Halogenated organic compounds are extensively used in the cosmetic, pharmaceutical, and chemical industries. Several naturally occurring halogen-containing natural products are also produced, mainly by marine organisms. These compounds accumulate in the environment due to their chemical stability and lack of biological pathways for their degradation. However, a few enzymes have been identified that perform dehalogenation reactions in specific biological pathways and others have been identified to have secondary activities toward halogenated compounds. Various mechanisms for dehalogenation of I, Cl, Br, and F containing compounds have been elucidated. These have been grouped into reductive, oxidative, and hydrolytic mechanisms. Flavin-dependent enzymes have been shown to catalyze oxidative dehalogenation reactions utilizing the C4a-hydroperoxyflavin intermediate. In addition, flavoenzymes perform reductive dehalogenation, forming transient flavin semiquinones. Recently, flavin-dependent enzymes have also been shown to perform dehalogenation reactions where the reduced form of the flavin produces a covalent intermediate. Here, recent studies on the reactions of flavoenzymes in dehalogenation reactions, with a focus on covalent catalytic dehalogenation mechanisms, are described.

卤代有机化合物广泛用于化妆品，制药和化学工业。主要由海洋生物也生产几种天然存在的含卤素的天然产物。这些化合物由于其化学稳定性和缺乏生物降解途径而在环境中积累。然而，已经鉴定出一些在特定的生物途径中进行脱卤反应的酶，并且已经鉴定出对卤代化合物具有次级活性的其他酶。已经阐明了各种使含I，Cl，Br和F的化合物脱卤的机理。这些已分为还原，氧化和水解机理。已显示出黄素依赖性酶利用C4a-氢过氧黄素中间体催化氧化脱卤反应。另外，黄素酶进行还原性脱卤作用，形成瞬时黄素半醌。最近，还显示出黄素依赖性酶能够进行脱卤反应，其中还原形式的黄素可产生共价中间体。在此，描述了有关黄素酶在脱卤反应中的反应的最新研究，重点是共价催化脱卤机理。