New Bromopyrrole Alkaloid from the Marine Sponge Agelas wiedenmayeri

Soest, R.W.M. van; Assman, M.; Lichte, Ellen; Köck, Matthias

doi:10.1021/ol990664h

Cited by 36 publications

(19 citation statements)

References 13 publications

(8 reference statements)

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“…[31] The proposition that 2 is a biosynthetic precursor of the other more-complex members of the family is supported by the extremely high concentrations of 2 found in many of the organisms that produce ageliferin (8) [8e, 32] (compound 2 has also been isolated from the same organism as palauamine (25) [7b]…”

Section: Biosynthesis Of the Pyrrole-imidazole Alkaloidsmentioning

confidence: 99%

The Pursuit of Palau'amine

et al. 2007

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Since its discovery in 1993, the marine natural product palau'amine has intrigued natural product chemists. Its exotic molecular architecture and purported bioactivity made it an ideal target for synthesis. However, as the years went by and related marine alkaloids were isolated, a skeptical eye was cast on the structure of palau'amine; recently these suspicions were confirmed and the structure of palau'amine revised. This Minireview gives a careful overview of the structural revision and its ramifications to both its biogenesis and total synthesis.

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Section: Biosynthesis Of the Pyrrole-imidazole Alkaloidsmentioning

confidence: 99%

The Pursuit of Palau'amine

et al. 2007

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“…Final purification of the isolated compounds was achieved by preparative RP 18 HPLC to afford compounds 1 (140 mg), 2 (13 mg), and 3 (3 mg). HPLC analysis was carried according to ref 10.…”

Section: Methodsmentioning

confidence: 99%

New Antifeedant Bromopyrrole Alkaloid from the Caribbean Sponge Stylissa caribica

2001

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In this first report on the chemistry of the sponge Stylissa caribica, two known bromopyrrole metabolites and a new compound, N-methyldibromoisophakellin (1), were isolated and identified. The structure of 1 was determined using spectroscopic methods and the computer program COCON. N-Methyldibromoisophakellin (1) was shown to be the only secondary metabolite in Stylissa caribica that, at its natural concentration, is active as a feeding deterrent against a common omnivorous reef fish.In a recent survey of the chemical antipredatory defenses of 71 species of Caribbean sponges, it was discovered that all of the five species within the family Axinellidae yielded crude organic extracts that deterred the feeding of predatory reef fish in aquarium assays. 1 More recently it has been shown that one species, Axinella corrugata (previously Teichaxinella morchella), yielded high concentrations of stevensine as the single compound responsible for feeding deterrency. 2 The purpose of the study reported herein was to isolate and identify the metabolite(s) responsible for the chemical defense of Stylissa caribica, a sponge closely related to A. corrugata. To the best of our knowledge, this is the first report on the chemistry of S. caribica.A series of brominated pyrrole alkaloids have been isolated from a specimen of the sponge S. caribica collected off the coast of Sweetings Cay, Bahamas. Bioassay-guided fractionation of the methanol extract of this sponge resulted in the isolation of two known bromopyrrole-derived alkaloids, dibromoisophakellin (2, 13 mg) and ageliferin (3, 3 mg), as well as the new compound N-methyldibromoisophakellin (1, 140 mg). We describe herein the isolation, structural elucidation, and antifeedant properties against the common predatory reef fish Thalassoma bifasciatum of the new bromopyrrole alkaloid 1.The compounds 1-3 could be isolated using previously reported methods (details see Experimental Section and Supporting Information). The brominated alkaloids dibromoisophakellin (2) and ageliferin (3) Table 1). By comparison of δ C of 1 with all known intramolecular cyclized oroidin derivatives, the isophakellin skeleton was obtained. 4 Therefore, the structure of 1 was identified and confirmed by COCON 5 as the N-methyl derivative of dibromoisophakellin (2). The absolute configuration of 1 was determined by comparison of the optical rotation of 1 with that of 2. 3a Since recent studies 6 have found no evidence for structural or nutritional defenses, deterrent metabolites appear to be the principal defensive strategy of Caribbean sponges against predatory reef fishes. To investigate the feeding deterrency of the major metabolite of S. caribica, aquarium assays were performed using previously reported methods. 7 When incorporated into artificial foods at the same volumetric concentration as found in sponge tissue (0.9 mg/mL), N-methyldibromoisophakellin (1) deterred

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“…Scheme 7.3 gives an overview of the different proposals. Pyrrole-2-carboxylic acid (16) and 2-amino-5-(3-amino)propylimidazole (13) have been isolated from many sponges. This ''misleading'' result suggests that clathrodin (1) could be formed by the acylation of 13 by 16 (Scheme 7.3).…”

Section: Proposed Biogenetic Hypothesis For Clathrodin (1) and Relatementioning

confidence: 99%

“…According to us, the origin of the 2-aminoimidazole moiety could actually be much more subtle. In fact, 2-amino-5-(3-amino)propylimidazole (13), supposed to be the precursor of oroidin, might rather be the product of its hydrolysis.…”

Section: Proposed Biogenetic Hypothesis For Clathrodin (1) and Relatementioning

confidence: 99%