Paula
WHAT, I thought it came from the Fluoreo tree that grows out in West Texas and
in the mountains in Utah. I heard the way it was discovered was when the Glow
Injuns were hunting Jacklopes at night under a blue moon after the Jacklopes
had eaten berries off of the Fluoreo tree all day
Bill
Paula Morris <paula.morris@xxxxxxxxxxxx> 7/9/2010 2:07 PM >>>
Hey Sarah,
The rumor exists because it was stated to be a vegetable dye extracted from a
plant resin first by Duke-Elder, and then by J Federman in the Intravenous
Fluorescein Angiography chapter in Duane's Clinical Ophthalmology, 1991. That
has since been corrected in more recent editions of Duane's.
Fluorescein's basic component is naphthalene (an extract from the carbolic
acid fraction of coal tar). It is heated with mercury sulfate and copper
sulfate to 400-500 degrees Celsius to become phthallic anhydride. It is then
heated with resorcinol to 200 degrees C. to become resorcinolphthalein, or
fluorescein, which is highly insoluble. When resorcinolphthalein is dissolved
in sodium hydroxide solution, it becomes fluorescein sodium which is highly
soluble and what we use in retinal angiography.
Why do I know this? Because our own Joe Warnicki challenged me back in 1990 to research
"Where Does Fluorescein Come From?" That quest led me to research HJ Conn's
biological Stains, the Merck index: An Encyclopedia of Chemicals, Drugs and Biologicals,
Remington's Pharmaceutical Sciences, and Drug Facts and Comparisons. Fluorescein Sodium is a
synthetic dye assigned by the government to be called F,(food), D (drugs), & C(cosmetics)
color yellow #8. The F,D,C colors are only given to synthetic dyes.
So - it has a vegetable base if you want to harken back to pre-historic history
as plants contributed to the formation of coal deposits, but more recently I
think you could safely say it has a mineral source - naphthalene, ths tuff that
makes moth balls stink. Probably don't want to tell you patients
that...............
And Thus endeth the chemistry lesson!
p
From: optimal-bounce@xxxxxxxxxxxxx [mailto:optimal-bounce@xxxxxxxxxxxxx] On
Behalf Of Sarah Moyer
Sent: Friday, July 09, 2010 10:06 AM
To: optimal@xxxxxxxxxxxxx
Subject: [optimal] Vegetable Dye
July is here and so are the new residents! During a lecture/discussion about
fluorescein sodium yesterday, we discussed how fluorescein sodium is a
synthetic dye and NOT a vegetable dye. One of them had already read/heard it
was a vegetable dye. He asked if there were ever ingredients in the dye that
were vegetable based and if that is why this rumor exists. Does anybody know
why some people refer to it as a vegetable dye?
Thanks!
Sarah Moyer
University of North Carolina
