Two new cytotoxic tetrabromodibenzo-p-dioxins, spongiadioxins A (1) and B (2), were isolated from an Australian marine sponge Dysidea dendyi. The structures of these compounds were established by 1D and 2D NMR spectroscopy, X-ray analysis of the methyl ether of spongiadioxin A (3), and synthesis of the methyl ether of spongiadioxin B (4) from diphenyl ether (9) isolated from Dysidea herbacea.

No abstract

No abstract

No abstract

No abstract

Two new minor tribromodibenzo-p-dioxins, spongiadioxin C (1) and its methyl ether (2), were isolated from an Australian marine sponge Dysidea dendyi, together with the known minor metabolites methyl ethers of spongiadioxins A (4) and B (6) and polybrominated diphenyl ethers (7-9). The structures of the new compounds were established by 1D and 2D NMR spectroscopy and confirmed by synthesis of 2 from diphenyl ether 9. All isolated compounds inhibited the cell division of fertilized sea urchin eggs.

Four new sesquiterpenoid arenarone derivatives, 18-aminoarenarone (1), 19-aminoarenarone (2), 18-methylaminoarenarone (3), and 19-methylaminoarenarone (4), and the new dimeric popolohuanone F (5), a derivative of 19-aminoarenarone (2) and arenarol (6), have been isolated from the Australian marine sponge Dysidea sp. together with the known compounds arenarol (6) and popolohuanone A (7). The structures of the new compounds 1-5 were established from extensive NMR spectroscopic data. Popolohuanones A (7) and F (5) and arenarol (6) showed DPPH radical scavenging activity with IC(50) values of 35, 35, and 19 microM, respectively.

No abstract