BiomarkerOf theophylline A dimethylxanthine having the two methyl groups located at positions 1 and 3. It is structurally similar to caffeine and is found in green and black tea. InChI=1S/C7H8N4O2/c1-10-5-4(8-3-9-5)6(12)11(2)7(10)13/h3H,1-2H3,(H,8,9) CHEBI:28177 C07130 | D00371 ZFXYFBGIUFBOJW-UHFFFAOYSA-N FOBI:030656 HMDB01889 2153 Xanthines tea based beverage product coffee based beverage product cacao food product