Re: HYB: more questions - pigment extraction

Linda, I share your frustration as to what these various molecularly pure
pigments would look like.

I want to refer back to something Chuck Chapman pointed out in a Lycopene
discussion some time ago.  In Tomatoes, the "red" we see is a result of two
pigments (at least two, I might suggest)--one of which is the orange-red
Lycopene, the other something resulting in an expressed color much redder than
Lycopene alone.  He didn't say what, but my guess is that it is a red
anthocyanin.

Your mention of going after Impatiens or geranium (Pelargonium) pigments in
hoping to find redder oil-soluble forms may result in a surprise.  Pelargonium
flowers are "red" due to an anthocyanin not a whole lot different from our
familiar Delphinidin in bearded irises, not to Lycopene.  If you are after
Lycopene, try Capsicum (peppers), which I think you already have.

The parent molecule of the Pelargonium (geranium)--Pelargonidin--reds has a
hydroxyl -OH at the 4' position of the B ring substituted for the hydrogen H
of the flavylium molecule ancestral to all anthocyanins and about five other
classes of pigments.  In contrast, the Delphinidin parent molecule has
hydroxyls at the 3', 4' and 5' of the B ring.  Pelargonidin-based pigments can
range from scarlet forward toward mauve.

Delphinidin, at least in the  form we have in irises, is a dull mauve isolated
and in "pure" form.  The slightly violet side of blue we call "true blue" in
iris is a result of a whole raft of modifying factors, and apparently in at
least one case (JANE PHILLIPS) to the co-factors without any Delphinidin at
all.

The reason I say "parent" molecule is that in living tissues, these
anthocyanidin molecules have various sugars substituting for the hydrogen ion
at one or more positions on the A ring.  Which sugar, how many and where they
are hung makes for variation in the expressed color of the pigments.

So do some other factors--the presence of co-pigments and chelation of various
metal ions, plus other things we haven't even identified as yet, I suspect.

Also, since plastids, which carry the oil-soluble pigments, occur primarily in
the central, supportive layer of the petals (the mesophyll) in discrete dot
form, and the water-soluble pigments occur primarily in the relatively large
vacuoles of the cells in the epidermal layers, front and back, in diffuse
solution form, both additive color and subtractive color mixing occurs.

Our human color vision has a complex of sorting or splitting procedures
beginning at the retina and continuing in a structure just above the ears,
both sides of the head but rather deep inside, then final processing,
including the merger of the vision from the two parts of our vision giving
"stereo" effects in the back of the head.

Additive and subtractive color mixing are very different when some parts of
color mixing are involved.  Yellow plus blue makes green in "subtractive" yet
makes white in "additive" mixtures.  The fact that  Color TV's have three
colors--red, green and blue--and we end up seeing yellow illustrates how
complex our color vision is.

Nearly everything I've said above can be found in TWOI.  It just gives a
person a headache, perhaps worse than those that result from reading some of
my posts.

Whew!  How complex can this get!

So, Linda, who is going to clean up your kitchen when you get through?

Neil Mogensen  z 7 western NC mountains

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