Precisely the same reaction occurs every time a mushroom is Slash or bruised. The color change is due to an enzyme identified as coprine. This enzyme is present in all species of fungi but is not really unsafe to humans in little doses. Psilocybe mushrooms comprise the psychoactive compounds psilocin https://liberty-cap-mushroom32096.dreamyblogs.com/22399481/the-smart-trick-of-edible-uk-mushrooms-that-nobody-is-discussing