Photo-oxidation products from the reaction of a series of alkyl-benzenes, (benzene, toluene, p-xylene and 1,3,5-trimethyl-benzene) with hydroxyl radicals in the presence of NOx have been investigated using comprehensive gas chromatography (GCXGC). A GCXGC system has been developed which utilises valve modulation and independent 5 separations as a function of both volatility and polarity. A numb...

A protease, ;trypsinogenase', secreted in small amounts by the sea-urchin blastula, is assayed in two steps as an example of enzyme-amplifying kinetics. In reaction 1 the trypsinogenase catalyses the activation of trypsinogen to trypsin. In reaction 2 the trypsin catalyses the hydrolysis of N-alpha-toluene-p-sulphonylarginine methyl ester, at a rate that is linear with trypsinogenase concentrat...

A general study is undertaken to examine the scope of the reductive ring opening of aziridine-2-carboxylates with samarium diiodide. The competition between C-C and C-N bond cleavage is examined as a function of the nature of the N-substituent of the aziridine, the nature of the substituent in the 3-position of the aziridine, and whether the substituent in the 3-position is in a cis or trans re...

Techniques for detecting and quantifying anaerobic transformations of benzene, toluene, ethylbenzene, and xylene (BTEX) are needed to assess the feasibility of using in situ bioremediation to treat BTEX-contaminated groundwater aquifers. Deuterated surrogates of toluene (toluene-d8) and xylene (o-xylene-d10) were injected into BTEX-contaminated aquifers during single-well push-pull tests to mon...

The study analyzed the exposure factors that may lead to neuropsychological symptoms among 92 workers who were exposed to xylene and toluene and 100 workers who were not exposed to the solvents. The airborne concentration of xylene and toluene was evaluated with personal passive badges. The levels of methyl hippuric acid and hippuric acid in urine were assessed, and interviews were performed to...

In the structure of the title compound, C30H40O6S, the cyclo-hexene and heterocyclic rings are linked by a double bond. The cyclo-hexene ring has a half-chair conformation (the methyl-ene group adjacent to the hy-droxy substituent lies above the remaining atoms) and the hy-droxy and eth-oxy groups have equatorial and bis-ectional dispositions, respectively. The heterocyclic ring has an envelope...

The enzyme-substrate complex is inherently transient, rendering its detection difficult. In our framework designed for bisubstrate systems-isotope-labeled, activity-based identification and tracking (IsoLAIT)-the common substrate, such as S-adenosyl-l-methionine (AdoMet) for methyltransferases, is replaced by an analogue (e.g., S-adenosyl-l-vinthionine) that, as a probe, creates a tightly bound...

The possible role of alterations of histone methylation by ethionine in the mechanism of ethionine carcinogenesis was studied. In regenerating rat liver, histone synthesis was inhibited by only 20 to 30% with large doses of ethionine (0.75 to 1.0 mg/g body weight). The effect of ethionine on the in vivo methylation of histones was studied by giving 0.5 mg ethionine and [methyl-3H]methionine per...