| Pages:
1
2 |
Drunkguy
Hazard to Others
Posts: 172
Registered: 23-12-2005
Member Is Offline
Mood: somewhat pissed.
|
|
great stuff guys. can this be used to isolate the piperidine? I might try this at some point along with some steam distillation extractions etc.
|
|
|
phangue
Harmless
Posts: 18
Registered: 1-10-2006
Member Is Offline
Mood: No Mood
|
|
Someone ask what piperine is used for.
I hope the following is not redundant!
Back in the early 80’s I examined a book in a university library on the manufacture of tranquilizers. Most of those described started with piperine
as the first building block for synthesis. This is interesting considering the most bless-ed piper-related kava-kava that has saved so many from
faint-at-the-sight-of-blood attacks, and problems associated with anxiety and panic. This is the preparation that the FDA and other powers-that-be
strive to outlaw in deference to the big pharmaceutical industry that advertises its wares with warnings of lever damage and thoughts of suicide. Yes,
I would be careful when using it-- to take it only as needed. Never to be taken as a daily regemin. Oops! Sorry!
At the farm supply store today, I noticed wormers that contain goodly amounts of piperazine. They also stock a wormer in Walmart. Oops! Sorry!
|
|
|
Maya
Hazard to Others
Posts: 263
Registered: 3-10-2006
Location: Mercury
Member Is Offline
Mood: molten
|
|
strange what a little knowledge of chemistry can make people think, piperine; piperidene; piperazine are all similar sounding but COMPLETELY different
compounds!!!!!!!!!
Please stop posting non-scientific gibberish , and stick to absolute chemistry.
sorry but, dis-inforformation by non skilled or people that have not taken a course in OC is not the answer
\"Prefiero ser yo extranjero en otras patrias, a serlo en la mia\"
|
|
|
pantone159
National Hazard
Posts: 586
Registered: 27-6-2006
Location: Austin, TX, USA
Member Is Offline
Mood: desperate for shade
|
|
Piperine extraction prep
I haven't tried any of this myself (yet) but I did just track down this procedure, from the book:
Natural Products, A Laboratory Guide, 2nd ed., by Raphael Ikan, Academic Press NY, 1991, p 233-238.
(P.S. This book seemed chock-full of interesting experiments to do.)
Excerpts from the prep:
D. Isolation of Piperine from Black Pepper
1. Introduction - The piperine content of black pepper varies from 6 to 9 %.
2. Principle - The crude EtOH extract contains, in addition to piperine and chavicine (its geometric isomer), some acidic, resinous material. In
order to prevent co-precipitation of piperine and the resin acids, dilute ethanolic KOH solution is added to the concentrated extract to keep acidic
material in solution and/or as solid gummy material that is precipitated in the vessel.
6. Procedure - 10.0 g black pepper is ground to a fine powder and extracted with 150 ml 95% EtOH in a Soxhlet for 2 hr. The solution is filtered and
concentrated in vacuo on a water bath at 60 C. Alcoholic KOH (ten ml 10%) is added to the filtrate residue and after a while decanted from the
insoluble residue. The alcoholic solution is left overnight, whereupon yellow needles of mp 125-126 C are deposited; yield, 0.3 g.
As a bonus, the book then follows with the following experiment:
E. Degradation of Piperine (to Piperidine and Piperic acid)
1. Introduction - Mild oxidation (KMnO4 in basic solution) of piperic acid yields piperonal, piperonylic acid, and oxalic acid. (The book stated
'tartaric' instead of 'oxalic' in this specific line, this is almost surely an error.) Note that this specific experiment does not involve the
oxidation of piperic acid, this tidbit of useful info was provided, however.
2. Principle - Piperine is treated with ethanolic KOH, yielding piperic acid and piperidine (isolated as the hydrochloride).
6. Procedure - Piperine (1 g) and 10 ml 10% alcoholic KOH are refluxed for 90 min. The ethanolic solution is evaporated to dryness under reduced
pressure, the reciever being cooled in an ice-salt bath. The solid potassium piperinate is suspended in hot water and acidified with HCl. The
voluminous yellow precipitate is collected on a Buchner funnel, washed with cold water, and recrystallized from ethanol to yield piperic acid as
yellow needles of mp 216-217 C. The strongly basic ethanolic distillate in the receiver is saturated with HCl and evaporated to dryness to give
piperidine hydrochloride, which melts at 244 C after recrystallization from EtOH.
Recommended review - Marion L (1950). The pyridine alkaloids. In "The Alkaloids", (RHF Manske and HL Holmes, eds), Vol 1 p 167, Academic Press, NY.
[Edited on 20-2-2007 by pantone159]
|
|
|
S.C. Wack
bibliomaster
Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline
Mood: Enhanced
|
|
I'm a bit suspect of the short times given. Spot tests at 8 hours that I've done can still detect piperine (a drop of extract from the Soxhlet outlet
on a plate and evaporated, reddish brown color on adding conc. sulfuric, sensitive only to 1 mg/ml). But yeah, the majority is extracted after two
hours. I also found piperine more resistant to hydrolysis than the two hours bit would lead one to believe. Maybe I'll have to repeat my experiments.
They're good methods though. The decantation after adding KOH is not necessary but can be done - without improving the purity of the crystals, and
solid hydroxide can be used. As one can see the stated "piperine content" of pepper has nothing at all to do with the actual amount of piperine that
one can actually obtain. The melting point there is low because those crystals are quite impure, really. Quite similar to this that I wrote a while
ago but never posted, as more experiments were planned and some done to add to it:
100 g of McCormick ($3.48/248 g [label, actual ~263 g], specific brand mentioned due to illustrated yields from this brand which follow) ground black
pepper are placed in a Soxhlet and extracted with 350-500 ml denatured alcohol for 12 hours. After much qualitative and quantitative experimentation
with different methods and variations for isolating and purifying the piperine, the following was devised.
The Soxhlet and its condenser are removed, and the solvent in the boiling flask is distilled off until all but 50-75 ml of its contents have
distilled. The contents are poured out of the flask into a beaker, and up to 25 ml of denatured alcohol washings from the flask added. A quantity of
NaOH or KOH - say, 5-8 g - is added to the beaker while the contents are still warm, and the mixture stirred until the hydroxide has dissolved. The
beaker is allowed to stand for 24 hours and the alcohol allowed to evaporate freely.
Then the liquid portion of the extract is poured off and discarded. Hot water is added to the beaker and the whole is poured into an ordinary coffee
filter in an ordinary coffee filter holder. Boiling hot water is added as necessary to rid the solids of everything that will dissolve in the hot
water. The oily crystals are spread out to dry, then recrystallized by boiling 50 ml 91-100% IPA with them until dissolved, cooling the solution to 0C
for 24 hours, decanting from the finely crystalline deposit, washing the crystals with fresh ice-cold IPA, drying, and recrystallizing again. Yellow
powdery crystals result. The residue left upon evaporation of the IPA is a golden oil which solidifies. The solid is extracted with room temp IPA and
recrystallized from a small amount of boiling IPA to give a small amount of additional piperine on cooling. Total yield 3 g. Saturated solutions of
piperine in boiling IPA yields on freezing very small crystals in a slush. With vacuum filtration and washing with ice-cold IPA in the filter, these
crystals are a much lighter and less yellow color, mp 134C.
I also came across a potentially interesting Chem Pharm Bull article studying piperine in the mouse. "In conclusion, we have shown that piperine, an
active piperidine alklaoid from P. longum, reversibly inhibited mouse brain MAO-A and MAO-B activities. In addition, piperine has in vivo
antidepressant-like activity against the tail suspension test. Although the precise mechanism involved in the observed antidepressant activity is not
yet clear, piperine has potential therapeutic value for the management of depressive disorders and is considered a good candidate for further
evaluation." We've cured just about everything that ails mice. Why exactly the "tail suspension test" has anything to do with human depression just
because fluoxetine produces similar results with the test is beyond me.
Toluene and xylene are OK recrystallization solvents if you use freezing. MEK is similar to acetone, and adding water to either is not helpful.
(m)ethanol by itself or with water is no good. The 3:2 acetone/petroleum ether is similar to everything else. Nothing really gets it any purer than
the other, and weighing precipitate by volume of each for quantitative comparison does not give reproducible results in the few trials done. It can be
said that IPA with and without water and salt dissolves piperine with the most difficulty hot, for sure. Addition of alcoholic KOH to hot concentrated
alcoholic piperine will make it crystallize pretty fast on cooling to room temp.
[Edited on 21-2-2007 by S.C. Wack]
[Edited on 21-2-2007 by S.C. Wack]
|
|
|
Random
International Hazard
Posts: 1018
Registered: 7-5-2010
Location: In ur closet
Member Is Offline
Mood: Energetic
|
|
Can I just take black pepper powder and dissolve it in acetone? I would after that filter it and what should I do after filtration?
|
|
|
| Pages:
1
2 |
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
