Durinskiol A: a long carbon-chain polyol compound from the symbiotic dinoflagellate Durinskia sp.

A long carbon-chain polyol compound with a molecular weight of 2128 mu, durinskiol A (1) was isolated from the cultured symbiotic dinoflagellate Durinskia sp. Its planar structure was elucidated based on 2D-NMR and MS/MS analysis. Durinskiol A (1) caused a short body length, abnormal pigment pattern, and pericardiac and yolk-sac edema in zebrafish.     

Amphidinolide T, novel 19-membered macrolide from marine dinoflagellate Amphidinium sp

A novel 19-membered macrolide, amphidinolide T (1), has been isolated from a marine dinoflagellate Amphidinium sp., and the structure was elucidated on the basis of spectroscopic data. Relative stereochemistry at C-7, C-8, and C-10 was deduced from the NOESY correlations, while absolute configurations at C-2, C-13, C-14, and C-18 were assigned on the basis of NMR data of the MTPA esters of 1 and those of degradation products of 1.     

Amdigenols E and G,long carbon-chain polyol compounds,isolated from the marine dinoflagellate Amphidinium sp.

The novel polyol compounds, amdigenols E and G, were isolated from the dinoflagellate Amphidinium sp. that was found to adhere to the surface of the marine alga Digenea simplex. The structures of the two amdigenols were elucidated by NMR spectroscopy and ESI–CID-MS/MS analyses. Both amdigenols E and G shared partial structures with amdigenol A. Amdigenols E and G inhibited N-type Ca²⁺ channel-opening.     

A new unsaturated glycoglycerolipid from a cultured marine dinoflagellate Amphidinium carterae

From the cultured marine dinoflagellate Amphidinium carterae, a new unsaturated glycoglycerolipid (2S)-1,2-O-6,9,12,15-dioctadecatetraenoyl-3-O-[alpha-D-galactopyranosyl-(1'-->6')-O-beta-D-galactopyranosyl]-glycerol (1), has been isolated together with two known saturated ones, (2S)-1,2-distearoyl-3-O-(6-sulpho-alpha-D-quinovopyranosyl)-glycerol (2) and (2S)-1-stearoyl-3-O-(6-sulpho-alpha-D-quinovopyranosyl)-glycerol (3). Their structures were elucidated on the basis of chemical and spectral data.     

Amphidinolide W, a new 12-membered macrolide from dinoflagellate Amphidinium sp

A new cytotoxic 12-membered macrolide, amphidinolide W (1), has been isolated from a marine dinoflagellate Amphidinium sp., and the structure was elucidated by spectroscopic data including (13)C-(13)C INADEQUATE correlations for its (13)C-enriched sample. The absolute stereochemistry of 1 was assigned by combination of J-based configuration analysis and modified Mosher method. Amphidinolide W (1) is the first macrolide without an exomethylene unit among all amphidinolides obtained so far.     

Colopsinols D and E, new polyhydroxyl linear carbon chain compounds from marine dinoflagellate Amphidinium sp

Colopsinols D (1) and E (2), two new polyhydroxyl linear carbon chain compounds, have been isolated from the cultured marine dinoflagellate Amphidinium sp. The structures of 1 and 2 were elucidated on the basis of two-dimensional NMR and FAB-MS/MS data.     

Amphidinolide X,a novel 16-membered macrodiolide from dinoflagellate Amphidinium sp

A novel cytotoxic 16-membered macrodiolide, amphidinolide X (1), has been isolated from a marine dinoflagellate Amphidinium sp. (strain Y-42). The gross structure of 1 was elucidated on the basis of spectroscopic data including one-bond and long-range (13)C-(13)C correlations. The relative and absolute stereochemistries were determined by combined analyses of NOESY data and (1)H-(1)H and (1)H-(13)C coupling constants of 1 and NMR data of the degradation products. Amphidinolide X (1) is the first macrodiolide consisting of polyketide-derived diacid and diol units from natural sources. The biosynthetic origins of 1 were investigated by means of feeding experiments with (13)C-labeled acetates.     

Karatungiols A and B, two novel antimicrobial polyol compounds, from the symbiotic marine dinoflagellate Amphidinium sp.

Karatungiols A (1) and B (2), two novel antimicrobial polyol compounds, were isolated from the cultivated symbiotic marine dinoflagellate Amphidinium sp. Their structures were elucidated based on spectroscopic analysis and degradation reactions. Karatungiols A (1) and B (2) consisted of a C69-linear chain with a ketone moiety, 24 or 25 hydroxyl groups, and two tetrahydropyran rings. Karatungiol A (1) exhibited antifungal activity against Aspergillus niger at 12 μg/disc and antiprotozoan activity against Trichomonas foetus at 1 μg/ml.     

Symbiodinolide, a novel polyol macrolide that activates N-type Ca channel, from the symbiotic marine dinoflagellate Symbiodinium sp.

A 62-membered novel polyol macrolide with a molecular weight of 2859 mu, symbiodinolide, was isolated from the symbiotic dinoflagellate Symbiodinium sp. Symbiodinolide exhibited a potent voltage-dependent N-type Ca²⁺ channel-opening activity at 7 nM and immediately ruptured the tissue surface of the acoel flatworm Amphiscolops sp. at 2.5 μM. The planar structure of symbiodinolide was elucidated by spectroscopic analysis and chemical degradations including hydrolysis and ethenolysis using the second-generation Grubbs' catalyst. Symbiodinolide was found to be a structural congener of zooxanthellatoxins. The relative stereochemistries of C26-C32, C44-C51, and C64-C66 parts, and the absolute stereochemistries of C69-73, C83-C103, and C3′-C18′ parts in symbiodinolide were established.     

Amphezonol A, a novel polyhydroxyl metabolite from marine dinoflagellate Amphidinium sp.

Amphezonol A (1), a novel polyhydroxyl linear carbon-chain metabolite, has been isolated from the cultured marine dinoflagellate Amphidinium sp., which was isolated from an Okinawan marine acoel flatworm Amphiscolops sp. The structure of 1 was elucidated by detailed analyses of 2D NMR spectra. Amphezonol A (1) possesses one tetrahydrofuran ring, two tetrahydropyran rings, and twenty-one hydroxyl groups on C₆₀-linear aliphatic chain with one exo-methylene and one methyl branch. Amphezonol A (1) exhibited a modest inhibitory activity against DNA polymerase α.     

Zooxanthellamide A, a novel polyhydroxy metabolite from a marine dinoflagellate of Symbiodinium sp.

A novel polyhydroxy metabolite named Zooxanthellamide A, C₁₂₈H₂₂₂N₂O₅₄S₂, was isolated from a cultured marine dinoflagellate, Symbiodinium sp., and the chemical structure was determined by spectroscopic methods.     

Amphidinolide Y, a novel 17-membered macrolide from dinoflagellate Amphidinium sp.: plausible biogenetic precursor of amphidinolide X

A novel cytotoxic 17-membered macrolide, amphidinolide Y (1), has been isolated from a marine dinoflagellate Amphidinium sp., and it was elucidated to exist as a 9:1 equilibrium mixture of 6-keto- and 6(9)-hemiacetal forms (1a and 1b, respectively) on the basis of 2D NMR data and chemical means. The feeding experiments with (13)C-labeled acetates suggested that amphidinolide Y (1) may be a biogenetic precursor of 16-membered macrodiolide, amphidinolide X (2).     

Symbiodinolactone A,a new 12-membered macrolide from symbiotic marine dinoflagellate Symbiodinium sp.

A new 12-membered macrolide, symbiodinolactone A, was isolated from the culture broth of symbiotic marine dinoflagellate Symbiodinium sp. The gross structure of symbiodinolactone A was elucidated by spectroscopic analyses, and the relative configuration was elucidated by the J-based configuration analysis and density-functional theory calculations. Symbiodinolactone A is the new 12-membered macrolide possessing an E double bond between C-4 and C-5, a branched methyl group at C-7, and a 1,2,3-trihydroxybutyl group at C-11. Symbiodinolactone A is the first usual size macrolide and the first non-nitrogen-containing macrolide from dinoflagellate Symbiodinium sp. Symbiodinolactone A might be generated by the unexplained dinoflagellate polyketide biosynthetic machinery.     

A new antibacterial compound produced by an indigenous marine bacteria--fermentation, isolation, and biological activity

The use of microorganisms for biological purpose has become an effective alternative to control pathogens. A marine bacterium Pseudomonas aeruginosa was isolated from Eal fish of Baluchistan coast of Pakistan. This strain produced a bactericidal antibiotic against environmental and clinical isolates. In this study, we purified bactericidal antibiotic from the ethyl acetate extract of the cells of P. aeruginosa and analyzed its chemical structure. Based on spectrometric analysis, this compound 1 is proposed to be 1-methyl-1,4 dihydroquinoline and is active against methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive S. aureus (MSSA), Salmonella typhi, Shigella flexneri, Escherichia coli, Proteus mirabilis, Vibrio aliginolyticus, Micrococcus luteus, Enterococcus faecalis, Enterobacter faecium but it is not active against G streptococci, Candida albicans, Aspergillus niger. Minimal inhibitory concentration for Gram-positive bacteria was between 50 and 75 microg mL(-1) and for Gram-negative bacteria 75-100 microg mL(-1).     

Prorocentin-4, a novel linear polyketide from a marine dinoflagellate Prorocentrum sp.

Prorocentin-4, isolated from a cultured marine dinoflagellate Prorocentrum sp. was possessed of two tetrahydrofuran rings, conjugated dienes, four branched methyl groups, and a ketone moiety. The gross structure was elucidated by spectroscopic studies and the relative stereostructure was determined on the basis of spectral data.     

Formosalides A and B, cytotoxic 17-membered ring macrolides from a marine dinoflagellate Prorocentrum sp.

Formosalides A (1) and B (2), two novel cytotoxic 17-membered ring macrolides with all-cis tetraenes, a tetrahydropyran ring, and a tetrahydrofuran ring, were isolated from the cultured marine dinoflagellate Prorocentrum sp. Their gross structures, including local relative stereostructures, were elucidated by extensive spectroscopic studies.     

Symbioimine exhibiting inhibitory effect of osteoclast differentiation, from the symbiotic marine dinoflagellate Symbiodinium sp

An amphoteric iminium metabolite, symbioimine (1), was isolated from a cultivated symbiotic marine dinoflagellate Symbiodinium sp. Its structure was deduced by spectroscopic analysis and X-ray crystallographic analysis. Symbioimine (1) has a characteristic 6,6,6-tricyclic iminium ring structure and an aryl sulfate moiety. The plausible biogenetic pathway of 1 can be explained by an intramolecular Diels-Alder reaction followed by imine cyclization. Symbioimine (1) inhibited the differentiation of RAW264 cells into osteoclasts, whereas its cell viability was not affected. Thus, symbioimine (1) is an antiresorptive drug candidate for the prevention and treatment of osteoporosis in postmenopausal women.     

Citriperazines A-D produced by a marine algae-derived fungus Penicillium sp. KMM 4672

Abstract

Four new diketopiperazine alkaloids, citriperazines A-D were isolated from algae-derived Penicillium sp. KMM 4672. The structures of compounds 1–4 were determined using spectroscopic methods. The absolute configurations of compounds 1 and 4 were established by comparison of calculated and experimental ECD spectra. The cytotoxicity of compounds 1–4 against several human prostate cell lines was evaluated.     

Lingshuiols A and B, two new polyhydroxy compounds from the Chinese marine dinoflagellate Amphidinium sp.

Lingshuiols A and B, two new polyhydroxyl compounds with linear carbon-chains, were isolated from the cultured Chinese marine dinoflagellate Amphidinium sp. Their structures were elucidated by extensive analysis of 2D NMR spectral data.     

Padanamides A and B, highly modified linear tetrapeptides produced in culture by a Streptomyces sp. isolated from a marine sediment

Two highly modified linear tetrapeptides, padanamides A (1) and B (2), are produced by laboratory cultures of a Streptomyces sp. obtained from a marine sediment. Padanamide B is cytotoxic to Jurkat cells, and a chemical genomics analysis using Saccharomyces cerevisiae deletion mutants suggested that padanamide A inhibits cysteine and methionine biosynthesis or that these amino acids are involved in the yeast's response to the peptide.