Structure and antioxidant activity of a novel polysaccharide derived from Amanita caesarea.

A heteropolysaccharide was isolated from the fruiting bodies of Amanita caesarea using a diethylaminoethyl-cellulose column, Sephacryl S­300 gel column and Sephadex G­200 column. The Amanita caesarea polysaccharide was predominantly composed of α-D-glucose and α-D-lyxose at a ratio of 2:1, and it had a molecular weight of 19,329 Da. The structural features of the Amanita caesarea polysaccharide were investigated by a combination of total hydrolysis, methylation analysis, gas chromatography-mass spectrometry, and infrared spectra and nuclear magnetic resonance spectroscopy. The results showed that Amanita caesarea polysaccharide (termed AC­1) had a backbone of 1,4­linked α­D­glucose and 1,3,6­linked α­D­glucose, with branches of one 1­linked α­D­lyxose residue. The antioxidant activity of AC­1 was evaluated by two biochemical methods, 2,2-azino-bis diammonium (ABTS+) radical scavenging activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH-) radical scavenging activity. The uncontrolled production of free radicals is involved in various diseases, including cancer, atherosclerosis and degenerative aging processes. The results indicated that the Amanita caesarea polysaccharide exhibits strong antioxidant activity, thus, it may be a useful natural product antioxidant.

Structure elucidation and anti-tumor activities of water-soluble oligosaccharides from Lactarius deliciosus (L. ex Fr.) Gray.

BACKGROUND: Oligosaccharides are composed of a variable number of monosaccharide units and very important in the biologically diverse of biological systems. MATERIALS AND METHODS: Crude water-soluble oligosaccharide was extracted from the fruiting bodies with water and then successively purified by DEAE-cellulose 52 and Sephadex G-100 column chromatography, yielding one major oligosaccharides fractions: LES-A. Structural features of Lactarius deliciosus (L. ex Fr.) Gray oligosaccharide (LDGO-A) were investigated by a combination of monosaccharide component analysis by thin layer chromatography, infrared spectra, nuclear magnetic resonance spectroscopy, scanning electron microscopy, and high-performance gel permeation chromatography analysis. RESULT: The results indicated that LDGO-A was composed of D-glucose and D-xylose, and the average molecular sizes was approximately 945 Da. The anti-tumor activity of LDGO-A was evaluated in vivo. The inhibitory rate in mice treated with 40 mg/kg LDGO-A can reach 40.02%, being the highest in the three doses, which may be comparable to mannatide. Histology of immune organs shows that the tissues arranged more regular and firmer, but the tumor tissue arranged looser in LDGO-A group than those in the control group. Meanwhile, there is no obvious damage to other organs, such as heart. The anti-tumor activity of the LDGO-A was usually believed to be a consequence of the stimulation of the cell-mediated immune response because it can significantly promote the lymphocyte and macrophage cells in the dose range of 100-400 µg/mL in vitro. LDGO-A also effected the expression of some housekeeping genes mRNA in S180 tumor. CONCLUSION: Accordingly, the LDGO-A might serve as an effective healthcare food and source of natural anti-tumor compounds.

Structure elucidation, anticancer and antioxidant activities of a novel polysaccharide from Gomphus clavatus Gray.

A novel heteropolysaccharide from the fruiting bodies of Gomphus clavatus Gray was isolated through Sephadex G-200 and DEAE-cellulose columns. The Gomphus clavatus Gray polysaccharide (GCG-1) was mainly composed of ß-D-glucosepyranose (ß-D-Glu) and α-D-galactopyranose (α-D-Gal) in a ratio of 3:2 and had a molecular weight of ~50,000 Da. The structure of GCG-1 was investigated by a combination of total hydrolysis, gas chromatography-mass spectrometry, methylation analysis, nuclear magnetic resonance spectroscopy and infrared spectra. The results indicated that GCG-1 had a backbone of (1 → 4)-ß-D-glucosepyranose residues with branches at O-6 and the branches consisted of two with (1 → 3)-α-D-galactopyranose residue. Antioxidation test in vitro showed that it possessed strong free radical scavenging activity, which may be comparable to vitamin C and butylated hydroxytoluene. GCG-1 also induced the apoptosis of HepG-2 cells and affected the mRNA expression of various housekeeping genes in the HepG-2 cells. The results indicated that Gomphus clavatus Gray may be an ideal sources for antioxidant and anticancer agents.