Terpenoid constituents from two Phyllospongia spp.

Kazlauskas, Rymantas; Murphy, PT; Wells, RJ; Daly, J. W.

doi:10.1071/ch9801783

Cited by 43 publications

(74 citation statements)

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“…The active fraction that eluted with 100% EtOAc (45.1 mg) was separated by column chromatography over 450 mg silica gel with hexanes-CH 2 Cl 2 -EtOAc (1:1:2) to give 3 (7.0 mg, 0.17% yield), and 4 (10.0 mg, 0.25% yield). (4aR,4bS,6aS,7S,10aS,10bS,3,4,4b,5,6,6a,7,10,10a,10b,11,12,12a-t etradecahydro-1,1,6a,10b-tetramethyl-6-oxo-4a(2H)-chrysenecarboxylic acid. …”

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confidence: 99%

Cytotoxic Metabolites from an Indonesian Sponge Lendenfeldia sp.

et al. 2007

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The lipid extract of an Indonesian Lendenfeldia sp. sponge inhibited hypoxia-induced hypoxiainducible factor-1 (HIF-1) activation in T47D breast tumor cells. Chromatographic separation yielded the new substituted naphthalene dimer 1, the new furanolipid 2, and three known Marine natural products continue to be an invaluable source of new molecular-targeted antitumor agents. 1 An ongoing research program was initiated to discover potent and selective small molecule inhibitors of hypoxia-mediated tumor cell adaptation, survival and metastatic spread. 2 The primary molecular target for this drug discovery effort is the transcription factor hypoxia-inducible factor-1 (HIF-1), a heterodimer composed of the oxygen-regulated HIF-1α and the constitutively expressed HIF-1β subunits. 3 Numerous studies strongly support HIF-1 as a valid molecular target for drug discovery that targets tumor hypoxia. 4 Terrestrial and marine organisms have been shown to produce natural products that inhibit HIF-1. 5 The NCI Open Repository of marine invertebrates and algae lipid extracts was examined for HIF-1 inhibitory activity using a T47D human breast carcinoma cell-based reporter assay. 2 The crude extract of the sponge Lendenfeldia sp. (Spongiidae) inhibited hypoxia-induced HIF-1 activation (99% inhibition at 5 μg mL -1 ).The extract (4 g) was purified by silica gel column chromatography and preparative TLC to yield two structurally unrelated new compounds (1 and 2) and three known homoscalarane sesterterpenes (3 -5). The 1 H-13 C HMBC spectrum of 1 exhibited long-range correlations from C-2 to H-3, H-4, C-2-OCH 3 ; from C-1 to H-3, H-8; from C-5 to H-4, H-7; from C-9 to H-4, H-7, H-8; and from C-10 to H-3, H-4, and H-8. Therefore, the substitution pattern for each of the symmetrically substituted naphthalene ring systems was readily established. Compound 1 was optically active ([α] 25 D +10.4). The CD spectrum displayed a positive split Cotton effect indicating that 1 exhibits a right-handed helicity, signifying "S"-configuration. Thus, the structure of 1 was determined to be (S)-2,2′-dimethoxy-1,1′-binaphthyl-5,5′,6,6′-tetraol.Compound 2 was isolated as colorless oil. The HRESIMS indicated that the molecular formula of 2 is C 21 H 34 O. The 1 H NMR spectrum (Table 2) exhibited resonances typical of a β-substituted furan [δ 7.33 (1H, brs), 7.20 (1H, brs), 6.27 (1H, brs)]. The 13 C NMR spectrum (Table 2) contained resonances for 21 carbons, and the 13 C DEPT spectrum indicated the presence of three methyl, ten methylene, five methane, and three quaternary carbon atoms. Analysis of the 1 H-1 H COSY and 1 H-13 C HMQC spectra suggested that the structure of 2 contained four spin systems: -CH(1)-CH(2)-, -CH 2 (5)-CH 2 (6)-CH (7) H spin systems were connected through the observation of longrange 1 H-13 C correlations in the HMBC spectrum from C-3 to H-1, H-2, H-4, H-5, H-6; from C-8 to H-6, H-7, H-9, H-10, H-20; and from C-12 to H-10, H-11, H-13, H-14, H-21. Therefore, the structure was deduced to be that of a new furanolipid.The ...

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confidence: 99%

Cytotoxic Metabolites from an Indonesian Sponge Lendenfeldia sp.

et al. 2007

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“…From this search, seven compounds were extracted possessing the relevant structure suitable for comparative purposes [26][27][28][29][30][31]. Of these seven compounds, six possessed an s-trans configuration [26][27][28][29][30] while the seventh had an s-cis configuration [31]. The latter enone which was the enol form ofa 1,3-diketone, was locked in the s-cis conformation by an internal hydrogen bond and was thus excluded from this analysis.…”

Section: Resultsmentioning

confidence: 99%

Conformational studies on (+)-anatoxin-a and derivatives

Thompson

Manallack

Blaney

et al. 1992

J Computer-Aided Mol Des

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Anatoxin-a (AnTX) is a highly potent agonist acting at the nicotinic acetylcholine receptor (nAChR) and represents a valuable tool in the study of this receptor. Molecular mechanics, semi-empirical and ab initio molecular orbital energy minimization procedures were conducted to investigate the conformation of AnTX. For each minimization procedure, the s-trans enone isomer of protonated AnTX was the energetically favoured conformer due to intramolecular electrostatic interactions. Our studies are discussed in the light of previous experimental observations and conformational studies, in addition to their importance in the development of future pharmacophore models for nAChR agonist binding.

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“…PHC-1-PHC-7 have been isolated from the marine sponge of Phyllospongia chondrodes, which was collected at Yaeyama Islands, Okinawa, Japan in 1993. PHC-1-PHC-5 were identified with the authentic samples (8,9,10) Cell lines. Human chronic myelogenous leukemia cell line K562 was supplied from the RIKEN Cell Bank.…”

Section: Methodsmentioning

confidence: 99%