page_title: Carbon suboxide
section_title: Biological role
hierarchical_section_title: Carbon suboxide / Biological role
caption_attribution_description: English: it is a 6- or 8-ring macrocyclic polymer of carbon suboxide that was found in living organisms and is acting as an endogenous digoxin-like Na+/K+-ATP-ase and Ca-dependent ATP-ase inhibitor, a natriuretic and an antihypertensiveРусский: Это 6- или 8-кольцевые макроциклические полимеры недокиси углерода, которые были обнаружены в живых организмах и являются эндогенными дигоксиноподобными ингибиторами Na+/K+-АТФ-азы, кальций-зависимой АТФ-азы, эндогенными натриуретиками и антигипертензивными веществами
context_page_description: Carbon suboxide, or tricarbon dioxide, is an oxide of carbon with chemical formula C
  3O
  2 or O=C=C=C=O. Its four cumulative double bonds make it a cumulene. It is one of the stable members of the series of linear oxocarbons O=Cₙ=O, which also includes carbon dioxide and pentacarbon dioxide. Although if carefully purified it can exist at room temperature in the dark without decomposing, it will polymerize under certain conditions.
  The substance was discovered in 1873 by Benjamin Brodie by subjecting carbon monoxide to an electric current. He claimed that the product was part of a series of "oxycarbons" with formulas Cₓ₊₁Oₓ, namely C₂O, C
  3O
  2, C₄O₃, C
  5O
  4, ..., and to have identified the last two; however, only C
  3O
  2 is known. In 1891 Marcellin Berthelot observed that heating pure carbon monoxide at about 550 °C created small amounts of carbon dioxide but no trace of carbon, and assumed that a carbon-rich oxide was created instead, which he named "sub-oxide". He assumed it was the same product obtained by electric discharge and proposed the formula C
  2O. Otto Diels later stated that the more organic names dicarbonylmethane and dioxallene were also correct.
context_section_description: Carbon suboxide, C₃O₂, can be produced in small amounts in any biochemical process that normally produces carbon monoxide, CO, for example, during heme oxidation by heme oxygenase-1. It can also be formed from malonic acid. It has been shown that carbon suboxide in an organism can quickly polymerize into macrocyclic polycarbon structures with the common formula (C
  3O
  2)ₙ (mostly (C
  3O
  2)
  6 and (C
  3O
  2)
  8), and that those macrocyclic compounds are potent inhibitors of Na⁺/K⁺-ATP-ase and Ca-dependent ATP-ase, and have digoxin-like physiological properties and natriuretic and antihypertensive actions. Those macrocyclic carbon suboxide polymer compounds are thought to be endogenous digoxin-like regulators of Na⁺/K⁺-ATP-ases and Ca-dependent ATP-ases, and endogenous natriuretics and antihypertensives. Other than that, some authors think also that those macrocyclic compounds of carbon suboxide can possibly diminish free radical formation and oxidative stress and play a role in endogenous anticancer protective mechanisms, for example in the retina.
caption: Those are 6- or 8-ring macrocyclic polymers of carbon suboxide that were found in living organisms. They are acting as an endogenous digoxin-like Na+/K+-ATP-ase and Ca-dependent ATP-ase inhibitors, endogenous natriuretics, antioxidants and antihypertensives