Noncovalent interactions, namely ion pair interactions, hydrogen bonds, cation–π interactions and London
dispersion forces are considered to have a fundamental impact in molecular recognition. The relationship between
metal ions and natural products has been extensively studied. A great number of natural products possess ion
chelating ability, such as cyclic peptides, ionophores, siderophores, phytochelatins, flavonoids and other types of
compounds, namely polysaccharides and oligosaccharides. These findings spurred extensive research on the ion
chelating natural products over the past decade. This review provides a more detailed insight of siderophores, phytochelatins
and ion chelating flavonoids obtained from natural sources.