Inorganic chemistry,polyenes are poly-unsaturated,organic compounds that contain at least three alternatingdouble (C=C) andsingle (C−C)carbon–carbon bonds. These carbon–carbon double bonds interact in a process known asconjugation, resulting in some unusualoptical properties. Related to polyenes aredienes, where there are only two alternating double and single bonds.
The following polyenes are used asantimycotics for humans:amphotericin B,nystatin,candicidin,pimaricin, methyl partricin, andtrichomycin.[1]
Some polyenes are brightly colored, an otherwise rare property for a hydrocarbon. Normally alkenes absorb in theultraviolet region of aspectrum, but the absorption energy state of polyenes with numerous conjugated double bonds can be lowered such that they enter the visible region of the spectrum, resulting in compounds which are coloured (because they contain achromophore). Thus many naturaldyes contain linear polyenes.
Polyenes tend to be more reactive than simpler alkenes. For example, polyene-containingtriglycerides are reactive towards atmospheric oxygen.Polyacetylene, which partially oxidized or reduced, exhibits high electrical conductivity. Mostconductive polymers are polyenes, and many haveconjugated structures. Poly(aza)acetylenes are readily prepared frompyridine precursors without the necessity of a controlled atmosphere, simply byultraviolet irradiation of a mixture of pyridine and poly(4-vinyl) pyridine.[citation needed] Recent research at theWeizmann Institute andAix-Marseille University showed a clear transition between ionic and electronic conductivity with increasing UV dose over 30 hours.[2]
A fewfatty acids are polyenes. Another class of important polyenes arepolyene antimycotics,[3]
![Amphotericin B is an example of a polyene antifungal (antimycotic) agent.[4]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aAmphotericin_B_new.svg)
![Polyacetylenes are a synthetic polymer of theoretical interest because they exhibit metallic properties upon oxidation.[5]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aTrans-Polyacetylene.svg)
