Divicine

From Infogalactic: the planetary knowledge core
Jump to: navigation, search
Divicine
pyrimidine tautomer
pyrimidinone tautomer
Names
IUPAC name
2,6-Diamino-4,5-dihydroxypyrimidine
Other names
2,6-Diamino-4,5-pyrimidinediol; 2,6-diamine-5-hydroxy-4(3H)-pyrimidinone; 2,4-diamino-5,6-dihydroxypyrimidine
Identifiers
32267-39-3 YesY
ChemSpider 2971290 YesY
Jmol 3D model (pyrimidine tautomer): Interactive image
(pyrimidinone tautomer): Interactive image
PubChem 91606
  • InChI=1S/C4H6N4O2/c5-2-1(9)3(10)8-4(6)7-2/h9H,(H5,5,6,7,8,10) YesY
    Key: ZMWZGZSARWJATP-UHFFFAOYSA-N YesY
  • InChI=1/C4H6N4O2/c5-2-1(9)3(10)8-4(6)7-2/h9H,(H5,5,6,7,8,10)
    Key: ZMWZGZSARWJATP-UHFFFAOYAO
  • (pyrimidine tautomer): OC1=C(O)C(N)=NC(N)=N1
  • (pyrimidinone tautomer): O=C1C(O)=C(N)NC(N)=N1
Properties
C4H6N4O2
Molar mass 142.12 g·mol−1
Appearance Brownish needles
Solubility in 10% KOH Soluble[vague]
Vapor pressure {{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY verify (what is YesYN ?)
Infobox references

Divicine (2,6-diamino-4,5-dihydroxypyrimidine) is an oxidant and a base with alkaloidal properties found in fava beans and Lathyrus sativus. It is an aglycone of vicine. A common derivative is the diacetate form (2,6-diamino-1,6-dihydro-4,5-pyrimidinedione).[1]

Occurrence

Divicine is found in fava beans and in the legume Lathyrus sativus, also known as khesari, which is a cheap and robust food source commonly grown in Asia and East Africa.

Synthesis

In plants, reduced divicine is formed from the hydrolysis of the inactive β–glucoside, vicine.[2]

A simplified three-step process for artificial divicine synthesis: (1) The benzyl group of 2-amino-5-benzyloxy-4-hydroxypyrimidine is removed by acid hydrolysis, yielding 2-amino-4,5-dihydroxypyrimidine. (2) This intermediate is then treated with nitrous acid to yield the slightly soluble orange product, 2-amino-6-nitrosopyrimidine-4,5-diol (3) which is then reduced with sodium dithionite to yield divicine.[3]

Toxicity

Divicine has been deemed a hemotoxic component of fava beans and plays a role in the development of favism, a disorder that involves a hemolytic response to the consumption of broad beans due to glucose-6-phosphate dehydrogenase (G6PD or G6PDH) deficiency. This deficiency, an X-linked recessive hereditary disease, is the most common enzyme deficiency worldwide. It is particularly common in those of African, Asian, Mediterranean, and Middle-Eastern descent. Symptoms of favism include hemolysis, prolonged jaundice, kernicterus, and even acute renal failure in extreme cases.[4]

The specific mechanism of divicine’s toxicity is still unknown. It had been established that the β–glucosides vicine and convicine were linked to the precipitation of hemolytic crises in G6PDH-deficient individuals,[5] but in a more recent study of rat erythrocyte toxicity, exposure to 1.5 mM of divicine dramatically reduced survival rates while exposure to 5 mM of vicine did not. These results suggest that divicine is a direct-acting hemolytic agent and likely the direct cause of favism.[6]

Divicine is also present in and at least partially responsible for the poisonous action of Lathyrus sativus - a legume commonly grown in drought- and famine-prone regions of Asia and East Africa as an ‘insurance crop’ for human consumption and livestock feed when other crops fail to grow, despite their known health hazards.[7]

References

  1. Lua error in package.lua at line 80: module 'strict' not found.
  2. Lua error in package.lua at line 80: module 'strict' not found.
  3. Lua error in package.lua at line 80: module 'strict' not found.
  4. Lua error in package.lua at line 80: module 'strict' not found.
  5. Lua error in package.lua at line 80: module 'strict' not found.
  6. Lua error in package.lua at line 80: module 'strict' not found.
  7. http://www.biology-online.org/dictionary/Divicine