[Correlation between lipid-lowering efficacy and components of Pericarpium Citri Reticulatae].

Based on pharmacodynamics-component correlation analysis,the best effective part of hyperlipidemia of Pericarpium Citri Reticulatae( PCR) was screened out to confirm the possible constituents with the lipid regulating effect,in order to provide a basis for the development of new drugs. Hyperlipidemia rats induced by fat emulsion were used to screen out the best hypolipidemic parts of PCR with TC,LDL-c as the index. HPLC-ESI-MS were used to analyze common constituents of the different solvent extracts from PCR. The constituents were classified and identified based on the retention time,m/z and UV spectra. And the HPLC-DAD were used to determine the contents of flavonoids( narirutin,hesperidin,didymin,nobiletin,tangeretin,3,5,6,7,8,3',4'-heptemthoxyflavone).Correlation analysis was conducted on the constituents and efficacy with the method of SPSS ANOVA bivariate correlation. Five extracts could significantly decrease the content of TC,LDL-c of hyperlipemia rats induced by fat emulsion,and the best effective part were95% ethanol and ethyl acetate. There were 19 common peaks in five different solvent extracts from PCR,and 17 flavonoids were identified and classified,including 10 polymethoxyflavonoids and 7 other flavonoids. According to the raw material quantity,the order of content of flavonones arranged from high to low: n-butyl alcohol part> 95% ethanol part> water part> ethyl acetate part> petroleum ether part; and the order of PMFs arranged from high to low: n-butyl alcohol part≈95% ethanol part≈ethyl acetate part > petroleum ether part > water part. The decreased percentage of TC,LDL-c was positively correlated with 10 common PMFs constituents,which suggested that PMFs may be the effective components for reducing blood lipid.

High-speed counter-current chromatography assisted preparative isolation of bioactive compounds from stem bark of Juglans mandshurica.

High-speed counter-current chromatography was applied for the first time for the separation and purification of bioactive compounds contained in the stem bark of Juglans mandshurica Maxim. Silica gel column chromatography was first used to obtain three composition-enriched target fractions from a crude J. mandshurica methanol extract. Three independent high-speed counter-current chromatography processes were then used to further isolate 13 bioactive compounds, namely, six galloyl glucose derivatives, three flavonones, three naphthoquinones, and ethyl gallate. The isolates were identified by ultrahigh-performance liquid chromatography with tandem mass spectrometry, and ultraviolet and NMR spectroscopy, and compared with literature data. Their purities were determined to be >94.6% by ultrahigh performance liquid chromatography. Furthermore, based on the total phenolic content and results of a 2,2-diphenyl-1-picrylhydrazyl test, the methanol extract and two of the three initial fractions were observed to be rich in phenolic compounds and exhibit good free radical scavenging abilities, while nine of the isolated compounds exhibited remarkable antioxidant activity, superior to that of butyrate hydroxy-toluene and comparable to that of gallic acid. The results of this research confirm the effectiveness of high-speed counter-current chromatography for the separation of compounds contained in extremely complex samples, and provide a basis for the further utilization of J. mandshurica.

Anti-Hyperuricemic, Anti-Inflammatory and Analgesic Effects of Siegesbeckia orientalis L. Resulting from the Fraction with High Phenolic Content.

BACKGROUND: The medicinal plant Siegesbeckia orientalis L. has been commonly used for the treatment of acute arthritis, rheumatism, and gout in Vietnam. However, pharmacological research of this plant associated with gout has not been reported. Anti-hyperuricemic and anti-inflammatory effects were evaluated and observed for the crude ethanol extract (CEE) of S. orientalis. Retention of these biological properties was found in a n-butanol-soluble fraction (BuOH fr.) of the extract, and therefore further biological and chemical investigations were undertaken on the BuOH fr. to support the medical relevance of this plant. METHODS: The aerial part of S. orientalis was obtained in the mountainous region of Vietnam. The crude ethanol extract (CEE) and its BuOH fr. were prepared from the plant materials. Anti-hyperuricemic activities of the CEE and BuOH fr. were tested in vivo using the model oxonate-induced hyperuricemia rats through determination of serum uric acid levels and inhibitory effects on xanthine oxidase (XO) in the rat liver. Anti-inflammatory activities of the BuOH fr. were also evaluated in vivo using carrageenan-induced paw edema and urate-induced synovitis in rats. Active components of the BuOH fr. were characterized by comparison of HPLC retention time (t R) and spectroscopic data (UV, 1H-NMR) with those of reference compounds. RESULTS: The CEE of S. orientalis displayed anti-hyperuricemic activity, and the BuOH fr. was found to be the most active portion of the extract. Further in vivo studies on this fraction showed 31.4% decrease of serum uric acid levels, 32.7% inhibition of xanthine oxidase (XO), 30.4% reduction of paw edema volume, symptomatic relief in urate-induced synovitis and significant analgesic effect at the dose of 120 mg/kg, as compared to the corresponding values of the control groups. Chemical analysis of the BuOH fr. revealed high phenolic content, identified as caffeic acid analogues and flavonones. CONCLUSIONS: This study suggested that anti-hyperuricemic and anti-inflammatory mechanism of S. orientalis is related to XO inhibitory effect of the phenolic components. Our findings support the use of this plant as the treatment of gout and other inflammatory diseases.

Preparative isolation and analysis of alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root using ultrafiltration combined with high-performance liquid chromatography and high-speed countercurrent chromatography.

A simple, rapid, and effective assay based on ultrafiltration combined with high-performance liquid chromatography and high-speed countercurrent chromatography was developed for screening and purifying alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root extract. Experiments were carried out to optimize binding conditions including alcohol dehydrogenase concentration, incubation time, temperature, and pH. By comparing the chromatograms, three compounds were found possessing alcohol dehydrogenase binding activity in Glycyrrhiza uralensis root. Under the target-guidance of ultrafiltration combined with the high-performance liquid chromatography experiment, liquiritin (1), isoliquiritin (2), and liquiritigenin (3) were separated by high-speed countercurrent chromatography using ethyl acetate/methanol/water (5:1:4) as the solvent system. The alcohol dehydrogenase inhibitory activities of these three isolated compounds were assessed; compound 2 showed strongest inhibitory activity with an IC50 of 8.95 µM. The results of the present study indicated that the combinative method using ultrafiltration, high-performance liquid chromatography and high-speed countercurrent chromatography could be widely applied for the rapid screening and isolation of enzyme inhibitors from complex mixtures.

Isoprenylated flavonoids from Morus nigra and their PPAR γ agonistic activities.

A novel dihydroflavonol unprecedentedly with a prenyl group at C-2, nigragenon A (1), four new sanggenon-type flavonones, nigragenons B-E (2-5), along with six known isoprenylated flavonoids (6-11) were isolated from the twigs of Morus nigra. Their structures were elucidated through extensive analysis of spectroscopic data. Interestingly, compound 1 was the first reported biogenetic precursor of sanggenon-type flavanones and the biogenetic pathway from 1 to sanggenol F was proposed. The PPAR γ agonistic activity was investigated in HEK293 cells using dual luciferase reporter assay. Compounds 2, 4, 7, and 9 showed obvious agonistic activities on PPAR γ, and compound 2 was a potential PPAR γ partial agonist. Moreover, the preliminary structure-activity relationships for the tested compounds were discussed.

Correlation between lipid-lowering efficacy and components of Pericarpium Citri Reticulatae / 中国中药杂志

Based on pharmacodynamics-component correlation analysis,the best effective part of hyperlipidemia of Pericarpium Citri Reticulatae( PCR) was screened out to confirm the possible constituents with the lipid regulating effect,in order to provide a basis for the development of new drugs. Hyperlipidemia rats induced by fat emulsion were used to screen out the best hypolipidemic parts of PCR with TC,LDL-c as the index. HPLC-ESI-MS were used to analyze common constituents of the different solvent extracts from PCR. The constituents were classified and identified based on the retention time,m/z and UV spectra. And the HPLC-DAD were used to determine the contents of flavonoids( narirutin,hesperidin,didymin,nobiletin,tangeretin,3,5,6,7,8,3',4'-heptemthoxyflavone).Correlation analysis was conducted on the constituents and efficacy with the method of SPSS ANOVA bivariate correlation. Five extracts could significantly decrease the content of TC,LDL-c of hyperlipemia rats induced by fat emulsion,and the best effective part were95% ethanol and ethyl acetate. There were 19 common peaks in five different solvent extracts from PCR,and 17 flavonoids were identified and classified,including 10 polymethoxyflavonoids and 7 other flavonoids. According to the raw material quantity,the order of content of flavonones arranged from high to low: n-butyl alcohol part> 95% ethanol part> water part> ethyl acetate part> petroleum ether part; and the order of PMFs arranged from high to low: n-butyl alcohol part≈95% ethanol part≈ethyl acetate part > petroleum ether part > water part. The decreased percentage of TC,LDL-c was positively correlated with 10 common PMFs constituents,which suggested that PMFs may be the effective components for reducing blood lipid.