Marine sponge

Structures of marine sponge alkaloids manzamines and related compounds 97H(46)765. 

Alkylpiperidine alkaloids from marine sponges of Haploselerida order 96MI4. 

Negatively charged alkaloids are rare. The isolation of the zinc salt Clathridin (6) (Scheme 2) from the marine sponge Clathrina clathrus was reported in 1990 (90T4387). Other examples are bis(isonaamidinato) A Zinc... 

In the rosary pea Abrus precatorius L. Trigollenine as well as its gallic acid ester Precatorine (209) is found (71P195) (Scheme 69). 1-Carboxymethyl-nicotinic acid (210) was isolated as a colorless solid from the marine sponge Anthosigmella cf. raromicrosclera as a cysteine protease inhibitor (98JNP671). This compound was first synthesized in 1991. The sodium... 

More recently, miraziridine A (113) was isolated from a marine sponge related to Theonella mirabilis and shown to inhibit the cysteine protease cathepsin B. It has been shown that the aziridine ring plays a key role in this biological activity and gives rise to irreversible inhibition of cathepsins B and L, presumably through... 

Dysidazirine 130 was isolated by Ireland in 1988 from a Fijian sample of the marine sponge Dysidea fragilis [194] as the major lipophilic component of the sponge and was shown to possess cytotoxic activity against L1210 cells, as well as... 

Swinholide A, isolated from the marine sponge Theonella swinhoei, sequesters actin dimers and induces their formation. One molecule of swinholide A binds to one dimer. In addition, swinholide A can sever F-actin by binding to the neighbouring protomers. Increased depolymerization of F-actin has also been reported. 

Several toxins produced by marine sponges cause the destabilization of F-actin. They contain a macrocyclic ring and an aliphatic chain, by which they bind to actin protomers. The toxins that include reidispongiolides,... 

In contrast, jasplakinolide, a cyclodepsipeptide from the marine sponge Jaspis johnstoni, rapidly penetrates the cell membrane. It competes with phalloidin for F-actin binding and has a dissociation constant of approximately 15 nM. It induces actin polymerization and stabilizes pre-existing actin filaments. Dolastatin 11, a depsipeptide from the mollusk Dolabella auricu-laria, induces F-actin polymerization. Its binding site differs from that of phalloidin or jasplakinolide. 

In the seven-step stereoselective total synthesis of ptilocaulin 44 [21 ], a potent antileukemic and antimicrobial agent isolated [22] from marine sponges, the oxime 36 was treated with NaOCl providing the tricyclic isoxazoline 38 in 89% yield without isolation of the nitrile oxide intermediate 37 (Scheme 5) [23]. Isoxazoline 38 was obtained as a mixture of four diastereomers and their ratio was... 

The first compound is an antibiotic isolated from Streptomyces aureus [20], while the second compound is a cytotoxic antibiotic isolated from Dysidea fragilis, a marine sponge [21]. A logical approach to the synthesis of azirines would be an elimination reaction of a suitably M-substituted aziridine. Thus, AT-chlorination of aziridine-2-carboxylic esters was carried out using ferf-butyl hypochlorite (Scheme 8). 

Polycyclic Diamine Alkaloids from Marine Sponges... 

Marine sponges are a source of an array of polycyclic diamine alkaloids of common biogenetic origin. This class of secondary metabolites has been the subject of four previous reviews [4-7]. Therefore, the present review will include literature reports previously not discussed, dealing with the isolation, structure determination, biological activities, and total synthesis of polycycUc diamine alkaloids isolated from marine sponges. This review will not include guanidine alkaloids [8,9] or the manzamine alkaloids [10,11], since these compounds have been recently reviewed elsewhere. Only polycycUc... 

Further members of this class of alkaloids are the araguspongines K (10) and L (11), isolated from the marine sponge Xestospongia exigua collected at Bayadha, on the Saudi Arabian Red Sea coast [16]. After evaporation of the EtOH extract, it was partitioned between hexanes and MeCN. The polar fraction was subjected to a series of chromatographic separations by column chromatography on silica gel. The structures of both alkaloids 10 and... 

Haliclonacyclamine E (13) and arenosclerins A (14), B (15), and C (16) have been isolated from the marine sponge Arenosclera brasiliensis, endemic in Brazil. Crude extracts of this sponge displayed potent cytotoxic and antibiotic activities, and were subjected to fractionation by sihca-gel flash chromatography, medium pressure chromatography on a SiOH cyanopropyl-bonded column, and reversed-phase Cis column chromatography to give compounds 13-16 [18]. The structure elucidation was based on spectroscopic analysis, including HRFABMS, COSY, HSQC, HSQC-TOCSY, and HMBC NMR... 

Andersen RJ, van Soest RWM, Kong F (1996) 3-Alkylpiperidine alkaloids isolated from marine sponges in the order Haplosclerida. In Alkaloids chemical and biological perspectives. Pergamon, New York, p 301... 

Berlinck RGS (2007) Polycyclic Diamine Mkaloids from Marine Sponges. 10 211-238 Besson T, Thiery V (2006) Microwave-Assisted Synthesis of Sulfiu and Nitrogen-Containing Heterocycles. 2 59-78... 

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