Abstract: The environmental pollution by heavy metals became
more problematic nowadays. To solve the problem of Cadmium
accumulation in human organs which lead to dangerous effects on
human health, and to determine its concentration, the organic legand
1-phenyl-3-benzoyl-2-thiourea was used to extract the cadmium ions
from its solution. This legand as one of thiourea derivatives was
successfully synthesized. The legand was characterized by NMR and
CHN elemental analysis, and used to extract the cadmium from its
solutions by formation of a stable complex at neutral pH. The
complex was characterized by elemental analysis and melting point.
The concentrations of cadmium ions before and after the extraction
were determined by Atomic Absorption Spectrophotometer (AAS).
The data show the percentage of the extract was more than 98.7% of
the concentration of cadmium used in the study
Abstract: This research project aims to investigate difference in
relative rates concerning phosphoryl transfer relevant to biological
catalysis of DNA and RNA in the pH-independent reactions.
Activated Models of DNA and RNA for alkyl-aryl phosphate diesters
(with 4-nitrophenyl as a good leaving group) have successfully been
prepared to gather kinetic parameters. Eyring plots for the pH–
independent hydrolysis of 1 and 2 were established at different
temperatures in the range 100–160 °C. These measurements have
been used to provide a better estimate for the difference in relative
rates between the reactivity of DNA and RNA cleavage. Eyring plot
gave an extrapolated rate of kH2O = 1 × 10-10 s -1 for 1 (RNA model)
and 2 (DNA model) at 25°C. Comparing the reactivity of RNA
model and DNA model shows that the difference in relative rates in
the pH-independent reactions is surprisingly very similar at 25°. This
allows us to obtain chemical insights into how biological catalysts
such as enzymes may have evolved to perform their current
functions.