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.     

Peloruside A: a potent cytotoxic macrolide isolated from the new zealand marine sponge Mycale sp

A novel, polyoxygenated, pyranose ring containing 16-membered macrolide peloruside A (1) exhibiting cytotoxic activity in the nanomolar range was isolated from the New Zealand marine sponge Mycale sp. The structure of 1 and relative stereochemistry of the 10 stereogenic centers were determined on a 3 mg sample using a variety of spectroscopic methods. Compound 1 was isolated along with the previously reported cytotoxins mycalamide A (2) and pateamine (3) from a single specimen of this sponge.     

Ceratamines A and B, antimitotic heterocyclic alkaloids isolated from the marine sponge Pseudoceratina sp. collected in Papua New Guinea

[structure: see text] Two novel antimitotic heterocyclic alkaloids, ceratamines A (1) and B (2), have been isolated from the marine sponge Pseudoceratina sp., collected in Papua New Guinea. The structures of 1 and 2 were elucidated by analysis of spectroscopic data.     

Structure-activity studies of the pelorusides: new congeners and semi-synthetic analogues

Two new peloruside congeners (3 and 4) were isolated from wild and aquacultured collections of the New Zealand marine sponge Mycale hentscheli. Small-scale reactions on peloruside A (1) have been performed, which along with the isolation of 3 and 4, give further insight into the bioactive pharmacophore of 1.     

Neopetrosiamides, peptides from the marine sponge Neopetrosia sp. that inhibit amoeboid invasion by human tumor cells

[structure: see text] Neopetrosiamdes A (1) and B (2), two diastereomeric tricyclic peptides that inhibit amoeboid invasion of human tumor cells, have been isolated from the marine sponge Neopetrosia sp. collected in Papua New Guinea. The structures of the neopetrosiamides were elucidated by analysis of MS and NMR data and confirmed by chemical degradation.     

中国南海海绵化学成分的研究（Ⅱ）

海绵是目前海洋天然产物研究中最吸引人的海洋生物之一,海绵中含有丰富的结构新颖的次生代谢产物,它们大多数具有显著的生理活性,我们已报道了从海绵Phacellia fusca schmidt中分离及鉴定了3种生物碱,本文报道海绵P. fusca schmidt中A-降甾醇的分离和鉴     

Avinosol, a meroterpenoid-nucleoside conjugate with antiinvasion activity isolated from the marine sponge Dysidea sp

[structure: see text] The new meroterpenoids avinosol (1), 3'-aminoavarone (2), and 3'-phenethylaminoavarone (3) have been isolated from the marine sponge Dysidea sp. collected in Papua New Guinea, and their structures were elucidated by analysis of spectroscopic data. Avinosol (1), which is apparently the first example of a naturally occurring meroterpenoid-nucleoside conjugate, showed antiinvasion activity in a cell-based assay.     

Homophymine A, an anti-HIV cyclodepsipeptide from the sponge Homophymia sp

A new anti-HIV cyclodepsipeptide, homophymine A, was isolated from a New Caledonian collection of the marine sponge Homophymia sp. The structure of homophymine A was determined by interpretation of spectroscopic data, acid hydrolysis, and LC-MS analysis. Homophymine A contains 11 amino acid residues and an amide-linked 3-hydroxy-2,4,6-trimethyloctanoic acid moiety. Along with four D-, two L-, and one N-methyl amino acids, it also contains four unusual amino acid residues: (2S,3S,4R)-3,4-diMe-Gln, (2R,3R,4S)-4-amino-2,3-dihydroxy-1,7-heptandioic acid, L-ThrOMe, and (2R,3R,4R)-2-amino-3-hydroxy-4,5-dimethylhexanoic acid. In a cell-based XTT assay, homophymine A exhibited cytoprotective activity against HIV-1 infection with a IC50 of 75 nM.     

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.     

A New Isomalabaricane Triterpenoid from Sponge Jaspis sp.

From the marine sponge Jaspis sp., a new isomalabaricane triterpenoid 22, 23-dihydrostellettin D (1) was isolated, and its structure was established on the basis of IR, MS and extensive 2D NMR spectroscopic analysis. It is a unique skeleton compound rarely obtained from Chinese marine organisms.     

Total Synthesis of (-)-Irciniastatin B and Structural Confirmation via Chemical Conversion to (+)-Irciniastatin A (Psymberin)

The total synthesis and structural confirmation of the marine sponge cytotoxin (-)-irciniastatin B has been achieved via a unified strategy employing a late-stage, selective deprotection/oxidation sequence that provides access to both (+)-irciniastatin A (psymberin) and (-)-irciniastatin B.     

Exiguamine A, an indoleamine-2,3-dioxygenase (IDO) inhibitor isolated from the marine sponge Neopetrosia exigua

Exiguamine A (1), a hexacyclic alkaloid with an unprecedented skeleton, has been isolated from the marine sponge Neopetrosia exigua collected in Papua New Guinea. The structure of exiguamine A (1) was elucidated by a combination of spectroscopic analysis and single-crystal X-ray diffraction analysis. Exiguamine A (1) has a Ki of 210 nM for inhibition of indoleamine-2,3-dioxygenase (IDO) in vitro, making it one of the most potent IDO inhibitors known to date. A putative biogenesis for the new exiguamine skeleton starts from DOPA, tryptophan, and N,N-dimethylhydantoin.     

Biosynthetic pathways to isocyanides and isothiocyanates; precursor incorporation studies on terpene metabolites in the tropical marine sponges Amphimedon terpenensis and Axinyssa n.sp

The biosynthetic origins of the isocyanide and isothiocyanate functional groups in the marine sponge metabolites diisocyanoadociane (1), 9-isocyanopupukeanane (10) and 9-isothiocyanatopupukeanane (11) are probed by the use of [(14)C]-labelled precursor experiments. Incubation of the sponge Amphimedon terpenensis with [(14)C]-labelled thiocyanate resulted in radioactive diisocyanoadociane (1) in which the radiolabel is specifically associated with the isocyanide carbons. As expected, cyanide and thiocyanate were confirmed as precursors to the pupukeananes 10 and 11 in the sponge Axinyssa n.sp.; additionally these precursors labelled 2-thiocyanatoneopupukeanane (12) in this sponge. To probe whether isocyanide-isothiocyanate interconversions take place at the secondary metabolite level, the advanced precursor bisisothiocyanate 17 was supplied to A. terpenensis, but did not result in significant labelling in the natural product isocyanide 1. In contrast, in the sponge Axinyssa n.sp., feeding of [(14)C]-9-isocyanopupukeanane (10) resulted in isolation of radiolabelled 9-isothiocyanatopupukeanane 11, while the feeding of [(14)C]-11 resulted in labelled isocyanide 10. These results show conclusively that isocyanides and isothiocyanates are interconverted in the sponge Axinyssa n.sp., and confirm the central role that thiocyanate occupies in the terpene metabolism of this sponge.     

南海海绵Axinyssa aplysinoides的化学成份研究(一)

从南海海绵Axinyssaaplysinoides中分离得到一甘油醚类化合物C2 7H54 O3。利用IR ,MS,NMR等分析手段确定了它的结构为 1 -( 1 7Z -二十四碳烯基 ) -甘油醚。     

Total syntheses of brominated marine sponge alkaloids

Total syntheses of six brominated marine sponge bis(indole) alkaloids of the hamacanthin, spongotine, and topsentin classes are described. Retrosynthetic analysis shows that their structures all include the 1-(6'-bromoindol-3'-yl)-1,2-diaminoethane unit 13a. This key moiety has been prepared from brominated indolic N-hydroxylamine 5b via synthetic intermediate 8b.     

Ageladine A: an antiangiogenic matrixmetalloproteinase inhibitor from the marine sponge Agelas nakamurai

A novel MMP inhibitor, ageladine A (1) with antiangiogenic activity was isolated from a marine sponge Agelas nakamurai. Structure 1 was determined by a combination of spectroscopic and chemical methods to be an unprecedented structure of 4-(4,5-dibromo-1H-pyrrol-2-yl)]-1H-imidazo[4,5-c]pyridin-2-amine.     

Syntheses of a glycerophospholipid, C16-platelet activating factor and a palmitoyl analogue of M-5, an anti-inflammatory glyceroglycolipid.

From a chiral C4-epoxide (-)-3, which is one of the synthons in our synthetic strategy for complex lipids, a glycerophospholipid C16-platelet activating factor (C16-PAF, 1) and a palmitoyl analogue (2) of an anti-inflammatory glyceroglycolipid M-5, which was previously isolated from the Okinawan marine sponge Phyllospongia foliascens, have been synthesized.     

(-)-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.     

Synthetic approaches towards an indole alkaloid isolated from the marine sponge Halichondria melanodocia

The exocyclic analogue of the indole alkaloid isolated from the marine sponge Halichondria melanodocia has been prepared via olefination of a phosphonoester derived from 3-(2-bromoacyl)indole. The formation of an unexpected indolylazepine is also discussed.     

南海海绵Axinyssa aplysinoides的化学成分研究(三)

从南海海绵Ａｘｉｎｙｓｓａ　ａｐｌｙｓｉｎｏｉｄｅｓ中分离得到两个小分子化合物 Ｃ７Ｈ６Ｏ２和 Ｃ５Ｈ６Ｎ５Ｏ５。利用 ＩＲ、ＵＶ、ＮＭＲ、ＭＳ等分析手段确定了它的结构 为对羟基苯甲醛和胸腺嘧啶。