The fatty acids obtained from extractable lipids of the anaerobic sulfate bacterium Desulfovibrio desulfuricans were identified. Saturated and monoenoic iso (C15-C19) and anteiso (C15, C17) fatty acids and saturated normal (C14-C18) and monoenoic normal (C16, C18) fatty acids were shown to be shown to be present by capillary gas chromatography-mass spectrometry. Iso and anteiso beta-hydroxy fat...

252Cf plasma desorption mass spectrometry has been used in the characterization of more than 100 synthetic porphyrins ranging in mass from 614 u for tetraphenylporphyrin to over 2000 u for some porphyrin model systems. In virtually every case, 252Cf plasma desorption mass spectrometry yielded an intense ionized molecule ion [M.+ and/or (M+H)+], irrespective of the groups appended to the porphyr...

A method for isolation and quantification of fecal bile acids is described which allows sterol balance studies to be made in man or in small laboratory animals without requiring the use of radioisotopes in vivo. Bile acids are purified by column and thin-layer chromatography, converted to the trimethylsilyl ethers of their methyl esters, and quantified by GLC with detection by hydrogen flame io...

Liver microsomal cytochrome P-450 readily N-dealkylates N,N-dimethylamides. N-Methyl-N-hydroxymethyl amides were isolated as intermediates and characterized by gas chromatography-mass spectrometry as their trimethylsilyl ethers. Intramolecular kinetic deuterium isotope effects measured for the enzymic N-demethylation of a series of 12 aromatic and aliphatic N-methyl-N-trideuteriomethyl amides, ...

The mono- and disubstituted cholanoic acids present in human feces have been investigated. Extracts of feces were fractionated on silicic acid column and individual bile acids were isolated by preparative thin-layer chromatography. The isolated compounds were studied by gas-liquid chromatography of the methyl esters, partial trimethylsilyl ethers, oxidation products, and trifluoroacetates. The ...

We have isolated and characterized a monoglucuronide fraction of 9,10-secocholesta-5,7,10(19)triene-1 alpha, 3 beta, 25-triol, 5,6-cis isomer (1,25-dihydroxyvitamin D3) from rat bile. Polar radioactive metabolites of 1,25-dihydroxyvitamin D3 were purified by a sequence of chromatographic procedures which utilized Amberlite XAD-2, diethylaminohydroxypropyl Sephadex LH-20, liquid-liquid partition...

The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Q-fly), is a major horticultural pest in Eastern Australia. Effective monitoring, male annihilation technique (MAT) and mass trapping (MT) are all important for control and require strong lures to attract flies to traps or toxicants. Lure strength is thought to be related in part to volatility, but little vapour pressure data are available...

Bis(alkynyl)silanes (1a,b) react with bis(pentafluorophenyl)-borane to 3-boryl-2,5-bis(trimethylsilyl) substituted siloles 3a,b. Subsequent irradiation of 3 with Pyrex filtered UV light resulted in the complete conversion to the new 5-boryl-2,3-bis(trimethylsilyl) substituted siloles 4a,b.

We have developed a nickel-catalyzed transformation, in which phthalimides react with trimethylsilyl-substituted alkynes in the presence of Ni(0)/PMe3/MAD catalyst to provide isoindolinones. The reaction process displays an unusual mechanistic feature-decarbonylation and alkylidenation. The use of both trimethylsilyl-substiuted alkynes and MAD was found to be essential for the transformation wi...

The facile deprotection of methylene acetal protection of diols under mild conditions is established. The combination of trimethylsilyl triflate (TMSOTf) and 2,2'-bipyridyl followed by a weakly acidic hydrolysis was effective and the substrates having acid sensitive functional groups can be tolerated under the stated conditions. The selective deprotection between methylene acetal and benzopheno...