Date: 08 Mar 2012

Mechanisms of Halogenation of Marine Secondary Metabolites

Abstract

Chemical halogenation often requires harsh reaction conditions and results in unwanted by-product formation. It is thus of great interest to investigate the biosynthesis of halogenated natural products and the biotechnological potential of halogenating enzymes. Most of the biogenic organohalogens known today are marine-derived and often proposed to serve as antifeedant and antibacterial defense agents; however, knowledge on biological halogenation in marine organisms still is very limited. Today, mainly vanadate-depending haloperoxidases (Va-HPO) and nonheme FeII/α-ketoglutarate/O2-dependent halogenases are described for secondary metabolite biosynthesis in marine organisms. Beyond that, also enzymes utilizing S-adenosyl-l-methionine in halogen transfer are found in marine environments. This review aims to give a comprehensive overview on the different strategies used by nature to incorporate halogens into secondary metabolites.