Storing - Stability of mescaline in solution?

[Ontherooftops]

Someone did an extraction on a large amount of cactus about a year ago. After the first wash he threw more isopropanol onto the material, and then proceded to forget about it because he had a large bottle of cactus extract at his disposal for special ceremonies.

So now his original supply is nearly gone, and he recently noticed that huge bottle of cactus and isopropanol again. It has been stored in a cool place with no light. He's read that mescaline can survive inside the dried cactus for hundreds of years. He wonders if he were to evaporate the solution if he would be able to attain a little more mescaline, or if it has degraded over time?