes a comparative study using different chromatographic supports (fully N-acetylated chitin, chitin and silica gel) to separate the flavonoids swertisin and 2"-O-rhamnosylswertisin from Aleurites moluccana. The results show that the flavonoids have apparently been separated by the hydrogen bond between the stationary phase (chitin and chitin-100) and flavonoids under the conditions studied.