Chemistry

Direct resolution of enantiomers of dl-amino acids by thin-layer chromatography with vancomycin as impregnating agent
Direct resolution of enantiomers of dl-amino acids by thin-layer chromatography with vancomycin as impregnating agent.


Experimental determination of Naproxen solubility in organic solvents and aqueous binary mixtures: Interactions and thermodynamic parameters relating to the solvation process
The experimental solubility of Nap in fifteen pure solvents and in eight aqueous–organic cosolvent mixtures was determined. The results obtained indicate that the π⁎ parameter which describes the polarity/polarizability of the solvent, and the Hildebrand's solubility parameter, which accounts for the cohesive forces of the solvent, have a greater influence on the solubility of Nap. This dr...
Analysis of the entropy generation in a nanofluid-filled cavity in the presence of magnetic field and uniform heat generation/absorption
This paper examines the natural convection in a square enclosure filled with a water–Al2O3 nanofluid in the presence of magnetic field and uniform heat generation/absorption. The left wall is hot, the right wall is cold and the horizontal walls are insulated. Lattice Boltzmann method (LBM) is applied to solve the coupled equations of flow and temperature fields. The entropy generation due to ...


Biomolecular Structure and Dynamics with Neutrons: The View from Simulation
The characterization of the structure and internal dynamics of biomolecules is essential to understanding their biological function. Neutron scattering probes similar time- and length-scales to molecular dynamics simulation. Hence, simulation models of biomolecules have become invaluable in the interpretation of experimental neutron data. Here, we report on advances in the application of simula...
Whole Cell Modeling: From Single Cells to Colonies
A great deal of research over the last several years has focused on how the inherent randomness in movements and reactivity of biomolecules can give rise to unexpected large-scale differences in the behavior of otherwise identical cells. Our own research has approached this problem from two vantage points – a microscopic kinetic view of the individual molecules (nucleic acids, proteins, etc.)...


Knotted Proteins under Tension
We study the behavior of two knotted proteins under stretching by a constant force within a coarse-grained structure-based model. One protein, with the structure code 1J85, has a knot that is deep and another, 2ETL, has a knot that is shallow. We demonstrate that tightening of the deep knot may take place before the ultimate end-to-end distance is achieved. However, as with proteins without kno...
Modeling Non-Native Interactions in Designed Proteins
Natural proteins have evolved amino acid sequences that provide a native-structural bias to folding. Structure-based models (SBMs) of proteins ignore all non-native interactions and encode this bias by including only interactions present in the native state. SBMs have been remarkably successful at describing the folding mechanisms and folding rates of natural proteins. Non-native interaction-en...

Exploring the Protein Folding Dynamics of Beta3s with Two-Dimensional Ultraviolet (2DUV) Spectroscopy
Ultraviolet (UV) spectra of proteins originate from electronic excitations of their backbone chromophore and aromatic side chains and provide a sensitive probe of the secondary structure. Recently developed femtosecond lasers allow multidimensional spectroscopy to be extended into the UV regime. Two-dimensional UV (2DUV) techniques, with short pulses, provide a promising tool to study the struc...
QM/MM through the 1990s: The First Twenty Years of Method Development and Applications
The 2013 Nobel Prize in Chemistry was awarded to the authors of the first two publications utilizing the concept of combined quantum mechanical and molecular mechanical (QM/MM) methods. In celebrating this great event in computational chemistry, we review the early development of combined QM/MM techniques and the associated events that took place through the mid-1990s. We also offer some prospe...

Quantum dots modified with the Al(III)-pefloxacin complex as a novel bioprobe for the sensitive turn-on and dual-fluorescence detection of dsDNA
We describe a novel fluorescent bioprobe for the sensitive and selective detection of double-stranded DNA (dsDNA). It consists of quantum dots (Q-dots) whose fluorescence is quenched (through photoinduced electron transfer) on covering them with the Al(III)-pefloxacin complex. It is found, however, that dsDNA has an affinity for this complex that is so strong that it can break up the binding to...
Bioactivity studies of oxysporone and several derivatives
Recently oxysporone, a phytotoxic dihydrofuropyranone, was isolated along with two closely related compounds, afritoxinones A and B, from liquid cultures of Diplodia africana, an invasive fungal pathogen of Phoenicean juniper. In this study, eight derivatives were hemisynthesized and assayed for their phytotoxic and antifungal activities in comparison to the parent compound. Each compound was t...

Two new sesquiterpenes from the fungus Stereum sp. NN048997
Two new sesquiterpenes, sterostreins P (1) and Q along with a known compound sterostrein H were isolated from the EtOAc extract of a culture broth of Stereum sp. NN048997. Their structures were elucidated based on spectroscopic data from 1D, 2D NMR and HRMS experiments. Compound 1 exhibited weak nematicidal activity against the Caenorhabditis elegans nematode.
Water-Soluble Coenzyme Q10 Inhibits Nuclear Translocation of Apoptosis Inducing Factor and Cell Death Caused by Mitochondrial Complex I Inhibition
The objectives of the study were to explore the mechanism of rotenone-induced cell damage and to examine the protective effects of water-soluble Coenzyme Q10 (CoQ10) on the toxic effects of rotenone. Murine hippocampal HT22 cells were cultured with mitochondrial complex I inhibitor rotenone. Water-soluble CoQ10 was added to the culture media 3 h prior to the rotenone incubation. Cell viability ...
Effects of Lead on the Morphology and Structure of the Nucleolus in the Root Tip Meristematic Cells of Allium cepa L
To study the toxic mechanisms of lead (Pb) in plants, the effects of Pb on the morphology and structure of the nucleolus in root tip meristematic cells of Allium cepa var. agrogarum L. were investigated. Fluorescence labeling, silver-stained indirect immunofluorescent microscopy and western blotting were used. Fluorescence labeling showed that Pb ions were localized in the meristematic cells an...
The Constituents of Roots and Stems of Illigera luzonensis and Their Anti-Platelet Aggregation Effects
Phytochemical investigation of the roots and stems of Illigera luzonensis afforded two new aporphine alkaloids (1) and , one new bisdehydroaporphine alkaloid , and one new benzenoid , along with 28 known structures. The structures of new compounds were elucidated by spectral and MS analysis. Among the isolated compounds, (1) and (4–13) were subjected into the examination for their inhibitory ...