Complex sentence: The blue color of "Lactarius indigo" is largely due to the compound, 1-stearoyloxymethylene-4-methyl-7-isopropenylazulene, an azulene, that has been extracted and purified from fruit bodies.
Split into simpler sentences: The blue color of "Lactarius indigo" is largely due to a chemical pigment called an azulene. The compound, 1-stearoyloxymethylene-4-methyl-7-isopropenylazulene, has been extracted and purified from fruit bodies.