Abstract
We have determined the framework structure of Myochrysine (disodium gold(I)thiomalate) in the
solid state and extremely concentrated aqueous solution, previously. It consists of an open chain polymer
with linear gold coordination to two thiolates from the thiomalic acid moieties which bridge between pairs
of gold atoms providing an Au-S-Au angle of 95°. The question remained: was this structure relevant to
the dilute solutions of drugs administered and the still lower concentrations of gold found in the bodies of
patients (typically 1 ppm Au in blood and urine or 5 μM in Au). We have provided an answer to that
question using extended X-ray absorption spectroscopy (EXAFS) and capillary zone electrophoresis
(CZE). EXAFS studies confirm that the polymeric structure with two sulfur atoms per gold atom persists
from molar concentrations down to millimolar concentrations. CZE is able to separate and detect
Myochrysine at millimolar levels. More importantly, at micromolar levels Myochrysine solutions exhibit
identical CZE behavior to that measured at millimolar levels. Thus, aqueous solutions of the drug remain
oligomeric at concentrations commensurate with those found in patient blood and urine.The reactivity of Myochrysine with cyanide, a species especially prevalent in smoking patients,
was explored using CZE. Cyanide freely replaces thiomalic acid to form