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McLovin382
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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
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DJF90
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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?
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watson.fawkes
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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".
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octave
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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.
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Nicodem
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| 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.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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stoichiometric_steve
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| 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".
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To be more precise, the Trimethylamine-N-Oxide gets reduced to Trimethylamine, and THAT'S what makes the fish taste "fishier".
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McLovin382
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Fine...jesus I'm not trying to spread misinformation but apparently at least to some I am so carry on.
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watson.fawkes
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| 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.
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peach
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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".
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I love this forum... barely legal chemistry to tips on cooking your dinner
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idontlie
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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.
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bbartlog
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| 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.
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Hexagon
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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.
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idontlie
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| 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.
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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 =)
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eesakiwi
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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....
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Picric-A
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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.
 
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Picric-A
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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.
 
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peach
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COME ON PICRIC, POST! 
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DJF90
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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?
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Picric-A
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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.
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panziandi
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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.
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DJF90
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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..?
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panziandi
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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]
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DJF90
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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.
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Picric-A
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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]
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Picric-A
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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]
 
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