Penicillamine

• 2 -amino-3 -mercapto -3-methyl -butyric acid
• 3-mercapto- D -valine (D -penicillamine )
• (S ) -3,3 -Dimethyl -Cysteine
• (S)- penicillamine

M01CC01

White to off- white crystalline powder

Antidote

202-206 ° C

Slightly soluble in water, sparingly soluble in ethanol 96 %

Attention

6170 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Penicillamine is a non- proteinogenic α -amino acid. There are two enantiomers of penicillamine: D- and L- penicillamine. The D variant (D - amino acid to D, L- nomenclature, often just called DPA ) is used as a drug in Wilson's disease. D-penicillamine can also be used as chelating agents for heavy metal poisoning with lead, cadmium or mercury or rheumatism. The L- variant, however, is toxic because the body can not distinguish it from other proteinogenic amino acids, this variation of penicillamine.

Occurrence

D-penicillamine is a precursor of penicillin. In mold species that can produce penicillin in a natural way, it is therefore an intermediate product of the natural metabolism.

Production and representation

The starting material for synthetically produced from penicillin D -penicillamine is the amino acid valine. Alternatively, D -penicillamine is produced in a thirteen- step synthesis chain from isobutyraldehyde, ammonia and sulfur, with the Asinger reaction as the starting reaction.

Medical importance

D-penicillamine can also be used as a drug with

• Wilson's disease / hepatolenticular degeneration: D- penicillamine is due to its molecular structure easily chelate complexes. The thiol group has a high affinity for copper, thereby the illness excess copper can be bound to the molecule and excreted in the urine from the body.
• Heavy metal poisoning: Heavy metals can bind irreversibly to inhibit these enzymes and their function or turn it off completely. Here the chelating property of D -penicillamine is also exploited. The molecule binds any free metal ions in the body. These can then be discarded.
• Cystine: the cystine uroliths occur when excessively cysteine ​​and homocysteine ​​coalesces to form a disulfide bridge. The thiol group of D- penicillamine is able to cleave these disulfide bonds and thus dissolve the urinary stones.
• Rheumatoid arthritis: It influences here with unknown mechanism of the formation of collagen and lead to a reduction of the rheumatoid factor

Adverse effects of penicillamine (selection, sometimes to often ):

• Teratogenicity: In women of childbearing potential must be ensured an effective contraceptive.
• Skin symptoms ( often 1-10 %)
• Kidney injury (often )
• Bone marrow damage (often )
• Myasthenic syndrome ( occasionally, 0.1 to 1 %)

Interaction with other medicinal

With simultaneous use of gold preparations in the treatment of rheumatoid arthritis, the gold is bound in the complex, and thus ineffective, a combination is not suitable with azathioprine, which leads to increased bone marrow toxicity. Also, a joint application with chloroquine is contraindicated.

Toxicity

The LD50 for the oral administration of the racemate of D-and L- penicillamine is the model organism rat at 365 mg / kg. For the pure D-penicillamine no signs of toxicity even at a dose of 1200 mg / kg, however, given.

Trade names

Artamin (A), Metalcaptase (D)