Sciencemadness Discussion Board

Solubility of natural resin

Xrpdguy - 4-9-2018 at 03:12

Hello guys, for one of the my researches i need to disolve natural resin. The resin is from Cherry and Plum tree. I have tried to disolve it in abs. Ethanol, n-Hexane, THF, Acetone, but none of these solvents helped me. :(

Do you have any recomendition? The only condition is that solvent need to be suitable for IR Spectroscopy (without halogens e.g. CCl4, please).

Ubya - 4-9-2018 at 04:54

acetone and diethyl ether should work, keep in mind that tree resin is slow to dissolve, so you should heat the solvent and agitate with magnetic stirring even for a few hours

Xrpdguy - 4-9-2018 at 09:56

Quote: Originally posted by Ubya  
acetone and diethyl ether should work, keep in mind that tree resin is slow to dissolve, so you should heat the solvent and agitate with magnetic stirring even for a few hours


I tried with all solvents but on room temperature. :(
Which temperature you recommend? I am afraid of damaging the structure of resin.

Ubya - 4-9-2018 at 10:21

Most plant resins are composed of terpenes. their boiling points are over 100°C, so even heating acetone to its boiling point shouldn't produce big losses

Boffis - 4-9-2018 at 11:27

@ Xrpdguy, The "resins" from Prunus species (cherries, plums etc) are not strictly resins but gums and they are composed of polysaccharides. When fresh they are soluble in water but on exposure to air and light they harden and become completely insoluble in anything that doesn't decompose them. I have tried hydrolysing cherry gum with dilute hydrochloric acid acid and while it is slow it works. Concentrating the liquor, neutralizing the excess acid and then adding ethanol or methanol causes a sugar or mixture of sugars to crystallize out. Since you can prepare furfural (my interest) from these sugars in poor yield (c 20%) they must contain at least a proportion of some pentose. I am sure there is plenty of info out there on the composition of cherry and other gums. I have just never had the inclination to search for it.

unionised - 4-9-2018 at 11:37

It seems they dissolve in water.
https://pubs.acs.org/doi/abs/10.1021/ie2014179
https://www.ncbi.nlm.nih.gov/pubmed/22701057

Not usually ideal for IR spectroscopy

Magpie - 4-9-2018 at 13:36

I would suggest turpentine. If you can't find this try some other terpene.

Xrpdguy - 4-9-2018 at 23:43

Quote: Originally posted by Boffis  
@ Xrpdguy, The "resins" from Prunus species (cherries, plums etc) are not strictly resins but gums and they are composed of polysaccharides. When fresh they are soluble in water but on exposure to air and light they harden and become completely insoluble in anything that doesn't decompose them. I have tried hydrolysing cherry gum with dilute hydrochloric acid acid and while it is slow it works. Concentrating the liquor, neutralizing the excess acid and then adding ethanol or methanol causes a sugar or mixture of sugars to crystallize out.

In the beggining of the project i have used peroxy-hydrochloric acid and the resin was disolved within 10minutes but I think that the structure of the resin was degradated by using highly concentrated acid and peroxide (without heating).

I have determined the structure of pure resin in solid state by IR but now I want to determine the structure of the solution of the resin also with the IR. Do you think that the structure will be the same or changed?


DrScrabs - 5-9-2018 at 01:30

I did use water only to dissolve cherry gum, then vacuum filter (not fritted filter)
Its a disease called Gummosis
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/gummosis
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/cank ers/gummosis-of-fruit-trees.aspx

Xrpdguy - 5-9-2018 at 05:10

Quote: Originally posted by DrScrabs  
I did use water only to dissolve cherry gum, then vacuum filter (not fritted filter)
Its a disease called Gummosis
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/gummosis
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/cank ers/gummosis-of-fruit-trees.aspx


Can you describe a whole method? Which temperature you used?

DrScrabs - 5-9-2018 at 06:23

No I´m sorry I can´t describe something professional, it was a fun project to replace gum arabic in iron gallus ink and it worked out.
But I can do my best to share my little experience
I harvested the birght amber colored gum (appx 50g) wich was not dry and with as little visible impurities(dirt, insects, bark etc) and put it in a clean marmelade glass and filled it with dH2O to the top, closed it put at a dark place and let it dissolve at roomtemp until the viscosity did not increase (4 days for me). Don´t let it stay too long maybe, because as I was writing I remembered a glass sitting in my basement and I just opened it and smelled a faint odour of alcohol, but this one was forgotten for about two months+ (unfiltered, yeast?).
So when the viscosity does not increase I vacuum filtered trough a buchner funnel and I was left with a slight dim soln. Maybe some particles made it trough.
Gravity filtration takes like forever so I don´t expect a soxhlet to work. Also I have no clue how elevated temperatures do effect the composition of the gum, I´ll boil some these days the see what happens visually. I also tried to keep it away from oxygen as good as possible.

Hopefully this helps you a little, if you do need some samples I got a big sick cherrytree in my garden.

Xrpdguy - 5-9-2018 at 06:42

Quote: Originally posted by DrScrabs  
No I´m sorry I can´t describe something professional, it was a fun project to replace gum arabic in iron gallus ink and it worked out.
But I can do my best to share my little experience
I harvested the birght amber colored gum (appx 50g) wich was not dry and with as little visible impurities(dirt, insects, bark etc) and put it in a clean marmelade glass and filled it with dH2O to the top, closed it put at a dark place and let it dissolve at roomtemp until the viscosity did not increase (4 days for me). Don´t let it stay too long maybe, because as I was writing I remembered a glass sitting in my basement and I just opened it and smelled a faint odour of alcohol, but this one was forgotten for about two months+ (unfiltered, yeast?).
So when the viscosity does not increase I vacuum filtered trough a buchner funnel and I was left with a slight dim soln. Maybe some particles made it trough.
Gravity filtration takes like forever so I don´t expect a soxhlet to work. Also I have no clue how elevated temperatures do effect the composition of the gum, I´ll boil some these days the see what happens visually. I also tried to keep it away from oxygen as good as possible.

Hopefully this helps you a little, if you do need some samples I got a big sick cherrytree in my garden.


I am very sure that resin is insoluble in water maybe you have got a resin from the tree in the moment before the whole process of polymerisation has been ended. In that Period Even it is very short you can dissolve resin into water but mainly solution will be full of polysaccharides.

Thank you for replying every information is priceless.;)

Xrpdguy - 5-9-2018 at 06:51

Quote: Originally posted by Ubya  
acetone and diethyl ether should work, keep in mind that tree resin is slow to dissolve, so you should heat the solvent and agitate with magnetic stirring even for a few hours


Today I have tried with acetone because it is more polar than diethyletre and has higher b.p.
With stirring and heating (~60°C), after 1.5h a resin was in a state of "chewing gum". I used about 2ml of the solvent.
Do you know some " more powerful" polar solvent? :D

DrScrabs - 5-9-2018 at 07:24

Maybe DMSO, nitroethane or acetonitrile?

Magpie - 5-9-2018 at 07:25

Try limonene, which can be obtained from lemon, orange, grapefruit, and lime rinds (squeeze them to get the oil). Also, there is a commercial product for removing tree resin from cars, etc. It is "Dissolve-It" or something similar.

DrScrabs - 5-9-2018 at 07:50

Quote: Originally posted by Xrpdguy  

I am very sure that resin is insoluble in water maybe you have got a resin from the tree in the moment before the whole process of polymerisation has been ended. In that Period Even it is very short you can dissolve resin into water but mainly solution will be full of polysaccharides.

Thank you for replying every information is priceless.;)


Just saw you reply and you´re right I think, for the ink it was important to have water soluble stuff and the darker hard parts of the resin are insoluble but they become softer, that´s why I did not use fritted stuff.

Xrpdguy - 5-9-2018 at 08:42

Quote: Originally posted by Magpie  
Try limonene, which can be obtained from lemon, orange, grapefruit, and lime rinds (squeeze them to get the oil). Also, there is a commercial product for removing tree resin from cars, etc. It is "Dissolve-It" or something similar.


As I said the solvent need to be suitable for ir spectroscopy. Are you sure that limonene can a vapourize enough good and enough quick before the determination?

I dont want any peeks of other compounds in the sample.

Boffis - 5-9-2018 at 11:29

My experience is that once prunus gums have hardened they are insoluble. If finely ground they absorb water a little and swells and it is possible that a portion actually dissolve, that is certainly the impression I get from some of the papers I have seen following a quick google search yesterday. These papers (one attached below) show that these gums are complex polymers of pentoses, hexoses and glucouronic acid, they are therefore, basically, very complex hydrophillic polyesters that continue to polymerise after they have exuded from the tree. The end product is insoluble in water and I suspect all less polar solvents. If you wish to characterise them there are numerous papers that describe methods of doing this. Most rely on some form of hydrolysis, either partial or total, with or without prior derivatisation with say dimethyl sulphate or the like.

So I don't think your current line of attach is going to be very fruitful. What sort of mull are you trying to use? Is it possible to grind the gum with NaCl or KBr and make a pressed disc or an oil mull?

Take a look at this paper for some ideas or just search "hydrolysis of cherry gum" in google

Attachment: 224a248.pdf (3.5MB)
This file has been downloaded 257 times

Magpie - 5-9-2018 at 19:49

I suggest:

1. dissolve the resin in a terpene (limonene or turpentine).
2. extract the resin into water.

Xrpdguy - 6-9-2018 at 00:35

Quote: Originally posted by Boffis  

. If you wish to characterise them there are numerous papers that describe methods of doing this. Most rely on some form of hydrolysis, either partial or total, with or without prior derivatisation with say dimethyl sulphate or the like.

So I don't think your current line of attach is going to be very fruitful. What sort of mull are you trying to use? Is it possible to grind the gum with NaCl or KBr and make a pressed disc or an oil mull?


if I do hydrolize partial or total I will break the polymer chains and that is not my goal. I did before in the some of the steps in this project a reaction by peroxy-hydrochloric acid and resin can be very easily disolved.
But hydrogen-peroxide cuts the long chains into smaller and change the structure of resin.

A depertment of organic chemisty on my faculty has a device which allows me to determine the structure without KBr disc or oil. Its Nicolet IS 10 (ftir). The resin or some compound of it can be recorded directly.
Because of that i am not into making discs or search about them.

Xrpdguy - 11-9-2018 at 05:09

Nothing! Nothing! Nothing!
I just cannot dissolve fuckin' resin in any solvent (except limonene cause its hard to obtain it( a lot of time and peels)).
Acetone, n-Hexane, THF, acetonitrile.... And nothing!

I tried on boiling point of solvents and still nothing. Crashing into pieces is very hard job (cause resin is hard as a rock), but anyway its useless.:(

Any recomendition? Please :'(

DrP - 12-9-2018 at 00:32

Score up the resin first.... leave it to soak in the solvent for about a week - see if it has touched it after that.

Herr Haber - 12-9-2018 at 03:10

I dont think this will be of any help seeing you tried almost everything but...

I dissolved colophony with IPA. It took a very long time at ambiant temperature and was much faster in warm solvent.

Xrpdguy - 12-9-2018 at 07:20

Quote: Originally posted by DrP  
Score up the resin first.... leave it to soak in the solvent for about a week - see if it has touched it after that.


It stayed about 5 days in Acetone and THF (in separated vials, not a mixture of solvents). Nothing happened, and after evaporisation of solvents the resin became much harder than before.

Yesterday i tried with domestic cleaner. It has only three ingredients (Ethanol 70%, isopropyl alcohol 3% and chlorhexidinedigluconate 0.57%) onits boiling point and the resin was partly dissolved.

Do you think that Ethanol and isopropyl mixture can help?
Or any other mixture?

[Edited on 12-9-2018 by Xrpdguy]

Boffis - 12-9-2018 at 11:27

Your problem is that you don't read or listen to the answers you get.

Cherry gum and related gums are NOT resins like colophony or copal and once hardened they are highly cross linked polyesters that are not soluble in any simple solvent. End of story.

They are only soluble once at least some of the ester groups are hydrolyzed to give smaller units and these are then soluble in water and possibly other polar solvents like methanol.

Magpie - 13-9-2018 at 08:23

This might work:

https://www.de-solv-it.com/

draculic acid69 - 13-10-2018 at 03:13

I remember working at a car restoration shop and we used eucalyptus oil to get tree sap off of it .at first we couldn't figure out how tree sap got allover it.it was bought at an auction from an insurance company.it must have been stolen and then hidden under some branches or something.anyway try eucalyptus oil.

happyfooddance - 13-10-2018 at 07:17

Quote: Originally posted by Xrpdguy  

I just cannot dissolve fuckin' resin in any solvent (except limonene cause its hard to obtain it( a lot of time and peels)).


What planet do you live on? d-limonene is cheap as dirt and available everywhere, it is a waste product of a huge industry (citrus juicing). It is available in consumer products as well.

Xrpdguy - 15-10-2018 at 00:35

Quote: Originally posted by happyfooddance  
Quote: Originally posted by Xrpdguy  

I just cannot dissolve fuckin' resin in any solvent (except limonene cause its hard to obtain it( a lot of time and peels)).


What planet do you live on? d-limonene is cheap as dirt and available everywhere, it is a waste product of a huge industry (citrus juicing). It is available in consumer products as well.


I know on which planet do I live but before posting any comment you should check out in which country I live. So in my country the limonene isn't available for free buying (in the shop).

DrP - 15-10-2018 at 07:03

Quote: Originally posted by Xrpdguy  

Do you think that Ethanol and isopropyl mixture can help?
Or any other mixture?
[Edited on 12-9-2018 by Xrpdguy]



If THF and Acetone aren't working then I doubt alcohol will work. Sorry.

Can you smash the sample into a powder? The increased surface area will help speed up any dissolution, but you will need a solvent that actually has some ability to attack your resin.

Xrpdguy - 18-10-2018 at 06:40

Quote: Originally posted by DrP  
Quote: Originally posted by Xrpdguy  

Do you think that Ethanol and isopropyl mixture can help?
Or any other mixture?
[Edited on 12-9-2018 by Xrpdguy]



If THF and Acetone aren't working then I doubt alcohol will work. Sorry.

Can you smash the sample into a powder? The increased surface area will help speed up any dissolution, but you will need a solvent that actually has some ability to attack your resin.

I think that I have found the right solvent. I used fresh prepared ethyl-benzoate and a little sample of smashed resin. The mixture was heated with infrared lamp for about ten minutes and temperature about 50°C.
The resin was partly dissolved.
Thats big move in my research i think.

For preparing ethyl-benzoate i used 70% Ethanol and( twice precrystalized by sublimation)benzoic acid.

Xrpdguy - 25-10-2018 at 03:57

I still have a problem. Ethyl benzoate cannot dissolve the resin at all without IR lamp :(

I have tried MMA as a solvent with heating under 100 degrees of celsius and stirring, but nothing happened. The resin became more hard.:(
Then i tried with styrene (temp. above 100 degrees and stirring but i wasnt successful at all).

Do you have any idea? The solvent needs to dissolve resin but not to destroy its structure at all (so any kind of hydrolysus isnt a good option), thats the pity part.:o


kulep - 25-10-2018 at 06:36

When making propolis tincture you usually chill it and run it through a blender to make a fine powder, then keep it in 95% EtOH for weeks, some people prefer 70% but I don't really know which one is better.
If you evaporate out the alcohol you get a very brittle resin that softens a lot when heated.

Anyways the composition is different as others have pointed out that resin is highly polymerized, but maybe it helps.

[Edited on 25-10-2018 by kulep]

Xrpdguy - 26-10-2018 at 04:01

Thats it! The research is stopped until next Spring or Summer, because of resin.
The structure is highly polymerized isoprene molecules and because of that any kind of chemial reaction is useless (if you dont want to destroy its structure).

Chemical reactions are allow only when poly-(isoprene) is still low polymerized (in early Spring or Summer). I have to collect it in the moment when it leaves the tree.

andy1988 - 26-10-2018 at 18:22

Quote: Originally posted by Xrpdguy  
I have to collect it in the moment when it leaves the tree.


Perhaps you'll find this article informative: A New System of Gathering Turpentine.

Note the use of an air-tight jar, and the claimed 50% loss of turpentine (the volatile fraction) to evaporation via the box method.

In your upcoming harvest I suppose you could use a spile, vinyl tubing, and a mason jar, possibly with a rubber/silicone grommet. Pine trees (evergreens) produce sap year round, with less yield during winter... I don't know about cherry/plum or its composition. EDIT: Some tree species don't produce much sap. If you read on Maple sap extraction, it may be assisted to increase yield by mechanical vacuum, or even just the siphon effect by running the tube downhill (even a foot or two should give a helpful siphon, the more the height difference the better).

From my understanding, the volatile fraction of the sap (turpentine in the case of pine sap) acts as a "solvent" which allows the solid fraction of the sap (rosin) to flow through the tree. Perhaps this gives some insight into the turpentine & limonine suggestions?

Perhaps there are some chemical changes in the cherry/plum resin/rosin causing solidification, but I think evaporation of the volatile fraction may also have something to do with the solidification?

[Edited on 27-10-2018 by andy1988]