Biomedical subjects

Ji-Nian Fang

Publications and source records attributed to Ji-Nian Fang.

11 recordsLinked to original sources

PubMed2006

A beta-D-glucan isolated from the fruiting bodies of Hericium erinaceus and its aqueous conformation.

HEP3, a beta-D-glucan slightly soluble in water, was isolated from the alkaline extract of the fruiting bodies of Hericium erinaceus. Its chemical structure was investigated by methylation analysis, periodate oxidation, Smith degradation and by IR and NMR spectroscopy. It was shown to have a main chain composed of beta-(1-->3)-linked D-glucopyranosyl residues, with single unit glucosyl branches attached to O-6 of every third backbone residue. Viscometry and Congo red reaction indicated that HEP3 has a highly ordered hydrogen-bond dependent conformation in aqueous solution, which collapses in strong alkaline solution.

Carbohydrate Conformation↗

PubMed2005

[Isolation, purification and structural analysis of a polysaccharide MDG-1 from Ophiopogon japonicus].

AIM: To separate and purify the anti-myocardial ischemic polysaccharide fraction with a homogenous molecular weight from Ophiopogon japonicus, then study the chemical structure of the parts. METHODS: Crude polysaccharides were prepared by extracting the tube root fraction of Ophiopogon japonicus with water, then precipitation with ethanol. From the crude polysaccharides, the polysaccharide of MDG-1 was separated and purified using ultrafiltration, DEAE Sepharose FF and Sephadex G-25 column chromatography. Its structure was studied by complete hydrolysis, periodate oxidation, Smith degradation, methylation analysis, 1H NMR and 13C NMR analysis etc. RESULTS AND CONCLUSION: MDG-1 was a water-soluble beta-D-fructosan, containing a backbone composed of Fruf (2 --> 1), and a branch of Fruf (2 --> 6) Fruf (2 --> per average 2. 8 of main chain residues. Mn, Mw and Mp of MDG-1 were 3 400, 4 800 and 5 000, respectively. MDG-1 contains trace of Glc, which maybe connect to its reducing terminal. Molar ratio of Fru and Glc is approximately 35: 1.

Methylation↗

PubMed2004

Characterization of polysaccharides from the flowers of Nerium indicum and their neuroprotective effects.

Degeneration of neurons is a key problem in Alzheimer's disease (AD) and neuroprotection is a possible way to safeguard neurons from neurodegeneration. Polysaccharides isolated from Chinese medicinal herbs have been investigated extensively for their anti-tumor and immune stimulating effects. Yet, little is known about the effects of polysaccharides in neurons. Recently, two pure polysaccharides isolated from the flowers of Nerium indicum were shown to stimulate proliferation and differentiation of PC12 pheochromocytoma cells, an effect similar to that observed from nerve growth factor. In this notion, it is hypothesized that polysaccharides isolated from the flowers of N. indicum could exhibit beneficial effects in neurons. In this study, we isolated, characterized and investigated two new polysaccharides from the flowers of N. indicum for their neuroprotective effects on neurons against serum-deprivation and beta-amyloid (Abeta) peptide toxicity in primary rat cortical neuronal cultures. Pretreatment of the polysaccharides significantly reduced the number of apoptotic neurons revealed by DAPI staining when neurons were exposed to serum-free medium. Besides, the polysaccharides could also decrease the activity of caspase-3 triggered by Abeta peptides. Western blot analysis indicated that polysaccharides stimulated the phosphorylation of PDK-1 (Serine 241) and Akt (Threonine 308). In conclusion, the polysaccharides J2, J3 and J4 isolated from N. indicum provide a lead for future development of neuroprotective agent against neuronal death in neurodegenerative diseases and the neuroprotective mechanism may primarily rely on activation of Akt survival signaling pathway.

Animals↗

PubMed2003

Structure and potential immunological activity of a pectin from Centella asiatica (L.) Urban.

S3A was a RG-I pectin isolated from Centella asiatica that contained Rha, Ara, Gal, Glc and GalA in molar ratio of 1.0:0.6:1.5:0.2:1.1 and had been found to have a backbone composed mainly of the disaccharide repeat unit, -->4)-alpha-D-GalpA-(1-->2)-alpha-L-Rhap-(1-->. Based on methylation analysis, NaIO4 oxidation, partial acid hydrolysis and lithium-treatment, the structural features were elucidated. Side chains of S3A were predominantly linked to O-4 of 1,2,4-linked alpha-L-Rhap. The side chains are comprised of arabinosyl chains, galactosyl chains, arabinogalactosyl chains and short glucosyl chains. A total of 45% Rhap in the backbone was substituted by side chains. The arabinosyl residues were mostly distributed in the arabinosyl side chains. According to the immunological results of S3A and its degraded derivatives, S3A had no immunological activity, but its derivatives had immuno-stimulating activities to some extent.

Animals↗

PubMed2003

Characterization of a rhamnogalacturonan and a xyloglucan from neriumindicum and their activities on PC12 pheochromocytoma cells.

Two polysaccharides, a rhamnogalacturonan (J1) and a xyloglucan (J2), were isolated and purified from the whole flowers of Nerium indicum and characterized by GC, GC-MS, NMR, and ESMS. The rhamnogalacturonan was found to consist of repeating units of a linear trisaccharide with the structure [-->4)-alpha-GalpA(1-->2)alpha-Rhap(1-->4)-alpha-GalpA(1-->4)-](n)(), while the xyloglucan consisted of repeating units of the trisaccharide, which was (1-->4)-linked beta-glucopyranosyl residues as a backbone and substituted at position 6 linked to terminal alpha-xylopyranose side chains. These two polysaccharides were tested on the proliferation and differentiation on PC12 pheochromocytoma cells and found to have effects similar to nerve growth factor (NGF).

Animals↗

PubMed2002

Structural features of immunologically active polysaccharides from Ganoderma lucidum.

Three polysaccharides, two heteroglycans (PL-1 and PL-4) and one glucan (PL-3), were solubilized from the fruit bodies of Ganoderma lucidum and isolated by anion-exchange and gel-filtration chromatography. Their structural features were elucidated by glycosyl residue and glycosyl linkage composition analyses, partial acid hydrolysis, acetolysis, periodate oxidation, 1D and 2D NMR spectroscopy, and ESI-MS experiments. The data obtained indicated that PL-1 had a backbone consisting of 1,4-linked alpha-D-glucopyranosyl residues and 1,6-linked beta-D-galactopyranosyl residues with branches at O-6 of glucose residues and O-2 of galactose residues, composed of terminal glucose, 1,6-linked glucosyl residues and terminal rhamnose. PL-3 was a highly branched glucan composed of 1,3-linked beta-D-glucopyranosyl residues substituted at O-6 with 1,6-linked glucosyl residues. PL-4 was comprised of 1,3-, 1,4-, 1,6-linked beta-D-glucopyranosyl residues and 1,6-linked beta-D-mannopyranosyl residues. These polysaccharides enhanced the proliferation of T- and B-lymphocytes in vitro to varying contents and PL-1 exhibited an immune-stimulating activity in mice.

Adjuvants, Immunologic↗

PubMed2002

Purification, characterization, and modification of T lymphocyte-stimulating polysaccharide from spores of Ganoderma lucidum.

The hot-water extract of the spores of Ganoderma lucidum was shown to have a stimulating effect on concanavalin A-induced mitogenic activity of T lymphocytes. Bioassay-guided separation led to the isolation of a polysaccharide with potent T lymphocyte-stimulating activity by ethanol fractionation, anion-exchange, and size-exclusion chromatography. Based on the composition and methylation analyses, periodate oxidation, Smith degradation, and NMR spectroscopy, the native polysaccharide was shown to be a beta-D-(1-->3)-glucan with branches of terminal glucosyl residues substituted at C-6 of the glucose residues in the main chain. The branching ratio is approximately 20%. A series of sulfated or carboxymethylated derivatives were prepared and their structural features were elucidated by chemical and spectral analyses. The solution conformation and T lymphocyte proliferation effect of the glucans before and after derivatization were compared and discussed. The data obtained indicate that the introduction of ionic groups would significantly affect the original conformation of the native glucan in aqueous solution and further affect T lymphocyte-stimulating activity. The triple-helical structure of the glucans, the nature of the ionic groups, and the density of negative charge were considered to be closely related to this activity.

Animals↗

PubMed2002

Structural characterization and biological activities of SC4, an acidic polysaccharide from Salvia chinensis.

AIM: To study the chemical characterization and some biological activities of an acidic polysaccharide, named SC4 from Salvia chinensis. METHODS: Chemical and spectral methods were employed to identify the structural characterization of SC4. Effect of SC4 on the proliferation of T- and B-lymphocytes both in vivo and in vitro was measured at various concentrations, and the protective effects of SC4 on PC12 cells against H2O2-induced injury was observed. RESULTS: SC4 was a highly branched polysaccharide with mean molecular weight of 4.5 10(5), composed of Rha, Xyl, Ser, Gal, and GalA in the molar ratio of 1.0 7.0 5.3 1.2 4.2. Methylation analysis and NMR identified the linkages of the residues of SC4. SC4 increased the B-lymphocyte proliferation and spleen weight remarkably while no obvious changes were examined in T-lymphocyte proliferation, thymus weight, and the level of IgG and C3 in blood of mice. Moreover, SC4 enhanced the PC12 cells viability after H2O2 treatment. CONCLUSION: SC4, the acidic polysaccharide with complicated structure, was a B-lymphocyte stimulator and protected PC12 cells at the concentration of 20 mg/L against H2O2-induced injury.

Adjuvants, Immunologic↗

PubMed2000

Structure and Conformation Behavior of a Glucan from Spores of Ganoderma lucidum (Fr.) Karst.

A novel polysaccharide designated as beta-D-glucan LB-NB, [alpha](D)(21) -24.52(0)(c =0.81, H(2)O)and Mr 4.7x10(4), was isolated and purified from a 0.5 mol/L sodium hydroxide extract of the sporoderm-broken spores of Ganoderma lucidum. The results of NMR experiments, total hydrolysis, methylation analysis and Smith degradation of LB-NB showed that it possesses a backbone consisting of(1right curved arrow 3)- beta-D-glucosyl residues, about two out of nine glucosyl residues being substituted at O-6 by single glucosyl groups. The conformational behavior of LB-NB was studied. Measurements by specific rotations and viscometry showed that the glucan LB-NB takes an ordered structure in water or lower concentration(<0.05 mol/L)alkaline solution and dissolves as random coil in higher concentration(>0.1 mol/L)alkaline solution or in dimethyl sulfoxide(Me(2)SO). The ordered conformation melts into flexible chains with the increase of the concentration of alkali or the V(DMSO)(v/v)of H(2)O-Me(2)SO mixture. The former dissociation is reversible and the later is irreversible. The complex-formation with Congo red indicated that the LB-NB takes neither triple-stranded helical nor randomly coiled conformation in neutral or slightly alkaline solution, and most probably, it should contain single helical structure in aqueous solution. According to immunological test, the LB-NB showed remarkable activity of stimulating the proliferation of T-Cells in vitro, giving a good example for Kulicke's statement.

Journal Article↗

PubMed2000

Structure of a New Glucan from Cynanchum panilatum (Bunge) Kitagawa.

A polysaccharide was purified from a traditional Chinese drug, "Xu-Chang-Qing" (Cynanchum panilatum (Bunge) Kitagawa), and its molecular weight was estimated to be 1.5x10(4) by HPLC method. Its specific rotation [alpha](D) was 151.4 deg; (0.96, H(2)O). Sugar composition analysis indicated this polysaccharide was composed only of glucose. Methylation analysis, partially hydrolysis, acetolysis, IR and NMR data showed that its main chain was composed of alpha-D 1,4 linked glucosyl residues and its side chains were composed of alpha-D 1,4 and alpha-D 1,6 linked glucosyl residues. There was one branch located at O-6 of the glucosyl residue in every repeating unit containing five-glucosyl residues.

Journal Article↗

PubMed1999

Preparation and Structural Analysis of Sulfated Derivatives of Lentinan.

A series of sulfated derivatives of lentinan were prepared by the modified Wolfrom method. Sulfates content analysis indicated that the proportion of sulfate substitution depended on the reaction time and the ratio of chlorsulfonic acid and pyridine in the ester reagent. Methylation analysis by Needs method and Hakomori method was proved not to be suitable for the structural analysis of sulfated lentinan. (13)C-NMR data showed that sulfates were located on the carbon-6 in all sulfated derivatives of lentinan showing the higher reactivity of the hydroxyls on C-6 position than those at other position.

Journal Article↗