GOLD(I) SODIUM THIOMALATE 329

Preparation

Gold(III) oxide is prepared by heating gold(III) hydroxide, Au(OH)3 at 130 to 140°C:

130−140oC

2Au(OH)3 → Au2O3 + 3H2O

Analysis

Elemental composition: Au 89.15%, O 10.86%. Gold(III) oxide is acid digested, the acid extract diluted appropriately with water and analyzed for gold by atomic absorption spectrophotometry or other instrumental techniques (see Gold).

GOLD(I) SODIUM THIOMALATE

[12244-57-4]

Formula: Gold(I) sodium thiomalate is a mixture of monosodiumand disodi- um-salts of gold thiomalate; the respective molecular formulas being C4H4AuNaO4S (monosodium salt) and C4H3AuNa2O4S (disodium salt); a tetrameric structure with S—Au—S linear units.

Structure:
CH2COONa		CH2COONa
|		|
CHCOOH	• H2O	CHCOONa • H2O
|		|
S—Au		S—Au
(monosodium salt)		(disodium salt)

Synonyms: sodium aurothiomalate; mercaptobutanedioic acid monogold (1+) sodium salt; Myochrysine; Mycocrisin; Shiosol

Uses

The compound is a drug for the treatment of rheumatoid arthritis. The mode of transport of this drug in the body involves the exchange of thiomalate ligands in vivo and the binding of Au(I) to –SH and S—S units of proteins, such as blood serum albumin.

Physical Properties

White to yellowish white powder; odorless; metallic taste; highly soluble in water; practically insoluble in ethanol and ether.

Preparation

Gold(I) thiomalate is prepared by reacting sodium thiomalate with gold(I) halide. It is stored in the dark and otherwise protected from light.