Myricetin has known human metabolites that include (2S,3S,4S,5R)-6-[5,7-Dihydroxy-4-oxo-2-(3,4,5-trihydroxyphenyl)chromen-3-yl]oxy-3,4,5-trihydroxyoxane-2-carboxylic acid.
... Addition of apigenin, chrysin, fisetin, flavonone, galangin, hesperitin, kaempferol, morin, myricetin, haringenin, or quercetin to human liver microsomes inhibited the hydroxylation of benzo(a)pyrene. In contrast to these results, the addition of flavone, nobiletin, tangeretin, or 7,8-benzoflavone to human liver microsomes caused a many-fold stimulation in the hydroxylation of benzo(a)pyrene, the metabolism of aflatoxin B1 to 2,3-dihydro-2,3-dihydroxyaflatoxin B1, and the metabolic activation of aflatoxin B1 to mutagenic products. ... An examination of the structural features required for the inhibition and stimulation of benzo(a)pyrene hydroxylation indicated that all of the 12 flavonoid inhibitors that were studied possessed hydroxyl groups whereas the flavonoid activators were less polar molecules that lacked hydroxyl groups.
... Myricetin suppresses UVB-induced cyclooxygenase-2 (COX-2) expression in mouse skin epidermal JB6 P+ cells. The activation of activator protein-1 and nuclear factor-kappaB induced by UVB was dose-dependently inhibited by myricetin treatment. Western blot and kinase assay data revealed that myricetin inhibited Fyn kinase activity and subsequently attenuated UVB-induced phosphorylation of mitogen-activated protein kinases. Pull-down assays revealed that myricetin competitively bound with ATP to suppress Fyn kinase activity. Importantly, myricetin exerted similar inhibitory effects compared with 4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine, a well-known pharmacologic inhibitor of Fyn. In vivo mouse skin data also revealed that myricetin inhibited Fyn kinase activity directly and subsequently attenuated UVB-induced COX-2 expression. Mouse skin tumorigenesis data clearly showed that pretreatment with myricetin significantly suppressed UVB-induced skin tumor incidence in a dose-dependent manner. Docking data suggest that myricetin is easily docked to the ATP-binding site of Fyn, which is located between the N and C lobes of the kinase domain. Overall, these results indicated that myricetin exerts potent chemopreventive activity mainly by targeting Fyn in skin carcinogenesis.
... Bor-tezomib is a dipeptide boronate proteasome inhibitor that has activity in the treatment of multiple myeloma but is not effective in chronic lymphocytic leukemia (CLL). Although CLL cells are sensitive in vitro to bortezomib-induced apoptosis when cultured in medium, the killing activity was blocked when cultured in 50% fresh autologous plasma. Dietary flavonoids, quercetin and myricetin, which are abundant in plasma, inhibited bortezomib-induced apoptosis of primary CLL and malignant B-cell lines in a dose-dependent manner...
The purpose of this study was to investigate the potential neuroprotective effects of myricetin (flavonoid) and fraxetin (coumarin) on rotenone-induced apoptosis in SH-SY5Y cells, and the possible signal pathway involved in a neuronal cell model of Parkinson's disease. ... Rotenone caused a time- and dose-dependent decrease in cell viability and the degree of LDH release was proportionally to the effects on cell viability. Cells were pretreated with fraxetin, myricetin and N-acetylcysteine at different concentrations for 30 min before exposure to rotenone. Cytotoxicity of rotenone (5 uM) for 16 hr was significantly diminished as well as the release of LDH into the medium, by the effect of fraxetin, myricetin and N-acetylcysteine, with fraxetin (100 uM) and N-acetylcysteine (100 uM) being more effective than myricetin (50 uM)...
The effects of myricetin on either MRP1 or MRP2 mediated vincristine resistance in transfected MDCKII cells were examined. The results obtained show that myricetin can inhibit both MRP1 and MRP2 mediated vincristine efflux in a concentration dependent manner. The IC50 values for cellular vincristine transport inhibition by myricetin were 30.5+/-1.7 uM for MRP1 and 24.6+/-1.3 uM for MRP2 containing MDCKII cells. Cell proliferation analysis showed that the MDCKII control cells are very sensitive towards vincristine toxicity with an IC50 value of 1.1+/-0.1 uM. The MDCKII MRP1 and MRP2 cells are less sensitive towards vincristine toxicity with IC50 values of 33.1+/-1.9 and 22.2+/-1.4 uM, respectively. In both the MRP1 and MRP2 cells, exposure to 25 uM myricetin enhances the sensitivity of the cells towards vincristine toxicity to IC50 values of 7.6+/-0.5 and 5.8+/-0.5 uM, respectively. The increase of sensitivity represents a reversal of the resistance towards vincristine as a result of MRP1 and MRP2 inhibition...
... Significant quantities of quercetin and possibly myricetin and kaempferol are absorbed in the gut. A larger fraction probably remains in the lumen, and thus a substantial proportion of the gastrointestinal mucosa is exposed to biologically significant concentrations of these compounds. ...
Chemical modification of the natural flavonoid myricetin
摘要:
A review is presented of our own results on the synthesis of nitro-, amino-, azo-, and bromo- derivatives of myricetin, as a result which 19 new derivatives have been obtained The compounds synthesized are of interest as substances with potential antitumoral, antimicrobial, antifungal, antioxidant, and antitubercular activities.
Leaves of Eugenia edulis contain the new polyoxygenated flavonoid derivatives, gossypetin-3,8-dimethyl ether-5-O-beta-glucoside; gossypetin-3,5-dimethyl ether, and myricetin-3,5,3'-trimethyl ether. In addition, ten known polyphenolics were also isolated and identified. All structures were established on the basis of chemical and spectral evidence, including ESI-MS and C-13 NMR. (C) 2003 Elsevier Ltd. All rights reserved.
SUBSTITUTED BRIDGED UREA ANALOGS AS SIRTUIN MODULATORS
申请人:GLAXOSMITHKLINE LLC
公开号:US20150152108A1
公开(公告)日:2015-06-04
The present invention relates to novel substituted bridged urea compounds, corresponding related analogs, pharmaceutical compositions and methods of use thereof. Sirtuin-modulating compounds of the present invention may be used for increasing the lifespan of a cell, and treating and/or preventing a wide variety of diseases and disorders, which include, but are not limited to, for example, diseases or disorders related to aging or stress, diabetes, obesity, neurodegenerative diseases, cardiovascular disease, blood clotting disorders, inflammation, cancer, and/or flushing as well as diseases or disorders that would benefit from increased mitochondrial activity. The present invention also related to compositions comprising a sirtuin-modulating compound in combination with another therapeutic agent.
[EN] SUBSTITUTED BRIDGED UREA ANALOGS AS SIRTUIN MODULATORS<br/>[FR] ANALOGUES D'URÉE PONTÉS SUBSTITUÉS EN TANT QUE MODULATEURS DE SIRTUINE
申请人:GLAXOSMITHKLINE IP NO 2 LTD
公开号:WO2016079709A1
公开(公告)日:2016-05-26
The present invention relates to novel substituted bridged urea analog compounds of Formula (I) or pharmaceutically acceptable salts thereof, corresponding pharmaceutical compositions, processes for making and use of such compounds, alone or in combination with other therapeutic agents, as Sirtuin Modulators useful for increasing lifespan of a cell, and for use in treating and/or preventing a wide variety of diseases and disorders, which include, but are not limited to, for example, diseases or disorders related to aging or stress, diabetes, obesity, neurodegenerative diseases, cardiovascular disease, blood clotting disorders, inflammation, cancer, and/or flushing as well as diseases or disorders that would benefit from increased mitochondrial activity.
[EN] AMINE-LINKED C3-GLUTARIMIDE DEGRONIMERS FOR TARGET PROTEIN DEGRADATION<br/>[FR] DÉGRONIMÈRES DE C3-GLUTARIMIDE LIÉS À UNE AMINE POUR LA DÉGRADATION DE PROTÉINES CIBLES
申请人:C4 THERAPEUTICS INC
公开号:WO2017197051A1
公开(公告)日:2017-11-16
This invention provides amine-linked C3-glutarimide Degronimers and Degrons for therapeutic applications as described further herein, and methods of use and compositions thereof as well as methods for their preparation.
Accurate Prediction of Glucuronidation of Structurally Diverse Phenolics by Human UGT1A9 Using Combined Experimental and In Silico Approaches
作者:Baojian Wu、Xiaoqiang Wang、Shuxing Zhang、Ming Hu
DOI:10.1007/s11095-012-0666-z
日期:2012.6
Catalytic selectivity of human UGT1A9, an important membrane-bound enzyme catalyzing glucuronidation of xenobiotics, was determined experimentally using 145 phenolics and analyzed by 3D-QSAR methods. Catalytic efficiency of UGT1A9 was determined by kinetic profiling. Quantitative structure activity relationships were analyzed using CoMFA and CoMSIA techniques. Molecular alignment of substrate structures was made by superimposing the glucuronidation site and its adjacent aromatic ring to achieve maximal steric overlap. For a substrate with multiple active glucuronidation sites, each site was considered a separate substrate. 3D-QSAR analyses produced statistically reliable models with good predictive power (CoMFA: q2 = 0.548, r2 = 0.949, r pred 2 = 0.775; CoMSIA: q2 = 0.579, r2 = 0.876, r pred 2 = 0.700). Contour coefficient maps were applied to elucidate structural features among substrates that are responsible for selectivity differences. Contour coefficient maps were overlaid in the catalytic pocket of a homology model of UGT1A9, enabling identification of the UGT1A9 catalytic pocket with a high degree of confidence. CoMFA/CoMSIA models can predict substrate selectivity and in vitro clearance of UGT1A9. Our findings also provide a possible molecular basis for understanding UGT1A9 functions and substrate selectivity.
通过实验使用145种酚类化合物,并通过3D-QSAR方法分析,确定了人UGT1A9的催化选择性。UGT1A9是一种重要的膜结合酶,催化外源性物质的葡糖醛酸化反应。通过动力学分析确定了UGT1A9的催化效率。使用CoMFA和CoMSIA技术分析了定量结构活性关系。通过将葡糖醛酸化位点及其相邻的芳香环重叠,实现了底物结构的最大立体重叠。对于具有多个活性葡糖醛酸化位点的底物,每个位点被视为单独的底物。3D-QSAR分析产生了统计上可靠的模型,具有良好的预测能力(CoMFA:q2=0.548,r2=0.949,r pred 2=0.775;CoMSIA:q2=0.579,r2=0.876,r pred 2=0.700)。通过轮廓系数图阐明了底物中负责选择性差异的结构特征。将轮廓系数图叠加在UGT1A9的同源模型的催化口袋中,能够高度自信地识别UGT1A9的催化口袋。CoMFA/CoMSIA模型可以预测底物的选择性和UGT1A9的体外清除率。我们的发现还提供了理解UGT1A9功能和底物选择性的可能分子基础。
[EN] COMBINATIONS AND DOSING REGIMES TO TREAT RB-POSITIVE TUMORS<br/>[FR] COMBINAISONS ET RÉGIMES POSOLOGIQUES POUR TRAITER DES TUMEURS RB-POSITIVES
申请人:G1 THERAPEUTICS INC
公开号:WO2016040858A1
公开(公告)日:2016-03-17
This invention directed to methods for treating select RB-positive cancers and other Rb- positive abnormal cellular proliferative disorders using CDK4/6 inhibitors in specific dosing and combination or alternation regimes. In one aspect, treatments of select RB-positive cancers are disclosed using specific CDK4/6 inhibitors in combination or alternation with another chemotherapeutic, for example, an additional kinase inhibitor, PD-1 inhibitor, or BCL-2 inhibitor, or combination thereof.