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.Highlights► Three polysaccharides were isolated from whole seeds of Cassia obtusifolia. ► They were fractionated by Fehling solution complexing and chromatographic methods. ► CFAA-1 and CFAA-3 were elucidated to be both typical branched galactomannans. ► CFBB2 was shown to be a linear (1 → 4)-α-polygalacturonic acid.

Ganoderma lucidum is an edible and medicinal mushroom used widely in East Asia. In recent years, its spores have been used as a supplement in combination with other forms of antitumor therapies. The cell wall of Ganoderma lucidum spores contains a high amount of polysaccharides. In this study, a neutral polysaccharide, GLSA50-1B, was isolated from sporoderm-broken spores of Ganoderma lucidum, by hot-water extraction, graded ethanol precipitation, anion-exchange chromatography, and gel permeation chromatography. Using sugar compositional analysis, methylation analysis, partial acid hydrolysis, acetolysis, and NMR and ESI-MS spectroscopy, GLSA50-1B was elucidated to be a novel β-d-glucan featured by a 1,6-linked β-d-Glcp backbone with different length of branches consisting of terminal and 1,4-linked Glcp residues, attached to O-4 of alternative Glc residues in the backbone.

A polysaccharide, PGA4-3b, with an average molecular weight of 8.9 kDa estimated by high-performance gel-permeation chromatography (HPGPC), was isolated from radix of Platycodon grandiflorum (Jacq.) A. DC. Using monosaccharide analysis, methylation analysis and NMR spectroscopy, PGA4-3b was elucidated to be a linear poly-(1→4)-α-d-galactopyranosyluronic acid that contains no methyl ester groups. Partial acid hydrolysis of PGA4-3b yielded a series of poly- or oligogalacturonic acids with different degrees of polymerization (DP), that is, 4-3bde, 4-3bde-O-1, 4-3bde-O-2, 4-3bde-O-3, and 4-3bde-O-4. Cell tube formation inhibition tests with human microvascular endothelial cells (HMEC) for antiangiogenesis analysis showed that 4-3bde-O-1 and 4-3bde-O-2, the fractions with higher molecular weights, could inhibit tube formation, while the native PGA4-3b and low molecular weight fraction 4-3bde-O-3 and 4-3bde-O4 are ineffective. Moreover, 4-3bde-O-2 with DP 5-10 impaired cell tube formation in a dose-dependent way, suggesting its potential to be developed as an anti-angiogenesis drug. This is the first time oligogalacturonic acids are reported to show an anti-angiogenesis effect.PGA4-3b, a polygalacturonic acid was isolated from Platycodon grandiflorum. The oligogalacturonans prepared by partial hydrolysis of PGA4-3b showed inhibition on cell tube formation.

A water-soluble polysaccharide, PGAW1, with an average molecular mass of 9.2 kDa determined by high performance gel permeation chromatography (HPGPC), was isolated from radix of Platycodon grandiflorum. Monosaccharide composition analysis indicated that PGAW1 contains Ara and Gal in the molar ratio of 1.42:1.0. Using methylation analysis, partial hydrolysis, endo-1,4-β-d-galactanase digestion, NMR and ESI-MS, PGAW1 was determined to possess a backbone consisting of 1,4- and 1,6-linked galactopyranosyl residues, with branches attached to O-3 of 1,6-linked galactose residues. By the chlorosulfonic acid-pyridine method we produced a sulfated derivative of PGAW1, Sul-w1, with a substitution degree of 1.52. The substitution was at O-6 on 1,4-linked Gal residues according to the 13C NMR spectra. Bioactivity test showed that Sul-w1 could inhibit tube formation by human microvascular endothelial cells (HMEC) in a dose-dependent manner.