AndersHoveland
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Parrot feather pigments
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In many birds, red, orange and yellow feathers are coloured by carotenoid pigments, but parrots are an exception. For over a century, biochemists have
known that parrots use an unusual set of pigments to produce their rainbow of plumage colours, but their biochemical identity has remained elusive
until recently. Here, we use high-performance liquid chromatography to survey the pigments present in the red feathers of 44 species of parrots
representing each of the three psittaciform families. We found that all species used the same suite of five polyenal lipochromes (or psittacofulvins)
to colour their plumage red, indicating that this unique system of pigmentation is remarkably conserved evolutionarily in parrots. Species with redder
feathers had higher concentrations of psittacofulvins in their plumage.
Scientists believe that the brilliant parrot colors arise from either supramolecular or covalent interactions of the psittacofulvins with structural
proteins in feathers, with shorter chain psittacofulvins producing yellow colors and longer chains producing red. Green feathers arise from a
combination of a psittacofulvin and melanin, and blue and black feathers come from melanin alone.
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psittacofulvin chemical structure:
O=CH-(CH=CH)n-CH3
where n = 6-9
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1629064/
http://cen.acs.org/articles/88/i44/Parrot-Pigments-Preserve-...
I wonder if it is possible to make these colored psittacofulvins with amateur chemistry. Perhaps use HBr on a polyalcohol, and then use NaOH to pull
off the bromine groups, leaving the unsaturated chain? But what about that aldehyde group, which is not stable with respect to NaOH ? Are there any
selective oxidizing agents that can oxidize an alcohol to an aldehyde group without oxidizing unsaturated chains?
[Edited on 2-7-2013 by AndersHoveland]
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Morgan
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Parrot color tidbit.
"The two sexes of this species, unlike those of any other parrot, differ dramatically in color. The females, depending on the variety, are a
spectacular combination of red, purple, maroon, blue and yellow; the males are almost entirely green, with red under the wings and on the side of the
body, with a touch of turquoise on top of the "shoulders"."
http://www.eclectusparrot.com/crosbcc.shtml
"However, the plumage of both sexes appears spectacular when viewed in the ultraviolet spectrum, an ability which predators such as hawks and owls
lack."
http://en.wikipedia.org/wiki/Eclectus_Parrot
[Edited on 2-7-2013 by Morgan]
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solo
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Reference Information
Fascinating Organic Molecules from Nature
3. Colours in Flight – Pigments from Bird Feathers and Butterfly Wings
N R Krishnaswamy and C N Sundaresan
RESONANCE
January 2013
Abstract
Among the most colourful objects found in Nature are bird
feathers and butterfly wings. Their beauty is more obvious
when a bird or a butterfly is in flight as the colour of the
pigments present in wings and feathers is accentuated by
refraction and reflection of incident light by the nanokeratinoid
structural elements in the feather. Thus, when a
bird or a butterfly flaps its wings the effect is kaleidoscopic.
The pigments responsible for the primary colours of bird
feathers and butterfly wings are discussed here.
Attachment: facinating Organic Molecules fro Nature.pdf (1.3MB)
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It's better to die on your feet, than live on your knees....Emiliano Zapata.
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Morgan
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“There’s an average distance between particles, even though there is no ordering in the particles. It’s that average distance that is important
in determining the color,” says Manoharan, Gordon McKay Professor of Chemical Engineering and Professor of Physics at Harvard.
Brighter inks, without pigment
http://www.seas.harvard.edu/news/2014/03/brighter-inks-witho...
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