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At least 109 records · Page 6Linked to original sources
PubMed2000

A sesquiterpene acid and flavonoids from Polygonum viscosum.

4-Isobutyl-6-methyl-5-oxo-3a,4,5,7a-tetrahydro-1H-inden-13-oic acid (named viscosumic acid) and quercetin 3-O-(6"-feruloyl)-beta-D-galactopyranoside, and the known 3',5-dihydroxy-3,4',5',7-tetramethoxyflavone have been isolated from Polygonum viscosum. The structures of these isolates were determined primarily on the basis of extensive 1D and 2D NMR spectral analyses, notably, 13C PENDANT, COSY45, TOCSY, GOESY, NOESY, HMQC and HMBC.

Flavonoids↗
PubMed1998

Constituents and bioactive principles of Polygonum chinensis.

Isolation and characterization of the chemical constituents of Polygonum chinensis L. gave the new 25R-spirost-4-ene-3,12-dione. The known compounds stigmast-4-ene-3,6-dione, stigmastane-3,6-dione, hecogenin and aurantiamide acetate were also isolated from for the first time from this species. Their anti-inflammatory and anti-allergic properties are described.

Animals↗
PubMed2001

Cancer chemopreventive activity of phenylpropanoid esters of sucrose, vanicoside B and lapathoside A, from Polygonum lapathifolium.

To search for cancer chemopreventive agents from natural resources, many phytochemicals have been screened using the in vitro synergistic assay indicated by the inhibitory effects on the induction of Epstein-Barr virus early antigen (EBV-EA) by 12-O-tetradecanoylphorbol-13-acetate (TPA). Two phenylpropanoid esters of sucrose, vanicoside B and lapathoside A, were isolated from the aerial part of Polygonum lapathifolium as inhibitors on the EBV-EA induction. These compounds also exhibited significant anti-tumor-promoting effects on mouse two-stage skin carcinogenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA, as an initiator) and TPA as a promoter. Further, vanicoside B exhibited the remarkable inhibitory effect on two-stage carcinogenesis test of mouse skin tumors initiated with an NO donor, NOR-1.

Animals↗
PubMed1998

Inhibition of mast cell-dependent anaphylactic reactions by the pigment of Polygonum tinctorium (Chung-Dae) in rats.

1. The effect of the pigment obtained from the stem and leaf of Polygonum tinctorium Loar (PtP) on anaphylactic reactions was studied in rats. 2. PtP totally inhibited compound 48/80-induced anaphylactic shock with doses of 10(2) and 10(3) mg/ kg. When PtP was pretreated at concentrations ranging from 10(-2) to 10(3) mg/kg, the serum histamine levels induced by compound 48/80 were reduced in a dose-dependent manner. 3. We also investigated the effect of PtP on mast cell-dependent passive cutaneous anaphylaxis (PCA) activated by anti-dinitrophenyl (DNP) IgE antibody. PtP potently inhibited PCA when administered orally, topically, intraperitoneally and intradermally. However, it did not show inhibitory activity when administered intravenously. 4. PtP inhibited dose dependently histamine release from rat peritoneal mast cells (RPMCs) induced by compound 48/80 and anti-DNP IgE. Moreover, the level of cAMP in RPMC, when PtP was added, significantly increased about 12-fold at 4 min compared with that of basal cells. 5. These results indicate that PtP may possess strong antianaphylactic activity and suggest that differences in bioavailability may cause differential activity following different administration routes.

Anaphylaxis↗
PubMed2000

Quercetin 3-O-(6"-caffeoyl)-beta-D-galactopyranoside from Polygonum viscosum.

The methanol extract of the whole plant parts of Polygonum viscosum has yielded a flavonol glycoside, 3-O-(6"-caffeoyl)-beta-D-galactopyranoside (1), the structure of which has been determined unambiguously by UV and a series of one- and two-dimensional NMR experiments, notably, (1)H, (13)C, DEPT, COSY45, HMBC and HMQC.

Caffeic Acids↗
PubMed2000

Polygonum tinctorium extract suppresses nitric oxide production by activated macrophages through inhibiting inducible nitric oxide synthase expression.

Despite its beneficial role in host defense mechanisms, excessive nitric oxide (NO) production by activated macrophages has been implicated in several inflammatory diseases. To clarify the mechanisms of anti-inflammatory activities of Polygonum tinctorium, we evaluated whether extracts of P. tinctorium could modulate the production of NO by activated macrophages. An AcOEt extract of P. tinctorium markedly inhibited NO synthesis by interferon-gamma (IFN-gamma)/lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages and the macrophage-like cell line RAW 264.7 in a dose-dependent manner. Inhibition of NO synthesis was achieved by reducing inducible NO synthase (iNOS) expression at protein and mRNA levels. However, the AcOEt extract of P. tinctorium failed to inhibit NO synthesis when iNOS was already expressed following stimulation with IFN-gamma and LPS. The AcOEt extract also exhibited inhibitory activity on iNOS expression in human lung epithelial A549 cells stimulated with a combination of IFN-gamma, TNF-alpha and IL-1 beta without affecting the expression of constitutive isoforms of NOS. Furthermore, in vivo injection of the AcOEt extract of P. tinctorium into LPS-treated mice significantly reduced NO synthesis by peritoneal exudate cells under ex vivo conditions. These results suggest that P. tinctorium extract may be a potential therapeutic modulator of NO synthesis in various pathological conditions.

Animals↗
PubMed2001

Clinical effect of a Mexican sanguinaria extract (Polygonum aviculare L.) on gingivitis.

It is well known that gingivitis is a bacterially-elicited inflammation of the marginal gingiva. A number of chemical agents have been evaluated over the years with regard to their antimicrobial effects in the oral cavity; however, all are associated with side effects that prohibit regular long-term use. Therefore, the effectiveness of a natural Mexican Sanguinaria extract (Polygonum aviculare L.) against gingivitis, was assessed in 60 male dentistry students between the ages of 18 and 25 years. Over a period of 2 weeks, these students used the Sanguinaria extract (1 mg/ml) in oral rinse twice daily as a unique oral health measurement (no tooth-brushing was allowed). The O'Leary Plaque Index and the Löe and Silness Gingivitis Index were recorded at baseline (day 0) in all the subjects. Also, a complete prophylaxis was performed after both indices were obtained. The antibacterial and antiinflammatory effects of the extract were evaluated on days 7, 11 and 14. The results showed that the Mexican Sanguinaria extract in oral rinse significantly decreased gingivitis from day 0 (-x=1. 056) to day 14 (-x=1.011) (P</=0.05). In contrast, a significant increase in dental plaque was observed from day 0 (-x=91.38) to day 14 (-x=98.69) (P</=0.05); however, the consistency of this plaque permitted its mechanical flushing easily. From this study, it is concluded that the Mexican Sanguinaria extract in oral rinse can be employed supportively in the therapy of gingivitis.

Adult↗
PubMed1999

2,2-Diphenyl-1-picrylhydrazyl radical-scavenging active components from Polygonum multiflorum thunb.

An activity-directed fractionation and purification process was used to identify the antioxidative components of Polygonum multiflorum Thunb. (PM). Dried root of PM was extracted with 95% ethanol and then separated into water, ethyl acetate, and hexane fractions. Among these only the ethyl acetate phase showed strong antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test when compared with water and hexane phases. The ethyl acetate fraction was then subjected to separation and purification using silica gel column chromatography and Sephadex LH-20 chromatography. Three compounds showing strong antioxidant activity were identified by spectral methods ((1)H NMR, (13)C NMR, and MS) and by comparison with authentic samples to be gallic acid, catechin, and 2,3,5, 4'-tetrahydroxystilbene 2-O-beta-D-glucopyranoside.

Antioxidants↗
PubMed2000

Isolation and identification of stilbenes in two varieties of Polygonum cuspidatum.

The roots of two varieties of Polygonum cuspidatum (Hu Zhang and Mexican Bamboo) were analyzed for resveratrol and analogues. The roots of each variety were dried and ground into a powder. The powdered roots were then extracted with methanol and ethyl acetate. The ethyl acetate fraction of the Mexican Bamboo was then subjected to fractionation and purification using silica gel column chromatography and semipreparative HPLC. In addition to resveratrol (3,5,4'-trihydroxystilbene), three stilbene glucosides were identified by (1)H NMR, (13)C NMR, and MS. The stilbene glucosides were shown to be a piceatannol glucoside (3,5,3', 4'-tetrahydroxystilbene 4'-O-beta-D-glucopyranoside), resveratroloside (3,5,4'-trihydroxystilbene 4'-O-beta-D-glucopyranoside), and piceid (3,5,4'-trihydroxystilbene 3-O-beta-D-glucopyranoside). The levels of the piceatannol glucoside and piceid were twice as high in the Mexican Bamboo as compared to the Hu Zhang.

Chromatography, High Pressure Liquid↗
PubMed2000

New sucrose phenylpropanoid esters from Polygonum perfoliatum.

Five diferuloyl esters of sucrose, 6'-acetyl-3,6-diferuloylsucrose (helonioside B) (1); 2',4',6'-triacetyl-3,6-diferuloylsucrose (2); 1, 2',4',6'-tetraacetyl-3,6-diferuloylsucro se (3); 1,2',6'-triacetyl-3, 6-diferuloylsucrose (4); and 2',6'-diacetyl-3,6-diferuloylsucrose (5), were isolated, along with the 1,3,6-tri-p-coumaroyl-6'-feruloylsucroses, vanicoside A and vanicoside B, from the whole plant of Polygonum perfoliatum by various chromatographic methods. The structures of these phenylpropanoid glycosides were determined on the basis of their NMR and mass spectroscopic data. Compound 1 is a known compound, but 2-5 are new members of this class.

Chromatography, Gel↗
PubMed2000

Stilbene glycoside sulfates from Polygonum cuspidatum.

Ten naturally occurring stilbene glycoside sulfates (1-10) were isolated from an aqueous extract of the root of Polygonum cuspidatum. Their structures were established based on chemical evidence and spectroscopic techniques, including 2D NMR methods.

Magnetic Resonance Spectroscopy↗
PubMed1992

Emodin, a protein tyrosine kinase inhibitor from Polygonum cuspidatum.

Bioassay-directed fractionation of a Chinese medicinal plant, Polygonum cuspidatum (Polygonaceae), has led to the discovery of an anthraquinone, emodin [1], as a strong inhibitor of a protein tyrosine kinase (p56lck) partially purified from bovine thymus. Comparison of the IC50 values of emodin for protein tyrosine kinase inhibitory activity with physcion [2] and emodin-O8-D-glucoside [3], also isolated from the same plant, reveal the importance of the hydroxyl groups at C-6 and C-8 for the observed activity.

Animals↗
PubMed1993

Kinase inhibitors from Polygonum cuspidatum.

Bioassay-directed fractionation of a medicinal plant, Polygonum cuspidatum (Polygonaceae), has led to the discovery of a hydroxystilbene, resveratrol [1], as an inhibitor of a protein-tyrosine kinase (p56lck) partially purified from bovine thymus. Both trans and cis isomers of resveratrol possess comparable protein-tyrosine kinase inhibitory activity. Comparison of the IC50 values of resveratrol for protein-tyrosine kinase inhibitory activity with those of piceid (resveratrol-O3-beta-glucoside) [2] and resveratrol-O4'-beta-glucoside [3] shows the requirement of free hydroxyl groups on both phenyl rings for the protein-tyrosine kinase inhibition. Protein kinase C inhibitory analysis suggests the requirements of two free hydroxyl groups on one phenyl ring only.

Animals↗
PubMed1994

Vanicosides A and B, protein kinase C inhibitors from Polygonum pensylvanicum.

Two new protein kinase C inhibitory glycosides, vanicosides A [1] and B [2] were isolated from Polygonum pensylvanicum (Polygonaceae) by chromatographic techniques guided by bioassays for PKC inhibition. The structures of these glycosides were established primarily by analysis of 1H- and homonuclear correlated nmr and high-resolution fab mass spectra of 1 and 2 and the derived octaacetate, 3. Both glycosides were found to have p-coumaryl esters at the 1, 3, and 6 carbons of sucrose and a feruloyl ester at the 6' carbon. Vanicoside A [1] also had an acetate group at the 2' carbon.

Acetylation↗
PubMed1994

Novel Ca(2+)-ATPase inhibitors from the dried root tubers of Polygonum Multiflorum.

The MeOH extract of the dried root tubers of Polygonum multiflorum yielded three bioactive compounds with an inhibitory activity on calmodulin-depleted erythrocyte calcium-dependent ATPase. These compounds were identified as E-2,3,5,4'-tetrahydroxystilbene 2-O-beta-D-glucopyranoside [2] (IC50 = 240 microM) and cis- and trans-E-3-butylidene-4,5,6,7-tetrahydro-6,7-dihydroxy-1(3H)- isobenzofuranone [3 and 4](IC50 = 160 and 260 microM, respectively). E-2,4,6,4'-Tetrahydroxystilbene 2-O-beta-D-glucopyranoside [1] was also isolated but was found to have no inhibitory effect on the enzyme.

Australia↗
PubMed1998

Vanicosides C-F, new phenylpropanoid glycosides from Polygonum pensylvanicum.

The isolation of the protein kinase C inhibitors, vanicoside A (1) and vanicoside B (2), from Polygonum pensylvanicum prompted continued interest in the active principles of this plant. A new, more efficient isolation procedure has been developed to facilitate separation of homologues of vanicosides A and B from the complex extract. Several new phenylpropanoid glycosides have since been isolated. The structures of these principles were determined to be 2'-O-acetylhydropiperoside (4), 6'-O-p-coumarylhydropiperoside (5), 4'-O-acetylvanicoside A (6), and 3'-O-acetylvanicoside B (7) using negative ion FABMS, 1H NMR, and 2D NMR techniques.

Chromatography, High Pressure Liquid↗
PubMed1999

Phenylvaleric acid and flavonoid glycosides from Polygonum salicifolium.

(3R)-O-beta-D-Glucopyranosyloxy-5-phenylvaleric acid (1), (3R)-O-beta-D-glucopyranosyloxy-5-phenylvaleric acid n-butyl ester (2), and a new dihydrochalcone diglycoside 4'-O-[beta-D-glucopyranosyl-(1-->6)-glucopyranosyl]oxy-2'-hydroxy-3', 6'-dimethoxydihydrochalcone (3), together with six known flavonoid glycosides [kaempferol-3-O-beta-D-glucopyranoside (= astragalin) (4), kaempferol-3-O-beta-D-galactopyranoside (5), quercetin-3-O-beta-D-glucopyranoside (= isoquercitrin) (6), quercetin-3-O-beta-D-galactopyranoside (= hyperoside) (7), quercetin-3-O-(2''-O-galloyl)-beta-D-glucopyranoside (8), and quercetin-3-O-beta-D-glucuronopyranoside (9)] were isolated from the aerial parts of Polygonum salicifolium. The structure elucidation of the isolated compounds was performed by spectroscopic (UV, IR, ESI-MS, 1D- and 2D-NMR), chemical (methylation, enzymatic hydrolysis, partial synthesis), and chromatographic methods (HPLC, Chiralcel OD). The flavonoid glycosides (4-9) demonstrated scavenging properties toward the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical in TLC autographic assays.

Carbohydrate Sequence↗