[limpet chicken]

Could someone here perhaps give me a general introduction to chromatography?

I wish to ghetto-up a chromatography setup, for isolation of single materials from multi-part plant alkaloid, glycoside, terpene etc. isolates, for the most part.

If someone could give me a rough rundown of what I would need to buy, column substrates, solvents etc, the techniques used, Iwould appreciate it, it is all very well reading online textbooks, but it would help me if I could hear from someone actually experienced with the techniques

Thanks.

[Mitch]

You gotta be specific. Seperation is a science onto itself.

[limpet chicken]

Almost all of what I would use it for, is purifying, and seperating mixed alkaloids, purifying the recrystallised, multiple total alkaloid content after extraction, and in a single case, a diterpene.

If you mean the specific alkaloids, I wish to seperate the mixed alkaloid fraction from Atropa Belladonna, and in the case of the extracted, purified atropine, which happens to be racemic hyoscyamine, resolve it into its isomers and collect the pure fractions of D, and L-tropine, and that of tropinone.


The diterpenes I am interested in, is salvinorin-B, and closely related salvinorins, and divinitorins, specifically to EXCLUDE the kappa opiate agonist salvinorin A, that is, I wish to be able to purify commercially available salvinorin A, which is actually a recrystallised mixed diterpene fraction from the plant Salvia Divinorum, or diviner's sage, a currently uncontrolled plant used ritualistically by the mazatec people of mexico, to remove the salvinorin A, and isolate seperately, the other related salvinorins, and the divinitorins, which have proved themselves inactive in man.

Do not get me wrong in this, I am not after isolating the psychadelic compound salvinorin A itself, although legally uncontrolled, I have myself experienced this compound, but I am more curious about doing some studies myself on the physiologically INACTIVE compounds within the plant.

[hmx9123]

My friend, you are really asking for some difficult separations.  You should look into perfecting the art of recrystallization.

First, many of the things you want probably come out about the same place on a column.  I'm assuming that you're running a crude column and not with fancy HPLCs or anything.

Second, in order to separate the different enantiomers of the substances you're looking for, you're going to need a chiral column.  Those are not that old in the way of chromatography, and you better expect to pay out the ass for them.

Third, why exactly do you want to extract atropine?  Are you going to poison someone?  I'm assuming you know how toxic that is?

[movies]

Silica gel chromatography is the norm for organic chemists.  The silica generally can't be recycled so it can get to be pretty expensive.  Plus, you need some way of determining what is in your fractions, usually TLC plates, which can also be pretty pricey.  The glassware is fairly speciallized too --> $.  Standard chromatography in organic labs uses around 15 psi of compressed air pressure, so you would need some kind of tank or efficient compressor.  Then you need loads of disposable solvents.  For alkaloid isolation you're probably looking at very polar mixtures like 10% methanol in chloroform and you probably need around 10L all told.  Most isolation papers report acid/base extraction followed by 3 or more chromatography columns to isolate pure natural products.

As mentioned, chiral separation require chiral solid phases.  The chiral HPLC columns in our lab go for about $4000 a piece and they are purely analytical, not preparative.  Not to mention that the HPLC machine alone costs around 50k.

Good times.