Theophylline bears structural and pharmacological similarity to theobromine and caffeine, and is readily found in nature, being present in tea (Camellia sinensis) and cocoa (Theobroma cacao). A small amount of theophylline is one of the products of caffeine metabolic processing in the liver. Theophylline - Wikipedia #caffeine #tea #coffee https://en.wikipedia.org/wiki/Theophylline