Chemistry of verongida sponges. 10. Secondary metabolite composition of the caribbean sponge Verongula gigantea

A detailed analysis of the secondary metabolites of the Caribbean sponge Verongula gigantea has been performed. A number of bromotyrosine derivatives, 1, 2, and 6-17, were identified, one of which (17) is a novel compound. Its structure was determined on the basis of spectroscopic evidence. Additionally, aureol (18) and 5, 6-dibromo-N,N-dimethyltryptamine (19) were isolated from one of the five analyzed specimens.     

Chemistry of verongida sponges. 9.1 secondary metabolite composition of the caribbean sponge aplysina cauliformis

A detailed analysis of the secondary metabolites of the sponge Aplysina cauliformis has been performed. Eight compounds were identified, two of which (13 and 14) are new bromotyrosine derivatives whose structures were determinated from spectroscopic evidence, including 2D NMR. The new compounds were analyzed for cytotoxic activity, and compound 14 was shown to inhibit mammalian protein synthesis and cell proliferation.     

Sigmoidin F, a new prenylated flavonoid from Erythrina sigmoidea

Sigmoidin F, a new prenylated flavanone, as well as abyssinone IV and 5,7,4'-trihydroxy-3'-methoxy-5'-(1"-prenyl) flavonone have been isolated from the stem and bark of Erythrina sigmoidea. The structure of 1 has been confirmed by a combination of 1H-nmr and other spectroscopic techniques.     

Mappain, a new cytotoxic prenylated stilbene from Macaranga mappa

A new prenylated stilbene, mappain (1), was isolated from leaves of Macaranga mappa by bioassay-guided fractionation. The structure was established by application of spectroscopic methods. Mappain is cytotoxic but it appears to be a poor substrate for P-glycoprotein-mediated transport because it is equally potent and effective against the drug-sensitive SK-OV-3 and drug-resistant SKVLB-1 ovarian cancer cell lines, exhibiting an IC(50) value of 1.3 microM in both cases.     

Aplyzanzine A, a new dibromotyrosine derivative from a Verongida sponge.

Aplyzanzine A (1), a novel bisdibromotyrosine derivative, has been isolated from the Indo-Pacific sponge Aplysina sp. Its structure was elucidated mainly on the basis of 1D and 2D NMR and MS spectroscopic data.     

7-Hydroxyceratinamine, a new cyanoformamide-containing metabolite from a sponge, Aplysinella sp.

7-Hydroxyceratinamine (1) and the known compounds moloka'iamine (2), ceratinamine (3), and N,N,N-trimethyl-3,5-dibromotyramine (4), were isolated from a Micronesian sponge, Aplysinella sp. The structure of 1, which contains the unusual cyanoformamide moiety, was solved by spectroscopic analysis.     

Chemistry of sponges. 19. Novel bioactive metabolites from Hamigera tarangaensis

Seven new compounds (1-6 and 10) with a unique carbon skeleton have been isolated from the sponge Hamigera tarangaensis, and the structure of a previously reported metabolite has been revised from 12 to 8. The structures have been assigned from extensive NMR examination. Compounds 3-6 showed moderate in-vitro cytotoxicity against P-388, while 3 showed 100% in-vitro virus inhibition against both the Herpes and Polio viruses, with only slight cytotoxicity.     

Halisulfate 7, a new sesterterpene sulfate from a sponge, Coscinoderma sp.

A new sesterterpene sulfate, halisulfate 7 (1), has been isolated from a Coscinoderma sp. of sponge collected at Yap, Federated States of Micronesia. The structure was determined from spectroscopic evidence.     

Gelliusterols A--D, new acetylenic sterols from a sponge, Gellius species.

New acetylenic sterols, gelliusterol A (1, 26,27-bisnorcholest-5-en-23-yn-3 beta,7 alpha-diol), its corresponding 7-ketone, gelliusterol B (2, 26,27-bisnorcholest-5-en-23-yn-3 beta-ol-7-one), and gelliusterols C (4, cholest-5-en-23-yn-3 beta,7-one) and D (5, cholest-5-en-23-yn-3 beta,25-diol-7-one), were isolated from an unidentified species of sponge, Gellius sp. The structures of the steroids were established from spectroscopic data.     

Glycolipids from sponges. Part 17. Clathrosides and isoclathrosides, unique glycolipids from the Caribbean sponge Agelas clathrodes

Two families of unique glycolipids, clathrosides A-C (2a-4a) and isoclathrosides A-C (5a-7a) were isolated from the Caribbean sponge Agelas clathrodes. Clathrosides and isoclathrosides are glycosides of a very-long-chain alcohol derived from fatty acids, a new class of glycolipids that appears to be characteristic of marine sponges. The six compounds differ in configuration and in the branching of alkyl chains. Stereostructures of the clathrosides were determined by NMR and CD spectroscopy, mass spectrometry, and chemical degradation. Location of the methyl branch on the proper alkyl chain required an exceptional 1-D TOCSY experiment, in which coherence was transferred through as many as 13 vicinal couplings.     

Cacofurans A and B, new furanoditerpenes from a marine sponge.

Two new labdane-class diterpenes, cacofurans A (1) and B (2), have been isolated from a sponge Cacospongia sp. Their structures were determined by analyzing spectroscopic data, by chemical transformations, and by X-ray diffraction. Cacofurans 1 and 2 inhibited the development of fertilized sea urchin eggs at concentrations of 0.5 and 5 microg/mL and showed an actin-disrupting effect on the NBT-II cell line at 10 microg/mL.     

Glycolipids from sponges. Part 16.(1) discoside, a rare myo-inositol-containing glycolipid from the caribbean sponge Discodermia dissoluta

Discoside (1a), a glycolipid composed of 4,6-O-diacylated mannose attached to the 2-hydroxyl group of a myo-inositol unit, was isolated as a mixture of homologues from the marine sponge Discodermia dissoluta. The complete stereostructure of this new glycolipid was solved by interpretation of mass spectrometric and NMR data and CD analysis of degradation products.     

Mycgranol, a new diterpene from the marine sponge Mycale aff. graveleyi

Mycgranol, a new isocopalane diterpene (methyl 1beta-hydroxy-2-oxoisocopalanoate) was isolated from the Kenyan sponge Mycale (Aegogropila) aff. graveleyi. The structure of the compound was elucidated by interpretation of MS, COSY, HMQC, HMBC, and ROESY data. The absolute configuration of mycgranol was determined to be the same as that of the nudibranch isocopalane diterpenes rather than that of the ent-compounds known from sponges of the genus Spongia.     

Sventrin, a new bromopyrrole alkaloid from the Caribbean sponge Agelas sventres.

A detailed analysis of the secondary metabolites of a specimen of Agelas sventres was carried out here for the first time. The chemistry of Agelas sponges is dominated by bromopyrrole derivatives. Besides three known bromopyrrole metabolites, a new compound, sventrin (1), was isolated and its structure identified using spectroscopic methods. Sventrin (1) was shown to be a feeding deterrent compound against a common omnivorous reef fish.     

Nirurin: a new prenylated flavanone glycoside from Phyllanthus nirurii

A new prenylated flavanone glycoside, nirurin, has been isolated from Phyllanthus nirurii. On the basis of chemical and spectral studies, its structure is proposed as 5,6,7,4'-tetrahydroxy-8-(3-methylbut-2-enyl) flavanone-5-O-rutinoside (1). The aglycone, also a new flavanone, has been characterized as 5,6,7,4'-tetrahydroxy-8-(3-methylbut-2-enyl) flavanone, which may be designated as nirurinetin (2).     

Three new antibacterial alkaloids from a marine sponge Stelletta species.

From a marine sponge of the genus Stelletta we isolated three alkaloids, stellettazole B (3), stellettazole C (4), and stellettamide C (5), which were antibacterial against Escherichia coli. Their structures were determined on the basis of spectral and chemical methods.     

Bacteriohopanehexol, a new triterpene from the marine sponge Petrosia species

A new bacteriohopanoid, bacteriohopanehexol was isolated from the marine sponge Petrosia sp., and its structure 1a was established on the basis of the NMR and MS spectroscopic data of its hexaacetate derivative 1b. Bacteriohopanehexol is most likely a bacterial metabolite.     

A new antifouling hexapeptide from a Palauan sponge,Haliclona sp

Bioassay-guided fractionation of an extract of the sponge Haliclona sp. provided a known hexapeptide, waiakeamide (1), and a new sulfone derivative (2). The structures of hexapeptides 1 and 2 were elucidated by extensive NMR analyses and the advanced Marfey's method with LC/MS. These compounds showed repellent activity against the blue mussel, Mytilus edulis galloprovincialis.     

Guttiferone I, a new prenylated benzophenone from Garcinia humilis as a liver X receptor ligand

Liver X receptors (LXR) have been implicated in cholesterol homeostasis. Agonists of LXR are expected to increase cholesterol efflux, lower LDL, and raise HDL levels. Screening of a natural product library of plant extracts using a LXR-SPA binding assay and bioassay-guided fractionation of the bark and stem extract of Garcinia humilis led to the discovery of a new polyisoprenylated benzophenone named guttiferone I (1). The IC(50) value for this compound in the LXRalpha-SPA binding assay was 3.4 muM. Details of the isolation, structure elucidation, and ligand binding activity of 1 are described.