Restricted rotations of chemical bonds can lead to the presence of persistent conformational chirality in molecules 10 lacking stereocenters. We report the development of first-ofa- kind predictive rules that enable identification of conformational chirality and prediction of racemization barriers in the diarylether heptanoid (DAEH) natural products that do not possess...
The scientific method applies hypothesis testing to material samples through experimentation, measurement, and data analysis, which produce representations—or features—that describe phenomena of interest. Biomolecular features come in numerous forms such as values, matrices, graphs, three-dimensional structures, trajectories, and molecular surfaces. Researchers have tested thousands of features related to protein molecules...
State-of-the-art, high-resolution mass spectrometry techniques for acquisition of metabolomic and lipidomic data coupled with advanced computational methods provide new opportunities for interpreting large and complex datasets and comprehending the underlying biological processes of diseases. Both metabolomics and lipidomics strive to obtain comprehensive analyses of small molecules, i.e., metabolites and lipids,...
The need for field and laboratory studies of the physical and
chemical behavior of environmentally significant organic molecules often
poses problems because of the toxicity of the chemical and the difficulty
of detecting it at environmentally significant concentrations.
Two dysprosium tracers, dysprosium (III) trisacetylacetonate trihydrate
and dysprosium(III) trisdibenzoylmethane monohydrate, were...
The potent antitumor agent phorboxazole A was synthesized from six subunits comprising C1-C2 (115), C3-C8 (98), C9-C19 (74), C20-C32 (52), C33-C41 (84) and C42-C46 (85). Tetrahydropyrans B and C containing cis-2,6-disubstitution were fabricated via palladium(II)-mediated intramolecular alkoxycarbonylation which, in the case of tetrahydropyran C, was carried out with catalytic palladium(II)...
Manual and automatic solvent extraction techniques were used
to concentrate organic material from natural waters. Field and
laboratory extractions were compared to determine the most probable
method and best solvents for efficient concentration of organic
material from estuarine and sea waters.
The large scale extraction processes utilizing extractors made
from...
An oscillating plasma glow discharge detector for gas
chromatography is used to obtain fingerprint information
about an analyte by combining both the average cell
current and oscillation frequency signals. Five homologs
each of the n-alkanes, 1-alkenes, 1-alkynes, 2-ketones and
aldehydes are studied. Although triplicate determinations
had some scatter due to...
The development of a proline sulphonamide-catalysed method for enantioselective and diastereoselective construction of functionalized cyclohexenones is described. Impact of catalyst structure as well as solvent effects and additives are explored. A significant substrate scope is demonstrated by variation of both the aldehyde and the enone components. Diastereoselective derivatization of the...
Complex organic transformations, such as the addition of pyrrole to ketene using planar chiral organocatalyst (*PPY), the four-component anhydride- Manniach reactions, and the site-selective desymmetrization of meso-1,2-diol, are remarkable synthetic reactions that provide high yield and high selectivity. However, the exact mechanism and origins of stereocontrol for theses synthetic organic...
The intriguing size- and shape dependent properties of nanoparticles have garnered recent attention in many science and engineering areas. When the particle size is in the nanometer size range, the material exhibits very different properties such as surface plasmon resonance (of gold nanoparticles) and superparamagnetism (of iron oxide nanoparticles). The...