Laurencia

Hybridalactone, a novel marine derived eicosanoid from Laurencia hybrida, appears to be biosynthesized by a unique pathway from eicosapentaenoic acid. The synthesis of hybridalactone was carried out enantiospecifically from (+)-bicyclo[3.2.0]hept-4-ene-l-one so as to provide proof of stereochemistry (Ref. 4). 

Fig. 5.12 Compounds 488-505, halogenated terpenes from Portieria and Laurencia species...

Laurencia, which has also attracted a lot of attention because of its chemical constituents, is a comparatively large genus. In addition to examples of geographically distinct chemotypes, the examples below illustrate the considerable structural variety... 

Those authors also demonstrated that neither sexual stage nor age of plant had any effect on the qualitative composition of the lipid fractions. They did comment, however, on the possibility that the secondary chemical output of plants at these different sites might reflect local environmental conditions, especially considering that the distance between the sites at Castelluccio and Brucoli is only a few kilometers. They pointed to the work of Howard et al. (1980), who had demonstrated such effects on the chemical content of two species of Laurencia in California over... 

Fig. 5.13 Map of eastern Sicily showing Laurencia obtusa collection sites...

On the basis of morphological and secondary metabolic differences, Masuda et al. (1997c) concluded that an alga previously known as Laurencia obtusa (Hudson) Lamouroux var. snackeyi (Weber-van Bosse) Yamada (earlier name was L paniculata... 

Fig. 5.14 Compounds 506-518, more terpenes from Laurencia species...

Abe, T., Masuda, M., Suzuki, T. and Suzuki, M. 1999. Chemical races in the red alga Laurencia nipponica (Rhodomelaceae, Ceramales) Phycol. Res. 47 87-95. 

Amico, V., Caccamese, S., Neri, P., Russo, G. and Foti, M. 1991. BrasUane-type ses-quiterpenoids from the Mediterraanean red alga Laurencia obtusa. Phytochemistry 30 1921-1928. 

Ayyad, S. E. N., Jakupovic, J. and Abdel-Mogib, M. 1994. A sesquiterpene ether from Laurencia obtusa. Phytochemistry 36 1077-1078. 

Caccamese, S., R. Azzolina, R. M. Toscano and K. L. Rinehart, Jr. 1981. Variations in the halogenated metabolites of Laurencia obtusa from eastern Sicily. Biochem. Syst. Ecol. 9 241-246. 

Howard, B. M., Nonomura, A. M. and Fenical, W. 1980. Chemotaxonomy in marine algae secondary metabolite synthesis by Laurencia in unialgal culture. Biochem. Syst. Ecol. 8 329-336. 

Itoh, T., Matsuo, Y. and Suzuki, M. 1997b. Sesquiterpenoids of Laurencia majuscula... 

Oztunc, A., Imre, S., Loiter, H. and Wagner, H. 1991. Two C-15 bromoalleles form the red alga Laurencia obtusa. Phytochemistry 30 255-258. 

Suzuki, M. and Kurosawa, E. 1978. Two new halogenated sesquiterpenes from the red alga Laurencia majuscula. Tetrahedron Lett. 4805-4808. 

Kurosawa, E. and Kurata, K. 1987. Majusculone, a novel norchamigrane-type metabolite from the red alga Laurencia majuscula Harvey. Buh. Chem. Soc. Japan 60 3795-3796. 

Tanaka, J., Higa, T., Bernardinella, G. and Jefford, C. W. 1988. Itomanindoles A and B, meth-ylsulfinylindoles from Laurencia brongniartii. Tetrahedron Lett. 29 6091-6094. 

Fujiwara K (2006) Total Synthesis of Medium-Ring Ethers from Laurencia Red Algae. 5 ... 

Figure 4 Halogenated terpenoid and polyketide metabolites isolated from red algae in the genera Laurencia and Plocamium...

Figure 5 Proposed mechanism for biosynthetic introduction of bromine and chlorine atoms into the Laurencia sesquiterpenoid nidificine (24)...

Fukuzawa A, Masamune T (1981) Laurepinnacin and isolaurepinnacin, new acetylenic cyclic ethers from the marine red alga Laurenciapinnata Yamada. Tetrahedron Lett 22 4081 1084 Fukuzawa A, Kurosawa E, Tobetsu I (1979) Constituents of marine plants. XXXVI. Laurallene, new bromoallene from the marine red alga Laurencia nipponica yamada. Tetrahedron Lett 30 2797-2780... 

Irie T, Suzuki M, Kurosawa E, Masamune T (1966) Laurinterol and debromolaurinterol, constituents from Laurencia intermedia. Tetrahedron Lett 17 1837-1840 Janmaat ML, Rodriguez JA, Jimeno J, Kruyt FAE, Giaccone G (2005) Kahalalide F induces necrosis-like cell death that involves depletion of ErbB3 and inhibition of Akt signaling. Mol... 

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