theobromine is a chemical substance, also known as xantheose. it is an alkaloid. it occurs in the cacao plant. chemically, it is very similar to caffeine. because the cacao plant is used to make chocolate, it is also found in chocolate. despite its name, there is no bromine in it. the name ""theobromine" comes from the word "theobroma"" as the name of the genus of the cacao tree (which itself is made up of the greek roots "theo" ("god") and "brosi" ("food"), meaning "food of the gods") with the suffix given to alkaloids and other base nitrogen-containing compounds.