One-electron reductive intramolecular cyclization of enones with ketones or aldehydes mediated by samarium diiodide and electrolysis to afford cis-trimethyl- hydrindanolones. The reactions gave selectivities ranging from 1:1 to 100:0 depending on the conditions.

Trimethyl (octadecyl) ammonium and it's salts is widely used as a cationic surfactant. In this study, an analytical method for trimethyl in sediment by liquid chromatography tandem-mass spectrometry (LC-MS/MS) was developed. method, measured chloride. The detection limit (MDL) quantification (MQL) were 0.00026 μg/g-dry 0.00069 μg/g-dry, respectively. This able to measure the organic or inorgani...

Influences of matrix particle size distribution (PSD) (18, 25, 35 and 50 lm) and fat content (25%, 30% and 35%) on flavour release of dark chocolate volatiles were quantified by static headspace gas chromatography using GC–MS. Sixty-eight (68) flavour compounds were identified, comprising alcohols, aldehydes, esters, ketones, furans, pyrans, pyrazines, pyridines, pyroles, phenols, pyrones and t...

A new C11-norisoprenoid derivative, sargassumone (1), has been isolated from Sargassum naozhouense together with six known norisoprenoids and a highly oxygenated cyclopentene: (2R,6S,8S,9S)-hexahydro-2,9-dihydroxy-4,4,8-trimethyl-6-acetyloxy-3(2H)-benzofuranone (2), (6S,8S,9R)-hexahydro-6,9-dihydroxy-4,4,8-trimethyl-2(2H)-benzofuranone (3), (6S,8S,9R)-hexahydro-6,9-dihydroxy-4,4,8-trimethyl-2(2...

A commercial nonylphenol (NP) reagent was separated into 14 fractions, NP1 to NP14 using a gas chromatograph equipped with a preparative fraction collector (GC-PFC). The identifi cation of the major components of 14 fractions was attempted by analysis of their nuclear magnetic resonance (NMR) spectra, and the estrogenicity of the isomers was tested in a recombinant yeast screen system. Eleven s...

Quaternary ammonium compounds (QACS) are employed both as disinfectants for manual processing lines and surfaces in the food industry, and in human medicine area. QACS also cause cell death by protein denaturation . One of the QAC is cetyl trimethyl ammonium bromide (CTAB) that appears to rapture the cell membrane. The primary site of action of CTAB has been suggested to be the lipid components...

A chiral Mn(salen) complex exhibiting two lactam binding sites at two rigid 1,5,7-trimethyl-3-azabicyclo[3.3.1]nonan-2-one skeletons is capable of enantioselective sulfoxidation due to spatially remote substrate hydrogen bonding.

glucose 6- phosphate dehydrogenase from streptomyces aureofaciens was purified andinactivated by pyridoxal 5′-phosphate (plp). the inactivation was a pseudo-first order and time-dependentreaction. complete inactivation was achieved at 0.2mm plp within 16 minutes. the type of inhibition wascompetitive with respect to glucose 6- phosphate. spectral characteristics of plp-enzyme complexcorresponde...

interaction of glucose 6-phosphate dehydrogenase from s. aureofaciens with nad+, nadp+and glucose 6-phosphate were investigated using different fluorescent probes. binding of nad+, nadp+and s-nadph to the native enzyme quenched intrinsic protein fluorescence by 100%, 10% and 21%,respectively, from which kd values of nad+ (6.5 mm), nadp+ (92.0 μm) and s-nadph (122.0 μm)were calculated. binding o...

A convenient and efficient method for deprotection of N-(trimethyl)silylethoxymethyl (SEM) groups from thymidine dinucleoside and dinucleotide has been achieved. The SEM groups were easily removed in excellent yields from protected nucleosides, dinucleosides, and dinucleotides.