In organic chemistry, a cyclitol is a cycloalkane containing at least three hydroxyl, each attached to a different ring carbon atom.[1] The general formula for an unsubstituted cyclitol is C
nH
2n-x(OH)
x or C
nH
2nO
x where 3 ≤ x ≤ n.
The name is also used for compounds that can be viewed as result of substituting various functional groups for the hydrogen atoms in such a molecule, as well as similar molecules with one or more double bonds in the ring.[citation needed]
Cyclitols and their derivatives are some of the compatible solutes which are formed in a plant as a response to salt or water stress. Some cyclitols (e.g. quinic or shikimic acid) are parts of hydrolysable tannins.