title: Structure characterization of an arabinogalactan from green tea and its anti-diabetic effect.
abstract: A water-soluble polysaccharide, 7WA, with an average molecular mass of 7.1×10(4)Da, was isolated from the leaves of green tea. Monosaccharide composition analysis indicated that 7WA mainly contained Arabinose and Galactose in the molar ratio of 1.0:0.96. By using the methods of methylation analysis, partial hydrolysis, and NMR, 7WA was characterized to possess a backbone consisting of 1,3- and 1,6-linked galactopyranosyl residues, with branches attached to O-3 of 1,6-linked galactose residues, and O-4 and O-6 of 1,3-linked galactose residues. The results of glucose-stimulated insulin secretion (GSIS) showed that 7WA significantly augmented insulin secretion at high glucose level (25mM), however, such effect was not seen at low glucose level (5mM). The mechanism study results indicated 7WA, a type II arabinogalactan from Green Tea, enhances GSIS through cAMP-PKA pathway.
authors.affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, PR China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Wang
authors.affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, PR China.
authors.forename: Songshan
authors.initials: S
authors.lastname: Shi
authors.affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Bao
authors.affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, PR China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Li
authors.affiliation: The MOE Key Laboratory for Standardization of Chinese Medicines and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Shanghai 201203, PR China. Electronic address: shunchunwang@126.com.
authors.forename: Shunchun
authors.initials: S
authors.lastname: Wang
mesh_terms: D000818:Animals; D005685:Galactans / Q000737:chemistry* / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000737:chemistry* / Q000494:pharmacology*; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects; D015394:Molecular Structure; D051381:Rats; D013662:Tea / Q000737:chemistry*
chemical_list: D005685:Galactans; D007004:Hypoglycemic Agents; D007328:Insulin; D013662:Tea; C005653:arabinogalactan
keywords: Anti-diabetic; Arabinogalactan; Camellia sinensis; Glucose-stimulated insulin secretion (GSIS); Green tea; cAMP-PKA pathway