What is Phenylalanine?
Liebling
Is this the stuff that makes pop so addictive?
-Maura
Paul R. Brown
>This compound, listed as a "phenylketonuric", is in all diet sodas.
>Is this the stuff that makes pop so addictive?
It's nutrasweet(r), which sounds much more appetizing than phenylalanine...
Me personally, I'd rather get fat than die of some obscure brain condition
brought on by a supposedly safe chemical that makes lots of people lots of
money. (btw, diet pop, due to the fact that it still contains phosphoric
acid, is just as bad for your teeth as the straight stuff! And, to complete
my cliffclavenism, white bread, not candy, is responsible for most of
childhood toothdecay. Sugar is not really so bad...)
pb
David B. Gordon
>-Maura
Phenylalanine is one of the 20 natually occuring amino acids.
Its structure is simply a phenyl group attached to the C-alpha
carbon. What makes it interesting is that it is also the fundamental
component of Aspartame (made by Nutrasweet), which differs from the
natural amino acid only by the additon of a methyl group to the
carboxy terminus, and an aspartic acid to the amino-terminus. (Hence
the "Aspart-" part of the name.)
The other interesting thing about about Phenylalanine is that
a small percentage of the population (~1% ?) lacks the enzyme to
degrade proteins containing it. This condition is called
"phenylketonuria." Since the biochemistry of these individuals
doesn't know what to do with phenylalanine, it just leaves it alone,
and the peptides build up until they reach dangerous levels.
Therefore, phenylketonurics have to monitor their intake of
phenylalanine-containing products. The diet soda industry seems
happy to help.
Hope this helps,
--Ben
John Douglas Porter
>This compound, listed as a "phenylketonuric", is in all diet sodas.
>Is this the stuff that makes pop so addictive?
Phenylalanine is an amino acid. Amino acids are the building blocks of
proteins. Though not all possible amino acids are found in Nature,
phenylalanine is naturally-occurring. So, it is also naturally in many
foods. It is not addictive in the usual sense of the word [unless you are
a compulsive eater :) ]. The only thing I know of in pop that might be
considered clinically addictive is caffeine [CAS No. 58-08-2].
The artificial sweetner 'Nutrasweet' (tm) is aspartame [CAS no.
22839-61-8]. Chemically, it is a dimer composed of two amino acids linked
by an amide bond then terminated by a methyl ester, usually denoted as
ASP-PHE methyl ester. The two amino acid residues are aspartamine and
phenylalanine. Both are naturally-occurring in proteins.
The molecule can be 'hydrolysed' [literally translated: split apart by the
addition of water] in reactions that are catalyzed by acids (e.g. HCl in the
stomach) and bases, and the reaction rate is greatly enhanced at higher
temperatures. When aspartame undergoes hydrolysis, one of the products
is phenylalanine.
Products which contain aspartame also carry the warning "Phenylketonurics:
contains phenylalanine". This is aimed at people who have the disease
Phenylketonurea (sp?), usually abbreviated 'PKU'. People with this
disease have a greatly diminished capacity to metabolize phenylalanine
and/or its derivatives, so it builds up in their bodies to high levels,
with negative physiological consequences. I am not an M.D.; you can look
up the disease and its symptoms for yourself.
The important point, though, is that PKU is an inherited, genetic disease.
All babies born in NAm (at least) are tested for the presence of the
condition immediately after birth, because PKU has quite serious
consequences in terms of development if it is not treated (through diet).
If you have the disease, you already know it. You cannot get the disease
by eating or not eating a particualar food or substance. In particular,
you cannot acquire PKU by eating aspartame or phenylalanine, regardless of
the amount.
J.P.
Wendy Shaffer
of a lot of other things - it is a naturally occuring amino acid. The
reason why nutrasweet has been reported to have neurological effects in
large doeses is because it is converted in the body to tyrosine, which
can in turn be converted into several neurotransmitters - dopamine,
norepinephrine and epinephrine. So ingestion of large amounts of
phenylalanine can overload the body's ability to regulate these various
interconversions, and people develop overloads of neurotransmitters and
have seizures - but you have to drink at least a sixpack a day, maybe more.
The phenylketonurics part is a warning to people with phenylketonuria, a
disease resulting from a genetic deficiency of phenylalanine hydroxylase,
the enzyme that converts phenylalanine to tyrosine. Children born with
this defect have to eat a diet low in phenylalanine and high in tyrosine
for most of the early years of their life. If untreated, the disease
causes mental retardation. Most hospitals routinely screen children for
this condition when they are born.
--wendy
--
Wendy Shaffer
(sha...@minerva.cis.yale.edu)
Shaffer's Law: The length of the thread is proportional to the distance
from the topic.
Michael Moroney
Liebling <lieb...@smartdocs.com> wrote:
> This compound, listed as a "phenylketonuric", is in all diet sodas.
> Is this the stuff that makes pop so addictive?
It is an amino acid, harmless (and helpful) to most of us, but some people
have a genetic problem that prevents them from digesting it, and to these
it's toxic. They must only eat foods low in this amino acid. Nutrasweet
is composed of this and another amino acid and is therefore very high
in this amino acid, and thus bad for those people (phenylketonurics).
-Mike
Bryan Bertoglio
>This is the chemical name of the substance commercially marketed (by one
>manufacturer) as "Nutra-Sweet (R)." The warning is there because it's
>very bad news for that small segment of the population whose kidneys
>can't handle it and related compounds; those people are called
>phenylketonurics.
>people buy a lot of diet soda with it in. I'm just waiting for the Feds
>to decide it's even more harmful than saccharine or sodium cyclamate...
Correct me if I'm wrong, and I'm not looking up sources here, but it was
my beleif that phenylalanine is simply an amino acid, and one of the
products of the metabolism of Nutra-Sweet.
It is also my beleif that there have been no harmful effects baring side
effects in some linked to Nutra-Sweet, unlike both saccharine and sodium
cylamate.
Opinion =!= Misinformation
-Bryan Bertoglio
ScottK1845
Opinion =!= Misinformation
-Bryan Bertoglio
**
Phenylalanine is an amino acid that, in some people, can build up in
people lacking the proper enzyme that breaks it down. This can cause
servere brain damage. Infants that have PKU (1 in 100,000) have to have
their diets regulated as to not give them too much phenylalanine.
FYI: When beverages containg Nurta-Sweet reach a temperature of 85*C,
some of it breaks down into formaldehyde.
Timothy Gerard Connor
phenylalanine and asparagine? its IUPAC name is I believe
L-Aspartyl-L-Phenylalanine methyl ester
PKU is phenylketonuria an enzyme deficiency that leads to a faulty
metabolism of phenylalanine that leads to mental retardation.
isn't that lovely hhhhmmmmm?