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| Names | |
|---|---|
| IUPAC name (2R)-2-Amino-3-[[(2R)-2-amino-3-hydroxy-3-oxopropyl] sulfanylmethylsulfanyl]propanoic acid | |
| Other names Djenkolate; Jengkolic acid; S,S'-Methylenebiscysteine[1] | |
| Identifiers | |
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3D model (JSmol) | |
| ChEBI | |
| ChemSpider |
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| ECHA InfoCard | 100.007.150 |
| EC Number |
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| KEGG |
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| UNII | |
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| Properties | |
| C7H14N2O4S2 | |
| Molar mass | 254.33 g/mol |
| 1.02 g L−1 (at 30±0.5°C)[2] | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Djenkolic acid (or sometimesjengkolic acid) is asulfur-containing non-proteinamino acid naturally found in the djenkol beans of the Southeast Asian plantArchidendron jiringa. Its chemical structure is similar tocystine but contains a methylene (single carbon) unit in between the two sulfur atoms. There is about 20 grams of djenkolic acid per kilogram of dry djenkol beans, and it has also been reported in smaller amounts in the seeds of other leguminous plants such asLeucaena esculenta (2.2 g/kg) andPithecolobium ondulatum (2.8 g/kg).[3]
The toxicity of djenkolic acid in humans arises from its poorsolubility under acidic conditions after consumption of the djenkol bean.[3] The amino acid precipitates into crystals which cause mechanical irritation of therenal tubules andurinary tract, resulting in symptoms such as abdominal discomfort, loin pains, severecolic, nausea, vomiting,dysuria, grosshematuria, andoliguria, occurring 2 to 6 hours after the beans were ingested.[4] Urine analysis of patients reveals erythrocytes, epithelial cells, protein, and the needle-like crystals of djenkolic acid.Urolithiasis can also happen, with djenkolic acid as the nucleus. In young children, it has also been reported to produce painful swelling of the genitalia.[5]
Treatment for this toxicity requires hydration to increase urine flow and alkalinization of urine bysodium bicarbonate. Furthermore, this poisoning can be prevented when consuming djenkol beans by boiling them beforehand, since djenkolic acid is removed from the beans.[4]
Djenkolic acid was first isolated by Van Veen and Hyman in 1933[6] from the urine of the natives ofJava who had eaten the djenkol bean and were suffering from poisoning. They then isolated the djenkolic acid crystals by treating the djenkol beans withbarium hydroxide at 30°C for a prolonged period.[2]
Du Vigneaud and Patterson managed to synthesize djenkolic acid by condensation ofmethylene chloride with 2 moles of L-cysteine in liquidammonia.[2] Later on, Armstrong and du Vigneaud prepared djenkolic acid by the direct combination of 1 mole offormaldehyde with 2 moles of L-cysteine in a strongly acidic solution.[7]
