Structural characterisation of an anti-complementary arabinogalactan from the roots of Angelica acutiloba Kitagawa

An anti-complementary arabinogalactan (AGIIb-1), isolated from the roots of Angelica acutiloba Kitagawa, has been subjected to methylation analysis, digestion with alpha-L-arabinofuranosidase, controlled Smith-degradation, and partial acid hydrolysis. AGIIb-1 consisted of arabinose, galactose, rhamnose, galacturonic acid, and glucuronic acid in the molar ratios 1.8-2.2:1.0:0.2-0.3:0.2-0.4:0.1. AGIIb-1 contained mainly an arabino-3,6-galactan moiety, and most of the Ara was present as alpha-L-arabinofuranosyl residues in the non-reducing terminals and the highly polymerised and branched side-chains which were attached mainly to positions 3 and 6 of (1----6)- and (1----3)-linked Gal, respectively. Some Ara-containing chains were also attached to (1----4)-linked Gal residues. The 13C-n.m.r. data for AGIIb-1 showed that the Galp was beta. Mild acid hydrolysis of AGIIb-1 yielded several linear and highly branched arabino-oligosaccharides, a neutral arabinogalactan, and two acidic arabinogalactans. Some arabino-oligosaccharides contained a (1----4)-linked Arap at the reducing terminal. The neutral arabinogalactan contained (1----3)-, (1----4)-, and (1----6)-linked and 3,6-di-O-substituted Gal, whereas the acidic arabinogalactans contained, in addition, non-reducing terminal GlcA, (1----4)-linked GalA, and 2,4-di-O-substituted Rha. The anti-complementary activity was decreased when AGIIb-1 was partially hydrolysed with mild acid (10mM HCl, 100 degrees, 10 min), but treatment with exo-alpha-L-arabinofuranosidase markedly enhanced the activity.     

Ginseng root water-extracted pectic polysaccharides originate from secretory cavities

A range of molecular probes for cell wall polysaccharides has been used to explore the structure and location of water-extracted pectic polysaccharides occurring in fractions isolated from ginseng roots. The LM19 homogalacturonan (HG) epitope was abundant in an HG fraction and analysis of LM19 binding to a rhamnogalacturonan-I (RG-I) rich-fraction indicated that the LM19 epitope is sensitive to acetylation. A specific RG-I epitope (LM16), four arabinogalactan-protein (AGP) epitopes (LM2, LM14, JIM16, MAC207) and an extensin epitope (JIM20) were found to be abundant and co-located in several isolated polysaccharide fractions including an arabinogalactan fraction and two RG-I fractions. Detection of the RG-I, AGP and extensin epitopes identified in isolated polysaccharide fractions in sections of ginseng roots indicated that they were most abundant in secretory cavities found in the cortical regions of ginseng roots. In addition, the immunocytochemical study indicated that polysaccharide epitope masking is a widespread phenomenon in the primary cell walls of ginseng roots.     

Developmental regulation of pectic polysaccharides in the root meristem of Arabidopsis

JIM 5, an antibody that recognizes a relatively unesterifiedpectic epitope, distinguishes between dividing (meristematic)and non-dividing (central cells of the quiescent centre) cellsin the Arabidopsis root tip, indicating that non-dividing cellwalls contain higher levels of relatively unesterified pectinthan dividing cells. JIM 7, an antibody that recognizes a relativelymethyl esterified epitope, labels all cell walls uniformly throughoutthe root, suggesting that there is little variation in the relativelymethyl esterified pectic component in the two cell types. Theseobservations suggest that the characteristics of cell wallsin the root tip result in part from modulations in the amountof unesterified and non-methyl esterified pectin. Key words: Pectin, quiescent centre, roots, Arabidopsis     

Immunomodulatory activity of polysaccharide isolated from Angelica sinensis

The immunomodulatory activities of an Angelica sinensis polysaccharide (AP), purified from the fresh root of A. sinensis Diels, were investigated in vitro in relation to the specificity to immune cells. AP consisted of rhamnose, arabinose, mannose, glucose, galactose with the molar ratio of 1.00:4.54:2.98:11.09:7.45. Cell proliferation results showed that proliferation of total spleen cells, macrophages and T cells were promoted by the action of AP. The treatment of AP increased the production of IL-2 and IFN-γ, while that of IL-4 was decreased. RT-PCR analysis displayed that the IL-2 and IFN-γ gene expression were enhanced but the IL-4 gene expression was decreased. Some differences in cytokines secretion pattern were also detected, the expression of IFN-γ was rapidly augmented while that of IL-2 responded later. The flow cytometry results showed that the percentage of CD4⁺T cell in total spleen cells was remarkably increased by AP, while that of CD8⁺T cell was slightly decreased. In conclusion, AP has immunomodulatory activity by regulating expression of Th1 and Th2 related cytokines. The time–effect relation of cytokines response also suggests that macrophages and natural killer cells involved in nonspecific immunity were primary activated, and helper T cell were secondarily affected by AP.     

东当归化学成分研究及定量分析

从当归属植物东当归的根的乙醇溶液中分离得到了4个化合物,通过理化特性和波谱分析分别鉴定为双(5-甲酰基糠基)醚(bis(5-formylfurfuryl)ether,1)、5-羟甲基糠醛(5-hydroxymethyl-2-furaldehyde,2)、豆甾醇(stigmasterol,3)、十七烷酸(heptadecanoic acid4,)。所有化合物均为首次从该植物中分离得到,其中1为首次从该属植物中分离得到。采用高效液相色谱法对东当归所含该属特征活性成分紫花前胡素进行了定量分析。     

Enzymatic extraction and linkage analysis of pectic polysaccharides from onion

Pectin lyase was superior to polygalacturonase for the extraction of onion cell wall pectic polysaccharides. Exhaustive treatment of onion tissue with pectin lyase solubilized 89% of the total uronides of the tissue. The galacturonides released from the tissue were separated into three fractions (10.7, 5.3 and 84%, in order of MW) by gel filtration on Sephadex G-100. The low MW fraction was a mixture of oligogalacturonides. High and intermediate MW fractions were purified by DEAE-Sephadex column chromatography. The intermediate MW fraction was a rhamnogalacturonan II type component which contained 3- and 3,4-linked rhamnose. Methylation analysis showed that the pectic polysaccharides of onion resembled those of potato tuber.     

In-situ analysis of pectic polysaccharides in seed mucilage and at the root surface of Arabidopsis thaliana

Pectic polysaccharides are a complex set of macromolecules of the primary cell wall matrix with distinct structural domains. The biosynthesis, organisation and function of these domains within cell wall matrices are poorly understood. An immersion immunofluorescence labelling technique was developed for the in-situ analysis of pectic polysaccharides at the surface of seeds and seedlings of Arabidopsis thaliana (L.) Heynh., and used to investigate the occurrence of pectic homogalacturonan (HG) and rhamnogalacturonan-I (RG-I) epitopes. Seed mucilage appeared to consist of two regions: a highly methyl-esterified HG was a major component throughout the mucilage, while an inner region with relatively low porosity was stabilized by calcium-based HG cross-linking. The small size and transparency of Arabidopsis roots allowed the occurrence of pectic HG and RG-I epitopes at root surfaces to be directly determined on whole-mount preparations. Pectic epitopes were not distributed evenly over root surfaces and were notably absent from lateral root apices and from the surface of root hairs. The use of defined antibody probes in the immersion immunolabelling protocol will be useful for the analysis of the influence of growth conditions and genetic factors on pectic polysaccharides in Arabidopsis. Received: 13 July 2000 / Accepted: 15 September 2000     

Oxidative cross-linking of pectic polysaccharides from sugar beet pulp

Oxidative cross-linking of three beet pectin extracts with hydrogen peroxide/peroxidase resulted in an increase in viscosity at low concentrations and in the formation of a gel at higher concentrations. Gels were formed using concentrations of 1.5% for an autoclave preparation and one obtained by an acid extraction and of 3% for a second autoclaved extract. It was shown that in the autoclave extracts only rhamnogalacturonans and possibly the arabinans participated in the cross-linking reaction. Cross-linking of the autoclave extracts with ammonium persulfate resulted in a decrease in reduced viscosity and molecular weight, although ferulic acid dehydrodimers were formed. Treatment of the acid extracted pectin with ammonium persulfate gave a slow increase in viscosity and the formation of a high-molecular-weight population was observed. For both oxidative systems, the 8-5 dehydrodimer was predominant after cross-linking.     

伞形科东当归的果实形态和解剖结构

对伞形科(Apiaceae)当归属(Angelica L.)东当归〔A.acutiloba(Sieb.et Zucc.)Kitag.〕的分生果形态特征和解剖结构进行了全面观察。该种分生果的外观呈倒椭圆状长卵形,有三角状萼齿,果棱、棱槽和腹面表面均有黄白色斑点。果实横切面解剖结构具有以下特征:外果皮终止于果棱顶端的腹面处,合生面宽阔,外果皮和中果皮细胞中有大量淡黄色晶体,油管在棱槽和合生面处连续分布等。东当归的这些果实形态及解剖结构明显不同于当归属的其他种类,其分类地位有待重新探讨。     

Nematicidal activity of (Z)-ligustilide isolated from Angelica tenuissima Nakai root extract against the pine wood nematode Bursaphelenchus xylophilus

In this study, we investigated the nematicidal activities of the ethanol extracts of 49 medicinal plants against the pine wood nematode, Bursaphelenchus xylophilus, and isolated a main nematicidal constituent, (Z)-ligustilide, from Angelica tenuissima Nakai root extract. Among the 49 plant extracts, only the A. tenuissima root extract showed the strong nematicidal activity against the pine wood nematode, with a 92.3% mortality rate at a concentration of 2 mg/mL. Based on bioassay-guided isolation and gas chromatography-mass spectrometry (GC-MS) analysis, (Z)-ligustilide was identified as the active component of A. tenuissima root extract at 73.6% of the total content ratio. The LC₅₀ value of (Z)-ligustilide against the pine wood nematode was 0.24 mg/mL. Our results indicated that (Z)-ligustilide as well as A. tenuissima root extract can be potential candidates for novel trunk injection agents against the pine wood nematode.     

Structure and antitumor activity of polysaccharides from the micelles of Aspergillus oryzae

Three polysaccharide fractions active against mammary gland adenocarcinoma Ca-755 in mice but inactive against sarcoma C-180 were isolated from Aspergillus oryzae strain 5214. The main fraction, extracted from the mycelium by cold dilute alkali in the presence of sodium borohydride, was shown to be linear (1----3)-a-D-glucopyranan (pseudonigeran) according to 13C NMR spectroscopy, partial acid hydrolysis and periodate oxidation data.     

Studies of macrophage immuno-modulating activity of polysaccharides isolated from Paecilomyces tenuipes

The objective of this study was to evaluate the immunomodulatory effects of the Paecilomyces sinensis polysaccharides (PtP) on the activity of macrophages and human monocytes. A water-soluble polysaccharide, with estimated molecular weight of 2.04 × 10⁴ Da, was isolated from P. sinensis. The results indicate that PtP can increase the activity of LDH and ACP in AMφ and PMφ of rats and human mononuclear cells, and enhance the pinocytic activity of macrophages and TNF-α production by human peripheral blood mononuclear cells (PBMC), suggesting that PtP had potent immunomodulatory properties and could be explored as a novel potential immunostimulants for the food and pharmaceutical purpose.     

Immunostimulatory activity of polysaccharides isolated from Caulerpa lentillifera on macrophage cells

Polysaccharides were extracted from Caulerpa lentillifera by treating with water and then purified by size-exclusion chromatography. The purified polysaccharides, termed SP1, were found to be sulfated xylogalactans with a molecular mass of more than 100 kDa. Adding SP1 to murine macrophage RAW 264.7 cells increased the production of nitric oxide (NO) in a dose-dependent manner. NO was found by immunoblotting and RT-PCR analyses to be synthesized by an inducible NO synthase. SP1 caused the degradation of IκB-α and the nuclear translocation of nuclear factor (NF)-κB subunit p65 in macrophage cells. SP1 also increased the phosphorylation of p38 mitogen-activated protein kinase (MAPK). These results demonstrate that SP1 activated macrophage cells via both the NF-κB and p38 MAPK signaling pathways. Moreover, SP1 increased the expression of various genes encoding cytokines, and the phagocytic activity of macrophage cells. These combined results show that SP1 immunostimulated the activity of macrophage cells.     

Radioprotective activity of neutral polysaccharides isolated from the fruiting bodies of Hohenbuehelia serotina

In this study, the radioprotective effect of neutral polysaccharides from Hohenbuehelia serotina (NTHSP) against the damages induced by ⁶⁰Co-γ radiation was investigated. The results showed that NTHSP could significantly improve the activity of glutathione peroxidase (GSH-Px) and increase the contents of glutathione (GSH) and ceruloplasmin in plasma after treated with 6 Gy-radiation compared with the radiation controls (p < 0.05). Furthermore, administration with NTHSP could effectively increase the quantity of marrow DNA (p < 0.05) and reduce the rates of chromosome aberration and micronuclei (p < 0.01) in bone marrows of mice. In addition, NTHSP could markedly inhibit the expressions of Bax protein and promote the expressions of Bcl-2 protein, accordingly inhibit the releases of cytochrome c and expressions of activated Caspase-3, and therefore block the mitochondrial apoptotic pathway of splenocytes in mice induced by ⁶⁰Co-γ radiation. These results suggested that NTHSP might be a natural radioprotective agent against the injuries induced by radiation.     

Effect of polysaccharides from Angelica sinensis on gastric ulcer healing

Our previous study showed that a crude extract from Angelica sinensis (ASCE), which mainly consisted of polysaccharides, significantly promoted migration and proliferation of normal gastric epithelial cells. These results strongly suggest that ASCE has a direct wound healing effect on gastric mucosa. However, there is no report concerning the effect of ASCE on gastric ulcer healing in animal models. In this study, we found that ASCE promoted ulcer healing. The area of the ulcer was reduced. This was accompanied with a significant increase in mucus synthesis when compared with the control. Angiogenesis was inhibited by the treatment of ASCE. Cell proliferation, ODC and EGFR protein expression was not affected in this process. Thus, the mechanism of how ASCE accelerates ulcer healing in addition to its effect on mucus synthesis remains to be investigated.     

Structural features of pectic polysaccharides from the skin of Opuntia ficus-indica prickly pear fruits

After removal of the mucilage with water at room temperature, pectic polysaccharides were solubilized from Opuntia ficus-indica fruit skin, by sequential extraction with water at 60 degrees C (WSP) and EDTA solution at 60 degrees C (CSP). Polysaccharides with neutral sugar content of 0.48 and 0.36 mol/mol galacturonic acid residue were obtained, respectively, in the WSP and CSP extracts. These pectic polysaccharides were de-esterified and fractionated by anion-exchange chromatography, yielding for each extract five fractions, which were thereafter purified by size-exclusion chromatography. Two of these purified fractions were characterized by sugar analysis combined with methylation and reduction-methylation analysis. The study was then supported by (1)H and (13)C NMR spectroscopy. The results showed that the water-soluble fraction WSP3 and the EDTA soluble fraction CSP3, consisted of a disaccharide repeating unit -->2)-alpha-l-Rhap-(1-->4)-alpha-d-GalpA-(1--> backbone, with side chains attached to O-4 of the rhamnosyl residues. The side chains contained highly branched alpha-(1-->5)-linked arabinan and short linear beta-(1-->4)-linked galactan.     

Estrogen-like activity of glabrene and other constituents isolated from licorice root

Licorice root extract and its major isoflavan, glabridin, exhibited varying degrees of estrogen receptor (ER) agonism in different tissues in vitro and in vivo. Animals fed with licorice extract, compared with estradiol and glabridin, showed an increase in creatine kinase (CK) activity, a known marker for estrogen responsive genes, which was higher than expected from the levels of glabridin in the extract. This led us to test for other components that may contribute to this strong estrogen agonist activity. Results indicated that glabrene and isoliquiritigenin, (2',4',4-three hydroxy chalcone) (ILC) in the licorice extract can bind to the human ER with higher affinity (IC50, 1 and 0.5 microM) than glabridin (IC50, 5 microM). The stimulatory effects of glabrene in vivo were tissue specific and similar to those of estradiol. The effect of increasing concentrations of glabrene and ILC on the growth of breast tumor cell were biphasic. Both showed an ER-dependent growth-promoting effect at low concentrations (10 nM-10 microM), and ER-independent antiproliferative activity at concentrations >15 microM. This is the first study to indicate that glabrene, an isoflavene exerted varying degrees of ER agonism in different tissues.     

Degradation of pectic polysaccharides extracted from suspension cultures of carrot by purified exo-polygalacturonase

Highly purified exo-polygalacturonase was obtained from suspension cultures of carrot ( Daucus carota L. cv. Kintoki) by dialysis at pH 5.2, chromatography on DEAE-Sephadex A-50 and on Sephadex G-150, and preparative polyacrylamide disc gel electrophoresis. The enzyme did not attack the isolated carrot cell walls directly, but it had some effect on pectic polysaccharides extracted from the walls. The extracted polysaccharides were fractionated by DEAE-Sephadex A-50 column chromatography yielding four carbohydrate fractions. The major fraction (P-3) was then reacted with the exo-polygalacturonase. The enzyme treatment resulted in hydrolysis of approximately 18% of the glycosyl linkages of fraction P-3 with the release of galacturonic acids. The molecular size estimated by Bio-Gel A-5m gel filtration was not markedly affected by the enzyme action, but the percentage of galacturonosyl residues was clearly reduced. The specific activity of exo-polygalacturonase changed during the growth cycle, in relation to the cell growth.