Acesulfame potassium (UK: /æsɪˈsʌlfeɪm/,[1] US: /ˌeɪsiːˈsʌlfeɪm/ AY-see-SUL-faym[2] or /ˌæsəˈsʌlfeɪm/[1]), also known as acesulfame K (K is the symbol for potassium) or Ace K, is a synthetic calorie-free sugar substitute (artificial sweetener) often marketed under the trade names Sunett and Sweet One. In the European Union, it is known under the E number (additive code) E950.[3] It was discovered accidentally in 1967 by German chemist Karl Clauss at Hoechst AG (now Nutrinova).[4] In chemical structure, acesulfame potassium is the potassium salt of 6-methyl-1,2,3-oxathiazine-4(3H)-one 2,2-dioxide. It is a white crystalline powder with molecular formula C
4H
4KNO
4S and a molecular weight of 201.24 g/mol.[5]