Re: HYB: Abbey Road pigments

Just a comment about cell structure and dynamics that may reassure you,
Linda, that the solvents have access to the pigments, wherever they are
located.

Cells connect directly.  The internal solutions of cells connect through
cell walls so that in time some materials diffuse throughout a plant, some
do not, depending on the sizes of the molecules and their affinities for
water or lack thereof plus some other variables.

Some, for example, are highly responsive to gravity gradients, not just
solvents.

The plastid membranes (and other internal membranous structures in cells)
are double layer structures that are made up of various lipids ("-sterols"
including a substantial amount of cholesterol) with various inclusions that
allow for passage of various molecules inward and outward from the
enclosure.  Oil soluble pigments are held tightly in protected zones away
from aqueous solutions.

Your different solvents will access different structures within the cell
given time.  Maceration speeds up the process considerably.

The vacuolar pigments, including anthocyanins, are in enclosures of a
structure which can occupy a large proportion (up to 90% or more) of cell
volume in some cells, explaining why Dr. Meckenstock's recent micro-photos
at 100x make many of those cells containing visible anthocyanins appear
entirely full.  They aren't, but do look that way.  The internal makeup of a
vacuole is also complex with a great deal of activity going on, but so
transparent it is difficult to observe without extraordinary illuminations,
such as polarized lighting.

You will note in other photos that the carotenoid pigments, including
Lycopene, are in cells that give very different impressions from those with
anthocyanins.  The carotenoids form sharp, precise dots in the tissue.

I suspect that different alcohols and different oils will give unlike
results in "kitchen chemistry" extractions.  Just as a caution, one might
want to standardize on a set of solvents that match Chuck Chapman's that
have been shown to work.  That might make interpretation of the results
somewhat more certain, particularly as the two of you compare results.

Pigment molecules are subtle in their relation to other chemicals and can
shift values, color and various other properties depending on a lot of
variables, including but not limited to pH.

Neil Mogensen  z 7  Reg 4  western NC mountains

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