Extraction of Salvinorins from Salvia Divinorum

The original extraction of Salvinorin A from salvia divinorum leaves - partitioning of a crude extract between acetone and hexane - has been greatly developed/enhanced.

This is an extraction procedure from Gartz' book 'Salvia divinorum - Die Wahrsagesalbei' (2001):

10 g of dried and pulverized leaves are stirred for 3 h with 220 mL diethyl ether, and after filtration the plant material is washed twice with 50 mL of the same solvent. These extracts are united and the solvent evaporated. You will get 250 - 300 mg of a 10% preparation with a greenish colour [ie. wax/tar]. The greenish mass is stirred with 15 mL of petroleum ether (bp 50 - 60°C) for 24 h. After filtration and washing with 5 mL petroleum ether, the residue is dried and the solvent disgarded. The residue is now solved in 3 mL absolute ethanol by shortly heating in the waterbath to 60 °C. After cooling down to 30 °C, 1 mL of acetone is added and all is cooled down to 0 °C. After 12h at 0 °C filter off and dry. A second analogue precipitation from alcohol with acetone leads to a pure compound with a melting point of 240 °C. Yield: about 20 mg (0.2%)

Although vastly improved over the original, this procedure is still lacking, and not too efficient. Below is a method developed by amateur chemists working together over the internet. This method was initially kept semi-secret, for fears that Salvia would become prohibited. As this now seems to be inevitable in all 'civilised' countries, I see no reason not to distribute this procedure for use in the WoDaRE (War On Drugs And Religious Experience):

Experimental

100 g whole dried leaves are put into a 5 L bottle and left in a fridge for 6 h. At the same time, two bottles each containing 1 L food-grade anhydrous acetone are chilled to a temp. of -6 C in a freezer. The bottle of leaves is removed from the fridge and immediately one of the portions of chilled acetone is added. The bottle is capped and vigorously shaken for 150 s. The solvent is then decanted and filtered. The second bottle of chilled acetone is removed from the freezer and its contents added to the bottle of leaves. The vigorous shaking is repeated for another 120 s; the solvent is then decanted, filtered, and combined with the first extraction to give just under 2 L of a clear pale green liquid. The solvent is removed by distillation (can be recycled) to give 290 mg of green (traces of chlorophyll) crystals. Recrystallisation from a small volume of boiling IPA gives 260 mg beautiful white xtals.

Notes

1. Obviously, the yield of Salvinorin will depend on the potency of the leaf used for extraction.
2. Leaves that are brown seem to contain the same concentration of Salvinorin as green leaves, but do not contain chlorophyll which is readily soluble in acetone and causes the green colouration of the crystals. Fresh leaves can be made into brown leaves by freezing, thawing, and leaving to dry in a warm place.
3. I have noticed that if after the first acetone extraction, the leaves are left for any length of time, tars and chlorophylls, etc. are extracted from the plant cells by the residual acetone, and are instantly dissolved by the solvent of the second extraction resulting in a waxy non-crystalline product (albeit much less waxy than simple methanol extraction). Therefore the second volume of acetone should be added as soon as the first has been decanted.
4. The solution should be ASAP after extraction; Salvinorin A will decompose if left in solution in acetone and only waxy extracts will be produced if the solution is left to stand for more than a day or so.
5. It seems that there is always a deposition of a minute amount of a brown-white substance (fats? tannins? conglomerated leaf particles?) in the distillation flask after distillation. This substance seems to precipitate out as the solvent is distilled, and after distillation it is not soluble in acetone, unlike Salvinorin A, which is.
6. Recrystallisation is not really necessary; the greenish crystals are of sufficient purity to make them easily suitable for making standardised extracts or for vaporization.
7. Some of the extracted leaf can be further extracted with methanol to remove all chlorophyll, tars, etc. and dried to give a very 'clean' extract.
8. The times for shaking the solvent with the leaves are the ones I have found to be most effective. They are not fixed; experiment is king.
9. Acetonitrile is also an interesting solvent.