title: Isolation and structural characterization of the water-extractable polysaccharides from Cassia obtusifolia seeds.
abstract: The seed of Cassia obtusifolia is a food or herbal medicine used for improving eyesight, treating constipation and other disorders, and polysaccharides have been implicated in these pharmacological activities. The endosperm of the seeds, Cassia gum, is a commercial thickening or gelling agent, composed mainly of galactomannans. However, the whole seeds of C. obtusifolia, rather than the endosperm, are used in folk medicine or food, which might contain more complex constituents of polysaccharides. In this study, the whole seeds of C. obtusifolia were extracted with boiling water, and from the water extract, three homogeneous fractions were isolated, designated CFAA-1, CFAA-3, and CFBB2, respectively, after treatment with Fehling solution followed by anion-exchange and gel permeation chromatography. Using chemical and spectroscopic methods, CFAA-1, and CFAA-3 were elucidated to be both branched galactomannans with different molecular weights, consisting of 1,4-linked β-d-mannopyranosyl backbone with single-unit α-d-galactopyranosyl branches attached to O-6 of mannose, while CFBB2 was shown to be a linear (1→4)-α-polygalacturonic acid.
authors: Glycochemistry and Glycobiology Lab, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China.
authors: Mingsheng
authors: M
authors: Shang
authors: Xiaoman
authors: X
authors: Zhang
authors: Qun
authors: Q
authors: Dong
authors: Jian
authors: J
authors: Yao
authors: Qin
authors: Q
authors: Liu
authors: Kan
authors: K
authors: Ding
mesh_terms: D002366:Cassia / Q000737:chemistry*; D005690:Galactose / Q000031:analogs & derivatives; D006868:Hydrolysis; D008351:Mannans / Q000737:chemistry / Q000302:isolation & purification; D008954:Models, Biological; D008970:Molecular Weight; D019906:Nuclear Magnetic Resonance, Biomolecular; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D010946:Plants, Medicinal; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification*; D012639:Seeds / Q000737:chemistry*; D014783:Viscosity; D014867:Water / Q000494:pharmacology*
chemical_list: D008351:Mannans; D010936:Plant Extracts; D011134:Polysaccharides; D014867:Water; C012990:galactomannan; D005690:Galactose