Xiao-Qing Chen

Antidiabetic and antioxidant effects of extracts from Potentilla discolor Bunge on diabetic rats induced by high fat diet and streptozotocin.

AIM OF THE STUDY Potentilla discolor Bunge, commonly found at the north temperate and boreal zone, has been used for diabetes in China for a long time. Flavonoids and triterpenoids are two major types of compounds in P. discolor. This study was designed primarily to investigate the effects of total flavonoids extract (TFE) and total triterpenoids extract (TTE) of P. discolor Bunge on blood glucose, lipid profiles and antioxidant parameters on diabetic rats induced by high fat diet and streptozotocin. MATERIALS AND METHODS High fat diet-fed and streptozotocin-induced diabetic rats were treated with the TFE and TTE for 15 days, respectively. A range of parameters were tested including fasting blood glucose (FBG), serum insulin (SI), blood lipid profile, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glycosylated serum protein (GSP), and nitric oxide (NO). RESULTS Diabetic rats treated with TFE or TTE had decreased concentration of FBG and GSP compared with the control group. Meanwhile, the levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-c) in the TFE or TTE treated diabetic rats were lower, and the high-density lipoprotein cholesterol (HDL-c) level was higher than in the control diabetic rats. Furthermore, the extracts treatment decreased the MDA and NO level, while increased SOD and GSH levels in diabetic rats. Histopathologic examination also showed that the extracts have protective effects on β-cells in diabetic rats which are supported by the increase of SI. CONCLUSIONS All these experimental results highlighted the hypoglycemic and hypolipidemic properties of the two extracts from Potentilla discolor Bunge on diabetes and its complications, possibly through a strong antioxidant activity and a protective action on β-cells.

Simultaneous quantification of both triterpenoid and steroidal saponins in various Yunnan Baiyao preparations using HPLC-UV and HPLC-MS.

Yunnan Baiyao (YNBY) is one of the best known traditional Chinese medicines. Saponins are considered to be its active components. In this study, an HPLC method was first developed for the simultaneous quantitative analysis of thirteen saponins, including five triterpenoid saponins and eight steroidal saponins, in a series of YNBY preparations, i. e., powder, capsules, aerosol, toothpaste, plaster, and adhesive bandage. The pre-treatment methods for each dosage form were investigated and optimized. The HPLC separation was performed on a Shim-pack C(18) reversed-phase column in gradient mode with UV detection at 203 nm. All calibration curves showed good linear regression (r(2) > or = 0.9981) within the test ranges. Precisions and repeatabilities of the methods were better than 4.22 and 4.78%, respectively. Recoveries were better than 90.5%, even in the analysis of the least abundant saponins in a complex YNBY plaster. HPLC-ESI-TOF/MS was used for definite identification of compounds in the preparations. This proposed method was successfully applied to quantify the 13 bioactive constituents in 27 commercial samples to evaluate the quality of YNBY preparations. The overall results demonstrate that this method is simple, reliable, and suitable for the quality control of YNBY. Furthermore, the retention behavior of these saponins in reversed-phase chromatography is described.

Steroidal saponins from the rhizomes of Paris delavayi

Two new steroidal saponins, padelaosides A (1) and B (2), along with two other known steroidal saponins (3 and 4) were isolated from the rhizomes of Paris delavayi. Their structures were elucidated by 1D and 2D NMR techniques, HRFTMS, physical data and chemical methods. The two different absolute configurations of fucose, assigned as l and d that were found on compounds 1 and 2, respectively, were simultaneously reported in a natural medicine for the first time.

Baeckeins F–I, four novel C-methylated biflavonoids from the roots of Baeckea frutescens and their anti-inflammatory activities

Baeckea frutescens is an aromatic shrub used in South China as an ornamental and as a spice. Four unusual C-methylated biflavonoids named baeckeins F-I (1-4) were isolated from the roots of B. frutescens. The baeckeins F-I possessed a unique carbon skeleton, a flavonol conjugated with a coumaronochromone molecule via the unusual linkages of C-2-C-8 and C-3-O-C-7. Their structures were elucidated by analysis of the 1D ((1)H/(13)C) and 2D NMR (HSQC/HMBC/NOESY) and HR-ESI-MS spectroscopic data, and the absolute stereochemistry for chiral carbons of C-2 and C-3 was established by CD spectrometry combined with quantum chemical calculations. Baeckeins F-I (1-4) were also evaluated for their anti-inflammatory activities by detecting the NO production of LPS-induced RAW264.7 murine macrophage cell line; baeckein I (4) with the β-d-glucose unit and configuration of (2R,3R) exhibited the highest NO inhibitory activity (IC50=15.2 μM), which was similar to that of the positive control indomethacin.

A novel flavanone from Ilex hainanensis Merr.

Chemical investigation of the leaves of Ilex hainanensis Merr. yielded a new flavanone named Huazhongilexone-7-O-β-D-glucopyranoside, together with five known compounds, which included caffeic acid, quercetin, isoquercitrin, quercitrin-7-O-β-D-glucopyranoside and rutin. All of the compounds were isolated from the plant for the first time. The structure of the new compound was determined on the basis of high resolution mass, 1D and 2D NMR spectroscopies including ROESY. The antioxidant activity of the new compound was assessed using the DPPH spectrophotometric and IC50 value was 10.39 µmol L−1.

Structural determination of two new triterpenoids from Potentilla discolor Bunge by NMR techniques

Two new pentacyclic triterpenoids, 3α, 30‐dihydroxylup‐20(29)‐en‐27‐oic acid (1) and (20S)‐3α, 29‐dihydroxylupan‐27‐oic acid (2) were isolated from the whole herbs of Potentilla discolor Bunge. The structures of these two new compounds were elucidated, and complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, 1H1HCOSY and ROESY). Copyright

Baeckein E, a new bioactive C-methylated biflavonoid from the roots of Baeckea frutescens

A phytochemical study of Baeckea frutescens afforded a new biflavonoid named as baeckein E (1), along with four known C-methylated flavonols, baeckeins A (2) and B (3), 6-methylquercetin (6) and 6-methylquercetin-4′-O-β-d-glucopyranoside (7), and two known biflavonoids baeckeins C (4) and D (5). The structure of compound 1 was elucidated on the basis of spectroscopic analysis, including HR-ESI-MS, 1D and 2D NMR spectra, and the absolute configurations of C-2 and C-3 for compound 1 were assigned by circular dichroism spectrometry combined with quantum chemical calculations. The antioxidant and cytoprotective activities of compounds 1–7 were also investigated.

Complete assignments of 1H and 13C NMR spectral data for three new triterpenoid saponins from Ilex hainanensis Merr.

Three new oleanane‐type triterpenoid saponins, ilexhainanoside C, D and E, all with 24, 28‐dioic acid groups, were isolated from the leaves of Ilex hainanensis. They were 3β‐hydroxyolean‐12‐ene‐24, 28‐dioic acid‐28‐O‐β‐D‐glucopyranoside(1), 3β, 19α‐dihydroxyolean‐12‐ene‐24, 28‐dioic acid‐28‐O‐β‐D‐glucopyranoside(2) and 3β, 29‐dihydroxyolean‐12‐ene‐24, 28‐dioic acid‐28‐O‐β‐D‐glucopyranoside(3). The structures of these three new compounds were elucidated and complete assignments of the 1H and 13C NMR spectroscopic data were achieved by 1D and 2D NMR experiments [heteronuclear single quantum coherence (HSQC), HMBC and rotational nuclear Overhauser effect spectroscopy (ROESY)]. Copyright

Preventive Effects of Flavonoid Extracts from Ilex hainanensis Merr. on Rats with Hepatic Steatosis Induced by a High-Fat Diet

Strategy, Management and Health Policy Preclinical Research

Prostaglandin-like fatty acid derivatives from Artemisia anomala

Four prostaglandin-like fatty acid derivatives anomalone A–D (1–4) were isolated from the aerial part of Artemisia anomala S. Moore. Their structures were determined on the basis of extensive spectroscopic analyses.