Callyspongia truncata

In 1997 (-)-callystatin A (Fig. 1.2.2), a potent cytotoxic polyketide, was isolated from the marine sponge Callyspongia truncata and structurally elucidated by Ko-bayashi et al. [20] shortly afterward its absolute configuration was confirmed by the same authors by total synthesis [21]. The structure of (-)-callystatin A shows a polypropionate chain and a lactone ring connected to each other by two diene systems separated by two sp carbon atoms (Fig. 1.2.2). Since this arrangement is structurally related to several antitumor antibiotics and due to the fact that only very small amounts can be isolated from natural sources, callistatin A has been... 

Callyspongins A-B (617-618) are sulfated compounds from a Japanese sample of Callyspongia truncata. They inhibit fertilisation of starfish (Asterias amurensis) gametes [493]. 

Tsukamoto, S., Kato, H., Hirota, H., and Fusetani, N., Seven new polyacetylene derivatives, showing both potent metamorphosis-inducing activity in ascidian larvae and antifouling activity against barnacle larvae, from the marine sponge Callyspongia truncata, J. Nat. Prod., 60, 126, 1997. 

The natural polyenic lactone ( )-callystatin A, isolated in 1997 from the marine sponge Callyspongia truncata and exhibiting remarkable growth inhibition of cancer cells (IC50 10-20 pg/mL), was also prepared using this Heck-like reaction under Jeffery conditions (Scheme 10.31).53... 

Callystatin A (4) is a higly potent cytotoxic polyketide isolated from Callyspongia truncata Its absolute structure was determined by chemical method and confirmed by total synthesis. Its potent cytotoxicity (IC50 = 0.022 nmol against human pharyngeal carcinoma KB cells) was presumed to be due to the inhibition of nuclear export signal (NES)-dependent export of nuclear proteins. ... 

Uno, M., Otha, S., Otha, E., and Ikegami, S. (1996) Callyspongins A and B novel polyacetylene sulfates from the marine sponge Callyspongia truncata that inhibit fertilization of starfish gametes. J. Nat. Prod., 59, 1146-1148. 

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