title: Revisiting caffeine biosynthesis--speculations about the proximate source of its purine ring.
abstract: The prevailing hypothesis of caffeine biosynthesis starting from xanthosine was combined with Kremers' speculation on NAD as a biochemical precursor of caffeine and trigonelline in coffee. This bold sketch together with a few free-spirited ideas may channel future caffeine biosynthesis studies into novel directions.
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Baumann
mesh_terms: D002110:Caffeine / Q000096:biosynthesis* / Q000737:chemistry; D015394:Molecular Structure; D010944:Plants / Q000737:chemistry / Q000378:metabolism*; D011687:Purines / Q000737:chemistry / Q000378:metabolism*
chemical_list: D011687:Purines; D002110:Caffeine; C030985:purine