Flavin-dependent N-hydroxylating enzymes: distribution and application

Research output: Contribution to journalReview articleContributedpeer-review


  • Carolin Mügge - , Ruhr University Bochum (Author)
  • Thomas Heine - , Freiberg University of Mining and Technology (Author)
  • Alvaro Gomez Baraibar - , Ruhr University Bochum, Rottendorf Pharma GmbH (Author)
  • Willem J.H. van Berkel - , Wageningen University & Research (WUR) (Author)
  • Caroline E. Paul - , Delft University of Technology (Author)
  • Dirk Tischler - , Ruhr University Bochum (Author)


Amino groups derived from naturally abundant amino acids or (di)amines can be used as “shuttles” in nature for oxygen transfer to provide intermediates or products comprising N-O functional groups such as N-hydroxy, oxazine, isoxazolidine, nitro, nitrone, oxime, C-, S-, or N-nitroso, and azoxy units. To this end, molecular oxygen is activated by flavin, heme, or metal cofactor-containing enzymes and transferred to initially obtain N-hydroxy compounds, which can be further functionalized. In this review, we focus on flavin-dependent N-hydroxylating enzymes, which play a major role in the production of secondary metabolites, such as siderophores or antimicrobial agents. Flavoprotein monooxygenases of higher organisms (among others, in humans) can interact with nitrogen-bearing secondary metabolites or are relevant with respect to detoxification metabolism and are thus of importance to understand potential medical applications. Many enzymes that catalyze N-hydroxylation reactions have specific substrate scopes and others are rather relaxed. The subsequent conversion towards various N-O or N-N comprising molecules is also described. Overall, flavin-dependent N-hydroxylating enzymes can accept amines, diamines, amino acids, amino sugars, and amino aromatic compounds and thus provide access to versatile families of compounds containing the N-O motif. Natural roles as well as synthetic applications are highlighted.• N-O and N-N comprising natural and (semi)synthetic products are highlighted.• Flavin-based NMOs with respect to mechanism, structure, and phylogeny are reviewed.• Applications in natural product formation and synthetic approaches are provided. [Figure not available: see fulltext.].


Original languageEnglish
Pages (from-to)6481-6499
Number of pages19
JournalApplied Microbiology and Biotechnology
Issue number15
Publication statusPublished - 1 Aug 2020
Externally publishedYes

External IDs

PubMed 32504128
ORCID /0000-0002-7109-2788/work/142249508



  • Bioactive compounds, Biocatalysis, Biotransformation, Flavoproteins, Monooxygenases, N-Hydroxylases, Phylogenetics, Siderophores