Substituents

univalent group derived from alkanes by removal of a hydrogen atom from any carbon atom –CₙH₂ₙ₊₁

organic functional group derived from an aromatic ring

In organic chemistry, a substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule.

functional group derived from methane by removing three hydrogen atoms

300px|right|thumb|The β-D-glucopyranosyl group which is obtained by the removal of the hemiacetal hydroxyl group (bottom right) from β-D-glucopyranose