Laurencia pinnatifida

The C15 acetogenin ( )-dihydrorhodophytin (677), an isomer of the previously known (Z)-isomer (1). is found in Laurencia pinnatifida from the Canary Islands (779). An Easter Island variety of Laurencia claviformis has afforded (3Z)-13-epipinnatifidenyne (678) (780). Likewise, an epimer of the previously known laurencienyne, 13-epilaurencienyne (679), is found in Laurencia obtusa from the Aegean coast (781). This same seaweed and locale yielded laurencienyne B (680), the cis isomer of laurencienyne (782), and the acetate 681 (783). This Aegean Sea Laurencia obtusa has also provided (3Z)-13-epilaurencienyne (682), (3 )-13-epi-pinnatifidenyne (683) (revised in (785)), 684, and 685 (784). The (Z)-diastereomers 682 and 685 showed very potent insecticidal activity. Three enantiomers of known compounds were identified in the sea hare Aplysia dactylomela, (-)-(3E,6R,7R)-pinnatifidenyne (686), (+)-(3 , 6/ ,7/ )-obtusenyne (687), and (+)-(3Z,6/ ,7/ )-obtu-senyne (688) (785). 

Gonzalez AG, Arteaga JM, Fernandez JJ, Martin JD, Norte M, Ruano JZ (1984) Terpenoids of the Red Alga Laurencia pinnatifida. Tetrahedron 40 2751... 

Norte M, Fernandez JJ, Cataldo F, Gonzalez AG (1989) fi-Dihydrorhodophytin, a C15 Acetogenin from the Red Alga Laurencia pinnatifida. Phytochemistry 28 647... 

D. M. Bowker and J. R. Turvey, Water soluble polysaccharides of the red alga Laurencia pinnatifida. Part I. Constituent units, J. Chem. Soc. C (1968) 983-988. 

Dehydrothyrsiferol (3), an analogue of thyrsiferol (1), was the next marine metabolite discovered from Laurencia. In an effort to assess halogen-based secondary metabolite synthesis, Norte and co-workers isolated compound 3 in 1984 as a white crystalline solid [6]. This natural product was found in Laurencia pinnatifida located on the Cannary Islands of Spain. Its chemical structure was verified via chemical transformation into thyrsiferol (1). 

As a result of our studies on chemical constituents of marine plants and animals in 1 intertidal zone near Karachi, we have investigated red and brown algae and various mari animals. Laurencia pinnatifida belongs to the family Rhodomalaceae. Laurencia species i well known for the halogenated compounds of varied chemical structures and diverse biologi properties such as antimicrobial activity, cytotoxicity etc. We have isolated pinnatazs... 

During our work on active metabolites from starfish we have isolated from Astropecten indicus three novel steroidal glycosides named as indicoside A (26). B (27) and C (28). The red alga Laurencia pinnatifida yielded three new halogenated sesquiterpenoids pinnatificine (29) pinnatifidone (30) and 1(1 4(3,10d tr ibromo-3-chloro-7(14)-ene-a-chamigrene (31). ... 

Pinnatifidienynes (Zand ) Laurencia pinnatifida Norte et ai., 1991b... 

Laurencia spectabilis this species, harvested on the coast of Oregon, contains laurencione, a derivative with five carbon atoms in equilibrium between a diketonic linear form, 5-hydroxy-2,3-pentanedione, and the corresponding cyclical hemiketal, 2-hydroxy-2-methyl-dihydrofuran-3-one. Laurencione dimerizes on a silica gel column in spiro-bis-pinnaketal, which had been previously isolated from Laurencia pinnatifida (Wiedenfeld, Knoch, and Koch, 1985) and it is possible that the three cyclic derivatives of Laurencia chilensis are artifacts due to the polymerization of laurencione. 

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