Sciencemadness Discussion Board

Pepper to Piperine problem

stateofhack - 17-6-2008 at 03:16

Hello,

I am new here so please put up with me :(
Anyways, i have done this extraction numerous times at school but when done at home all i got was this:

A very sticky and spicy beaker, containing a green annoying residue :(:mad:

I followed the following procedure and used fresh powdered black pepper:


place 15g of ground black pepper and 1g of powdered CaCO3 (1) in a 250mL
boiling flask, add 100mL of IPA, and, after fitting the flask with a reflux condenser,
boil the mixture for about 1h on the steam bath. at the end of the heating period,
filter the mixture by gravity into a 125mL erlenmeyer flask, clean the 250mL
boiling flask, and return the filtrate to the boiling flask. fit the boiling flask with a
distillation adapter and condenser, and boil off all but about 10mL of the IPA (2).
transfer the residual solution from the boiling flask to a 25mL erlenmeyer flask,
and set the flask aside to cool for crystallization of piperine (3,4). collect the product
by suction filtration, using small portions of MeOH to rinse the flask and wash
the product. yield: about 0.5g.

(1) the addition of CaCO3 should prevent the extraction of acidic
components of pepper

(2) IPA boils at 80°C, only a little below the maximum temperature attainable on
the steam bath. to make the distillation proceed quickly, clamp the boiling flask so
that it is well down in the rings of the steam bath, and drape a towel over the flask
and the steam bath to make a tent that will hold steam around the top of the flask.

(3) crystallization occurs slowly, and the flask must be allowed to stand for
at least 24h.

(4) alternatively, add 25mL of water to the IPA solution of piperine, allow the mixture
to stand for at least 24h so that precipitation will be complete, collect the solid by
sucction filtration, and recrystallize it from either IPA or acetone.

I repeated this twice and i really can't see where i have gone wrong :(

Anyone has an idea?

Thanks

edit: picture doesn't seem to be wanting to show up :(

http://img99.imageshack.us/img99/161/img0351tx8.jpg

[Edited on 17-6-2008 by stateofhack]

[Edited on 17-6-2008 by stateofhack]

[Edited on 6-18-2008 by Polverone]

S.C. Wack - 17-6-2008 at 03:56

http://www.sciencemadness.org/talk/viewthread.php?tid=4698

Using lime/limestone in the extraction is in the literature, as above. Doesn't prevent shit in my hands.

Klute - 17-6-2008 at 06:03

Maybe your product simply oiled out? Try redissolving and letting it cool very slowly again

LSD25 - 17-6-2008 at 06:20

Looks a lot like what I got years ago when I based the green-yellow alcohol extract with NaOH - let me guess, did the whole thing stink there for quite a while? I strongly suspect that you have a nice yellow precipitate of calcium piperinate there (same as I had the sodium salt). In order to get it to crystallise you'll need to boil it dry, add water and then hydrochloric acid and collect the filtrate:

http://www.ias.ac.in/resonance/Sept1996/pdf/Sept1996p25-33.p...

In order to extract the piperine, you'll need to let the alcoholic extract sit COLD with the base (yeah, it seems that that is precisely what the carbonate has done, go figure - at a guess, I'd say refluxing it might be the culprit - that is why I asked about the smell, piperidine is a lot of things but as a fragrance, subtle or understated it ain't).

Then again, I'm often wrong - lets see what the more experienced readers think

stateofhack - 17-6-2008 at 06:51

Quote:
Originally posted by LSD25
Looks a lot like what I got years ago when I based the green-yellow alcohol extract with NaOH - let me guess, did the whole thing stink there for quite a while? I strongly suspect that you have a nice yellow precipitate of calcium piperinate there (same as I had the sodium salt). In order to get it to crystallise you'll need to boil it dry, add water and then hydrochloric acid and collect the filtrate:

http://www.ias.ac.in/resonance/Sept1996/pdf/Sept1996p25-33.p...

In order to extract the piperine, you'll need to let the alcoholic extract sit COLD with the base (yeah, it seems that that is precisely what the carbonate has done, go figure - at a guess, I'd say refluxing it might be the culprit - that is why I asked about the smell, piperidine is a lot of things but as a fragrance, subtle or understated it ain't).

Then again, I'm often wrong - lets see what the more experienced readers think


This sounds promising! I will look into it!

Thanks!

LSD25 - 18-6-2008 at 07:30

I think the majority of the problem with this extraction comes from the names of the various compounds - here is a couple of 'PIPERINE' extractions:

Quote:
Isolation of Natural Piperine (I)
Grind fresh peppercorns (25 g) to a fine powder, place in a Soxhlet thimble, and extract with ethanol (100 mL) for at least 90 minutes. At the end of the extraction, the ethanol should be pale yellow to colourless. Cool the resulting solution, filter if necessary, and concentrate on the rotary evaporator. Keep the water bath below 60 °C during the concentration. Dissolve the residue in 10 % alcoholic potassium hydroxide (25 mL). Decant the solution if any residue remains. Cool the solution in an ice bath, and add water dropwise (about 30 ml will be required) to precipitate the piperine. Collect the piperine on a sintered glass funnel, and dry it on the vacuum pump. If time allows, a recrystallization from acetone:hexanes (3:2) will produce cleaner material. Record the mp, ir and 1H nmr spectrum of piperine.

From page 3/4 of this paper: http://web.uvic.ca/~pmarrs/chem465/465e03piperine.pdf


Note that they cool the extract before letting it come into contact with the base. A very similar approach (but using much more expensive solvents) is used here: http://courses.chem.psu.edu/chem36/Chem36H/IndivExpt1/874%20... and here (and a lot more places on the web): http://www.wiu.edu/users/mftkv/Chem332/Experiment3.html.

It seems (well at least to me), that what most people here have got in their attempts to extract piperine is the piperinate (the salt of piperinic/piperonic acid), which is here:

Quote:
Hydrolysis of Piperine – Isolation of Piperic Acid
Reflux a solution of 1 g of piperine in 10 ml of 10% ethanolic KOH for 90 minutes. Evaporate the solution to dryness by distillation under reduced pressure, the receiver being cooled in an ice-salt bath. Suspend the solid potassium piperinate remaining in the distillation flask in hot water and add concentrated HCl. Collect the yellow precipitate, wash it with ice-cold water and recrystallise it from ethanol. Pure piperic acid is obtained as yellow needles, m.p. 216 – 217°C. Saturate the distillate (in the receiver) with HCl and evaporate it to dryness when piperidine hydrochloride separates out. Re-crystallise it from ethanol. Pure piperidine hydrochloride has a m.p. 244°C.

Pages 8-9/9: http://www.ias.ac.in/resonance/Sept1996/pdf/Sept1996p25-33.p...


Now, given that what you have (and what others have described) from the refluxing of the ethanolic piperine extract with the calcium carbonate looks for all the world more like what others have gotten from cleaving the alkaloid with ethanolic base, then I'd suggest that the cleavage is done with the carbonate under reflux. Easy way to find out, collect the yellow-green precipitate and hit it with HCl - see if you get crystals corresponding to piperic acid (ie. see if you get precipitation, if so, collect it and recrystalise from ethanol).

Nicodem - 18-6-2008 at 08:27

No, CaCO3 can not hydrolyze any such amide. It is probably added to catch various carboxylic acids in the peper (fatty acids, etc.) which would otherwise interfere with the crystallization and final recrystallization. Similarly as petroleum ether is often used to remove lipids from plant material in many extraction processes.
I would suggest to try the recrystallization on the resin directly even if you can't get it to crystallize. Alternatively crystallizations can often be nicely induced by removing the interfering impurities with trituration in solvents in which your product has low solubility. Since you don't know the nature of the impurities I would suggest to use both, a heavily hydrophobic solvent (petroleum ether) followed by a hydrophilic one (methanol). I think piperine should not be particularly soluble in either petroleum ether or methanol, but I'm not sure. Do not loose patience and triturate for some time before giving up, perhaps also by warming up.

stateofhack - 18-6-2008 at 09:18

Quote:
Originally posted by Nicodem
No, CaCO3 can not hydrolyze any such amide. It is probably added to catch various carboxylic acids in the peper (fatty acids, etc.) which would otherwise interfere with the crystallization and final recrystallization. Similarly as petroleum ether is often used to remove lipids from plant material in many extraction processes.
I would suggest to try the recrystallization on the resin directly even if you can't get it to crystallize. Alternatively crystallizations can often be nicely induced by removing the interfering impurities with trituration in solvents in which your product has low solubility. Since you don't know the nature of the impurities I would suggest to use both, a heavily hydrophobic solvent (petroleum ether) followed by a hydrophilic one (methanol). I think piperine should not be particularly soluble in either petroleum ether or methanol, but I'm not sure. Do not loose patience and triturate for some time before giving up, perhaps also by warming up.


Thanks, unfortunately I have disposed of the “product” but I will be trying it again and I will be trying what you said!
Anyone know any “quicker” and less involved methods to extract piperine? (soxhelt??)

not_important - 18-6-2008 at 17:56

From several articles on the subject, including some referenced in the old thread on the topic such as "Microwave-Assisted Extraction of Piperine", it looks as if pet ether is the way to go if you're specifically after piperine.

If you want it as raw material for one or another of its constituents, then use alcohol, acetone, or DMC, followed by hydrolysis, isolation, and purificationof the desired component. For those cases going for pure piperine is wasted effort, as several of the impurities will yield one or another of the desired compounds too. The major components of extracts besides oleoresins are listed as piperine, piperidine, piperettine, piperanine, and chavicine; check their structures to see what I mean.

Useful references you might want to chase down:


Separation and identification of piperine and chavicine in black pepper by TLC and GC-MS
Constantin Maărutoiu, Ioan Gogoasa, Ioan Oprean, Olivia-Florena Maărutoiu, Maria-Ioana Moise, Cristian Tigae, Maria Rada
JPC - Journal of Planar Chromatography - Modern TLC
Volume 19, Number 109/June 2006
Pages 250-252
DOI 10.1556/JPC.19.2006.3.16


Kinetics of Light-Induced Cis-Trans Isomerization of Four Piperines and Their Levels in Ground Black Peppers as Determined by HPLC and LC/MS
Nobuyuki Kozukue, Mal-Sun Park, Suk-Hyun Choi, Seung-Un Lee, Mayumi Ohnishi-Kameyama, Carol E. Levin, and Mendel Friedman
J. Agric. Food Chem., 55 (17), 2007
Pages 7131-7139
DOI 10.1021/jf070831p


Black Pepper: Piper Nigrum
By P. N. Ravindran
Published 2000 by CRC Press
ISBN:9057024535

MagicJigPipe - 18-6-2008 at 19:44

Quote:

Thanks, unfortunately I have disposed of the “product”


Why did you do that before you could run more tests etc... ?

stateofhack - 19-6-2008 at 01:44

Quote:
Originally posted by MagicJigPipe
Quote:

Thanks, unfortunately I have disposed of the “product”


Why did you do that before you could run more tests etc... ?


Well it was such a bitch to remove! You have no clue! Soaked in acetone, warm water, dilute hcl took for ever!

But i will be running some more test soon and i will post a full pictorial (with appropriate sized pictures ;) )

But yes, i should have tried to run some test :(

S.C. Wack - 19-6-2008 at 02:56

Quote:
Originally posted by not_important
Black Pepper: Piper Nigrum
By P. N. Ravindran
Published 2000 by CRC Press
ISBN:9057024535


It's a good book but it has nothing useful on isolation of piperine or anything else. Lots of information as to the chemicals present in there.

Not much of a surprise that water and HCl did not do much to the oleoresin.

Toluene and xylene are great for cleaning resinated glassware.

Everyone else here seems to think that the earlier thread is worthless, but that really is the best that can be done with old-fashioned organic solvent extraction.

Since 3base sadly no longer has a website that I know about, here is a link to the same files that I linked to before, should this thread come up in someone's search.

If I haven't already mentioned it somewhere else: some brands of pepper contain very little piperine. it is not necessarily related to price: the inexpensive Gel Spice Co. product gives at least the same yield as familiar McCormick. But the cheapest brands do tend to give little product.

[Edited on 19-6-2008 by S.C. Wack]

LSD25 - 19-6-2008 at 17:26

Quote:
Originally posted by Nicodem
No, CaCO3 can not hydrolyze any such amide. It is probably added to catch various carboxylic acids in the peper (fatty acids, etc.) which would otherwise interfere with the crystallization and final recrystallization. Similarly as petroleum ether is often used to remove lipids from plant material in many extraction processes.
I would suggest to try the recrystallization on the resin directly even if you can't get it to crystallize. Alternatively crystallizations can often be nicely induced by removing the interfering impurities with trituration in solvents in which your product has low solubility. Since you don't know the nature of the impurities I would suggest to use both, a heavily hydrophobic solvent (petroleum ether) followed by a hydrophilic one (methanol). I think piperine should not be particularly soluble in either petroleum ether or methanol, but I'm not sure. Do not loose patience and triturate for some time before giving up, perhaps also by warming up.


I figured that it probably 'shouldn't' be capable of doing so, yet the material in the photo - made up of at least 80% salt and less than 20% oil (after removal of solvent) suggests strongly otherwise. It is either that, or the particular brand of pepper used is degraded and contains an unusually high level of carboxylic acid(s), because the piperine is an oil and only crystallizes when purified to some extent and then allowed to cool (ie. the stuff in that photo ain't piperine - it is quite seriously exactly what I remember the piperinate to look like - ).

Dunno, maybe extract the water soluble salt (probably even better if you filter it and then wash the filter cake through the funnel with water) and then cool the filtrate to give the piperine a chance?:o

S.C. Wack - 20-6-2008 at 02:45

Quote:
Originally posted by LSD25
the material in the photo - made up of at least 80% salt and less than 20% oil (after removal of solvent) suggests strongly otherwise.


Where did you pull that out of?

Quote:
Originally posted by LSD25
the stuff in that photo ain't piperine - it is quite seriously exactly what I remember the piperinate to look like - ).


I don't see how you or anyone else can tell what is in that photo, or what it looks like - other than not white or black.

I don't see how CaCO3 could hydrolyze this amide or anything else, regardless of its base strength, with the handicap of being fairly insoluble in this and perhaps all other organic solvents, and water.

LSD25 - 20-6-2008 at 05:59

Have a look at the photo - do you see the solvent level - where the precipitated crud is about halfway up the wall? & where it is now? Do you see the yellowish-green precipitate? Is it extremely finely divided and in a dark-ish oil? Does it look like the entirety of the alcoholic extract is in that beaker?

You've done this too, what stage does it look like? What does it sound like from the description? The piperine is still in the oil, when it comes out it does not look like that crud. As the precipitated material can only be one of two things - the alkaloid(s) or the acid salt(s), there really is not a lot of guesswork that has to be entered into - is the precipitated material the alkaloid(s)? I think not (based upon days of fucking around with this before and looking at working out precisely what happened) thus for mine the precipitate is piperinate, while there is so much of it there there is no chance of the piperine crystallizing.

As to whether the carbonate could hydrolyze the amide, I cannot work it out, but in order for the precipitated material to be the piperinate something has happened, either the amide has been hydrolyzed or the pepper contained a LOT of carboxylic acid - perhaps this is the result of degradation, I dunno. All I know is that from the description and the photo, I am willing to bet that that is the salt not the alkaloid(s), in order for that to be the case, something unusual has to have occured. Alternatively, nothing of the sort has happened and the precipitated crap is the alkaloids and they have simply acted somewhat unusually? It certainly ain't the carbonate, the fact it ain't white (something you also must have seen?) tells me that.

Then again, this is all somewhat subjective - noone has run any conclusive tests on the material, it has not been identified (and now cannot be). That said, I don't regard the suggestions above as unnecessarily speculative, it is based upon what I see in the photo and what I have seen in person. I certainly don't think that is beyond the pale, it is simple deductive reasoning, what do I see, what could it be and what needs to have happened in order for that to be? Given the fact that this is the alcoholic extract of pepper, there really ain't that many alternatives.

McLovin382 - 26-9-2008 at 07:05

Pretty sure that piperine can be obtained from black pepper by heating in the microwave in dH2O for about a minute, followed by a filtration of the now empty peppercorns and evaporation/boiling off of the water.

http://www.erowid.org/archive/rhodium/chemistry/3base/pipero...

stoichiometric_steve - 28-9-2008 at 04:43

Quote:
Originally posted by McLovin382
Pretty sure that piperine can be obtained from black pepper by heating in the microwave in dH2O for about a minute


like piperine is water soluble or what

DJF90 - 28-9-2008 at 07:08

Googling "piperine" reveals that it can apparently be extracted from black peppercorns (if so wished) using DCM.

Nicodem - 29-9-2008 at 00:14

Quote:
Originally posted by McLovin382
Pretty sure that piperine can be obtained from black pepper by heating in the microwave in dH2O for about a minute, followed by a filtration of the now empty peppercorns and evaporation/boiling off of the water.

http://www.erowid.org/archive/rhodium/chemistry/3base/pipero...

I can not find anything like this in the page you referred to. Please avoid spreading misinformation whenever possible. Piperine is not water soluble, at least not to any useful level. Even if it was water soluble, just extracting pepper with water would also extract all kind of water soluble sugars, proteins and other plant products. So just evaporating the water would give you a mixture of all kind of stuff.

Baphomet - 1-10-2008 at 23:54

Try this:

- soak overnight in a closed glass container, filled with acetone to match the level of the pepper. or excess acetone - hardly matters

- filter through coffee paper or some other fine mesh. if you are careful it is possible to keep the water soluble solids separate from the pepper grinds (using coarse-grind pepper). though not particularly useful

- allow the acetone to evaporate.. takes a day or two

- there was thick oleoresin after evaporation, with lots of little rhombic crystals embedded in it

I tried the above, for shits & giggles last week. Did not bother to separate it but the following might work:

- dissolve the lot in EtOH or IPA, put it in the freezer to dewax

- base wash if you like

- evaporate the alcohol

- recrystallise

[Edited on 2-10-2008 by Baphomet]

Bander - 14-10-2008 at 09:33

I have always failed in purification of the alcoholic black pepper extract by active means. This is something I attribute to the crude nature of my attempts and not the methods themselves. I have ended up with an oily mess most times trying to recrystalize from acetone (picture). If you are willing to wait and have a stable location; store a closed container of the unpurified alcoholic extract at room temperature with little physical disturbance for about a year. I have done this twice with ~1 liter amounts and twice I have ended up with centimeter scale multiple crystal formations of piperine. It's not novel, efficient, or fast, but it works.

[Edited on by Bander]

piperine.jpg - 51kB

Ephoton - 15-10-2008 at 01:55

wow there huge.

I've never had prob with this extraction. I used a continuous extraction setup so the pepper never gets hot alcohol on it. this way most of the tar stays in the pepper.

I just add a little water to extract when finished and let sit over night. the more water the quicker the crystals form (though much smalller).

I never get any brown in the extract and hydrolisis is very smooth afterwards :).

McLovin382 - 8-12-2008 at 14:53

Quote:
[quote=stoichiometric_steve]like piperine is water soluble or what


Not usually, no - and when normal heating is applied, piperine is very insoluble in water.

However, the microwave radiation for whatever reason does a very good job at drawing the piperine out of the pepper and into the hot water. You then can filter it while it's hot to get the peppercorns out, then cool it and filter out the piperine.

Try it if ya don't believe me.

starman - 9-12-2008 at 02:25

Quote:
Quote:
Originally posted by McLovin382
[quote=stoichiometric_steve]like piperine is water soluble or what


Not usually, no - and when normal heating is applied, piperine is very insoluble in water.

However, the microwave radiation for whatever reason does a very good job at drawing the piperine out of the pepper and into the hot water. You then can filter it while it's hot to get the peppercorns out, then cool it and filter out the piperine.

Try it if ya don't believe me.

If you don't have results of your own experiments or literature references to offer in support of your assertions,I would suggest you pay attention to Nicodem's warning about misinformation.Steve will also tear you a new one if he thinks your talking crap.

stoichiometric_steve - 9-12-2008 at 02:29

Quote:
Originally posted by starman
Steve will also tear you a new one if he thinks your talking crap.


DAMN RIGHT!!!

McLovin382 - 9-12-2008 at 09:53

Okay sorry :/ I'm half wrong

Piperine is indeed insoluble in water (moreso cold as usual), however when a solution/suspension of (black) peppercorns is microwaved, the peppercorns split open to release the piperine into the liquid, regardless of its polarity. A low boiling-point (liquid) nonpolar solvent could then be added to the mixture to solute the piperine, then filtered to remove the broken-open peppercorns. The water and low boiling-point nonpolar solvent could then be boiled/distilled off to yield relatively pure piperine in high yields, or alternatively (maybe) do a separation of the two layers, keep the nonpolar piperine-containing layer and just boil off the nonpolar solvent -- which if a low enough boiling solvent is used becomes much easier now that the water is gone.

Guess it would be possible technically to not use the water at all and just microwave in a nonpolar solvent then filter and boil off the solvent - but that would require a higher boiling-point solvent and wouldn't be as clean of a procedure for the microwave (albeit if one has a microwave dedicated solely to chemistry this is not exactly an issue :p)

http://www.erowid.org/archive/rhodium/chemistry/3base/pipero...
http://www.erowid.org/archive/rhodium/chemistry/3base/pipero...

Sorry about the confusion guys, hope that sounds a little better :p

DJF90 - 9-12-2008 at 15:02

Is there any reason for using a microwave at all? What would be wrong with finely grinding the peppercorns and leaving to soak in an appropriate solvent, possibly with magnetic stirring for reduced extraction time?

watson.fawkes - 9-12-2008 at 16:56

If piperine differentially absorbs microwave radiation more than the solvent, they'll dissolve much quicker. I don't know that it does; you'd need to look at a spectrum.

This is related to the reason you should never microwave fish. The amine groups get very reactive at 2.4 GHz and that's what makes it taste "fishier".

octave - 9-12-2008 at 18:25

From that article I got that the microwave breaks open the cell in a sense making it easier to extract in a shorter amount of time.

Nicodem - 10-12-2008 at 00:22

Quote:
Originally posted by McLovin382
Okay sorry :/ I'm half wrong

Piperine is indeed insoluble in water (moreso cold as usual), however when a solution/suspension of (black) peppercorns is microwaved, the peppercorns split open to release the piperine into the liquid, regardless of its polarity. A low boiling-point (liquid) nonpolar solvent could then be added to the mixture to solute the piperine, then filtered to remove the broken-open peppercorns. The water and low boiling-point nonpolar solvent could then be boiled/distilled off to yield relatively pure piperine in high yields, or alternatively (maybe) do a separation of the two layers, keep the nonpolar piperine-containing layer and just boil off the nonpolar solvent -- which if a low enough boiling solvent is used becomes much easier now that the water is gone.

Guess it would be possible technically to not use the water at all and just microwave in a nonpolar solvent then filter and boil off the solvent - but that would require a higher boiling-point solvent and wouldn't be as clean of a procedure for the microwave (albeit if one has a microwave dedicated solely to chemistry this is not exactly an issue :p)

http://www.erowid.org/archive/rhodium/chemistry/3base/pipero...
http://www.erowid.org/archive/rhodium/chemistry/3base/pipero...

Sorry about the confusion guys, hope that sounds a little better :p

Stop spreading misinformation! How many times do you have to be told this? The paper you linked demonstrates all your claims are wrong and you still do not give up. Piperine is insoluble in water. Adding water in between the powdered seeds and extraction solvent only makes the access of the solvent to the inside of the organic matter more unlikely. The reason why humid seeds were extracted faster than dryer, in the paper you linked, is because they heated the mixture with microwaves and not because some fancy effects of microwaves on solubility that goes against all law of physics. Besides the paper was published in 2002 when microwaves were still a fad which only contributed to the decline in quality of scientific publications.

stoichiometric_steve - 10-12-2008 at 05:40

Quote:
Originally posted by watson.fawkes
This is related to the reason you should never microwave fish. The amine groups get very reactive at 2.4 GHz and that's what makes it taste "fishier".


To be more precise, the Trimethylamine-N-Oxide gets reduced to Trimethylamine, and THAT'S what makes the fish taste "fishier".

McLovin382 - 10-12-2008 at 15:00

Fine...jesus I'm not trying to spread misinformation but apparently at least to some I am so carry on.

watson.fawkes - 10-12-2008 at 17:38

Quote:
Originally posted by stoichiometric_steve
To be more precise, the Trimethylamine-N-Oxide gets reduced to Trimethylamine, and THAT'S what makes the fish taste "fishier".
Thank you. I had only ever seen the approximate version.

peach - 30-4-2010 at 19:49

Quote: Originally posted by watson.fawkes  

This is related to the reason you should never microwave fish. The amine groups get very reactive at 2.4 GHz and that's what makes it taste "fishier".


:D

I love this forum... barely legal chemistry to tips on cooking your dinner

idontlie - 13-5-2010 at 05:26

Oh the gunk.

Tried this earlier this year.

The cold acetone shake n stir method gives you shitty grey gunk that smells stronger, rather spicy, than the original pepper. Unfortunately the grey gunk simply clogs my filter paper and I gave up on it. Maybe I need a vacuum filtration flask.

Alcohol Reflux attempts:
Traditional Reflux (denatured alcohol) stirring strong before adding your pepper is important fyi unless you don't want anything to move. Brown liquid, filtered, brown grey residue left on beaker scraped w/ razor blade smelled fowl, kind of made my eyes water. Decided that was bad, accidentally spilled some and stepped in it. left sticky shit on my shoe that left nasty grey track marks on the floor. Got pissed and threw it away.

Microwave Alcohol extraction (191 proof grain alcohol) turned dark black, filtered hot. Filtrate is still black, leaves thick grey tinged green shit on your collection beaker as it cools. Second filtration left only dark alcohol. Left this for two months to dry ended up with grey shit resembling the stuff collected on the sides of the beaker.

Alcohol (Methanol, w/ possible NitroMe azeotrope) Thick black and nasty clogged the filter. Very sticky, smelled terrible, scraping w. razor blade got it off.

Pepper corns where ground in a food processor until about the thickness of a broken off pencil lead.

Setup for reflux was microwave, 1l rbf hanging in from top at about middle, 200mm viggy (used to give separation from the microwave for the true condenser), 400mm west running ice water toped w/ balloon when the balloon got bigger than my fat head I unplug the microwave. Yes I melted a kleck clamp in the microwave, I don't want to talk about it.
Originally started with the soda bottle method. Don't do that at all, the bottle warps, the cap blows off and burning hot irritating pepper blows into the microwave and if your unlucky the roof the walls and just fucking everywhere, leaving yellow stains on everything. They come up with scrubbing but take some paint with em. sucks. Tried deflatting the soda bottle, keeping a cup of water in the microwave with it, yada yada same result.

Traditional reflux was 500ml 400mm west, oil bath, stirring.

bbartlog - 13-5-2010 at 16:01

Quote:
Tried this earlier this year[...]Left this for two months to dry ended up with grey shit resembling the stuff collected on the sides of the beaker. (etc...)


You seem to have this idea that the piperine is just going to magically be extracted, all by itself with no impurities, with one simple soaking in ethanol. If you look at the procedure linked to above (on erowid), they concentrate the ethanolic extract (boil down 90%) and then add KOH, followed by water dropwise to precipitate piperine (or its base). Your 'grey shit' probably had what you were after in it. If you aren't going to learn enough chemistry to improvise your own workup you will at least need enough discipline to follow existing posted recipes more precisely.


Hexagon - 13-5-2010 at 18:06

My tech on pepper to crude piperine:

50 grams of powdered black pepper are stirred with 250 mls of EtOH for 2 hours, this is filtered and the solids are squeezed carefuly to obtain 200-225 mls of filtrate. This filtrate is evaporated on an stainless steel pan until a liquid but thick resinous mather is obtained. Next, I eyeball all this process, but a safe asumption is to mix that resinous mater with 15 mls of hot acetone, add 10 mls of lighter fluid (naphta) put a lid on and let this mixture sit at the freezer until crude crystals are obtained. If pure piperine is what is desired, then recrystalizations shoul get out all that gunk. A fair yield are 1,5 grams of crude piperine from 50 grams of pepper, but I'm sure that with a more refined technique yields of 2 grams can be obtained. That would be a 3-4% mass yield based on pepper, not bad!

One of the next things I'm going to work on is making sodium piperate without isolating the piperine, and degrading this same salt to piperonal with benedict's solution or fehling's solution.

idontlie - 14-5-2010 at 04:59

Quote: Originally posted by bbartlog  
Quote:
Tried this earlier this year[...]Left this for two months to dry ended up with grey shit resembling the stuff collected on the sides of the beaker. (etc...)


You seem to have this idea that the piperine is just going to magically be extracted, all by itself with no impurities, with one simple soaking in ethanol. If you look at the procedure linked to above (on erowid), they concentrate the ethanolic extract (boil down 90%) and then add KOH, followed by water dropwise to precipitate piperine (or its base). Your 'grey shit' probably had what you were after in it. If you aren't going to learn enough chemistry to improvise your own workup you will at least need enough discipline to follow existing posted recipes more precisely.



Ill admit it I'm an honest to god idiot, but I'm an idiot who's not quite dumb enough to really be a harm to anyone.

I just was curious, not really enough to actually do anything with it . The boiling hot pepper eye irritation in my kitchen kinda got me to thinking about what I was doing, Ive came a long way in a few months of taking classes and actually becoming sober. Thats what happened then and just wanted to share it "for the betterment of people much smarter than I."

Thank you though =)

eesakiwi - 26-5-2010 at 22:20

Its as easy as this.
Pour 1 Lb or 500gms of ground pepper into a plastic bottle.
The bottle our Meths (denatured alcohol) comes in works well. Its 1 Litre.

Pour in some Meths untill theres about 2 inches of alcohol above the pepper.
Shake it well & open it & squeeze out about 2/3rds of the air in there.

Put the bottle into the microwave & blast it, as the bottle heats up, stop & take it out & shake it well.
Do it every 20 seconds untill you get used to doing it.
You can hear the bottle expand as the air gets hot, the crinkles 'pop' out.

You have to make sure theres no 'Hot spots' in the pepper, once they get hot they attract the microwaves (don't ask, I know what you mean) & get hotter while the other stuffs still cold/warm.

As the crinkles pop out keep checking it, before its starting to pressurize the bottle, open it gain & push more air out.

Once the meths is a nice hotish & green/brown colour.
Open the bottle top up after tamping the bottle so the peppers at the bottom.
I let it sit for a while so I don't get so much stuff I have to filter out later.

Now top up the meths again & do the microwave thing again.
And again.
And again.
After the three extractions I don't bother doing any more.

Now filter it.
Boil the meths down untill it just starts to get thicker.
Recycle the meths if you can, its a meths greedy operation.
The less meths theres is the less of a need for water, well, less of a volume anyway.

Cool it down to cold.
Pour it into a tall glass bottle (2 - 3 times meths/pepper volume.)
& add water dropwise.

As the liquid volume increases that gooyey crap will drop out first.
Thats where I think 'idon'tlie' stopped...

With more water you will start to see tiny 'glitters' in the liquid, they look quite nice.
A little of a rainbow effect, more green/yellow as you would expect.

As soon as you see the 'glitters' (and next time, before you see the glitters)
pour the liquid into another tall bottle.
Now keep adding water as before & the Piperine will start to drop out.
You will be left with a big smudge of wet slightly gooey crystals on the bottom of the bottle & a ugly light brown/clear liquid above it.

Pour out the liquid & filter it to get the piperine as a yellow mush.
Now heat it till the waters gone.
Redissolve it in meths again if you want to add KOH & do the above water/meths thing again.
Now dissolve it in hot Acetone & boil for a while, then add Pet ether, Colmans fluid, ligroin, 1516, whateveryou call it.
Untill the crystals have dropped to the bottom of the flask, now freeze it for more.

Do that bit again to clean them again.
Try & grow some big ones like I saw here, much bigger than mine....

Picric-A - 13-7-2010 at 13:10

I attempted the extraction of piperine from pepper today.

This extraction was performed in a Soxhlet extractor and ethanol was used as the solvent. 100g of pepper was ground up into a coarse powder and this was loaded into the extracted. 150ml of ethanol (methylated 95%) was added to the 250ml round bottomed flask and the condenser was attached.

Extraction was allowed to continue for 6 hours. After 6 hours a TLC was run. The plate was then viewed under short and long wave UV light. The TLC suggested two compounds were present in the ethanol, one much more concentrated than the other (presumably at this stage the piperine). The ‘piperine’ glowed a yellow colour under the UV however the other compound circled fluoresced a nice pink/red colour.
(I tried to take a photo of the plate under UV however my camera would not capture the different colours so it was pointless.)

After taking the TLC I left the extraction to go over-night. I report tomorrow after rotovaping the ethanol down and precipitating the piperine to give you an idea of my yield.


soxhlet extractor-piperine.jpg - 23kB TLC piperine.jpg - 11kB

Picric-A - 13-7-2010 at 17:28

Now for the update.

After extracting the ethanolic piperine solution (150ml) it was evaporated down on a rotovap at 40degC at 20in.Hg. Evaporating was stopped when around 10ml of oily liquid was left, this was then transferred to a beaker.
10ml of additional ethanol was used to wash the evaporating flask, giving a total of 20ml of more concentrated piperine.

30ml of cold water was added. This instantly produced a creamy yellow ppt. Upon attempting to filter this ppt. it seemed to melt into an oil (as mentioned earlier in this post) and it proved very difficult to seperate.

As a result of this complication i have decided to proceed straight to the hydrolysis to piperic acid, without seperating the crude piperine.

rotovaping piperine.jpg - 17kBpiperine.jpg - 14kB

peach - 15-7-2010 at 16:23

COME ON PICRIC, POST! :P

DJF90 - 17-7-2010 at 06:03

Hey Picric, now you seem to have a camera how about pictures of the elusive "mini contact plant that produces oleum for 50p a liter" that Saber (a.k.a. you) supposedly built, eh?

Picric-A - 17-7-2010 at 08:10

Hey peach, more pics are comming, i just ran into some problems so had to repeat the whole extraction again so it is taking slightly longer than expected, sorry!
DJ- as i have said i disaccembled it after a SO3 leak caused serious damage to my home.

panziandi - 18-7-2010 at 06:07

Well I'm certain everyone saw that coming after all it was almost industrial scale SO3 production you were claiming! Shame we can't see photos of the disassembelled contact plant, photos of the oleum produced and the damaged caused... not so that we believe you, just so that we can judge the extent of damaged caused by the SO3 on whatever scale you were working on. If it was test tubes and sodagass by all means enlarge the images to make them appear industrial! As to the thread itself... not bad work. Although 20mL of "more concentrated piperine" seems a bit vague, was this 20mL of piperine or 20mL of a concentrated solution? 20mL of piperine from 100g of pepper seems rediculously high, it wouldn't occur at that concentration in the pepper let alone being able to isolate 100% of it via conventional solvent extraction. Such extractions are not uncommon to be run over night or for days. Be interesting to see the piperine characterised via a crystalline derivative such as the periodide.

DJF90 - 18-7-2010 at 06:11

Well given that 20g pepper yields about 0.3g of piperine (of the top of my head) then I would not expect the 20ml solution to contain more than about 1.5g. I'm confused by the comment "As a result of this complication i have decided to proceed straight to the hydrolysis to piperic acid, without seperating the crude piperine". What are you working towards..?

panziandi - 18-7-2010 at 06:18

Indeed it seems very high to me too! The crude isolate he has will also contain various esters, terepenes, resins, and likely isomers of piperine as well as various aldehydes, alcohols etc. All in all moving to hydrolysis step on a crude biological extract in vague hope to isolate pure piperic acid (I hope he is doing this all under the legal shelter of his licensed laboratory that he has registered (supposedly) with his local constabulary... lol what a joker!) will e a waste of time! Of course what he plans to do with the 5-(3,4-methylenedioxyphenyl)-2,4-pentadienoic acid is beyond me, I can have a good stab at it though judging the nature of this forum and the structure of the molecule...

[Edited on 18-7-2010 by panziandi]

DJF90 - 18-7-2010 at 06:23

Wikipedia (of all places) has a little advice regarding isolation of the crystalline material:
Quote:

Further, it may be prepared by treating the solvent-free residue from an alcoholic extract of black pepper, with a solution of sodium hydroxide to remove resin (said to contain chavicine, an isomer of piperine) and solution of the washed, insoluble residue in warm alcohol, from which the alkaloid crystallises on cooling.


There's no citation, but it sounds reasonable.

Picric-A - 18-7-2010 at 09:38

It was 20ml of piperine solution made form 250ml ofo piperine solution so i called it more concentrated, i am not claiming to have made 20ml of piperine!

DJ- The 'Complication' was the fact it was very hard to isolate a dry powder 'piperine' due to the large amount of other crude matter in the extract which made it into an oil, not a nice dry powder as it appears in the photo of the ppt. My aim was piperic acid and so i saw no need to isolate it.

Panziandi- i was not aiming to make amphetamines from the piperine, i thought you of all people would know i have no interest in such things.

Oh and this was done in my registered lab.

[Edited on 18-7-2010 by Picric-A]

Picric-A - 18-7-2010 at 09:51

My final set of photos for this synthesis;

After obtaining the crude oily piperine the solvent was decanted off and 50ml of 5M NaOH (aq) was added. This mix was boiled in a beaker for one hour (whilst constantly topping up the water level). After one hour a dark red/brown solution was obtained along with other insoluble material.

The solution was then gravity filtered to obtain a clear reddish solution. This was acidified to produce a cream-white precipitate which was presumably piperic acid. (sorry i couldnt get a picture of the piperic acid ppt, my lab partner threw it away (due to the toxic nature of the pyrazine and horrid smell of the solution) before i had a chance to take a final picture.

[Edited on 18-7-2010 by Picric-A]

hydrolysis of piperine.JPG - 36kBpiperic acid sodium salt.JPG - 12kB

Fleaker - 18-7-2010 at 13:31

I'd still like to see some pictures or a design of Picric/Saber's contact plant. As far as I know, I'm the only one here on SMDB to have built and documented a miniature version of this (and if anyone else has done it, please let them speak up).



Why all the interest in piperine? This is an extraction done in most freshman or sophomore organic chemistry laboratories.

Black Pepper to Piperine 91%IPA small scale

Bot0nist - 24-9-2011 at 11:15

This little extraction was a lot of fun. I learned a great deal about recrystallizations, which is a very valuable skill. It was also challenging and results in a beautiful crystalline and harmless end product.

I have some pictures of the process and some good notes, but I will try again on a larger scale and take pictures at every step to post with a writeup.


Here is how it happened.

Materials:
500ml RBF
30cm Fredrick's reflux condenser
assorted beakers
filters
eye droppers
Bottle of 91% IPA
Fresh ground black pepper
<a href="http://s1207.photobucket.com/albums/bb475/TheBot0nist/?action=view&amp;current=IPAandPepper-1.jpg" target="_blank"><img src="http://i1207.photobucket.com/albums/bb475/TheBot0nist/IPAandPepper-1.jpg" border="0" alt="Photobucket"></a>

Note - I thought that maybe if I used freshly ground, aromatic black pepper that I may yield more piperine. While I have not yet done a comparative run, It may not be worth all the effort. Next I will try on bulk ground restaurant pepper.

The extraction:

A stir bar and 25 grams of finely ground black pepper were funneled into the RBF. 100ml of 91% IPA was added to the round bottom flask and I then set up for reflux using a Fredrick's and a boiling brine bath for heat. The pepper was stirred and refluxed for 2 hours and then hot filtered. The result was about 75ml of a dark solution.

This was reduced to a thick dark oil of about 15ml in a hot water bath. I then dissolved .1g of NaHO into 20ml of hot IPA and added this solution to the 'oil.' After about 30min a small bottom layer of oil had separated out and the dark solution was decanted off of it.

This solution was evaporated to 15ml and 30ml of ice water was stirred into it. Resulting in a yellow, milky solution.
<a href="http://s1207.photobucket.com/albums/bb475/TheBot0nist/?action=view&amp;current=PercipitatewithdH2O.jpg" target="_blank"><img src="http://i1207.photobucket.com/albums/bb475/TheBot0nist/PercipitatewithdH2O.jpg" border="0" alt="Photobucket"></a>

This was allowed to stand in the fridge overnight and then filtered, leaving 1.2 grams of a waxy mass about the color of brown mustard. This mass was crumbled when dry. This waxy mass was added to 50ml of boiling water and pulverized and stirred. The 0.9grams of insoluble were filtered out and kept.
<a href="http://s1207.photobucket.com/albums/bb475/TheBot0nist/?action=view&amp;current=WetFilteredpercipitate.jpg" target="_blank"><img src="http://i1207.photobucket.com/albums/bb475/TheBot0nist/WetFilteredpercipitate.jpg" border="0" alt="Photobucket"></a>

The resulting golden waxy substance was dissolved into 20ml of boiling 91% IPA and allowed to slowly evaporate and cool to room temperature. Here are some shots of the recrystallization over the course of a night.
<a href="http://s1207.photobucket.com/albums/bb475/TheBot0nist/?action=view&amp;current=Recrystalize1.jpg" target="_blank"><img src="http://i1207.photobucket.com/albums/bb475/TheBot0nist/Recrystalize1.jpg" border="0" alt="Photobucket"></a>

<a href="http://s1207.photobucket.com/albums/bb475/TheBot0nist/?action=view&amp;current=Recrystalize2.jpg" target="_blank"><img src="http://i1207.photobucket.com/albums/bb475/TheBot0nist/Recrystalize2.jpg" border="0" alt="Photobucket"></a>

In the morning the remaining few ml of golden oil was poured off the crystal mass.
<a href="http://s1207.photobucket.com/albums/bb475/TheBot0nist/?action=view&amp;current=Recrystalize3.jpg" target="_blank"><img src="http://i1207.photobucket.com/albums/bb475/TheBot0nist/Recrystalize3.jpg" border="0" alt="Photobucket"></a>

The crystalls were washed with a few ml of IPA that sat in the freezer all night, and then dried, leaving 0.3g of pretty little needles from the first crop.
<a href="http://s1207.photobucket.com/albums/bb475/TheBot0nist/?action=view&amp;current=Washedanddriedpiperine.jpg" target="_blank"><img src="http://i1207.photobucket.com/albums/bb475/TheBot0nist/Washedanddriedpiperine.jpg" border="0" alt="Photobucket"></a>


simba - 24-9-2011 at 11:44

wow, impressive...beautiful crystals you got there...going for piperonal now? If so, keep us updated. :)

Bot0nist - 24-9-2011 at 12:40

I am not really interested in piperonal. Just trying to brush up on my technique. This was a gratifying and challenging project. Going to try with 10 oz of fine ground black aromatic pepper this weekend, with a few tweaks to hopefully improve. I will use my camera instead of my phone and capture every step.

MeSynth - 3-10-2011 at 21:15

Quote: Originally posted by Bot0nist  
I am not really interested in piperonal. Just trying to brush up on my technique. This was a gratifying and challenging project. Going to try with 10 oz of fine ground black aromatic pepper this weekend, with a few tweaks to hopefully improve. I will use my camera instead of my phone and capture every step.


I tried this before too but used the ethanol / potassium hydroxide method which resulted in a small yield. Your pictures were great and motivational. Next time I do this I'm going to try it with IPA. If that doesn't work I'm buying new pepper.

MeSynth - 3-10-2011 at 21:21

Also.. Has anyone here ever ate this stuff? I ate some and all it did was make me STARVING. lol

SWilkin676 - 13-3-2012 at 19:53

WTF no one's ever heard of steam distillation via microwave? The author was incorrect in using the term solubility in regards to pepper and water because steam distillation works when what's being distilled is insoluble in water.

Not saying this is the best way to extract pepper but it's pretty basic chemistry and doesn't rise to the level of misinformation to say heating pepper and water in a microwave will extract stuff.


S.C. Wack - 14-3-2012 at 05:51

There's a level of misinformation there all right; it's true, the author does not say piperine is steam volatile.

david101 - 6-6-2012 at 05:51

Quote: Originally posted by Bot0nist  

The extraction:

A stir bar and 25 grams of finely ground black pepper were funneled into the RBF. 100ml of 91% IPA was added to the round bottom flask and I then set up for reflux using a Fredrick's and a boiling brine bath for heat. The pepper was stirred and refluxed for 2 hours and then hot filtered. The result was about 75ml of a dark solution.

This was reduced to a thick dark oil of about 15ml in a hot water bath. I then dissolved .1g of NaHO into 20ml of hot IPA and added this solution to the 'oil.' After about 30min a small bottom layer of oil had separated out and the dark solution was decanted off of it.



Ok so you add the solution of NaOH + IPA to the oil. Then after 30 min, the oil seperates into 2 layers.

But, just to clarify, are the piperine crystals extracted from the top or bottom layer?

Can anyone help pls? Thank you kindly.


Bot0nist - 6-6-2012 at 16:00

No, there was no organic layer. Sorry for being unclear. By "oil" I meant the thick, dirty, super-saturated extract.

zenosx - 7-2-2013 at 00:28

Quote: Originally posted by idontlie  
Oh the gunk.

Tried this earlier this year.

The cold acetone shake n stir method gives you shitty grey gunk that smells stronger, rather spicy, than the original pepper. Unfortunately the grey gunk simply clogs my filter paper and I gave up on it. Maybe I need a vacuum filtration flask.

Alcohol Reflux attempts:
Traditional Reflux (denatured alcohol) stirring strong before adding your pepper is important fyi unless you don't want anything to move. Brown liquid, filtered, brown grey residue left on beaker scraped w/ razor blade smelled fowl, kind of made my eyes water. Decided that was bad, accidentally spilled some and stepped in it. left sticky shit on my shoe that left nasty grey track marks on the floor. Got pissed and threw it away.

Microwave Alcohol extraction (191 proof grain alcohol) turned dark black, filtered hot. Filtrate is still black, leaves thick grey tinged green shit on your collection beaker as it cools. Second filtration left only dark alcohol. Left this for two months to dry ended up with grey shit resembling the stuff collected on the sides of the beaker.

Alcohol (Methanol, w/ possible NitroMe azeotrope) Thick black and nasty clogged the filter. Very sticky, smelled terrible, scraping w. razor blade got it off.

Pepper corns where ground in a food processor until about the thickness of a broken off pencil lead.

Setup for reflux was microwave, 1l rbf hanging in from top at about middle, 200mm viggy (used to give separation from the microwave for the true condenser), 400mm west running ice water toped w/ balloon when the balloon got bigger than my fat head I unplug the microwave. Yes I melted a kleck clamp in the microwave, I don't want to talk about it.
Originally started with the soda bottle method. Don't do that at all, the bottle warps, the cap blows off and burning hot irritating pepper blows into the microwave and if your unlucky the roof the walls and just fucking everywhere, leaving yellow stains on everything. They come up with scrubbing but take some paint with em. sucks. Tried deflatting the soda bottle, keeping a cup of water in the microwave with it, yada yada same result.

Traditional reflux was 500ml 400mm west, oil bath, stirring.


I'm sorry but I LMAO at this post for at least 10 minutes. I can only imagine if OrgSyn had posts like this for syntheses.

Piperine extraction (and to piperidine) using ethanol

ChemPlayer_ - 23-6-2015 at 20:58

I worked on this recently with good results. Some tips:

1. Microwave extraction is awesome and magic.
2. Use white pepper if you can (less nasty gunk to separate).
3. If you use black pepper then filtering after alcoholic KOH addition is really important to help remove black tarry gunk - otherwise the quality of product is terrible.
4. Lots of reviews say that the extraction of piperidine from the subsequent hydrolysis of piperine isn't worth it, but I didn't find it too difficult (gas the alcoholic distillate with HCl, then evaporate).

I got 3.6% piperine from black pepper (in the video) and 4-5% from white.

Video here: https://www.youtube.com/watch?v=FdFEEwon6nI

Antiswat - 4-12-2017 at 04:22

http://puu.sh/yz8G6.png

xlogp3 of piperine is 3.4, naptha is approx 4. i have had some slight success with naptha. the procedure was to boil white pepper with ethanol, then let that evaporate off slowly - let it catch some foul smelling fungi and thereafter scrape the horror into a small flask with some naptha, about 3 times the volume naptha. eventually with heating the goop seperated and piperine crystals magically grew ontop of the goop. these yellow puffy looking crystals were scraped out, they werent sticky at all and i included them in the picture above.

i have noticed a bunch of times now that a yellowish ppt forms when a hot naptha-pepper extract is stashed in the freezer, however it seems to turn brown when you let it heat up to room temperature, and it also turns out to be a sticky mess once the naptha is out from the ppt.
seemingly piperine and a bit of other stuff has quite low solubility in -17*C naptha, but doable solubility at higher temperature, this could make for quick seperation if one were to acquire a vacuum filtration device to continously use the same solvent.
i tested the yellow crystals by first carefully melting and it would seem to be about 200*C melting point, also stings your tongue greatly. the yellow crystals dissolves easily in ethanol. they crumble apart easily so seemingly at room temperature naptha keeps the greasy stuff seperated from the piperine itself.

Antiswat - 2-4-2018 at 23:53

i was suggested by a fellow chemist to try precipitating the piperine from alcohol solution with water
at the point where it precipitates the solution is then heated up to redissolve the piperine, and its then left to slowly cool down
i stashed it in freezer straight from 60*C, 800 mL. next morning i found a gelatinous precipitate of glittering piperine crystals, quite small, but big enough to partially settle to the bottom and make filtration a whole lot easier
i realize on inspecting the filter how much easier this makes the seperation method, the piperine flakes off dry! struggled so far to get just somewhat dry piperine
on top of that i could let the piperine-alcohol mix slowly cool down to form bigger crystals instead of stashing it in freezer immediatedly, i found practically zero insolubles in the filtrate which again suggests larger than usual particle size of the piperine
http://puu.sh/zVeSk.jpg

another thing: when you take it straight from freezer and pour into filter its adviced to add a bit of cold water to make sure the polarity maintains and the solution doesnt redissolve piperine as it heats up from sorrounding atmosphere

actually i added too much water and added a bit of ethanol again until i precipitate was gone while solution was hot, havent worked out water-ethanol ratios yet.

LearnedAmateur - 3-4-2018 at 04:03

I’ve had a go at the extraction before, and precipitating with cold water (until it no longer becomes cloudy when water is added dropwise) is the best way to go about it. Albeit, I never had any issues with filtering the piperine through a Büchner funnel without reheating and then hot isopropanol was poured in to dissolve it where the filtrate went onto being evaporatively crystallised, got a nice mass of sparkly crystals that way.

If you want to avoid reheating then freezing, I recommend letting the precipitate sit for a couple of hours so the micro particles can pick up more piperine thus making them easier to filter. Just my suggestion to make it more efficient, but if that works (only way or is better) then stick to that - also if you notice that the filtrate is still cloudy I’ve read that it is due to a negligible amount of piperine in suspension and there is really no point in trying to extract the rest out, would probably total a few milligrams if that.

[Edited on 3-4-2018 by LearnedAmateur]

Antiswat - 12-4-2018 at 08:49

i believe you mean vacuum filtration when you say buchner funnel - this is what i dont have so far and as such ppt particle size is critical to avoid multiple days for filtration to go through and ending up with a thick slurry in the filter, after redissolving the crystalline mass left in the filter and letting it crystallize out i was left with this, or well i threw in a bit of acetone and poured it into another beaker, just to get as many impurities out as possible, as a beautiful crystalline product is my goal with piperine im quite satisfied

http://puu.sh/A1Hyi.jpg


eesakiwi - 5-5-2018 at 08:16

If using the 'soda bottle method' squeeze air out of the before microwaving.
as the solvent heats up you can hear the bottle 'popping' as it expands.
when it stops popping. STOP!
Its expanded as much as it should...

If using the alcohol/water idea, dissolve the brown toffe leftover lump in boiling Hexane.
as it cools down clean crystals will drop out, once enough have, pour it into another beaker and reheat.
Pick the crystals out of the first beaker, or dissolve in alcohol while the 2 nd beakers reheating.
keep doing this till you have all the crystals & a ceramic like lump of the brown toffee.
hexane dissolves piperine well when its boiling, but not well when its warm.

PhenethylamineMachine - 5-5-2018 at 09:18

Just posting to mark this thread so I can find it later.

DraconicAcid - 6-7-2018 at 14:59

Yesterday, I was playing with this. I've got several different versions of this experiment- some extract with alcohol, some extract with dichloromethane, some purify the compound by chromatography, some call for washing with potassium hydroxide.....

The little chromatography columns I have suck, and I'm trying to reduce the amount of dichloromethane we use.

One thing that I did try was adding petroleum ether to the extract after rotovaping off most of the dichloromethane. That gave me a golden yellow solution, with some black oil at the bottom. Removing the yellow solution with a pipette, and allowing it to stand, gave me some really nice crystals of piperine. I'll be testing their purity later.

Gl3n - 7-7-2018 at 19:34

Maybe it’s been said or not... things change dramatically over time. Piperine is freely available on eBay etc atm. I acknowledge people’s desire to reach a molecule BUT if said molecule was a step along a chain. I’ll take extreme help when it makes sense in every way

DraconicAcid - 7-7-2018 at 19:42

I'm only interested because its a cool extraction for my students to do.