page_title: Polyyne
section_title: Biological origins
hierarchical_section_title: Polyyne / Natural occurrence / Biological origins
caption_attribution_description: English: Skeletal structure of Z-dihydromatricaria acid.
context_page_description: In chemistry, a polyyne is any organic compound with alternating single and triple bonds; that is, a series of consecutive alkynes,
  ₙ with n greater than 1. The simplest example is diacetylene or butadiyne, H−C≡C−C≡C−H.
  These compounds have also been called oligoynes, or carbinoids after "carbyne"
  ∞, the hypothetical allotrope of carbon that would be the ultimate member of the series. The synthesis of this substance has been claimed several times since the 1960s, but those reports have been disputed. Indeed, the substances identified as short chains of "carbyne" in many early organic synthesis attempts would be called polyynes today.
  Polyynes are distinct from polyacetylenes, polymers formally obtained by polymerization of acetylenes. The backbones of polyacetylenes have alternating single and double bonds n. In biochemistry and plant biology, "polyacetylene" is routinely used to describe naturally occurring polyynes and related species.
  Along with cumulenes, polyynes are distinguished from other organic chains by their rigidity, which makes them promising for molecular nanotechnology. Polyynes have been detected in interstellar molecular clouds where hydrogen is scarce.
context_section_description: A wide range of organisms synthesize polyynes. These chemicals have various biological activities, including as flavorings and pigments, chemical repellants and toxins, and potential application to biomedical research and pharmaceuticals.
  The simple fatty acid 8,10-octadecadiynoic acid is isolated from the root bark of the legume Paramacrolobium caeruleum of the family Caesalpiniaceae and has been investigated as a photopolymerizable unit in synthetic phospholipids.
  Thiarubrine B is the most prevalent among several related light-sensitive pigments that have been isolated from the Giant Ragweed (Ambrosia trifida), a plant used in herbal medicine. The thiarubrines have antibiotic, antiviral, and nematocidal activity, and activity against HIV-1 that is mediated by exposure to light.
  Falcarindiol is the main compound responsible for bitterness in carrots, and is the most active among several polyynes with potential anticancer activity found in Devil's club (Oplopanax horridus).
  Other polyynes from plants include oenanthotoxin and cicutoxin. Polyynes including falcarindiol can be found in Apiaceae vegetables like carrot, celery, fennel, parsley and parsnip where they show cytotoxic activities. Aliphatic C₁₇-polyynes of the falcarinol type were described to act as metabolic modulators and are studied as potential health-promoting nutraceuticals.
  Ichthyothere is a genus of plants whose active constituent is a polyyne called ichthyothereol. This compound is highly toxic to fish and mammals. Ichthyothere terminalis leaves have traditionally been used to make poisoned bait by indigenous peoples of the lower Amazon basin.
  Dihydromatricaria acid is a polyyne produced and secreted by the soldier beetle as a chemical defense.
caption: Z-Dihydromatricaria acid
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