Elemental and spectroscopic characterization of fractions of an acidic extract of oil sands process water.

'Naphthenic acids' (NAs) in petroleum produced water and oil sands process water (OSPW), have been implicated in toxicological effects. However, many are not well characterized. A method for fractionation of NAs of an OSPW was used herein and a multi-method characterization of the fractions conducted. The unfractionated OSPW acidic extract was characterized by elemental analysis, electrospray ionization-Orbitrap-mass spectrometry (ESI-MS), and an esterified extract by Fourier Transform infrared (FTIR) and ultraviolet-visible (UV) absorption spectroscopy and by comprehensive multidimensional gas chromatography-MS (GCxGC-MS). Methyl esters were fractionated by argentation solid phase extraction (Ag(+) SPE) and fractions eluting with: hexane; diethyl ether: hexane and diethyl ether, examined. Each was weighed, examined by elemental analysis, FTIR, UV, GC-MS and GCxGC-MS (both nominal and high resolution MS). The ether fraction, containing sulfur, was also examined by GCxGC-sulfur chemiluminescence detection (GCxGC-SCD). The major ions detected by ESI-MS in the OSPW extract were assigned to alicyclic and aromatic 'O2' acids; sulfur was also present. Components recovered by Ag(+) SPE were also methyl esters of alicyclic and aromatic acids; these contained little sulfur or nitrogen. FTIR spectra showed that hydroxy acids and sulfoxides were absent or minor. UV spectra, along with the C/H ratio, further confirmed the aromaticity of the hexane:ether eluate. The more minor ether eluate contained further aromatics and 1.5% sulfur. FTIR spectra indicated free carboxylic acids, in addition to esters. Four major sulfur compounds were detected by GCxGC-SCD. GCxGC-high resolution MS indicated these were methyl esters of C18 S-containing, diaromatics with ≥C3 carboxylic acid side chains.

Analogues of the styrylquinoline and styrylquinazoline HIV-1 integrase inhibitors: design and synthetic problems.

In our work, leading to new styrylquinoline and styrylquinazoline inhibitors of HIV integrase, we analyzed virtual combinatorial library that includes these compounds. Using this method we were able to find interesting synthetic targets. We optimized synthetic procedure yielding such compounds and obtained a couple of new analogues. Their activity will be evaluated in the near future.

Self-organizing neural networks for modeling 3D QSAR--a comparative study.

Different architectures of self-organizing neural networks (SOM) have been used for modeling 3D QSAR. The atomic coordinates and partial atomic charges were used as input signals. In particular, the steroids complexing corticosteroid binding globulin (CBG) that are used as a benchmark measuring the performance of drug design methods have been applied to compare between individual methods. The sensitivity of the different architectures for changes of the alignments of the molecules within series, as well as the possibility for alignments based on the molecular inertial axes have been tested.