IB-00208, a new cytotoxic polycyclic xanthone produced by a marine-derived Actinomadura. I. Isolation of the strain, taxonomy and biological activites.

A new compound, IB-00208, has been isolated from the fermentation broth of an actinomycete isolated from a marine environment. The strain was identified as Actinomadura sp. by its chemical and phylogenetic characteristics.

Pachastrissamine, a cytotoxic anhydrophytosphingosine from a marine sponge, Pachastrissa sp.

An anhydrophytosphingosine named pachastrissamine (3) has been isolated as a cytotoxic principle of a sponge, Pachastrissa sp., and the structure including the absolute configuration determined by spectroscopic and chemical analysis.

Synthesis and cytotoxic activities of analogues of thuriferic acid.

Several analogues of thuriferic acid and derivatives, with the 3,4-methylenedioxyphenyl ring replaced by naphthalene, furan, thiophene and carbazole ring systems, have been prepared. The synthetic strategy is based on a conjugate addition-alkylation methodology followed by cationic cyclization in order to obtain the isopodophyllone analogues, which are transformed in the thuriferic acids. Their cytotoxic activities against several tumour cells lines are also described.