Dimercaptosuccinic acid

Structural formula
Structural formula without specifying the stereochemistry
General
Non-proprietary name	Succimer (mixture of the three stereoisomers)
other names	2,3-disulfanyl succinic acid ( IUPAC ) 2,3-disulfanylbutanedioic acid 2,3-dithio tartaric acid DMSA
Molecular formula	C 4 H 6 O 4 S 2
Brief description	colorless solid
External identifiers / databases
CAS number 2418-14-6 (unspecified) 304-55-2 ( meso ) 10008-75-0 (2 R , 3 R ) 27887-82-7 (2 S , 3 S ) EC number 219-334-5 ECHA InfoCard 100.017.577 PubChem 9354 ChemSpider 8988 DrugBank DB14089 Wikidata Q56604713
properties
Molar mass	182.22 g mol −1
Physical state	firmly
Melting point	196  ° C
solubility	soluble in water and ethanol (25 g / l)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 315-319-335-361 P: 302 + 352
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dimercaptosuccinic acid ( DMSA from English Dimercaptosuccinic acid ) is an organic acid. In the meso form it forms water-soluble complexes with most heavy metals . This is therefore used in chelation therapy after heavy metal poisoning (Chemet ^® , USA).

Isomerism

Dimercaptosuccinic acid contains two stereocenters substituted by the same radicals, so there are three stereoisomers : the (2 R , 3 R ) form, the mirror image (2 S , 3 S ) form and the diastereomeric meso- dimercaptosuccinic acid.

Stereoisomers of 2,3-dimercaptosuccinic acid

(2 rows , 3 rows )	(2 R , 3 S ) ≡ (2 S , 3 R ) = ( meso )	(2 S , 3 S )

In the meso form, one of the stereocenters is ( R ) - the other ( S ) -configured .

use

As a complexing agent for the radioactive technetium isotope ^99m Tc, DMSA is also used in medical diagnostics (e.g. in kidney scintigraphy ).

In the case of acute heavy metal poisoning with mercury , lead or arsenic , DMSA or DMPS are used in infusion solutions as part of chelation therapy and are the means of choice here; In the case of chronic heavy metal poisoning - with the exception of lead poisoning in childhood - there are not yet sufficient data for meaningful use. Because of reported side effects succimer (DSMA) is subject to an opinion of the since 2017 BfArM the prescription .

Reports that DMSA can cross the blood-brain barrier in mice do not seem to have a solid basis, as DMSA lacks the lipophilic property necessary to cross the blood-brain barrier. It is rapidly metabolized by the human body and almost entirely excreted in the urine. Their half-life in the blood is around 3.2 hours. Known side effects include skin rashes , digestive tract disorders, and in some cases neutropenia . Nevertheless, DMSA is considered to be the most tolerated of the dimercapto chelates.

Individual evidence

1. ↑ ^{a b c d e} data sheet meso-2,3-Dimercaptosuccinic acid, 97% from AlfaAesar, accessed on December 26, 2019 ( PDF )(JavaScript required) .
2. ↑ External identifiers of or database links to (2 R , 3 R ) -dimercaptosuccinic acid : CAS number: 10008-75-0, PubChem : 197883 , ChemSpider : 171276 , Wikidata : Q81978333 .
3. ↑ External identifiers or database links to meso-2,3-dimercaptosuccinic acid : CAS number: 304-55-2, EC number: 206-155-2, ECHA InfoCard: 100.005.597 , PubChem : 2724354 , ChemSpider : 2006502 , DrugBank : DB00566 , Wikidata : Q423814 .
4. ↑ Use of chelating agents in environmental medicine? (PDF; 16 kB) Announcement of the Federal Environment Agency , Bundesgesundheitsbl - Gesundheitsforsch - Gesundheitsschutz 42 (19), (1999), pp. 823–824.
5. ↑ Succimer opinion of the Expert Committee on Prescription Requirements of the Federal Institute for Drugs and Medical Devices (June 28, 2016)
6. ↑ Jan Aasath, Dag Jacobsen, Ole Andersen, Elsa Wickstrøm: Treatment of Mercury and Lead Poisonings with Dimercaptosuccinic Acid (DMSA) and Sodium Dimercaptopropanesulfonate (DMPS) . In: Analyst . 120, March 1995, pp. 853ff.
7. ↑ Wolfgang Bayer: Implementation, reference ranges and interpretation of the DMPS test A critical data analysis (PDF; 1.8 MB) www.himbeerrot-design.de. 2008. Retrieved on February 22, 2011.
8. ^ ^{A b} James Rooney: The role of thiols, dithiols, nutritional factors and interacting ligands in the toxicology of mercury . In: Toxicology . 234, 2007, pp. 145-156. doi : 10.1016 / j.tox.2007.02.016 . PMID 17408840 .
9. ↑ GianPaolo Guzzi, Caterina AM La Porta: Molecular mechanisms triggered by mercury . In: Toxicology . 244, 2008, pp. 1-12. doi : 10.1016 / j.tox.2007.11.002 . PMID 18077077 .

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !