New cytotoxic furanosesterterpenes from an Okinawan marine sponge,Ircinia sp

Five new sesterterpenes have been isolated from a lipophilic extract of a sponge, Ircinia sp., and their structures elucidated by spectroscopic and chemical methods. The absolute configurations of two metabolites (1, 3) were established by chemical degradation. These compounds showed moderate cytotoxicity against KB cells.     

Oxocyclostylidol, an intramolecular cyclized oroidin derivative from the marine sponge Stylissa caribica

Pyrrole-imidazole alkaloids are widely distributed in marine sponges of the orders Halichondrida and Agelasida. Chemical investigation of the Caribbean sponge Stylissa caribica has led to the isolation of the first brominated pyrrole-imidazole alkaloid containing an oxidized pyrrole moiety. The isolation and structure elucidation of oxocyclostylidol (1) are discussed in detail.     

Haterumadysins A-D, sesquiterpenes from the Okinawan marine sponge Dysidea chlorea

Haterumadysins A-D (1-4) and two known compounds, spirodysin (5) and dehydroherbadysinolide (6), were isolated from the sponge Dysidea chlorea. Their structures were successfully determined by detailed spectroscopic analysis. Compounds 1-5 all showed the ability to inhibit the division of fertilized sea urchin eggs.     

Metachromin C, a new cytotoxic sesquiterpenoid from the Okinawan marine sponge Hippospongia metachromia

A new sesquiterpenoid quinone, metachromin C[1], with potent cytotoxic activity has been isolated together with a known terpenoid metachromin A[2] from the Okinawan marine sponge Hippospongia metachromia and the structure determined by spectroscopic data, especially several types of 2D nmr spectra including 1H-detected heteronuclear multiple-bone correlation (HMBC).     

New strongylophorines from the Okinawan marine sponge Petrosia (Strongylophora) corticata

New strongylophorines-22 (1), -23 (2), -24 (3), and -25 (4) were isolated from the Okinawan sponge Petrosia (Strongylophora) corticata along with other known strongylophorines. The structures of these strongylophorines were determined on the basis of spectroscopic analysis and chemical conversions. Assessment was also made of the cytotoxicity of strongylophorines-1, -2, -3, -4, -22 (1), -23 (2), and -24 (3) toward HeLa cells.     

Acetylenic strongylodiols from a Petrosia (Strongylophora) Okinawan marine sponge

Seven new long-chain acetylenic alcohols, strongylodiols D-J, were isolated from an Okinawan marine sponge of the genus Petrosia (Strongylophora). The structures of these compounds were elucidated on the basis of the results of spectroscopic analysis and chemical reaction. Analysis of the MNA esters of the acetylenic alcohols disclosed that these compounds were each an enantiomeric mixture in a different ratio.     

Dactyloquinones A and B, new sesquiterpenoid quinones from the Okinawan marine sponge Dactylospongia elegans.

Structurally unique new sesquiterpenoid quinones dactyloquinone A (1) and B (2), each possessing a dihydropyran moiety, were isolated from an Okinawan sponge Dactylospongia elegans, along with known sesquiterpenoid quinones. The structures of these compounds were determined by spectroscopic analysis.     

Cytotoxic polyacetylenes from the marine sponge Petrosia sp

Three C46 (1-3) and three C30 (4-6) polyacetylenic alcohols with cytotoxic activity against a small panel of human solid-tumor cell lines have been isolated from the marine sponge Petrosia sp. Although compound 1 was identified as the stereoisomer of petrocortyne A, the structures of compounds 2-5 have not been previously reported and were established by spectral methods. Compound 6 was identified as the known compound petrosiacetylene D. The stereochemistry of compounds 1-5 was determined by the modified Mosher's method.     

Diterpenes from the Pohnpeian marine sponge Chelonaplysilla sp

Nine diterpenes have been isolated from the marine sponge Chelonaplysilla sp. collected in Pohnpei, Federated States of Micronesia. These include the known diterpenes 1-bromo-8-ketoambliol A acetate, dendrillolide A, dendrillolide D, norrisolide, 12-desacetoxyshahamin C, and aplyviolene. Three novel rearranged spongian diterpenes, chelonaplysins A, B, and C, were identified by interpretation of spectral data and chemical correlation with known compounds. Aplyviolene, chelonaplysin B, and chelonaplysin C exhibited antimicrobial activity against the bacterium Bacillus subtilis. The secondary metabolite composition of this collection of Chelonaplysilla sp. is compared to the composition previously reported for samples from Palau.     

A new sesquiterpenoid quinone and other related compounds from the Okinawan marine sponge Dactylospongia elegans

The new sesquiterpenoid quinone, neodactyloquinone (1), and dactylolactones A-D (2-5) were isolated from the Okinawan sponge Dactylospongia elegans. The structures of these compounds were determined by spectroscopic analysis.     

Cyclic heptapeptides from the Jamaican sponge Stylissa caribica

Two new cyclic heptapeptides, stylisin 1(1) and stylisin 2 (2), were isolated and characterized from the Jamaican sponge Stylissa caribica, in addition to the cyclic heptapeptide phakellistatin 13 (3) and the known bromopyrrole alkaloids sceptrin (4), stevensine (5), and oroidin (6). The new structures were assigned on the basis of 1D and 2D NMR spectroscopic data, as well as chemical methods for the elucidation of the absolute configuration of amino acids. The peptides and alkaloids have been evaluated for their antimicrobial, antimalarial, anticancer, anti-HIV-1, anti-Mtb, and antiinflammatory activities.     

Potent inhibitors of histamine release, two novel triterpenoids from the Okinawan marine sponge Penares incrustans.

Two novel triterpenoids with an unusual 14-carboxyl group, penasterone [1] and acetylpenasterol [2], were isolated from the Okinawan marine sponge Penares incrustans. The structures of 1 and 2 were established mainly on the basis of nmr spectroscopic data. The relative stereochemistry of 1 was confirmed by single-crystal X-ray diffraction analysis. Compounds 1 and 2 potently inhibited histamine release from rat peritoneal mast cells induced by anti-IgE in a dose-dependent manner.     

New lysophosphatidylcholines and monoglycerides from the marine sponge Stelletta sp

Two new lysophosphatidylcholines (1, 2) and four new monoglycerides (5-8) were isolated from the marine sponge Stelletta sp. by bioactivity-guided fractionation. The planar structures of the new compounds were established on the basis of NMR and MS analyses. The stereochemistry was defined by comparison of the optical rotation. The compounds were evaluated for cytotoxicity against a small panel of five human tumor cell lines.     

Minor steroidal alkaloids from the marine sponge Corticium sp

Four new steroidal alkaloids, plakinamine G (1), plakinamine H (2), 4alpha-hydroxydemethylplakinamine B (3), and tetrahydroplakinamine A (4), along with three known compounds, were isolated from the marine sponge Corticium sp. The structures of these metabolites were elucidated largely by 1D and 2D NMR methods and accurate mass measurements (HR-EIMS). Compounds 1, 2, and 4 show significant in vitro cytotoxicity.     

Cytotoxic furanosesterterpenes from a marine sponge Psammocinia sp

Three new (1-3) and seven known (4-10) cytotoxic furanosesterterpenes were isolated from a marine sponge Psammocinia sp. by bioactivity-guided fractionation. The structures were established on the basis of NMR and MS analyses. The geometry and absolute configuration were determined on the basis of optical rotation, NMR, and CD data. These compounds were evaluated for cytotoxicity against a small panel of five human tumor cell lines, and most of the compounds showed toxicity to SK-MEL-2. The mixture of compounds 7 and 8 displayed significant inhibition of DNA replication and moderate antioxidant profile.     

Cytotoxic oxylipins from a marine sponge Topsentia sp

By a bioactivity-guided fractionation, seven new oxylipins, topsentolides A(1)-C(2) (1-7), were isolated from the MeOH extract of a marine sponge Topsentia sp. Detailed NMR and MS analyses established the planar structures of these structurally related oxylipins, which are proposed to be biosynthesized by lipoxygenation followed by cyclization of unsaturated fatty acids. Acetonide derivatives and MTPA esters were prepared to elucidate the stereochemistry of topsentolides B(1) (3), B(2) (4), and C(2) (7). All compounds were tested against a panel of five human solid tumor cell lines and displayed moderate cytotoxicity.     

Lehualides E-K, cytotoxic metabolites from the Tongan marine sponge Plakortis sp

Spectroscopy-guided chemical analysis of a marine sponge from the genus Plakortis, collected in Tonga, yielded seven new metabolites of polyketide origin, lehualides E-K (5-11), four of which incorporate various sulfur functionalities. The structures of compounds 5-11 were elucidated by interpretation of spectroscopic data and spectral comparison with model compounds. The biological activities of compounds 6-9 were investigated against human promyeloid leukemic HL-60 cells and two yeast strains, wild-type and a drug-sensitive mutant.     

Plakolide A, a new gamma-lactone from the marine sponge Plakortis sp

Plakolide A (1), a new alpha-exomethylene-gamma-lactone isolated from the marine sponge Plakortis sp., was found to inhibit inducible nitric oxide synthase (iNOS) activity. The isolation, structure elucidation, and biological activity of plakolide A is described.     

Amphimedosides, 3-alkylpyridine glycosides from a marine sponge Amphimedon sp

Five 3-alkylpyridine alkaloids, amphimedosides A-E (1-5), have been isolated from a marine sponge Amphimedon sp. The structures of 1-5 have been determined by analysis of NMR and FABMS data and chiral GC analyses of the acid hyrolyzates. In particular, the site of glycosylation in 1 was confirmed by the 1H-15N HMBC experiment, and the location of the double bond in 5 was assigned on the basis of tandem FABMS data. Amphimedosides are the first examples of beta-D-glucosylated 3-alkylpyridine alkaloids and exhibited cytotoxic activities comparable with those of the nonglycosylated congeners.     

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.