Xylitol is an organic compound with the formula (CHOH)3(CH2OH)2. This achiral species is one of three isomers of 1,2,3,4,5-pentapentanol. This sugar alcohol is used as a naturally occurring sugar substitute found in the fibres of many fruits and vegetables, including various berries, corn husks, oats, and mushrooms. It can be extracted from corn fibre, birch, raspberries, plums, and corn. Xylitol is roughly as sweet as sucrose with only two-thirds the food energy. Xylitol was first derived from Birch trees in Finland in the 20th century and was first popularized in Europe as a safe sweetener for people with diabetes that would not impact insulin levels. Today, commonly hardwood and maize sources are used as raw materials.