Isolation of polysaccharides from tea and their hypoglycemic activity
- VernacularTitle:茶叶中多糖的分离及降血糖活性的研究
- Author:
Yuanfeng WANG
;
Zhengyu JIN
- Publication Type:Journal Article
- Keywords:
tea;
neutral polysaccharide(NTPS);
acidic polysaccharide(ATPS);
alloxan;
diabetic mice
- From:
Chinese Traditional and Herbal Drugs
1994;0(10):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To isolate water-soluble neutral polysaccharides(NTPS) and acidic polysaccharides(ATPS) from tea,investigate their hypoglycemic effects,and elucidate the relationship between structure and activity.Methods Weak base macroporous anion-exchange resin D315 was used to isolate two kinds of tea polysaccharides NTPS and ATPS based on electric charge of tea polysaccharides.Their monosaccharide compositions were analyzed by gas chromatography and ion chromatography.NTPS and ATPS were further isolated by DEAESepharose FF.Molecular weights of the main fractions were analyzed by HPGPC.The model of diabetic mellitus was established by ip alloxan in mice.The blood samples were collected with tail vein puncture to determine blood glucose.The hypoglycemic activity between neutral and acidic polysaccharides was compared after ig tea polysaccharides for 12 d successively.Results Both NTPS and ATPS were(heteropolysaccharides.) NTPS was mainly composed of neutral polysaccharide and its main monopolysaccharide was D-galactose.NTPS contained 6.82% galacturonic acid.Whereas,ATPS was mainly composed of acidic polysaccharide and contained 33.02% D-galactose,whose neutral polysaccharide was mostly(L-)rhamnose,D-arabinose and D-galactose. The molecular weights of both two kinds of tea polysaccharides were less than 3?10~4.Continuous ig administration of NTPS and ATPS [200 and 400 mg/(kg?d)] for 12 d was found to depress glucose increases in alloxan-dependent diabetic model mice.Conclusion Two different structures of tea polysaccharides NTPS and ATPS are isolated by anion-exchange resin D315 firstly.Both tea polysaccharides show good hypoglycemic effect.
