Secondary metabolites halogenation

Masuda, M., Abe, T., Sato, S., Suzuki, T. and Suzuki, M. 1997a. Diversity of halogenated secondary metabolites in the red alga Laurencia nipponica (Rhodomelaceae, Ceramales) J. Phycol. 33 196-208. 

While common biosynthetic pathways may provide the framework for the various classes of secondary metabolites, their functionality is imparted by specialized tailoring enzymes that are often unique to natural products (Walsh 2004 Hertweck et al. 2007). Whether it is the addition of alcohol groups, halogenation (Gribble 1998), oxidation, reduction, stereochemical manipulation, or cyclization, it is often these functionalities that make secondary metabolites unique and bioactive. 

Fluorine is found in nature as mineral fluorides, and it is the most abundant halogen in the Earth s crust. Thus, it is rather surprising that less than 15 fluorinated organic molecules have been isolated from plants. They are aU secondary metabolites of fluoroacetate. Among these compounds, all monofluorinated, half are composed of (w-fluorinated homologues of fatty acids. ... 

A myriad of structural types are found amongst the secondary metabolites of marine invertebrates. Halogenation is typical of marine natural products, which is not unexpected, given that seawater contains... 

Masuda M, Abe T, Sato S, Suzuki T, Suzuki M (1997) Diversity of Halogenated Secondary Metabolites in the Red Alga Laurencia nipponica (Rhodomelaceae, Ceramiales). J Phycol 33 196... 

Masuda M, Takahashi Y, Okamoto K, Matsuo Y, Suzuki M (1997) Morphology and Halogenated Secondary Metabolites of Laurencia snackeyi (Weber-van Bosse) Stat. Nov. (Ceramiales, Rhodophyta). Eur J Phycol 32 293... 

Aydogmus Z, Imre S, Ersoy L, Wray V (2004) Halogenated Secondary Metabolites from Laurencia obtusa. Nat Prod Res 18 43... 

To illustrate mechanisms by which complex halogenated secondary metabolites are elaborated, the haloperoxidase-mediated biosynthesis of selected halometabolites elaborated by marine microorganisms will be described. The discussion given by Neidleman20 of chloramphenicol biosynthesis provides an example of bacterial halometabolite biosynthesis, while fungal halometabolite biosynthetic schemes are found in the monograph by Turner21. 

Suzuki M, Vairappan CS. Halogenated secondary metabolites from Japanese species of the red algal genus Laurencia (Rhodomela-ceae, Ceramiales). Curr. Topic. Phytochem. 2005 7 1-34. 

In order to confirm the biotransformation capability of the sea hare -Aplysia punctata, Quinoa et al. (46) studied a number of marine algae for the presence of halogenated monoteipenes and compared the hplc and gc profiles of the extracts of the hepatopancreas of A. punctata with algal extracts. The results of this study showed a direct correlation between the chromatographic and gc-ms profile of the secondary metabolites of Plocamium coccineum and A. punctata. However, no biotransformation capability was noticed. 

---