C18H18O5

The molecular formula C18H18O5 (molar mass: 314.33 g/mol, exact mass: 314.115424 u) may refer to:
 * Flavokavain A, a flavokavain found in the kava plant
 * 7-Hydroxy-2,3,4,8-tetramethoxyphenanthrene, a phenanthrene found in the rhizome of Dioscorea communis