Studies on a biomimetic approach to aerothionin and psammaplysin-A

Okamoto, Kelvin T.; Clardy, Jon

doi:10.1016/s0040-4039(00)96672-3

Cited by 35 publications

(9 citation statements)

References 12 publications

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“…This taxonomic order has been the source of numerous bromotyrosine-derived secondary metabolites, many of which contain a distinctive spiroisoxazoline system. [15][16][17][18][19][20][21][22][23][24][25] HPLC/MS data of the CH 2 Cl 2 /CH 3 OH extract from one Pseudoceratina sp. identified UV-active peaks that contained ion clusters in the (+)-LRESIMS at m/z 787/789/791/793/795, 744/746/748/750/752, and 772/774/776/778/780.…”

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confidence: 99%

Psammaplysin H, a new antimalarial bromotyrosine alkaloid from a marine sponge of the genus Pseudoceratina

Andrews

Birrell³

et al. 2011

Bioorganic & Medicinal Chemistry Letters

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Mass-directed isolation of the CH(2)Cl(2)/CH(3)OH extract from a marine sponge of the genus Pseudoceratina resulted in the purification of a new antimalarial bromotyrosine alkaloid, psammaplysin H (1), along with the previously isolated analogs psammaplysins G (2) and F (3). The structure of 1 was elucidated following 1D and 2D NMR, and MS data analysis. All compounds were tested in vitro against the 3D7 line of Plasmodium falciparum and mammalian cell lines (HEK293 and HepG2), with 1 having the most potent (IC(50) 0.41μM) and selective (>97-fold) antimalarial activity.

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confidence: 99%

Psammaplysin H, a new antimalarial bromotyrosine alkaloid from a marine sponge of the genus Pseudoceratina

Andrews

Birrell³

et al. 2011

Bioorganic & Medicinal Chemistry Letters

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“…The following compounds were prepared as described in the literature: 3,5-dibromo-4-methoxybenzyl alcohol, 11 3,5-dibromo-4-hydroxybenzyl alcohol, 12 1-(3′,5′-dibromo-4′-hydroxyphenyl)ethanol 10 and 3,5-dibromobenzyl alcohol. 13 3-Bromo-4-methoxybenzyl alcohol was isolated 11 as a minor product (by column chromatography on silica gel using 20% ethyl acetate in hexane) during preparation of 3,5-dibromo-4-methoxybenzyl alcohol, using LiAlH 4 instead of NaBH 4 .…”

Section: Synthesesmentioning

confidence: 99%

Rearrangement and Loss of Bromine Radical and CO from Some Bromobenzyl Alcohols following Electron Ionisation

Kubišta

Hanuš

Havlı́cěk

et al. 2000

Eur J Mass Spectrom (Chichester)

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The electron ionisation spectra of bromine-containing derivatives of benzyl alcohol are often dominated by ions which do not contain bromine. We use the experimental data on a series of selected bromobenzyl alcohols to elucidate the easy loss of bromine atoms. In this process, arene-bonded bromines are displaced by hydrogens which originate from the benzyl group. Thus, we conclude that this reaction occurs during the “hydrogen ring-walk”. The suggested reaction mechanism and structures of intermediates, which can be considered, are discussed and graphically illustrated.

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“…The racemic syntheses of aerothionin, homoaerothionin, and aerophobin-1, which are isolated from sponges of Aplysia aerophoba , Aplysia fistularis , and Verongia thiona , by the oxidative cyclization of o -phenolic oxime-ester 1a using Tl(OCOCF 3 ) 3 as oxidant have been reported (Scheme ), 2g, showing that spiroisoxazoline methyl ester 2a is a key compound in the synthesis of these marine natural products. However, asymmetric synthesis of these natural products is not known…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Oxidative Cyclization of o-Phenolic Oxime-Esters: First Synthesis of Enantiomerically Enriched Spiroisoxazoline Methyl Esters

1997

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A new method for the synthesis of enantiomerically enriched cyclohexadienone spiroisoxazoline (-)-2a has been described. Asymmetric intramolecular oxidative cyclization of the o-phenolic oxime-ester 1c using a novel optically active tertiary alcohol (-)-3 as a chiral auxiliary proceeded smoothly to afford cyclohexadienone spiroisoxazoline 2c in 83% yield. Opitcally active tertiary alcohol (-)-3 was synthesizied from racemic (1S,8R,9R,10R)-8-phenyl-1-decalol (4) by optical resolution. Removal of the chiral auxiliary in 2c with CF(3)COOH followed by methylation gave methyl ester (-)-2a in 74% ee (71% chemical yield) having S-configuration. The absolute configuration of 2awas determined by the synthesis of the marine natural product (+)-aerothionin.

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Studies on a biomimetic approach to aerothionin and psammaplysin-A

Cited by 35 publications

References 12 publications

Psammaplysin H, a new antimalarial bromotyrosine alkaloid from a marine sponge of the genus Pseudoceratina

Psammaplysin H, a new antimalarial bromotyrosine alkaloid from a marine sponge of the genus Pseudoceratina

Rearrangement and Loss of Bromine Radical and CO from Some Bromobenzyl Alcohols following Electron Ionisation

Asymmetric Oxidative Cyclization of o-Phenolic Oxime-Esters: First Synthesis of Enantiomerically Enriched Spiroisoxazoline Methyl Esters

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