RESUMO
The structure of a water-soluble pectic polysaccharide (PS) isolated from immature onion stick (Allium cepa) was investigated using acid hydrolysis, methylation analysis, periodate oxidation study, and NMR studies ((1)H, (13)C, DQF-COSY, TOCSY, NOESY, ROESY, HSQC, and HMBC). The results of the above experiments indicated that the PS contained d-galactose, 6-O-Me-D-galactose, 3-O-acetyl-D-methyl galacturonate and D-methyl galacturonate in a molar ratio of nearly 1:1:1:1 and possesses a backbone of [â4)-α-D-GalpA6Me-(1â4)-α-D-GalpA6Me-(1â] in which one methyl galacturonate was substituted at O-3 position by an acetyl group and the neighboring methyl galacturonate being substituted at O-2 with a side chain, α-D-Galp-(1â4)-6-O-Me-ß-D-Galp-(1â. The probable structure of repeating unit of the pectic polysaccharide was established as: [formula in text] The pectic polysaccharide showed in vitro splenocyte, thymocyte as well as macrophage activations.
Assuntos
Galactose , Cebolas/química , Pectinas/química , Polissacarídeos/química , Animais , Galactose/análogos & derivados , Galactose/química , Galactose/isolamento & purificação , Galactose/farmacologia , Ativação de Macrófagos/efeitos dos fármacos , Ativação de Macrófagos/imunologia , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Polissacarídeos/imunologia , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Timócitos/efeitos dos fármacos , Timócitos/imunologia , ÁguaRESUMO
A water-soluble polysaccharide (PS-I), isolated from the aqueous extract of the stems of Amaranthus tricolor Linn. (Amaranthus gangeticus L.), was found to consist of L-arabinose, methyl-D-galacturonate, D-galactose, and 3-O-Ac-L-rhamnose in a molar ratio of nearly 1:1:1:1. On the basis of total acid hydrolysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of the PS-I is determined as: -->5)-alpha-L-Araf-(1-->4)-beta-D-Galp-(1-->2)-3-O-Ac-beta-L-Rhap-(1-->4)-alpha-D-Gal-A6Me-(1-->
Assuntos
Amaranthus/química , Polissacarídeos/química , Sequência de Carboidratos , Temperatura Alta , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Extratos Vegetais/química , Caules de Planta/química , Polissacarídeos/isolamento & purificação , ÁguaRESUMO
A water-soluble polysaccharide was isolated from hot aqueous extracts of fruits of Psidium guajava. The polysaccharide was found to contain 2-O-methyl-l-arabinose, 2-O-acetyl-D-galactose, and D-methyl galacturonate in a molar ratio of approximately 1:1:1. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR studies ((1)H, (13)C, TOCSY, DQF-COSY, NOESY, ROESY, HMQC, and HMBC), the structure of the repeating unit of the polysaccharide was established as [carbohydrate structure: see text].