I think you would be able to get to that purity with about any solvent. If evertything is cracker dry and your solvents are dry as well you want to prewash your mushroom powder with something that does not dissolve your target component. Mushrooms have fats and esters (?) and protiens and all sorts of things in them. Many of these things will dissolve in both your specific solvent and your nonspecific solvent so you want to wash as much of that crap from your product as possible. I don't remember which is the best - petrolium either maybe? It is a tough research because everyone has a different approach and even A. Shilgin winds up being wrong (about a precipitate being the target substance when in fact it is not). Anyway, after you have filtered that and tossed the solvent, and dried your materiel you can wash it with methanol - methanol without water, and get a yellow gum or tar like substance. It is not very stable and of course the strength can vary but if you mix that gum up with ascorbic acid and keep the mixture in the freezer it will last some amount of time.
I once did this with 91 percent rubbing alcohol and mixed the resulting almost orange gum (one would have thought there to be some blue in there somewhere), with flour. The resulting pills were a huge hit. I figure each pill was in the 15 - 20 mg range, no stomach cramps, no confusion. The ones I had left over I put in the freezer and when
I took them out to distribute them again, they were a shadow of their former selves, perhaps a third the potency. there is much to be learned about this sort of extraction and the results, when done right are far superior to the mushroom itself, without the nausea, the frenetic energy, the confusion and the stomach discomfort (contrary to mescaline which, no matter how pure, will still impart cramps and nausea).