J. Chem. Soc., Perkin Trans. 2, 1989, 1617 - 1622, DOI: 10.1039/P29890001617
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Kinetic study of the Schiff-base formation between glycine and pyridoxal 5-phosphate (PLP), pyridoxal (PL), and 5-deoxypyridoxal (DPL)
Miguel Angel Vázquez, Gerardo Echevarría, Francisco Muñoz, Josefa Donoso and Francisco García Blanco
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The formation of Schiff bases between pyridoxal 5-phosphate (PLP), pyridoxal (PL), 5-deoxypyridoxal (DPL), and glycine has been investigated as a
function of proton concentration at 25 °C and 0.1 mol dm–3 ionic strength. Ionization constants as well as equilibrium and microscopic kinetic
constants of the ionic species present in solution have been determined.The results show that all the protonatable groups of the aldehyde molecule are
involved in the intramolecular acidic catalysis of the dehydration process undergone by the -hydroxyamine intermediate. Results also reveal that the
formation of Schiff base with pyridoxal is greatly affected by the formation of the cyclic hemiacetal of this aldehyde.
D/L alanine meets vitaminb6
(where have you been all my life)
Study of the hydrolysis and ionization constants of Schiff base from pyridoxal 5'-phosphate and n-hexylamine in partially aqueous solvents. An
application to phosphorylase b.
its happening, by standing on the shoulders of giants with NMR and IR's
the perfect reaction, coming to a theatre near you...
Isolating pyridoxal-5-phosphate alanine schiff base
roamingnome - 24-2-2007 at 15:43
1 gram alanine at 89.1 G/mol = .011 mols
.011 mols of pyridoxal-5-phosphate depending on whether it is the hydrate or not comes to 2.71-2.97 grams.
Taken, a few vitamins for health and energy.
The rest crushed and taken up in water and in another bottle methanol
approx. 2.5 grams pyridoxal
The insoluble binders were filtered from each, resulting in brilliant piss colored water and methanol respectively.
Added 2.5 grams (excess) alanine.
The pH of the water experiment was 3.4 and the methanol was 5
Aqueous 10N hydroxide was added to the water till pH 10.3 was achieved
The color changed to a different yellow, darker, stirred, 300mls sitting reaching equilibrium
.5 grams NaOH pellets was added to the methanol which slowly rose to pH 10
The alanine is struggling to dissolve in the methanol even with hot plate and microwaves currently. stirring 300 mls sitting reaching equilibrium.
From the above articles, DCM will be used to “solve” the Schiff base from the aqueous.
And evaporated later in the bat cave. At the moment forming the imine of pyridoxal-5-phosphate and alanine in water seems convenient, depending on
how the DCM works.JohnWW - 28-2-2007 at 17:09
I read somewhere that taking 50 mg (or more) of vitamin B6 daily results in very vivid dreams. Does anyone know anything more about this?.torNO - 1-3-2007 at 07:12
It does in sensitive individuals.So does cheese,but all this is off topic.I'm all for compulsory B6 for P.M. ladies.roamingnome - 1-3-2007 at 10:13
as of now i dont think the reaction really occurred to completion in either medium.
the DCM is cloudy at best with white fluffy things in it( probably alanine)( peptides that ive worked with remind me of cotton candy)
I added a chemist's splash of DMSO to the methanol run, still no dissolve. Then i boiled it down to less then 200 mls and saw the fluffy white things
in it upon chilling...
finally i took the rest of the vitamins binders and all( cellouse and stearic acid) crushed and powdered with 1 gram alanine... in strait DMSO with
1 ml of saturated NaOH(dried) in DMSO ( handy little reagent)
40 seconds in the microwave and it turned very red/brown.... now you might say that is foolish you dumby…but something remarkable happened…. Even
if stearic acid just turned brown…
im eager to finish boiling of the methanol leaving DMSO and purer reactants( i filtered the binders out through a good filter) and see if similar
observations are had….
p.s i dont dream or remember them or like talking about them but a friend who does says
MSM, methyl sulphonyl methane is good... so eat cheese B6 and MSM for a fun project...Pyridinium - 19-3-2007 at 14:28
Quote:
Originally posted by roamingnome
as of now i dont think the reaction really occurred to completion in either medium.
You should be getting Schiff base with pyridoxal phosphate and alanine at room temp, after all a number of other Schiff base reactions will occur at
moderate temps. But... I hadn't thought about something until I found this: http://www.uib.es/depart/dqu/dqf/abstract/1992/hca92.htm
<blockquote>"We studied the stability of the Schiff bases formed between pyridoxal 5'-phosphate (PLP) and leucine in presence of
(hexadecyl)trimethylammonium bromide (CTAB) over a wide pH range by determining the kinetic constants of formation and hydrolysis of these compounds.
The results show that the stability of the Schiff bases is increased by the presence of CTAB as a result of increases rates of formation and decreased
hydrolysis rate constants. The ionic head groups of CTAB favour the formation of the vases, while its hydrophobic rests protect the imine double bond
from hydrolysis. This model system permits one to obtain partially hydrophobic media with no need for any non-aqueous solvents."</blockquote>
So a quat stabilizes the base in that environment. Spray-Nine, anyone?
I suppose this is the 3rd cousin's wife's uncle of what enzymatic non-covalent interactions do for the pyridoxal-P when it is inside a 'pocket' in an
enzyme.
For compound2a, D-alanine methylester hydrochloride (0. 2g, 1. 43mmol) was reacted with 4-hydroxybenzaldehyde (0.175g, 1.43mmol), which gave the
compound as anoff-white solid (0. 2 g, 67%).
For compound 2b, L-alanine methylester hydrochloride (0. 2g, 1. 43 mmol) was reacted with 4-hydroxybenzaldehyde (0.175 g, 1. 43mmol), which gave
compound 2b (0. 2 g, 67%).
Example 2
This example provides syntheses of compounds comprising Schiff base condensation products of aromatic amino acids with a benzyaldehyde reactant. To a
suspension of anhydrous MgSO4(0. 2 g) and thehydrocloride salt ofL-phenylalanine methyl ester (0. 3, 1. 4 mmol) inCH2CI2 (4. 8 mL), triethylamine (0.
35 ml, 2.5 mmol) was added followed by 4hydroxybenzaldehyde (0. 17 g, 1. 4 mmol). The reaction was left stirring for 24 hrs. TheMgS04 was filtered off
and the crude product was concentrated under reduced pressure. The crude product was re-dissolved in a mixtureof CH2CI2/EtOAc, (40/60) and washed
twice with brine(2x20 mL). The organic phase was dried over MgS04 and decolorized with activated carbon. The crude product was then purified by flash
chromatography in basic alumina to give the desired product, compound 8 (0. 23g, 58%).
Armed with a more plausible prepartion of said shiff-base. They are reporting that the product is uncolored which was a question i had. They are
using the methyleter of alanine. Unforntunitaly, in my lastest run, I turned my back on evaporating methanol and charred my vitamen’s to a red
crap… pushing results farther away like a buoy in the tide…. curses… maybye ill just make up a song to go with those funcky lyrics… hahah..
how did my picture get on the net!!
Of course i mixed the somewhat decomposed pyrodoxal with alanine (withagrinder) and added anhydrous Calciumchloride, A very small amount of methnaol
cuased the reactants to become a paste and it heated up a lot…. Was the CaCl2 absorbing water and schiff base was forming.? Ill put it on the
shelf next to the other brown goo i create…
