Amycomycins C and D,new angucyclines from Kitasatospora sp.

Two new angucycline compounds containing O-glycosylated 6-deoxy-α-l-talose were isolated from Kitasatospora sp. The compounds were elucidated based on spectroscopic methods including UV, HR-ESIMS, and NMR. A feeding experiment using alizarin led to the conversion of alizarin to a monoglycosylated product with high efficiency, which allows isolation of the sugar after hydrolysis and determination of the absolute configuration of the sugar.     

Lyngbyacyclamides A and B, novel cytotoxic peptides from marine cyanobacteria Lyngbya sp.

Lyngbyacyclamides A (1) and B (2), novel cyclic peptides, were isolated from marine cyanobacteria Lyngbya sp. collected in Okinawa, Japan. Their structures were determined by spectroscopic analyses and degradation studies. They moderately inhibited the growth of B16 mouse melanoma cells.     

Acremoxanthones A and B, novel antibiotic polyketides from the fungus Acremonium sp. BCC 31806

Acremoxanthones A and B, novel anthraquinone-xanthone heterodimers with a unique linkage pattern, together with two known compounds, acremonidins A and C, were isolated from the fungus Acremonium sp. BCC 31806. The structures of the acremoxanthones were determined by analysis of 2D NMR and mass spectrometric data. Acremoxanthones and acremonidins exhibited antibacterial, antifungal, antiplasmodial, and cytotoxic activities.     

Benzosceptrin C, a new dimeric bromopyrrole alkaloid from sponge Agelas sp.

A new dimeric bromopyrrole alkaloid possessing a benzocyclobutane ring, benzosceptrin C (1), has been isolated from an Okinawan marine sponge of the genus Agelas (SS-956), and the structure and relative stereochemistry were elucidated from spectroscopic data. Benzosceptrin C (1) showed antimicrobial activity.     

Trisorbicillinone A, a novel sorbicillin trimer, from a deep sea fungus, Phialocephala sp. FL30r

A novel sorbicillin trimer, trisorbicillinone A (1), was isolated from a deep sea fungus, Phialocephala sp. FL30r. The structure and relative stereochemistry of 1 were determined based on spectroscopic methods. Trisorbicillinone A (1) showed cytotoxicity against P388 and HL60 cells with the IC₅₀ value of 9.10 and 3.14 μM, respectively.     

Halichonadins A-D, new sesquiterpenoids from a sponge Halichondria sp.

A new dimeric sesquiterpenoid with two eudesmane skeletons through a urea linkage, halichonadin A (1), as well as three new eudesmane sesquiterpenoids having a carbamate, an isonitrile, or an amino functionality, halichonadins B (2), C (3), and D (4), respectively, have been isolated from a marine sponge Halichondria sp., and the gross structures and relative stereochemistry of 1-4 were elucidated on the basis of spectral data and chemical means.     

Untenolide A, a new polyketide from an Okinawan marine sponge Plakortis sp.

A new polyketide, untenolide A (1), has been isolated from an Okinawan marine sponge Plakortis species, and the structure was elucidated from spectroscopic data and X-ray analysis. Untenolide A (1) is a new polyketide possessing a fused-pentacyclic skeleton with two hexadecanyl chains.     

Halichonadins G-J, new sesquiterpenoids from a sponge Halichondria sp.

Three new dimeric sesquiterpenoids, halichonadins G-I (1-3), and one new eudesmane sesquiterpenoid possessing a 1-phenethyl urea moiety, halichonadin J (4), were isolated from a marine sponge Halichondria sp. Halichonadins G (1) and H (2) are homo-dimers of eudesmane sesquiterpenoid, linked through a methyl 2-{1-(2-amino-2-oxoethyl)ureido}acetate fragment and a 2-hydroxymalonamide fragment, respectively, while halichonadin I (3) is a new hetero-dimer of eudesmane sesquiterpenoid linked through a urea fragment. The structures of 1-4 were elucidated on the basis of spectroscopic data.     

Sinularianins A and B, novel sesquiterpenoids from the Formosan soft coral Sinularia sp.

Two novel sesquiterpenoids, sinularianins A and B (1 and 2), have been isolated from the Formosan coral Sinularia sp. The skeleton of sinularianins A (1), namely sinulariolane, was found to be unprecedented. Sinularianin B (2), with a novel spiro-butenolide moiety, possesses a valerenane skeleton, which had been reported mostly from the plant. The structures of both metabolites were established by extensive analysis of spectroscopic data.     

Armillariols A to C from the culture broth of Armillaria sp.

Three novel compounds were isolated from the culture broth of Armillaria sp. Their structures were elucidated mainly by spectroscopic data analyses. All the compounds regulated hypocotyl and root growth of lettuce.     

Plakoridine C, a novel piperidine alkaloid from an Okinawan marine sponge Plakortis sp.

A new piperidine alkaloid plakoridine C (1) has been isolated from an Okinawan marine sponge Plakortis species, and the structure was elucidated from spectroscopic data. Plakoridine C (1) is a new alkaloid possessing a piperidine ring connected to a β-keto-γ-lactone through a double bond.     

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.     

Salarins D-J, seven new nitrogenous macrolides from the madagascar sponge Fascaplysinopsis sp.

Seven new nitrogenous macrolides, designated salarins D-J (4-10), closely related to salarins A-C (1-3), have been isolated from the Madagascar Fascaplysinopsis sp. sponge. The structure and relative stereochemistry of compounds 4-10 were elucidated by interpretation of MS, COSY, HSQC, HMBC, and NOESY spectra. Salarin B's structure (2), based on the structure of salarin J (10), is now amended to also incorporate the C-14 to -17 THF ring system. All compounds were evaluated for their cytotoxicity against K562 and UT-7 human leukemia cells. While salarins D, E, H, and J displayed dose and time dependent inhibition of proliferation, salarins F and I were not active in these assays.     

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.     

Lobozoanthamine, a new zoanthamine-type alkaloid from the Indonesian soft coral Lobophytum sp.

A new member of the family of zoanthamine-type alkaloids, lobozoanthamine (1), has been isolated from the Indonesian soft coral Lobophytum sp. This represents the first report of a zoanthamine-type alkaloid from a marine invertebrate different from zoanthids. The densely functionalized heptacyclic stereostructure of lobozoanthamine (1) has been established through the interpretation of 2D NMR data and application of the modified Mosher method.     

Isolation and synthesis of N-acyladenine and adenosine alkaloids from a southern Australian marine sponge, Phoriospongia sp.

Chemical fractionation of the southern Australian marine sponge Phoriospongia sp. (CMB-03107) yielded phorioadenine A (1) as a nematocidal agent and the first reported example of a 6-N-acyladenine natural product. The structure of 1 was confirmed by spectroscopic analysis and the chemical synthesis of racemic (1a) and enantiomeric (1b) analogues. HPLC–ESIMS analysis of the crude sponge extract with comparisons to the synthetic 6-N-acyladenosine 2a provided evidence that the biosynthetically related adenosine, phorioadenosine A (2), was present as a trace co-metabolite. The rare starfish metabolite asterubine (3) was also isolated as a co-metabolite, and its structure confirmed by spectroscopic analysis and chemical synthesis. Biological investigations confirmed that natural products 1–3 and synthetic analogues 1a–e and 2a were not cytotoxic to multiple mammalian cancer cell lines, or Gram-positive or -negative bacteria. Nematocidal activity (inhibition of larval development of Haemonchus contortus) detected in the Phoriospongia sp. extract was attributed to 1 (LD₉₉ 31 μg/mL), with preliminary structure–activity relationship investigations confirming the importance of the N-acyl side chain.     

Formamidobisabolene-based derivatives from a sponge Axinyssa sp.

Chemical examination of a Chinese sponge Axinyssa sp. resulted in the isolation of 12 new formamidobisabolene-based analogues named axinyssines A–L (1–12), along with a new natural product (13) and three known formamidobisabolenes (14–16). Their structures were determined on the basis of extensive NMR and mass spectroscopic analyses in association with ICD data, Mosher reaction and chemical conversion for the assignment of absolute configurations. All compounds were evaluated for antitumor and antimicrobial activities.     

Chaetominedione, a new tyrosine kinase inhibitor isolated from the algicolous marine fungus Chaetomium sp.

A marine fungal isolate, identified as Chaetomium sp., was cultivated and found to produce a novel benzonaphthyridinedione derivative, chaetominedione (1). In addition to the known fungal metabolites, 2-furancarboxylic acid (2) and 5-(hydroxymethyl)-2-furancarboxylic acid (3) were obtained. The structures of all the compounds were determined based on extensive spectroscopic measurements (1D and 2D NMR, MS, UV, and IR). The total extract and compound 1 had significant inhibitory activity toward p56^lck tyrosine kinase (18.7% and 93.6% enzyme inhibition at 200 μg/mL, respectively).     

Aphapolynins A and B, two new limonoids from the fruits of Aphanamixis polystachya

Two new highly oxidized A,B-seco limonoids, aphapolynins A (1) and B (2), were isolated from the fruits of Aphanamixis polystachya. Their structures were elucidated by spectroscopic analysis, in particular, the absolute configuration of aphapolynin A was determined by a single-crystal X-ray study using a mirror Cu Kα radiation. Aphapolynin A exhibit moderate cytotoxicities when tested against a panel of tumor cell lines.     

Jaspolides G and H, unique bisisomalabaricanes from the Chinese marine sponge Jaspis sp.

Two unique bisisomalabaricanes jaspolides G (1) and H (2) were isolated from the marine sponge Jaspis sp. Their structures were elucidated on the basis of extensive spectroscopic data (IR, MS, and 1D and 2D NMR) analyses. A possible biogenetic pathway via Diels-Alder dimerization for jaspolides G and H was also proposed.