Can someone help me understanding how solvents work?

[Neuroborean]

I mean, I want to do my own extraction of STRICTLY LEGAL plants and substances,
for example, if I find a good batch of mulungu, I would like to do a proper extraction so I need to see how to use the best solvent,
I know that different substances are extracted better by different solvents so something like kratom may have different substances that some are extracted in methanol and maybe another in petroleum ether or whatever,

I would like to know how to understand why that happens, and have the basic notions to buy the most easy to get solvents, like for example limonene, methanol, ethanol and acetone and then knowing how to operate when searching for the best solvent for each substance.

The thing is that I mostly would prefer to do full expectrum extracts but maybe in some cases I would like to separate different fractions (how to that properly?)

for example, I've read a paper about Vitex-Agnus-castus, that seems to have opioidergic activity (probably weak and in high doses but... seems interesting to try!!)

Opioidergic mechanisms underlying the actions of Vitex agnus-castus L - PubMed

Vitex agnus-castus (VAC) has been used since ancient Greek times and has been shown clinically to be effective for the treatment of pre-menstrual syndrome. However, its mechanism of action has only been partially determined. Compounds, fractions, and extracts isolated from VAC were used in this...

pubmed.ncbi.nlm.nih.gov

"The highest affinity for MOR was concentrated in the CHCl(3) fraction, whereas the highest affinity for DOR was found in the CHCl(3) and EtOAc fractions. The petroleum ether fraction had the highest agonist activity at MOR and DOR. Several flavonoids from VAC were found to bind to both MOR and DOR in a dose-dependent manner; however only casticin, a marker compound for genus Vitex, was found to have agonist activity selective for DOR at high concentrations."

Isn't this interesting? that's the thing, I probably wouldn't get easily petrolium ether where I live so I would like to know what else use to get a mor agonist while extracting vitex, or whatever else.
I like a lot this things and want to learn as much as possible. Mulungu or magnolia are interesting plants but probably buying in bulk and doing extractions would be much better to operate.

Thanks guys/gals, you're awesome!

 

[ions]

Here's a link to a site. If you want solvents according to polarity, or chromatographic series, it's table 2 on that page.

Solvents

I should also add that solvents work to extract things according to polarity. Like petroleum ether being very non-polar, and water being the most polar. everything ranked relative to, well in this case, cyclohexane being least polar, and water most. So if you can find relative polarity of a substance to extract, dielectric constant, then you might find a suitable solvent that will capture natural products out of plant or something.

In the case of cocaine, it's a lot of back and forth with acids and bases and gasoline to get mostly pure cocaine.

 

[Neuroborean]

Here's a link to a site. If you want solvents according to polarity, or chromatographic series, it's table 2 on that page.

Solvents

I should also add that solvents work to extract things according to polarity. Like petroleum ether being very non-polar, and water being the most polar. everything ranked relative to, well in this case, cyclohexane being least polar, and water most. So if you can find relative polarity of a substance to extract, dielectric constant, then you might find a suitable solvent that will capture natural products out of plant or something.

In the case of cocaine, it's a lot of back and forth with acids and bases and gasoline to get mostly pure cocaine.

So basically I need to know if a substance is more polar or apolar and then search a solvent that will attract that molecule/s because they fit in the relative polarity
something like that?

 

[ions]

If you want them to dissolve. or go into solution.
If you want something to separate, it would go like this. Let's say you have A and B in a mixture of solids. You want B, so find something to dissolve A, and B will stay a solid in the liquid. THen you can do a filter.

It's not always that easy. Which is why chromatography is a popular topic in chemistry. It's basically separation science.
What they teach you is to dissolve what you want in a solution, filter off what you don't want. The opposite of what I described above. ANd then precipitate it off with by adding another solvent to alter the solvent system polarity slightly to the point that somethign falls out of solution. It's called recrystallization.

Buchner funnels and filter papers help for collecting solids of interest, or disinterest, depending. Beakers for making solutions.

 

[G_Chem]

So basically I need to know if a substance is more polar or apolar and then search a solvent that will attract that molecule/s because they fit in the relative polarity
something like that?

More or less yes. You can follow some rules, such as plant alkaloids are often soluble in polar solvents as salts but have better solubility in non-polar solvents as freebase. It’s this property that makes the A/B purification method ideal for alkaloids.

There there’s psychoactive terpenes and flavonoids which are more soluble in non-polar solvents.

-GC

 

[Neuroborean]

More or less yes. You can follow some rules, such as plant alkaloids are often soluble in polar solvents as salts but have better solubility in non-polar solvents as freebase. It’s this property that makes the A/B purification method ideal for alkaloids.

There there’s psychoactive terpenes and flavonoids which are more soluble in non-polar solvents.

-GC

So then, if you have a plant that have both alkaloids and terpenes/flavonoids you can do a wash with water (let's say), get the alkaloids and then do a second wash with hexane and get the terpenes/flavonoids?
I mean, I guess the both would have different ratios, not just alkaloids or just terpenes..

Let's say you have A and B in a mixture of solids. You want B, so find something to dissolve A, and B will stay a solid in the liquid. THen you can do a filter.

Allright, super interesting message of yours, but need to study it carefully
let's take an example that I did, the 69ron's calamus acetone wash
according to 69ron there's a psychedelic and euphoric substance in calamus, but you need to wash it first with acetone, it should be alkaloid like and very soluble in water but not in acetone,
so with acetone you dissolve the unwanted fraction (it seems to be the sedating and unwanted emetic asarones) and then the solids that remain after the acetone extraction (the acetone evaporates and then you have the unwanted A, isn't it?) keep the interesting shit that is soluble in water...
It's basically that?
I didn't try it yet, cause I didn't have time enough to plan the trip (seems to be like a light dose of mescaline as I remember) but there I have the solids...

 

[ions]

Don’t know about calamus or it’s psychedelics.

Mimosa hostilis for I know they run a naphtha bath.

Cannabinoids goes in ethanol or butane.

There may be something in the inter webs.

 

[Fertile]

Solvents tend to be classed in various manners. Whether they have a bare hydrogen (protonic) or not (aprotonic), how polar they are and if they are organic or inorganic. Also if they are miscible with water (important for a lot of organic synthesis)

From that, it's possible to work out roughly which solvent you need but the rule is 'like dissolves like'.

Often one will need to know if 2 solvents are miscible. That is why tables such as this are common:

solvent

Image solvent hosted in ImgBB

ibb.co

It's also important to know a solvent's physical properties such as melting point and boiling pointL

solvent

Image solvent hosted in ImgBB

ibb.co

It's almost always the case that a solvent will dissolve more of a material the hotter the compound is, so one needs to know this.

I suppose the best example of this is the perfluorocarbons. Often chemicals are totally insoluble in the cold perfluorocarbon solvent but freely soluble in the hot perfluorocarbon solvent. About 15 years ago much was made of this... until people realised that while they had many virtues, perfluorcarbons are 'forever' chemicals.

Lastly one should be aware of the dangers of each solvent. Some are flammable, some are toxic and because of this many of the common solvents of the 1970s (and before) are now almost never encountered. I remember hexamethyl triaminophosphine & diethyl ether being as common as dichloromethane and methanol in labs. Now they are virtually never used. THF & N-methyl pyrrolidine replace them. The former is still flammable.... but it's melting point and vapour pressure mean that you don't end up with as many fumes. The latter isn't a known carcinogen unlike the compound it replaced.

An organic chemist generally just has to produce a workable route to a product that can be patented. It's the job of chemical engineers to find better routes that use less and of less hazardous solvents. If memory serves the history of tramadol's synthesis is a very good example. Often chemical engineers will purposefully use a mixture of 2 or more solvents to maximise solvation and thus minimise the volume of solvent, They also work on solvent management. A solvent is not used once, it is used over and over again. It can bring the price of the product down to a fraction of the cost the patent route uses.

It IS a complex subject but read papers and every time you see a solvent used, work out why it's THAT solvent. Sometimes what would be excellent reagents prove to be of only marginal utility because they aren't very soluble.

At the extremes, remember that metals melt to become liquids and some inorganic chemistry takes place in these liquid metals.