Structural development of liver X receptor (LXR) antagonists derived from thalidomide-related glucosidase inhibitors

Following our previous discovery of LXR antagonistic activity of 2'-substituted phenylphthalimides derived from thalidomide-related glucosidase inhibitors, structure-activity studies and further structural development led to 5-chloro-N-2'-n-pentylphenyl-1,3-dithiophthalimide (5CPPSS-50), with IC50 values of about 10 and 13 microM for LXRalpha and LXRbeta, respectively.     

Hydrolyzed metabolites of thalidomide: synthesis and TNF-alpha production-inhibitory activity

Putative hydrolyzed metabolites of thalidomide were prepared and characterized, and their inhibitory activity on tumor necrosis factor (TNF)-alpha production in the human monocytic leukemia cell line THP-1 was evaluated. Alpha-(2-Carboxybenzamido)glutarimide was a more potent TNF-alpha production inhibitor than thalidomide.     

Light-scattering detection with a fluorimetric detector in high-performance liquid chromatography

Non-fluorescence compounds were detected by a fluorescence detector based on scattering light. The fluorescence detector was used without any modification, and the scattering light was observed at the wavelength twice as long as the excitation wavelength. Actually the wavelength of the observed scattering light was the same as that of the excitation light. The maximum signal was achieved at around 280 nm. The signal was increased with increasing molecular weight or size of analytes. Colloidal silica with nanometer sizes, ethylene glycol oligomers, saccharides and cyclodextrins could be visualized by the present detection method. The detection limit at S/N=3 for colloidal silica with 78 nm was 39 pg for 20-microL injection.     

Simple one-step extraction and cleanup by pressurized liquid extraction for gas chromatographic-mass spectrometric determination of pesticides in green leafy vegetables

A simple one-step extraction and cleanup using a pressurized liquid extraction method was developed for the gas chromatographic-mass spectrometric determination of pesticides in vegetables. The pressurized liquid extraction conditions were optimized and cleanup agents were evaluated. The investigated pesticides included six insecticides, chlorpyrifos methyl, pirimiphos-methyl, malathion, chlorpyrifos, O-ethyl O-4-nitrophenylphenyl phosphonothioate (EPN) and permethrins, a fungicide, isoprothiolane, and a herbicides, thiobencarb. The cleanup agent and a mixture of the vegetable and anhydrous sodium sulfate were separately packed in an extraction vessel. A transparent and colorless extract was obtained using graphitized carbon as the cleanup agent. The overall recoveries were 71-103% and the relative standard deviations ranged from 5.6 to 24%. The limit of detection values were 3-8 microg kg(-1). This method was successfully applied to green leafy vegetables.     

Titanocene(II)-promoted stereoselective alkenylation utilizing (Z)-alkenyl sulfones

The stereoselective alkenylation of unsaturated compounds by means of a (Z)-alkenyl sulfone-titanocene(II) system is described. Treatment of alkynes and (Z)-alkenyl methyl sulfones with the titanocene(II) reagent Cp2Ti[P(OEt)3]2 produced conjugated dienes. This alkenylation system is also applicable to polar C=O bonds; the simple mixing of carbonyl compounds, (Z)-alkenyl methyl sulfones, and the titanocene(II) reagent formed allylic alcohols. The advantages of alkenylation are that it requires no prepreparation of the alkenylmetal reagent and that it proceeds with complete stereoselectivity.     

Resin-packed nanoelectrospray in combination with video and mass spectrometry for the direct and real-time molecular analysis of mast cells

A nano-electrospray ionization (nanoESI) emitter for analysis of a biological solution was developed by packing a nanoESI needle with two types of resins for desalting and preconcentration of target molecules. Determination of secreted histamine and serotonin molecules in cell culture buffers was demonstrated using 5-methyltryptamine as internal standard. The results showed good linearity of target signals in the concentration range from 0.25 to 50.0 ng/mL of histamine or serotonin. These molecules were monitored to be secreted by A23187 (calcium ionophore) stimulant in rat peritoneal mast cells. Using a combination of a video-microscope and a mass spectrometer, we could visualize exocytotic moments and analyze secreted molecules by mass spectrometry simultaneously. Time-dependent release of histamine and serotonin from activated mast cells showed that significant production of these molecules occurred and reached a maximal level at 15 min for serotonin and at 30 min for histamine, respectively. These results showed that this method allows the direct and timely analysis of secreted molecules in biological responses.     

Preparation of 2-deoxy-2-C-p-tolylsulfonyl-beta-D-glucopyranosyl p-tolylsulfones having non-chair conformation and their elimination reactions

When the title sulfones, which have non-chair conformations, were stirred with silica gel, elimination of sulfinic acid occurred to give a 1-enitol derivative, if the hydroxyl group at C-6 was protected, whereas such an elimination did not proceed if the hydroxy group was free.     

Nucleophilic deoxyfluorination of catechols

Nucleophilic deoxyfluorinaiton of one of the two hydroxyl groups of catechols has been developed via the Umpolung concept. This method was successively applied to naturally occurring catechols, such as catechins and dopamine, to produce novel fluorinated analogues.     

Triacylglycerol/phospholipid molecular species profiling of fatty livers and regenerated non-fatty livers in cystathionine beta-synthase-deficient mice, an animal model for homocysteinemia/homocystinuria

Fatty liver is one of the typical manifestations in homocysteinemia/homocystinuria patients and their genetic animal model, mice lacking cystathionine ??-synthase (Cbs ^?/?). The vast majority of Cbs ^?/? die within 4?weeks after birth via yet unknown mechanisms, whereas a small portion survive to adulthood, escaping fatty degeneration of the liver during lactation periods, through regeneration. To investigate the molecular basis of such fatty changes, we analyzed lipid components in fatty livers of 2-week-old Cbs ^?/? and regenerated non-fatty livers of 8-week-old Cbs ^?/? survivors using a chip-based nanoESI (electrospray ionization)-MS system, which allows quantitative detection of triacylglycerol/phospholipid molecular species. Hepatic levels of all major triacylglycerol species were much higher in Cbs ^?/? than in wild-type mice at 2?weeks, although not at 8?weeks. Levels of some phospholipid species were either up- or downregulated in 2-week-old Cbs ^?/?; e.g. saturated (16:0 and 18:0) or mono-unsaturated (16:1 and 18:1) fatty acids-containing phosphatidylcholine/phosphatidylethanolamine species were upregulated, while poly-unsaturated fatty acids-containing phosphatidylcholine (18:2?C18:2 and 18:2?C20:5), phosphatidylethanolamine (18:1?C20:4), and phosphatidylinositol (18:0?C20:4) were downregulated. Capillary electrophoresis-MS analysis identified high-level accumulation of S-adenosylmethionine and S-adenosylhomocysteine in fatty livers of 2-week-old Cbs ^?/? but much less in non-fatty livers of 8-week-old Cbs ^?/?. Although hepatic S-adenosylmethionine/S-adenosylhomocysteine ratios were comparable between 2-week-old Cbs ^?/? and wild-type, global protein arginine methylation was disturbed in fatty livers of Cbs ^?/?. Our results suggest that cellular signaling mediated by altered phospholipid contents might be involved in pathogenesis of fatty liver in Cbs ^?/?C.