stilbenes and rhein

Visualization of tumor necrosis can determine tumor response to therapy. Our previous study showed that the rhein-based magnetic resonance imaging (MRI) contrast agent with alkane linker (GdL. Three rhein-based MRI agents were synthesized with a tetracarbon ether (GdP1), a hexacarbon ether (GdP2), and a lysine (GdP3) linker, respectively. Their octanol-water partition coefficients (log P) and cytotoxicity were determined. Necrosis avidity of the leading agent was explored on HepG2 cells and ischemia reperfusion-induced liver necrosis (IRLN) rats by MRI. The effect of visualization of tumor necrosis was tested on nude mice with W256 tumor treated by combretastatin-A4 phosphate (CA4P). DNA binding assays were applied to evaluate the possible necrosis-avidity mechanism of the leading agent.. The log P of three agents (- 1.66 ± 0.09, - 1.74 ± 0.01, - 1.95 ± 0.01) decreased when compared with GdL. GdP1 may serve as a potential candidate for early evaluation of tumor response to CA4P treatment.

Topics: Animals; Anthraquinones; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Contrast Media; Disease Models, Animal; Drug Design; Humans; Liver Neoplasms, Experimental; Magnetic Resonance Imaging; Male; Mice; Mice, Nude; Necrosis; Rats; Rats, Sprague-Dawley; Stilbenes; Tissue Distribution

This study aimed to synthesize a necrosis-avid agent using rhein as a precursor and labeled with gallium-68 (Ga-68) for positron emission tomography/computed tomography (PET/CT) imaging, to evaluate response to anticancer treatment in a mouse model.

Topics: Animals; Anthraquinones; Antineoplastic Agents, Phytogenic; Cattle; Cell Line, Tumor; DNA; Gallium Radioisotopes; Heterocyclic Compounds, 1-Ring; Male; Mice; Necrosis; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Sarcoma 180; Stilbenes; Tissue Distribution; Treatment Outcome

Two new anthraquinone glucosides [aloe-emodin 8-O-β-d-(6'-galloyl)glucopyranoside (1) and rhein 8-O-β-d-(6'-galloyl)glucopyranoside (2)], together with 16 known compounds (3-18), were isolated from the roots and rhizomes of Rheum hotaoense C.Y. Cheng et C.T. Kao. Their structures were elucidated on the basis of extensive investigation of 1D and 2D NMR, HR-ESI-MS, and chemical evidence. In addition, the free-radical-scavenging activity was tested using the 1,1-diphenyl-2-picrylhydrazyl assay.

Topics: Anthraquinones; Biphenyl Compounds; Drugs, Chinese Herbal; Free Radical Scavengers; Glucosides; Picrates; Plant Roots; Plants, Medicinal; Rheum; Rhizome; Stilbenes

A facile method using high performance liquid chromatography/electrospray ionization-ion trap-time-of-flight mass spectrometry (HPLC/ESI-IT-TOF MS) has been established for the analysis of multiple constituents in Polygonum cuspidatum Sieb. et Zucc. Six chemical standards including emodin, chrysophanol, physcion, rhein, aloe-emodin and polydatin were studied systematically and their fragmentation pathways were concluded. The methanol extract of Polygonum cuspidatum Sieb. et Zucc. was separated and analyzed by HPLC/ESI-QIT-TOF MS system in negative ion mode. A total of 10 constituents were identified or tentatively characterized with supporting results on the fragmentation pathways of 6 chemical standards and relative references. These constituents are mainly anthraquinones, stilbenes, torachryson and their derivatives, including resveratroloside, polydatin, emodin-8-O-glucoside, resveratrol, torachryson-8-O-glucoside, emodin-1-O-glucoside, torachryson-8-O-(6'-acetyl)glucoside (newly discovered), physcion-8-O-glucoside, physcion-8-O-(6'-acetyl)glucoside (newly discovered) and emodin. It is an extremely simple way by using HPLC/ESI-IT-TOF MS to provide chemical information concerning the constituents in herbal medicines and making the identification results more convinced.

Topics: Anthraquinones; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Fallopia japonica; Glucosides; Spectrometry, Mass, Electrospray Ionization; Stilbenes

A reverse-phase HPLC method was developed for simultaneous quantification of six bioactive compounds in Rhizoma et Radix Polygoni Cuspidati. These compounds--polydatin (1), resveratrol (2), rhein (3), emodin (4), chrysophanol (5) and physcion (6)--were analysed from 24 authentic samples of the herb using UV HPLC. Based on the UV absorption characteristics of the six compounds, absorption wavelengths of 306 nm were chosen to quantify compounds 1 and 2, and 290 nm for compounds 3-6. A reliable and reproducible quantitative HPLC method for analysing authentic samples of Rhizoma et Radix Polygoni Cuspidati from different cultivation regions was developed. The results showed that the concentration of compound 1 in samples from Sichuan was almost 2 fold higher than that of samples acquired in Guangxi. Furthermore, compounds 3 and 5 were not found in all the samples tested. Thus, instead of using polydatin (1) and emodin (4) as markers for quality assessment, as in conventional practice, these findings show that compounds 2 and 6 are more suited to act as marker compounds for a more specific assessment of the quality of this herb.

Topics: Anthraquinones; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Emodin; Fallopia japonica; Glucosides; Molecular Structure; Reproducibility of Results; Resveratrol; Rhizome; Stilbenes; Technology, Pharmaceutical

Extracts from Rhei Rhizoma extracts (RR) have been reported to attenuate metabolic disorders such as diabetic nephropathy, hypercholesterolemia and platelet aggregation. With this study we investigated the anti-diabetic action of 70% ethanol RR extract in streptozotocin-induced diabetic mice, and determined the action mechanism of active compounds of RR in vitro. In the diabetic mice, serum glucose levels at fasting and post-prandial states and glucose area under the curve at modified oral glucose tolerance tests were lowered without altering serum insulin levels, indicating that RR contained potential anti-diabetic agents. The fractions fractionated from RR extracts by XAD-4 column revealed that 60%, 80% and 100% methanol fractions enhanced insulin sensitivity and inhibited alpha-glucoamylase activity. The major compounds of these fractions were sennosides, rhein and rhaponticin. Rhaponticin and rhein enhanced insulin-stimulated glucose uptake in 3T3-L1 adipocytes. Rhaponticin increased adipocytes with a differentiating effect similar to pioglitazone, but rhein and sennoside B decreased triglyceride accumulation. Sennoside A and B inhibited alpha-glucoamylase activity as much as acarbose. In conclusion, a crude extract of RR improves glucose intolerance by enhancing insulin-stimulated glucose uptake and decreasing carbohydrate digestion via inhibiting alpha-glucoamylase activity. Rhein and rhaponticin are potential candidates for hypoglycemic agents.

Topics: Adipocytes; Animals; Anthraquinones; Blood Pressure; Body Weight; Cell Differentiation; Cell Line; Diabetes Mellitus, Experimental; Enzyme Inhibitors; Ethanol; Fibroblasts; Glucan 1,4-alpha-Glucosidase; Hypoglycemic Agents; Insulin; Insulin Resistance; Male; Mice; Mice, Inbred C57BL; Plant Extracts; Senna Extract; Sennosides; Solvents; Stilbenes; Triglycerides

To determine six effective components (aloe-emodin, rhein, emodin, rhaponticin, physcion and chrysophanol) in Rheum.. Using buffer solution containing 20 mmol.L-1 borax, 20 mmol.L-1 sodium deoxycholate (SDC), 20 mmol.L-1 sodium taurocholate (STC), 15 mmol.L-1 beta-cyclodextrin (beta-CD) and O-phthalic acid as the internal standard, the six components were determined by cyclodextrin modified micellar electrokinetic chromatography.. In less than 25 min, aloe-emodin, rhein, emodin, rhaponticin, physion and chrysophanol were separated. The separation conditions were optimized by adjusting buffer pH, concentrations of SDC, STC and beta-CD. The linearity ranges of aloe-emodin, rhein, emodin, rhaponticin, physcion and chrysophanol were 4-34, 5-40, 4-60, 5-80, 6-90 and 5-85 micrograms.mL-1 respectively. Relative standard deviation (RSD) of the method was less than 2.2%. The recoveries of aloe-emodin, rhein, emodin, rhaponticin, physcion and chrysophanol were 100.0%, 98.3%, 100.4%, 94.6%. 95.2% and 93.8% respectively. Raw Rheum, Mongolian Rheum and Rheum tanguticum samples were analyzed.. This method can be an effective one for identification of Rhubarb.

Topics: Anthraquinones; Chromatography, Micellar Electrokinetic Capillary; Cyclodextrins; Emodin; Plants, Medicinal; Quality Control; Rheum; Stilbenes