Acid: Vinegar ()
Base: NaOH, lab grade
Plant: MHRB, powdered, JJ
Solvent: DCM, lab grade
pH A/B range: 5/11
Chopsticks (wood) and glass rods.
Pot: Stainless steel (inox)

Quick notes:
Experimental: 17 ml of acetic acid [1] was added to 3500 of H20. 2500 ml of this solution was added the powdered root bark[2], and the resulting suspension was brought to a light boil for 30 minutes. The solution was left to stand for 30 minutes and then filtered. The procedure was repeated with the remaining 1000ml of the acidic solution.

After that both solutions were combined reduced to ~400ml and set aside overnight.

In the morning the solution was transfarred to the separatory funnel. It was made basic [3] with NaOH and was extracted with DCM[4]. The DCM solution was isolated and the aqueous layer was re-extracted with a second volume of DCM. The extracts were left to evaporate and recrystallized with heptane[5].

[1]%=8,9, pH = 5, volume = 2000ml
[2]mass(MHRB) = 250g
[3]volume (MHRB/H20) = ~700ml
[3]pH = 11, mass(NaOH) = 4g
[4]volume (DCM) = 50 ml
[5]volume (heptane) = 10ml, T (heptane) =~50C
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This is the goo that didn't dissolve in hot (~50 C) heptane.

Any ideas on what this might be ? I understand that DCM pulls a lot but damn.

Questions.
1. Possible origins of the green goo ?
2. Possible reasons for the 0.14% yield.
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Extraction log:

I took the bucket with 3500 ml water and with the help of the pipette added the acid. 13 pipettes (1,5 each therefore ~17ml) gave a ph5.0 (Meter #1) and 4.84 (Meter #2). I poured 2500 ml of acidified water from the bucket into the 5L pot. 1000 ml was left in the bucket for the second boil.

I added the cup with 250g of mim to the acidified water in the 5L pot. I did that in several portions. The mix isn't really mixable. Despite the lack of lumps there is A LOT of foam forming. The volume of the decreases with time and is pretty much non existing at the end. I put the crock pot on the stove and used high heat.

It took about 12 minutes to boil. When this occurred the volume of the solution started to rise up pretty quickly.

The color became darker, coffee like.The smell was not present from the beginning but it increased during the cooking. Surprisingly it didn't not have any acidic components, it was more like what dirt would smell if boiled.

The simmer, with the lid on, runned for 30 minutes, with occasional stirring via chopsticks.

After 30 minutes the pot was taken from the stove and was let to cool down, with the lid off, for 30 minutes*. A lot of steam raised. On the surface on the solution a milk-fat looking layer appeared. It was discarded. The solution was then filtered through a strainer into the 2,5 L crock pot. The first few 100 mls ran straight through but at the end some bigger chunks were present and caught by the strainer so the usage is advisable. Due to infrequent mixing at the start, some bark got stuck to the bottom and burn.

It seems that quite a lot of liquid was sucked up by the MHRB since I recovered about 1600 ml of liquid (I started with 2500 ml).

1.2.2.1 Boil #2
I added the remaining 1000 ml of acidified water from the bucket to the 5l crock pot in which I had the soaked bark from the previous boil.

I let that simmer for 30 minutes and after that, removed the pot from the heat and let it sit for 30 minutes. Filtering was done after that. The solution was filtered through a strainer into the 2,5 L crock pot (which already contained the filtered solution from the first boil).

This time there was a lot less foaming and also less smell. I presume that was due to smaller volume.

I recovered 700 ml of liquid (started with 1000 ml). Combined with the previous one (1600) that meant 2300 ml of liquid (total volume at the beginning was 3500).

1.2.2.3 Reducing

The 2,5 L crock pot, containing 2300 ml of liquid, was put on high heat, lid off. It started boiling approximately after 8 minutes.

Good ventilation in necessary since, when on high, large amount of steam was rising. Smell was present although in a subtle manner. I still to needed to mix occasionally sicen the bubbles can stick to the walls of the pot and get burned in although the mixing is less frequently then it was with the first two boils.

When the solution reached 400 ml, I turn off the gas. That took about 40 minutes of boiling, meaning 48 minutes of total time on the stove. The pot was let to cool down for 30 minutes.

pH was checked after the reducing. There readings were 4.4 (Meter #1) and 4.84 (Meter #2). I also tested with narrow range pH papers and the estimation of the Ph was somewhere in between 4.4 - 4.6.

1.3 Decanting ;

I took the pot with 400 ml of liquid filtered through a strainer into a high cylinder. Sludge at the bottom was discarded and that left with me with ~330ml of liquid.

I let that sit still overnight.
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2. Day 2

The solution was decanted, a very small amount of sludge was stuck to the bottom. 300 ml of liquid was retrieved.

I prepared a 5M NaOH solution (20g in 100ml) which had a pH of 12.2. I added 20 ml of this solution to the mixture and checked for pH. It was 11.0.

The now basified solution was transferred to the separatory funnel. 50ml of DCM was added. Some sort of dirty bubblish layer formed at the top of the DCM layer, therefore only 30ml of DCM was recovered. I added another 50 ml. This time 50 ml was recovered giving a total of 80ml which were left to evaporate.

Re-X was done with 10 ml (evaporated producted yielded ~350mg) of hot (~50C) heptane.
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Pictures:

1. Scraped mimosa extract
2. Petri dish after evaporation DCM
3. Skin that formed after letting the mimosa solution stand after a boil
4. Goo that didn't dissolve in heptane
5. Filtered acidified solution

if the acidified bark is still available, try another acid boil. maybe use more water, don't use so high a heat, and get the ph a bit lower.

next, if the basified water is still available, this acid boil could be combined with it, and more base added- get the ph to at least 12.

dcm is supposed to be good, so try another 3 solvent pulls on the whole combined soup.--or maybe just pull with heptane.

also, the sludge that was discarded, next time, add back to acid boil to re wash. careful not to burn the mimosa.

good luck

biopsylo: This is not a rescue mission but more of a assessment, ergo why things got screwed up.

Your presumption is that the pH range was too narrow ?

Of which sludge were you talking about ?

Water was 10Volume in one and 4Volume. This was based on an experiment done by another member, where he used only 600 ml (150-200g bark) for the second "boil".

was it, at any point, yellow?
dcm usually give yellow product with A/B, and pink product with STB

B: The liquid itself was colorless until dried. At first there was no color, then yellowish and then greenish (just on the corners where "bigger" amounts resided).

I've extracted in an A/B type tek and the result after evaporation of DCM was a light yellow oily substance. I subsequently recrystalized this in hexane and got a fairly white product. Much of the yellow did not dissolve in the heated hexane and I still have the beaker on my desk... it still smells of indole after two months of sitting there.

Rivea, can you give more details about your process ? pH range, DCM amount, rootbark,...

Green goo reappeared after duplicating the process although this time it appeared only after hot heptane was added (Re-X).

Boiling time was changed to 4*50 and pH range increased to 3-13. First two extractions were done with DCM and the last two with hot heptane (65-70C). 100g of MHRB was used.

Amount from DCM (2*15ml): 60mg
Amount from heptane (2*50ml) : 170 - 180mg (some sticky brown goo present therefore the range).

230mg from 100 mg, 0.23% yield. Fail. Suggestions welcome.

DCM extract: Light brown, pieces, similar to sawdust. This Wiki image would be very close, maybe mine it's a little bit more brown.

Heptane extract: Crystalline, very white, fluffy with two pieces of brown goo.

Pictures:
1. DCM extract
2. Heptane extract