Glycerolipids from a Sarcotragus species sponge

One known and two new glycerolipids have been isolated from a Sarcotragus sp. marine sponge. The gross structures were established based on NMR and MS analysis.     

Facile ring transformation from gluconolactone to cyclitol derivative via spiro sugar ortho ester

[reaction: see text] A short step preparation of cyclitol derivative 8 which is a versatile synthon for the synthesis of valiolamine and its related compounds is described. Key steps in this preparation are a novel enol ether formation from spiro sugar ortho esters with AlMe3 and an intramolecular Aldol condensation of alkyl enol ethers catalyzed by ZnCl2 in THF-H2O. With these reactions, gluconolactone derivative 1 was efficiently converted into 8 in short steps.     

New tetrahydropyrans from a marine sponge

Two new tetrahydropyrans have been isolated from the sponge Haliclona sp. From chemical and spectroscopic evidence they are shown to be (1′$\text{R}$, 2$\text{S}$, 2″$\text{E}$, 5$\text{R}$, 6$\text{R}$)-2-(1′-bromethyl)-2,5-dimethyl-6-(penta-2″,4″-dienyl)-tetrahydropyran and (1′$\text{R}$, 2$\text{S}$, 5$\text{R}$, 6$\text{R}$)-2-(1′-bromoethyl)-2,5-dimethyl-6-(pent-4″-enyl)-tetrahydropyran.     

New diterpene isocyanides from a sponge

Six new diterpene isocyanides have been isolated from a sponge ($\text{Adocia}$ sp.). Their structures support the biosynthetic suggestion for the formation of diisocyanoadociane reported from the same sponge.     

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.     

New cytotoxic spongian-class rearranged diterpenes from a marine sponge

Chemical investigation of an Okinawan marine sponge resulted in the isolation of two new spongian-class diterpenes 1 and 2 together with two known compounds, chromodorolide B (3) and chromodorolide C (4). Compound 1, named chromodorolide D, is an example of a diterpenoid with a highly rearranged chromodorane carbon skeleton, while compound 2 retains the open side chains. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis and chemical conversion. Compounds 1–4 exhibited significant cytotoxicity against NBT-T2 rat bladder epithelial cells.     

Nagelamide J, a novel dimeric bromopyrrole alkaloid from a sponge Agelas species

A novel dimeric bromopyrrole alkaloid, nagelamide J (1), with antimicrobial activity has been isolated from an Okinawan marine sponge Agelas species, and the structure and stereochemistry were elucidated from spectroscopic data. Nagelamide J (1) is the first bromopyrrole alkaloid possessing a cyclopentane ring fused to an amino imidazole ring.     

Cytotoxic macrolides from a new species of the deep-water marine sponge Leiodermatium

Chemical investigation of a new species of the deep-water marine sponge Leiodermatium, collected by manned submersible at a depth of 740 feet in Palau, resulted in the isolation of two cytotoxic macrolides, leiodolides A (1) and B (2). The leiodolides represent the first members of a new class of 19-membered ring macrolides, incorporating several unique functional groups including a conjugated oxazole ring, a bromine substituent, and an alpha-hydroxy-alpha-methyl carboxylic acid side-chain terminus. The structures of these new metabolites were established by spectroscopic analysis, chemical modification, and degradation. The relative and absolute stereochemistries at most chiral centers were assigned on detailed interpretation of spectroscopic data, coupled with chemical degradation and application of the modified Mosher ester method. Leiodolide A showed significant cytotoxicity (average GI(50) = 2.0 microM) in the National Cancer Institute's 60 cell line panel with enhanced activity against HL-60 leukemia and OVCAR-3 ovarian cancer cell lines.     

New quinone from a marine sponge of the order dictyoceratida

Two pigments of quinoid nature, one of which has been identified as ilimaquinone, have been isolated from a hexane extract of a marine spongeHyatella sp., family Spongiidae, order Dictyoceratida. The second was a new benzoquinone of the drimane series with the composition C₂₂H₃₂O₅, which has been called hyatoquinone. Its structure has been established on the basis of spectral characteristics and chemical transformations.     

New quinone from a marine sponge of the order dictyoceratida

Two pigments of quinoid nature, one of which has been identified as ilimaquinone, have been isolated from a hexane extract of a marine spongeHyatella sp., family Spongiidae, order Dictyoceratida. The second was a new benzoquinone of the drimane series with the composition C₂₂H₃₂O₅, which has been called hyatoquinone. Its structure has been established on the basis of spectral characteristics and chemical transformations.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, USSR Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 793–796, November–December, 1987.     

New sphingolipids from marine sponge Iotrochota baculifera

Chemical examination of the marine sponge Iotrochota baculifera of the Indian Ocean furnished a sphingolipid (1), a new glycosphingolipid (iotroridoside-B, 2) and a four-component mixture of sphingolipids (3a-d) with two new components. Structure elucidation was carried out by spectral and chemical methods.     

New sesquiterpenoids from the sponge axinella cannabina

The structures of three sesquiterpenoids, axisothiocyanate-2(4), axamide-1(5) and axamide-2(6), present in the marine sponge Axinella cannabina, have been determined on the basis of chemical and spectral evidences.     

New coumarin derivative from Euphorbia wallichii

One new coumarin derivative (1) and two known compounds, quercetin (2) and glyceraldehyde (3) have been isolated from the whole plants of Euphorbia wallichii. Their structures were elucidated by means of extensive spectroscopic analysis (NMR and ESI-MS) and by comparison with data reported in the literature. This is the first isolation of dihydrocoumarin (1) from the genus of Euphorbia.     

New diterpenes from the Caribbean sponge Epipolasis reiswigi

Two diterpenes, epipolone (1) and epipolol (3), produced by terpenoid pathways leading to a tricarbocyclic structure with an irregular "head to tail" isoprene configuration, have been isolated from the Caribbean marine sponge Epipolasis reiswigi collected in Puerto Rico. The structures of 1 and 3 were elucidated largely by 1D and 2D NMR methods and chemical conversion.     

New antimicrobial diterpenes from the sponge spongia officinalis

The methanol extract of the sponge Spongia officinalis from Pt. Guimar, Tenerife (Canary Islands) contained new diterpenoids which inhibited the growth of microbes. The structures of the new diterpenes isolated were determined as; 11β-hydroxyspongi-12-en-16-one ($\text{2}$), 11β-acetoxyspongi-12-en-16-one ($\text{3}$), 7β,11β-dihydroxy8pongi-12-en-16-one ($\text{5}$), and 7β,11α-dihydroxy-spongi-12-en-16-one ($\text{6}$), by spectral and chemical degradation studies. The previously reported diterpenes isoagatholactone ($\text{1}$) and aplysillin ($\text{4}$) were also found in the extract.