3 research outputs found
Multigram Scale Synthesis of A21, A New Antibiotic Equally Effective and Less Toxic than Amphotericin B
A21
(<b>2</b>) is a new polyene macrolide Amphotericin B
amide antibiotic derived from amphotericin B AmB (<b>1</b>),
which has been tested extensively on preclinical trials showing the
same antimycotic effectiveness and increased margin of safety over
AmB (<b>1</b>). We present the multigram scale synthesis, isolation,
purity assessment by HPLC, and key aspects of its characterization
by NMR studies of A21 (<b>2</b>)
Xāray Accelerated Photo-Oxidation of As(III) in Solution
We performed near edge X-ray absorption
spectroscopy (XANES) measurements on the arsenic K-edge of AsĀ(III)
in solution under acidic and basic conditions, after exposure of the
solutions to air. Spectra were recorded for increasing exposure times
to the X-rays used to perform absorption spectroscopy measurements.
We did not find changes for the solution under acidic conditions,
whereas we observed significant changes in the case of solution under
alkaline conditions. To interpret these changes, we compared the obtained
spectra with XANES spectra of AsĀ(III) and AsĀ(V) solutions under alkaline
conditions, not exposed to air, and used as standards. Principal component
fits using these standards indicate an accelerated conversion of AsĀ(III)
to AsĀ(V) due to the exposure to X-rays