Acetogenins, halogenation

Several new halogenated bicyclic acetogenins of the laurefucin type have been discovered in marine organisms since the first survey (1). Thus, the Coral Sea red seaweed Dasyphila plumariodes contains the new isolaurefucin methyl ether (696) (789). Neoisoprelaurefucin (697) was characterized from a Japanese... 

Manzo E, Ciavatta ML, Gavagnin M, Puliti R, Mollo E, Guo Y-W, Mattia CA, Mazzarella L, Cimino G (2005) Structure and Absolute Stereochemistry of Novel C15-Halogenated Acetogenins from the Anaspidean Mollusc Aplysia dactylomela. Tetrahedron 61 7456... 

Suzuki M, Takahashi Y, Matsuo Y, Guiry MD, Masuda M (1997) Scanlonenyne, a Novel Halogenated C15 Acetogenin from the Red Alga Laurencia obtusa in Irish Waters. Tetrahedron 53 4271... 

Suzuki M, Nakano S, Takahashi Y, Abe T, Masuda M (1999) Bisezakyne-A and -B, Halogenated C15 Acetogenins from a Japanese Laurencia Species. Phytochemistry 51 657... 

SCHEME 43.1. Murai et al. s synthesis of C15 acetogenins via enzymatic halogenation. 

The most characteristic aspect of the chemistry of secondary metabolites of the red algae is the extreme abundance of halogenated derivatives, whether they are of terpenic nature or are derived from acetogenins. It is, however, important to note that the presence of halogens on carbon skeletons applies only to three orders, Ceramiales, Giga-rtinales and Nemaliales, which total about 1000 different structures. A second characteristic of the secondary metabolites of Rhodophyceae is the precision of the chemo-taxonomic relationships between the orders and the nature of the metabolites they produce. As a general rule, it was fotmd that the chemical structures vary somewhat within an order, but much more from one order to another, with hardly any exceptions to these observations in just over 1500 structures. These chemotaxonomic relationships are collected in Table 13.6, where we consider the classification of six orders. 

Presence of many cyclic ethers and halogenated acetogenins with 15 carbon atoms that might be characteristic of the order. 

Ji, N.-Y, Li, X.-M., and Wang, B.-G. (2008a) Halogenated terpenes and a Ci5-acetogenin from the marine red alga Laurencia saitoi. Molecules, 13, 2894-2899. 

Suzuki, M., Matsuo, Y, and Masuda, M. (1993b) Structures of laurenenyne-A and -B, novel halogenated acetogenins from a species of the red algal Laurencia. Tetrahedron, 49,2033-2042. 

Suzuki, M., Takahashi, Y, Matsuo, Y, Guiry, M.D., and Masuda, M. (1997) Scanlonenyne, a novel halogenated C-15 acetogenin from the red alga Laurencia obtusa in Irish waters. Tetrahedron, 53, 4271-4278. 

Suzuki, M., Nakano, S., Takahashi, Y, Abe, T., and Masuda, M. (1999) Bisezakyne-A and -B, halogenated C-15 acetogenins from a Japanese Laurencia species. Phytochemistry, 51, 657-662. 

Manzo, E., Ciavatta, M.L., Gavagnin, M., Puliti, R., MoUo, E Guo, Y.-W., Mattia, C.A., Mazarella, L., and Cimino, G. (2005a) Structure and absolute stereochemistry of novel Cjs-halogenated acetogenins from... 

Ojika, M., Nemoto, T, and Yamada, K. (1993a) Doliculol-A and doliculol-B, the non-halogenated C15 acetogenin with cyclic ether from the sea hare Dolabella auriadaria. Tetrahedron Lett., 34, 3461-3462. 

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