Hydroxylation

Hydroxylation is important in detoxification since it converts lipophilic compounds into water-soluble (hydrophilic) products that are more readily removed by the kidneys or liver and excreted.

[6] Hydroxylation occurs at the γ-C atom, forming hydroxyproline (Hyp), which stabilizes the secondary structure of collagen due to the strong electronegative effects of oxygen.

Since citrus fruits are rich in vitamin C, British sailors were given limes to combat scurvy on long ocean voyages; hence, they were called "limeys".

[8] Several other amino acids aside from proline are susceptible to hydroxylation, especially lysine, asparagine, aspartate and histidine.

Mixtures of ferrous sulfate and hydrogen peroxide, the Fenton reagent, behaves similarly.

[11] Whereas many hydroxylations insert O atoms into C−H bonds, some reactions add OH groups to unsaturated substrates.

The hydroxy groups are provided by hydrogen peroxide, which adds across the double bond of alkenes.

Nature has evolved enzymes called methane monooxygenases, which are efficient but impractical for commercial applications.