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Jaspines A and B: two new cytotoxic sphingosine derivatives from the marine sponge Jaspis sp.

Abstract The ethanolic extract of the sponge Jaspis sp. collected in Vanuatu showed cytotoxicity against KB tumour cells (IC 95 =10 μg/ml). A bioassay-guided fractionation led to the isolation of two new cytotoxic sphingosine derivatives, jaspine A and jaspine B. Structures were elucidated by spectroscopic methods, and absolute configuration by chemical derivatisation. The cytotoxicity of jaspine B hydrochloride was evaluated against the A549 lung tumour cell line (IC 50 =3.4×10 −7 M).

Homophymine A, an Anti-HIV Cyclodepsipeptide from the Sponge Homophymia sp

A new anti-HIV cyclodepsipeptide, homophymine A, was isolated from a New Caledonian collection of the marine sponge Homophymia sp. The structure of homophymine A was determined by interpretation of spectroscopic data, acid hydrolysis, and LC-MS analysis. Homophymine A contains 11 amino acid residues and an amide-linked 3-hydroxy-2,4,6-trimethyloctanoic acid moiety. Along with four D-, two L-, and one N-methyl amino acids, it also contains four unusual amino acid residues: (2S,3S,4R)-3,4-diMe-Gln, (2R,3R,4S)-4-amino-2,3-dihydroxy-1,7-heptandioic acid, L-ThrOMe, and (2R,3R,4R)-2-amino-3-hydroxy-4,5-dimethylhexanoic acid. In a cell-based XTT assay, homophymine A exhibited cytoprotective activity against HIV-1 infection with a IC50 of 75 nM.

Callipeltins B and C; Bioactive Peptides from a. Marine Lithistida Sponge Callipelta sp.

Abstract Following the characterization of callipeltin A (1), two new cytotoxic peptides, callipeltin B (2) and C (3), were isolated from the New Caledonian sponge Callipelta sp.. Callipeltin B (2) possess the same cyclic depsipeptidal structure as in callipeltin A (1) and differs from 1 by having the N-terminal 2,3-dimethylpyroglutamic acid unit instead of the tripeptide chain with the N-terminus blocked by an hydroxyacid. Callipeltin C (3) is simply the acyclic callipeltin A. The structures 2–3 have been determined by NMR experiments, FAB mass spectrometry, evaluation of the aminoacids obtained by acid hydrolysis and by comparison of the data with those of callipeltin A (1). Following the characterization of callipeltin A (1), two new peptides, callipeltin B (2) and C (3), were isolated form Callipelta sp.. Callipeltin B (2) possess the same cyclic depsipeptidal structure as in callipeltin A (1) and differs from 1 by having the N-terminal 2,3-dimethylpyroglutamic acid unit instead of the tripeptide chain with the N-terminus blocked by an hydroxyacid. Callipeltin C (3) is the acyclic callipeltin A. Callipeltins have been found to be cytotoxic against various human carcinoma cells.

Callipeltosides B and C, two novel cytotoxic glycoside macrolides from a marine lithistida sponge Callipelta sp.

Following the characterization of callipeltoside A (1), the first member of a novel class of marine glycoside macrolides, two more bioactive constituents, callipeltoside B (2) and C(3), were isolated from Callipelta sp. in very low amounts. The structures, assigned on the basis of spectral analysis, include the same 14-membered macrolide as in callipeltoside A (1) but differed in the saccharide moieties.

Dactylolide, a New Cytotoxic Macrolide from the Vanuatu SpongeDactylospongia sp.

Dactylolide (1), a new cytotoxic 20-membered macrolide, was isolated from a marine sponge of the genus Dactylospongia collected off the coast of the Vanuatu islands. It co-occurred with other known bioactive macrolides: latrunculin A (2), laulimalide (3), isolaulimalide (4) and with the anthelminthic mycothiazole (5). The structure of 1, which is a minor metabolite, was elucidated by spectroscopy (mainly by 1D/2D NMR and MS techniques). It showed cytotoxic activity against the L1210 and SK-OV-3 tumor cell lines (63% and 40% inhibition at 3.2 μg/mL).

Solomonamides A and B, New Anti-inflammatory Peptides from Theonella swinhoei

Two unprecedented cyclic peptides, solomonamides A and B, were isolated from the marine sponge Theonella swinhoei. The structures were elucidated on the basis of comprehensive 1D and 2D NMR analysis and high-resolution mass spectrometry. A combined approach, involving Marfeys method, QM J based analysis, and DFT J/(13)C calculations, was used for establishing the absolute configuration of the entire molecule. Solomonamide A showed in vivo anti-inflammatory activity.

Reidispongiolide A and B, two new potent cytotoxic macrolides from the New Caledonian sponge Reidispongia coerulea

Abstract Two new 26-membered macrolides, reidispongiolide A ( 1 ) and B ( 2 ), have been isolated from the New Caledonian marine sponge Redispongia coerulea n.gen.n.sp. Levi and Levi and their structures elucidated. They are related to sphinxolides previously isolated from an unknown nudibranch and later from the sponge Neosiphonia superstes . 1 and 2 co-occurr with sphinxolide B ( 4 ) and D ( 3 ). These macrolides exhibited potent cytotoxicity against various human carcinoma cells.

Theonellasterols and Conicasterols from Theonella swinhoei. Novel Marine Natural Ligands for Human Nuclear Receptors

Silica gel column chromatography, followed by HPLC purification on the apolar fraction of the methanol extract of marine sponge Theonella swinhoei, resulted in the isolation of a library of 10 polyhydroxylated steroids which we named theonellasterols B-H (1-7) and conicasterols B-D (8-10). The structures were determined on the basis of extensive spectroscopic data (MS, (1)H and (13)C NMR, COSY, HSQC, HMBC, and ROESY) analysis, and the putative binding mode to nuclear receptors (NRs) has been obtained through docking calculations. Pharmacological and structure-activity relationship analysis demonstrate that these natural polyhydroxylated steroids are potent ligands of human nuclear pregnane receptor (PXR) and modulator of farnesoid-X-receptor (FXR). In addition, the molecular characterization of theonellasterol G allowed the identification of the first FXR modulator and PXR ligand so far identified. Exposure of liver cells to this agent resulted in potent induction of PXR-regulated genes and modulation of FXR-regulated genes, highlighting its pharmacological potential in the treatment of liver disorders.

New jaspamide derivatives from the marine sponge Jaspis splendans collected in Vanuatu.

Two new jaspamide derivatives (1 and 2) along with jaspamide have been isolated from the marine sponge Jaspis splendans collected in Vanuatu. Their chemical structures were determined from 1D and 2D NMR studies and MS data. These two compounds inhibited the in vitro growth of the NSCLC-N6 human tumor cell lines with IC50 values in the microg/mL range.

Ptilomycalin A, crambescidin 800 and related new highly cytotoxic guanidine alkaloids from the starfishes Fromia monilis and Celerina heffernani

Abstract Two novel pentacyclic guanidine alkaloids, celeromycalin 3 and fromiamycalin 4 , have been isolated from the New Caledonian starfishes Celerina heffernani and Fromia monilis , respectively. Also found in Celerina heffernani are the known ptilomycalin A ( 1 ) and crambescidin 800 ( 2 ), which latter has been also isolated from Fromia monilis . The new compounds exhibited an high cytotoxic activity like the previous crambescidins. These complex pentacyclic guanidines are typical sponges metabolites and their occurence in starfishes is noteworthy. Fromia monilis also contained the less active component 5 , made up from an hydroxyspermidine residue linked to a long chain ω-hydroxyacid.