Acesulfame potassium is a calorie-free artificial sweetener, also known as Acesulfame K or Ace K (K being the symbol for potassium), and marketed under the trade names Sunett and Sweet One. In the European Union, it is known under the E number (additive code) E950. It was discovered accidentally in 1967 by German chemist Karl Clauss at Hoechst AG (now Nutrinova). 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 C4H4KNO4S and a molecular weight of 201.24.