Mushroom bouillon

A few days ago I went to the grocery store, and one of the things I wanted to buy was garlic rice flavored bouillon cubes.  I couldn't find that, so instead I bought --reluctantly--, mushroom flavored bouillon cubes.

Tonight I used one of those cubes, and man, are they good!  I can't believe how delicious, and how strong is the mushroom flavor.  I wonder how much of that flavor is artificial.  I can't believe it's all natural.