Djenkolic acid
Encyclopedia
Djenkolic acid is a sulfur
-containing non-protein amino acid
naturally found in djenkol beans of the South-East Asian legumes jengkol
(Archidendron jiringa). This compound consists of two cysteine
radicals connected by a methylene group between the sulfurs, or it is 2-amino-3-[(2-amino-3-hydroxy-3-oxopropyl)sulfanylmethylsulfanyl] propanoic acid. It is toxic to humans, especially causing nephrotoxicity
.
under acidic conditions after consumption of the jenkol bean. The amino acid precipitates into crystals which cause mechanical irritation of the renal tubules and urinary tract, resulting in symptoms such as abdominal discomfort, loin pains, severe colic
, nausea, vomiting, dysuria
, gross hematuria
, and oliguria
, occurring 2 to 6 hours after the beans were ingested. 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.
Treatment for this toxicity requires hydration to increase urine flow and alkalinization of urine by sodium bicarbonate
. Furthermore, this poisoning can be prevented when consuming djenkol beans by boiling them beforehand, since djenkolic acid is removed from the beans.
who had eaten the djenkol bean and were suffering from poisoning. They then succeeded in isolating the djenkolic acid crystals from the djenkol beans treated with Ba(OH)2 at 30°C for a prolonged period of time.
Djenkolic acid was later reported to be found as much as 20 grams in every kilogram of dry djenkol beans, and it has also been reported to be found to a lesser extent in the seeds of other leguminous plants such as Leucaena esculenta (2.2 g/kg) and Pithecolobium ondulatum (2.8 g/kg).
Du Vigneaud and Patterson managed to synthesize djenkolic acid by the condensation of methylene chloride with 2 moles of L-cysteine in liquid ammonia
and to show that their synthetic compound was identical with the naturally occurring djenkolic acid. Later on, Armstrong and du Vigneaud prepared djenkolic acid by the direct combination of 1 mole of formaldehyde
with 2 moles of L-cysteine in a strongly acid solution.
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
-containing non-protein amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
naturally found in djenkol beans of the South-East Asian legumes jengkol
Jengkol
Archidendron pauciflorum, commonly known as Jengkol, Dogfruit, or Jering is a species of flowering tree in the pea family, Fabaceae, that is native to Southeast Asia...
(Archidendron jiringa). This compound consists of two cysteine
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
radicals connected by a methylene group between the sulfurs, or it is 2-amino-3-[(2-amino-3-hydroxy-3-oxopropyl)sulfanylmethylsulfanyl] propanoic acid. It is toxic to humans, especially causing nephrotoxicity
Nephrotoxicity
Nephrotoxicity is a poisonous effect of some substances, both toxic chemicals and medication, on the kidneys. There are various forms of toxicity. Nephrotoxicity should not be confused with the fact that some medications have a predominantly renal excretion and need their dose adjusted for the...
.
Toxicity
The toxicity of djenkolic acid in humans arises from its poor solubilitySolubility
Solubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a solid, liquid, or gaseous solvent to form a homogeneous solution of the solute in the solvent. The solubility of a substance fundamentally depends on the used solvent as well as on...
under acidic conditions after consumption of the jenkol bean. The amino acid precipitates into crystals which cause mechanical irritation of the renal tubules and urinary tract, resulting in symptoms such as abdominal discomfort, loin pains, severe colic
Colic
Colic is a form of pain which starts and stops abruptly. Types include:*Baby colic, a condition, usually in infants, characterized by incessant crying*Renal colic, a pain in the flank, characteristic of kidney stones...
, nausea, vomiting, dysuria
Dysuria
In medicine, specifically urology, dysuria refers to painful urination.Difficult urination is also sometimes described as dysuria.It is one of a constellation of irritative bladder symptoms, which includes urinary frequency and haematuria....
, gross hematuria
Hematuria
In medicine, hematuria, or haematuria, is the presence of red blood cells in the urine. It may be idiopathic and/or benign, or it can be a sign that there is a kidney stone or a tumor in the urinary tract , ranging from trivial to lethal...
, and oliguria
Oliguria
Oliguria is the low output of urine, It is clinically classified as an output below 300-500ml/day. The decreased output of urine may be a sign of dehydration, renal failure, hypovolemic shock, HHNS Hyperosmolar Hyperglycemic Nonketotic Syndrome, multiple organ dysfunction syndrome, urinary...
, occurring 2 to 6 hours after the beans were ingested. Urine analysis of patients reveals erythrocytes, epithelial cells, protein, and the needle-like crystals of djenkolic acid. Urolithiasis
Urolithiasis
A bladder stone is a solid concretion or crystal aggregation found in the urinary bladder...
can also happen, with djenkolic acid as the nucleus. In young children it has also been reported to produce painful swelling of the genitalia.
Treatment for this toxicity requires hydration to increase urine flow and alkalinization of urine by sodium bicarbonate
Sodium bicarbonate
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...
. Furthermore, this poisoning can be prevented when consuming djenkol beans by boiling them beforehand, since djenkolic acid is removed from the beans.
Discovery and synthesis
Djenkolic acid was first isolated by Van Veen and Hyman from the urine of the natives of JavaJava
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
who had eaten the djenkol bean and were suffering from poisoning. They then succeeded in isolating the djenkolic acid crystals from the djenkol beans treated with Ba(OH)2 at 30°C for a prolonged period of time.
Djenkolic acid was later reported to be found as much as 20 grams in every kilogram of dry djenkol beans, and it has also been reported to be found to a lesser extent in the seeds of other leguminous plants such as Leucaena esculenta (2.2 g/kg) and Pithecolobium ondulatum (2.8 g/kg).
Du Vigneaud and Patterson managed to synthesize djenkolic acid by the condensation of methylene chloride with 2 moles of L-cysteine in liquid ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
and to show that their synthetic compound was identical with the naturally occurring djenkolic acid. Later on, Armstrong and du Vigneaud prepared djenkolic acid by the direct combination of 1 mole of formaldehyde
Formaldehyde
Formaldehyde is an organic compound with the formula CH2O. It is the simplest aldehyde, hence its systematic name methanal.Formaldehyde is a colorless gas with a characteristic pungent odor. It is an important precursor to many other chemical compounds, especially for polymers...
with 2 moles of L-cysteine in a strongly acid solution.