wedelolactone and coumestan

Biocatalysis plays an important role in the synthesis of complex organic molecules. Wedelolactone, a natural coumestan, has been reported to have many bioactive properties. A novel and efficient enzyme obtained from sweet potato juice was used for condensation of 4-hydroxycoumarins with catechols to produce wedelolactone and its structurally diverse analogs in moderate to good yields under mild reaction conditions. Hence, this enzymatic approach creates an opportunity to access many coumestan-based compounds that are potential building blocks for the synthesis of pharmaceutically important molecules.

Topics: Biocatalysis; Coumarins; Secondary Metabolism

Suberase®, a commercial laccase from Novozymes, was used to catalyse the synthesis of coumestans. The yields, in some cases, were similar to or better than that obtained by other enzymatic, chemical or electrochemical syntheses. The compounds were screened against renal TK10, melanoma UACC62 and breast MCF7 cancer cell-lines and the GI

Topics: Antineoplastic Agents; Biocatalysis; Cell Line, Tumor; Cell Proliferation; Coumarins; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Laccase; Molecular Structure; Structure-Activity Relationship

Wedelolactone (WEL), a medicinal plant-derived coumestan, has been reported to exhibit a diverse range of pharmacological activities. However, the metabolism and disposition of WEL remain unexplored.. The present study aims to investigate the metabolism of WEL in rats and identify the enzymes responsible for forming major WEL metabolites.. Plasma, urine, feces, and bile samples were collected before and after 50 mg/kg WEL was orally administered to rats. Metabolites were profiled by ultrahigh performance liquid chromatography/quadrupole time-of-flight mass spectrometry and identified by high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy. The in vitro WEL glucuronidation activities of human liver microsomes, human kidney microsomes, human intestine microsomes, and 12 recombinant human uridine diphosphate-glucuronosyltransferase (UGT) isoforms were screened. Molecular docking simulation of the interaction between WEL and UGT1A9 was conducted.. WEL underwent extensive metabolism, and 17 metabolites were identified. The major metabolic pathways observed were glucuronidation and methylation. Glucuronic acid was preferentially introduced into 5-OH, whereas no obvious regioselectivity was observed in the methylation of 11-OH and 12-OH. Multiple UGTs, including UGT1A1, UGT1A3, UGT1A6, UGT1A7, UGT1A8, UGT1A9, and UGT1A10, were involved in forming WEL glucuronides and O-methylated WEL glucuronides.. The extensive glucuronidation and methylation is responsible for the low oral bioavailability of WEL in rats. UGT1A1 and UGT1A9 were the major enzymes involved in the glucuronidation of WEL and O-methylated WEL. Molecular docking studies revealed that 5-OH was accessible to the catalytic domain of UGT1As; therefore, 5-OH exhibited a high probability of glucuronidation.

Topics: Animals; Asteraceae; Biological Availability; Coumarins; Glucuronic Acid; Glucuronides; Glucuronosyltransferase; Humans; Intestinal Mucosa; Kidney; Liver; Male; Mass Spectrometry; Methylation; Microsomes; Molecular Docking Simulation; Plant Extracts; Protein Isoforms; Rats; UDP-Glucuronosyltransferase 1A9; Uridine Diphosphate

Signal transducers and activators of transcription 1 (STAT1) transduces signals from cytokines and growth factors, particularly IFN-γ, and regulates expression of genes involved in cell survival/death, proliferation, and migration. STAT1 is activated through phosphorylation on its tyrosine 701 by JAKs and is inactivated through dephosphorylation by tyrosine phosphatases. We discovered a natural compound, wedelolactone, that increased IFN-γ signaling by inhibiting STAT1 dephosphorylation and prolonging STAT1 activation through specific inhibition of T-cell protein tyrosine phosphatase (TCPTP), an important tyrosine phosphatase for STAT1 dephosphorylation. More interestingly, wedelolactone inhibited TCPTP through interaction with the C-terminal autoinhibition domain of TCPTP. We also found that wedelolactone synergized with IFN-γ to induce apoptosis of tumor cells. Our data suggest a new target for anticancer or antiproliferation drugs, a new mechanism to regulate PTPs specifically, and a new drug candidate for treating cancer or other proliferation disorders.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cell Survival; Coumarins; Drug Screening Assays, Antitumor; Gene Expression Regulation, Neoplastic; Genes, Reporter; Hep G2 Cells; Humans; Interferon-gamma; Phosphoric Monoester Hydrolases; Phosphorylation; Plant Extracts; Promoter Regions, Genetic; RNA Interference; STAT1 Transcription Factor

Coumestan wedelolactone is an important phytocomponent from Eclipta alba (L.) Hassk. It possesses diverse pharmacological activities, which have prompted the development of various extraction techniques and strategies for its better utilization. The aim of the present study is to develop and optimize supercritical carbon dioxide assisted sample preparation and HPLC identification of wedelolactone from E. alba (L.) Hassk.. The response surface methodology was employed to study the optimization of sample preparation using supercritical carbon dioxide for wedelolactone from E. alba (L.) Hassk. The optimized sample preparation involves the investigation of quantitative effects of sample preparation parameters viz. operating pressure, temperature, modifier concentration and time on yield of wedelolactone using Box-Behnken design. The wedelolactone content was determined using validated HPLC methodology. The experimental data were fitted to second-order polynomial equation using multiple regression analysis and analyzed using the appropriate statistical method.. By solving the regression equation and analyzing 3D plots, the optimum extraction conditions were found to be: extraction pressure, 25 MPa; temperature, 56 °C; modifier concentration, 9.44% and extraction time, 60 min. Optimum extraction conditions demonstrated wedelolactone yield of 15.37 ± 0.63 mg/100 g E. alba (L.) Hassk, which was in good agreement with the predicted values.. Temperature and modifier concentration showed significant effect on the wedelolactone yield. The supercritical carbon dioxide extraction showed higher selectivity than the conventional Soxhlet assisted extraction method.

Topics: Calibration; Carbon Dioxide; Chemical Fractionation; Chromatography, High Pressure Liquid; Coumarins; Eclipta; Indicators and Reagents; Quality Control; Regression Analysis; Reproducibility of Results; Research Design

Coumestans 2a-i, bearing different patterns of substitution in A- and D-rings, were synthesized and evaluated as inhibitors of kidney Na+, K+ -ATPase and ligands for the central benzodiazepine (BZP) receptor. The presence of a hydroxyl group in position 2 favours the effect on Na+, K+ -ATPase but decreases the affinity for the BZP receptor, allowing the design of more selective molecules than the natural wedelolactone. On the other hand, the presence of a catechol in ring D is important for the effect on both molecular targets.

Topics: Catechols; Coumarins; Drug Design; Enzyme Inhibitors; Humans; Kidney; Ligands; Protein Binding; Receptors, GABA-A; Sodium-Potassium-Exchanging ATPase; Structure-Activity Relationship