Tedanolide C: a potent new 18-membered-ring cytotoxic macrolide isolated from the Papua New Guinea marine sponge Ircinia sp

Cytotoxicity-guided fractionation of the crude methanol extract of a marine sponge, Ircinia sp., yielded tedanolide C (1), a new 18-membered macrolide. The structure was solved by interpreting NMR and MS data, and the relative stereochemistry was determined from a combination of homo- and heteronuclear coupling constants in conjunction with molecular modeling. Compound 1 exhibited potent cytotoxicity against HCT-116 cells in vitro. Cell cycle analysis showed that treatment of cells with compound 1 arrested cells in the S-phase.     

Mycapolyols A-F, new cytotoxic metabolites of mixed biogenesis from the marine sponge Mycale izuensis

[structure: see text]. Mycapolyols A-F (1-6), six new unusual PKS/NRPS metabolites, were isolated from the marine sponge Mycale izuensis. The gross structures were elucidated by analysis of spectroscopic data, while the stereochemistry was established using chemical method and the universal NMR database.     

A new cytotoxic and tubulin-interactive milnamide derivative from a marine sponge Cymbastela sp

[structure: see text] The crude methanol extract of a marine sponge Cymbastela sp. collected in Papua New Guinea was selected for chemical investigation due to its significant cytotoxicity. Fractionation of the extract led to the isolation of jaspamide (1), hemiasterlin (2), milnamide A (3), and a new metabolite, milnamide D (4). The structure was solved by interpretation of NMR and mass spectra data. The cytotoxic and antitubulin activities of milnamide D (4) were evaluated.     

Pyrinodemins B-D, potent cytotoxic bis-pyridine alkaloids from marine sponge amphimedon sp

New bis-pyridine alkaloids, pyrinodemins B-D (1-3), have been isolated together with pyrinodemin A (4) and related 3-alkyl pyridine alkaloids 5-8 from the Okinawan marine sponge Amphimedon sp. and the structures were elucidated from spectroscopic data. Pyrinodemins B-D (1-3) showed potent cytotoxicity, while compounds 5-8 exhibited antimicrobial activity.     

Phorbasins G-K: new cytotoxic diterpenes from a southern Australian marine sponge, Phorbas sp

Fractionation of a cytotoxic extract obtained from a southern Australian marine sponge, Phorbas sp., yielded the known diterpenes phorbasins B-F () together with five new members of the phorbasin family, phorbasins G-K (). Structures were assigned to the new phorbasins based on detailed spectroscopic analysis. A preliminary structure activity relationship (SAR) evaluation based on the co-metabolites phorbasins B-K () revealed aspects of the phorbasin pharmacophore.     

Two new spongian diterpene analogues isolated from the marine sponge Acanthodendrilla sp

Abstract

Two new marine natural compounds, 3β-acetoxy-15-hydroxyspongia-12-en (1) and 3-methylspongia-3,12-dien-16-one (2), were isolated from the marine sponge Acanthodendrilla sp., collected in Pulau-Pulau. Compounds 1 and 2 represent new chemical entities of the known spongian diterpene family. Compound 1 is a new 3-acetoxyspongia and compound 2 presents an unreported rearranged 3-methylspongia-3-en. Their structures, including relative configurations, were fully elucidated based on 1D and 2D NMR analyses, as well as HRESTOFMS experiments. No significant bioactivities were found for these compounds. This work reports two new chemical structures, compounds 1 and 2, together with the first isolation of spongian diterpenes from Acanthodendrilla genus.     

A new 3-alkylpyridine alkaloid from the marine sponge Haliclona sp. and its cytotoxic activity

A new alkaloid, 3-dodecyl pyridine containing a terminal cyano group (1), was isolated from the methanol extract of an Indonesia marine sponge Haliclona sp. Its chemical structure was determined by a combination of spectroscopic methods, including 1D and 2D NMR. Bioassay results indicated that compound 1 had moderate cytotoxity against tumour cell lines A549, MCF-7 and Hela with IC₅₀ values of 41.8, 48.4 and 33.2 μM, respectively.     

A new thiodiketopiperzaine from the marine sponge Tedania sp.

Abstract

A new thiodiketopiperzaine, tedanizaine A (1), together with six known ones, were isolated from the marine sponge Tedania sp. Their structures were determined by spectroscopic analyses. The absolute configuration of 1 was established by ECD calculation. Compound 1 was the second example of thiodiketopiperazine bearing a thiazolidine unit. Cytotoxic activities of 1 were also evaluated.     

Spirastrellolide A,an antimitotic macrolide isolated from the Caribbean marine sponge Spirastrella coccinea

Sprirastrellolide A, a novel antimitotic macrolide, has been isolated from the Caribbean marine sponge Spirastrella coccinea. It has a 47-carbon linear polyketide backbone incorporated into a highly functionalized 38-membered lactone containing a tetrahydropyran and two spiro bispyran substructures embedded in the macrocycle and a side chain terminating in a carboxylic acid. Sprirastrellolide A's structure was elucidated by detailed spectroscopic analysis of its methyl ester 2. Spirastrellolide A methyl ester 2 shows potent activity in a cell-based assay that detects mitotic arrest, but it does not affect tubulin polymerization in vitro. It has the unusual biological property of being able to accelerate the entry of cells into mitosis from other cell-cycle stages, before it arrests them in mitosis.     

A new cytotoxic cholesterol sulfate from marine sponge Halichondria rugosa

A new steroid, 24xi,25-dimethyl-3alpha-hydroxyl-cholest-5-ene-2beta-ol sodium sulfate (1), together with a known steroid, 24xi,25-dimethyl-cholest-5-ene-2beta,3alpha-diol disodium sulfate (2), was isolated from the ethanol extract of marine sponge Halichondria rugosa. Their structures were elucidated on the base of spectroscopic analysis. Both compounds showed cytotoxicity to four human cancer cell lines (BEL-7402, HT-29, SPC-A1 and U-251) with IC(50) values between 6.5 and 23.1 microM.     

Duryne,a new cytotoxic agent from the marine sponge Cribrochalinadura

Duryne, 1, a cytotoxic metabolite which inhibits the growth of both mouse and human tumor cell lines invitro has been isolated from the marine sponge Cribrochalinadura. Its structure has been assigned by spectral methods.     

Exiguolide, a new macrolide from the marine sponge Geodia exigua

A new 20-membered macrolide designated exiguolide has been isolated from the marine sponge Geodia exigua, and its structure determined by interpretation of spectroscopic data. Exiguolide specifically inhibited fertilization of sea urchin (Hemicentrotus pulcherrimus) gametes but not embryogenesis of the fertilized egg.     

Stereochemical determination of dictyostatin, a novel microtubule-stabilising macrolide from the marine sponge Corallistidae sp

The relative stereochemistry of the 22-membered marine macrolide dictyostatin, a Taxol-like antimitotic agent, was determined based on a combination of extensive high field NMR studies, including J-based configuration analysis, and molecular modelling.     

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

The ethanolic extract of the sponge Jaspis sp. collected in Vanuatu showed cytotoxicity against KB tumour cells (IC₉₅=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 (IC₅₀=3.4×10⁻⁷ M).     

Koshikamide B, a cytotoxic peptide lactone from a marine sponge Theonella sp

Koshikamide B (1) has been isolated from two separate collections of the marine sponge Theonella sp. as the major cytotoxic constituent. Koshikamide B is a 17-residue peptide lactone composed of six proteinogenic amino acids, two D-isomers of proteinogenic amino acids, seven N-methylated amino acids, and two unusual amino acid residues. The unusual amino acids are N(delta)-carbamoylasparagine and 2-(3-amino-2-hydroxy-5-oxopyrrolidin-2-yl)propionic acid (AHPP); the former is first found as the constituent of peptides, whereas the latter is a new amino acid residue. The N-terminus of koshikamide B is blocked by a methoxyacetyl group. The structure of koshikamide B (1) has been determined by interpretation of spectral data and analysis of chemical degradation products. Koshikamide B (1) exhibits cytotoxicity against P388 murine leukemia cells and the human colon tumor (HCT-116) cell line with an IC50 value of 0.45 and 7.5 microg/mL, respectively.     

Phorbasides A-E, cytotoxic chlorocyclopropane macrolide glycosides from the marine sponge Phorbas sp. CD determination of C-methyl sugar configurations

Five new cytotoxic macrolide glycosides phorbasides A-E (3-7), each possessing a macrolide ring appended to a rare ene-yne-trans-2-chlorocyclopropane, were isolated from the same Western Australian sponge (Phorbas sp.) that provided phorboxazoles A and B. The structures of 3-7 were solved by analysis of spectroscopic data including NMR, MS, and CD. A synthesis of methyl 2-O-methyl-alpha-L-evalose from L-rhamnose was completed and used for configurational assignment of the sugar residue in 3. Acid-catalyzed methanolysis of 3 followed by two-step derivatization of the liberated O-methyl glycoside gave a vicinal 4-O-naphthoyl/tertiary 3-N-(2-aminonaphthyl)carbamate derivative that exhibited exciton coupled CD identical with that of the derivative prepared from synthetic 1,2- O-dimethyl-alpha-L-evalose.     

Amphimelibiosides A-F, six new ceramide dihexosides isolated from a Japanese marine sponge Amphimedon sp

Six new ceramide dihexosides, amphimelibiosides A-F (1-6), were isolated from a Japanese marine sponge Amphimedon sp. The structure of amphimelibioside C (3), which is a major component of amphimelibiosides, was determined by 2D NMR techniques, chemical degradation, and a semisynthetic method to be 1-O-[beta-D-glucopyranosyl-(1-->6)-alpha-D-galactopyranosyl]-(2S,3S,4R,6E)-2-[(2'R)-2-hydroxydocosanoyl]-2-amino-6-octadecene-1,3,4-triol. The structures of the other constituents were elucidated by a combination of mass spectra, (1)H NMR, and GC-MS analysis.     

(-)-Axinyssene: a novel cytotoxic diterpene from a Japanese marine sponge Axinyssa sp

[structure: see text] A novel diterpene, (-)-axinyssene, was isolated from the Japanese marine sponge Axinyssa sp. The structure of (-)-axinyssene was determined on the basis of spectroscopic and synthetic evidence to be 1-methyl-4-[(4E)-5',9'-dimethyl-1'-methylene-4',8'-decadienyl]-(4S)-cyclohexene. (-)- and (+)-axinyssene showed mild cytotoxicity against acute promyelocytic leukemia, HL-60 cells.