Enzymatic hydroxylation of aromatic compounds

Area of Science:

• Biocatalysis
• Synthetic Chemistry
• Enzymology

Background:

• Selective hydroxylation of aromatic compounds is a challenging but crucial reaction in synthetic chemistry.
• Hydroxylated aromatics are vital precursors for synthesizing pharmaceuticals.
• Biocatalytic oxygen transfer using enzymes or microbial cells provides an efficient and selective approach.

Purpose of the Study:

• To review diverse enzymes and mechanisms for aromatic hydroxylation.
• To explore oxygen donors like dioxygen (O(2)) and hydrogen peroxide (H(2)O(2)).
• To discuss biocatalytic pathways, including free radical intermediates.

Main Methods:

• Overview of Rieske-type and alpha-keto acid-dependent dioxygenases.
• Discussion of non-heme monooxygenases (di-iron, pterin, flavin enzymes), tyrosinase, and laccase.
• Focus on heme-containing enzymes: cytochrome P450 monooxygenases, peroxidases, and novel heme-thiolate haloperoxidases (peroxygenases).

Main Results:

• Detailed examination of various enzymatic systems for aromatic hydroxylation.
• Comparison of different oxygen donors and reaction mechanisms.
• Highlighting the versatility of heme-biocatalysts, including hybrid peroxygenases.

Conclusions:

• Biocatalysis is a powerful strategy for selective aromatic hydroxylation.
• A wide array of enzymes offers diverse mechanistic pathways.
• Heme-containing enzymes, particularly peroxygenases, represent significant advancements in this field.