Five new diterpenoids 1– 5 were isolated from an Okinawan soft coral, Cespitularia sp., together with the known diterpenoid, alcyonolide ( 6). New diterpenoid structures were elucidated by spectroscopic methods and by comparison of their NMR data with those of related compounds. Alcyonolide ( 6) was cytotoxic against HCT 116 cells (IC 50 5.85 μM), while these new diterpenoids 1– 5 were much less active (IC 50 28.2–91.4 μM).
Ueda, K.; Hu, Y. Haterumalide, B: A new cytotoxicmacrolide from an Okinawan ascidian Lissoclinum sp. Tetrahedron Lett. 1999, 40, 6305–6308, doi:10.1016/S0040-4039(99)01290-3.
[4]
Takada, N.; Sato, H.; Suenaga, K.; Arimoto, H.; Yamada, K.; Ueda, K.; Uemura, D. Isolation and structures of haterumalides NA, NB, NC, ND, and NE, novel macrolides from an Okinawan sponge Ircinia sp. Tetrahedron Lett. 1999, 40, 6309–6312, doi:10.1016/S0040-4039(99)01291-5.
[5]
Kokubo, S.; Yogi, K.; Uddin, M.J.; Inuzuka, T.; Suenaga, K.; Ueda, K.; Uemura, D. Kohamaic acids A and B, novel cytotoxicsesterterpenic acids, from the marine sponge Ircinia sp. Chem. Lett. 2001, 2, 176–177.
[6]
Kobayashi, M.; Yasuzawa, T.; Kobayashi, Y.; Kyogoku, Y.; Kitagawa, I. Alcyonolide, a novel diterpenoid from a soft coral. Tetrahedron Lett. 1981, 22, 4445–4448, doi:10.1016/S0040-4039(01)82979-8.
[7]
Vanderah, D.J.; Steudler, P.A.; Ciereszko, L.S.; Schmitz, F.J.; Ekstrand, J.D.; Van der Helm, D. Marine natural products. Xenicin: A diterpenoid possessing a nine-membered ring from the soft coral, Xenia elongata. J. Am. Chem. Soc. 1997, 99, 5780–5784.
[8]
Kashman, Y.; Groweiss, A. New diterpenoids from the soft corals Xenia macrospiculata and Xenia obscuronata. J. Org. Chem. 1980, 45, 3814–3824, doi:10.1021/jo01307a017.
[9]
Fattorusso, E.; Romano, A.; Taglialatela-Scafati, O.; Achmad, M.J.; Bavestrello, G.; Cerrano, C. Xenimanadins A–D, a family of xenicane diterpenoids from the Indonesian soft coral Xenia sp. Tetrahedron 2008, 64, 3141–3146.
[10]
Coll, J.C.; Kearns, P.S.; Rideout, J.A. Isolation of a novel diterpene triacetate from two soft corals of the order alcyonacea. J. Nat. Prod. 1998, 61, 835–837, doi:10.1021/np9705672.
[11]
Ueda, K.; Kadekaru, T.; Siwu, E.R.O.; Kita, M.; Uemura, D. Haterumadysins A–D, sesquiterpenes from the Okinawan marine sponge Dysidea chlorea. J. Nat. Prod. 2006, 69, 1077–1079, doi:10.1021/np058130e.
