Structure and cytotoxicity of new polyhydroxylated sterols from the Caribbean gorgonian Plexaurella grisea.

The gorgonian Plexaurella grisea contains the new steroids 9-hydroxygorgosterol (1), 9,11 alpha,14-trihydroxygorgosterol (2), 5 beta,6 beta-epoxyergost-24(28)-ene-3 beta,7 beta-diol (3), ergost-24(28)-ene-3 beta,5 alpha,6 beta,7 beta-tetrol (4), an unseparable 1:1 mixture of the epimers (25R) and (25S)-26-acetoxy-3 beta,5 alpha-dihydroxyergost-24(28)-en-6-one (5/6), and seven related, known compounds (7-13). The structures of these new compounds were defined by spectroscopic analysis. All the compounds (1-13) isolated from P. grisea were tested against P 388, A 549, and HT 29 tumor cell lines. Compounds 3, 5/6, and 12 exhibited selective activity against the HT 29 cell line (ED(50) = 0.1 microg/ml).

New acyclic sesquiterpenes and norsesquiterpenes from the Caribbean Gorgonian Plexaurella grisea.

The gorgonian Plexaurella grisea from Punta Cana, Dominican Republic, contains five new acyclic sesquiterpenes, (3E,5E)-3,7,11-trimethyl-9-oxododeca-1,3,5-triene (3), (3Z,5E)-3,7,11-trimethyl-9-oxododeca-1,3,5-triene (4), (3E)-6-acetoxy-3,11-dimethyl-7-methylidendodeca-1,3,10-triene (5), (3E,5E)-7-hydroxy-3,7,11-trimethyldodeca-1,3,5,10-tetraene (6), and (3E,5E,9E)-8,11-diacetoxy-3,7,11-trimethyldodeca-1,3,5,9-tetraene (7), and two new linear norsesquiterpenes, (2E,4E,7Z)-2,6,10-trimethylundeca-2,4,7,9-tetraenal (8) and (2E,4E)-2,6,10-trimethylundeca-2,4,9-trienal (9), in addition to the known compounds 1, 2, and 10. The structures of the new compounds 3-9 were elucidated by interpretation of spectroscopic data. In general, the new compounds are mildly cytotoxic against tumor cell lines, and although norsesquiterpene 8 was inactive, norsesquiterpene 9 exhibited the greatest and selective activity against the P-388 tumor cell line.

Isolation and structure elucidation of new cytotoxic steroids from the gorgonian Leptogorgia sarmentosa.

The gorgonian Leptogorgia sarmentosa contains three new steroids, (20S)-20-hydroxycholestane-3,16-dione (1), (16S, 20S)-16,20-dihydroxycholestan-3-one (2), and (20S)-20-hydroxycholest-1-ene-3,16-dione (3) together with a known related compound (4). Their structures were defined by spectroscopic analysis. The new steroids exhibited significant cytotoxicity against four tumor cell lines (ED50 = 1 microg/ml).

New metabolites from the sponge Spongia agaricina.

The sponge Spongia agaricina from Tarifa, Cadiz, Spain, contains two new 9,11-secosterols, [3-0-deacetylluffasterol B (1) and 3-0-deacetyl-22,23-dihydro-24,28-dehydroluffasterol B (2)] and two new sesterterpenoids [12,16-di-epi-12-0-deacetyl-16-0-acetylfuroscalarol (3) and 16-epi-scalarolbutenolide (4)], in addition to the known compounds 5-15. The structures of all compounds were elucidated by interpretation of' spectroscopic data. The metabolites 1-3 showed significant cytotoxicity against four tumor cell lines (C50 1 microgram/mL).

3-Epi-aplykurodinone B, a new degraded sterol from Aplysia fasciata.

The anaspidean mollusk Aplysia fasciata from Río San Pedro (Cádiz, Spain) contains the known degraded sterols aplykurodinone B (2) and aplykurodin B (4) together with the new 3-epi-aplykurodinone B (5). The structure of 5 was elucidated by interpretation of spectral data, and its relative stereochemistry was established using NOEDS experiments. The new compound 5 exhibited cytotoxicity against four tumor cell lines.

New polyhalogenated monoterpenes from the sea hare Aplysia punctata.

The sea hare Aplysia punctata from Sancti Petri (Cádiz, Spain) contains four new unusual acetates of linear polyhalogenated monoterpenes (5-8) together with four known cyclic derivatives (1-4). The structures were elucidated by interpretation of spectral data. It is suggested that the new constituents of A. punctata might be biotransformation products. Compounds 6-8 showed significant in vitro cytotoxicity against four tumor cell lines.

Structure and absolute configuration of palmonine F, a new eunicellin-based diterpene from the gorgonian Eunicella verrucosa.

In addition to the palmonines reported in a previous communication, a new eunicellin-type diterpene, palmonine F [1], has been isolated from the gorgonian Eunicella verrucosa. Its structure was elucidated by interpretation of spectral data and chemical interconversions and its absolute configuration was established using the Mosher's method. The cytotoxicity assay results for the palmonines are reported.

Allelochemicals fromPilocarpus goudotianus leaves.

The effect on germination, shoot, and root growth by bergapten, xanthotoxin, imperatorin, xanthyletin, xanthoxyletin, luvangetin, donatin and alloxanthoxyletol fromPilocarpus goudotianus leaves, onLactuca sativa var. nigra seedlings has been evaluated. A structure-activity correlation is discussed based on the bioassay results. Furanocoumarins appear to be the most active compounds in comparison with pyrano- and simple coumarins. The presence of an oxygenated function at C-8 decreases the germination effect in furano- and pyranocoumarins, while C-5 substituents do not cause significant changes on the activity.

New Coumarins from Pilocarpus goudotianus.

The leaves of PILOCARPUS GOUDOTIANUS afforded in addition to eight known coumarins three new ones, donatin, alloxanthoxyletol, and (+)-elisin. The structures were elucidated on the basis of spectroscopic evidence and chemical derivatives.