A colorless crystalline compound with a fruit-like taste that is found in fumitory, bolete mushrooms, lichen, and Iceland moss. It is also produced naturally by human skin when exposed to sunlight and is used by cells to produce energy from food.
Molecular formula: C4H4O4
Molar mass: 116.07 g/mol
Melting point: 287 °C
Fumaric acid is the trans isomer of maleic acid.