Ancistroguineines A and B as well as ancistrotectorine-naphthylisoquinoline alkaloids from Ancistrocladus guineënsis

Bringmann, Gerhard; Günther, Christian; Busemann, S.; Schäffer, Manuela; Olowokudejo, J. D.; Alo, Babajide I.

doi:10.1016/s0031-9422(97)00511-6

Cited by 29 publications

(34 citation statements)

References 17 publications

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“…[16][17][18][19] Semiempirical conformational analyses (PM3 parametrization) to obtain all relevant conformers for the calculation of the chiroptical properties were performed starting with the (S)-configured enantiomers.…”

Section: Resultsmentioning

confidence: 99%

Anthraquinones and Betaenone Derivatives from the Sponge-Associated Fungus Microsphaeropsis Species: Novel Inhibitors of Protein Kinases

et al. 2000

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An undescribed fungus of the genus Microsphaeropsis, isolated from the Mediterranean sponge Aplysina aerophoba, produces two new betaenone derivatives (1, 2) and three new 1,3,6, 8-tetrahydroxyanthraquinone congeners (5-7). The structures of the compounds were established on the basis of NMR spectroscopic and mass spectrometric data and by CD spectroscopy. This is the first report wherein the (1)H and (13)C NMR data of the betaenone congeners are fully and unambiguously assigned on the basis of two-dimensional NMR spectroscopy. Furthermore, we describe the first elucidation of the absolute configuration of 1-(2'-anthraquinonyl)ethanols such as 5 and 6, by quantum chemical calculation of their circular dichroism (CD) and comparison with experimentally measured spectra. Moreover, it was shown that compounds 1, 5, 6, and 7 are inhibitors of PKC-epsilon, CDK4, and EGF receptor tyrosine kinases.

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Section: Resultsmentioning

confidence: 99%

Anthraquinones and Betaenone Derivatives from the Sponge-Associated Fungus Microsphaeropsis Species: Novel Inhibitors of Protein Kinases

et al. 2000

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“…Therefore, we chose the semiempirical method CNDO/S, [30] which, as shown in the successful application to similar problems, is well suited to the calculation of πǞπ* transitions of compounds with a large system of conjugated double bonds. [20,22,31] As a consequence, the wavelength range from 200 to 300 nm, which is mainly dominated by πǞπ* transitions in the case of 2 and 3, is decisive for the attribution of their absolute configurations. This assumption was supported by the assignment of UV bands observed experimentally in this region to the πǞπ* type of compounds that have similar chromophores as 2 or 3 (e.g.…”

Section: Calculationsmentioning

confidence: 99%

Determination of the Absolute Configurations of γ-Rubromycin and Related Spiro Compounds by Quantum Chemical CD Calculations

et al. 2000

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The absolute configurations of the spiro compounds γ-and β-rubromycin (2 and 3), natural antibiotics derived from actinomycetes, have been elucidated as (S) by quantum chemical calculations of their chiroptical properties and comparisons with the respective experimental CD spectra. Surprisingly, their spiro centers show an absolute configuration opposite to that of heliquinomycin (1), the only related spiro compound for which the configuration has hitherto been as-

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“…44 This alkaloid has also recently been isolated from the leaves of Ancistrocladus guineensis. 45 Ancistrotectorine 1.100 exhibited a similar IH NMR spectrum to that of ancistrocladidine 1.99, apart from the appearance and position of the Cl-methy1 group, and an N-Me singlet at () 2.48.…”

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confidence: 88%

Total Synthesis of the 7,3‘-Linked Naphthylisoquinoline Alkaloid Ancistrocladidine

Bungard

Morris

2006

J. Org. Chem.

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The first total synthesis of ancistrocladidine, a rare 7,3‘-linked naphthylisoquinoline alkaloid, has been completed, with the key feature of the synthesis being the formation of the extremely hindered biaryl linkage by ortho-arylation of a naphthol with an aryllead triacetate. Initial efforts were focused on the generation of a heteroaryl lead species, which would have allowed a convergent synthesis to be developed. However, it was not possible to generate such a lead species. A simpler aryl lead triacetate was prepared and reacted. The resulting biaryl aldehyde was elaborated in 10 steps to form a 1:1 mixture of ancistrocladidine and its atropisomer. Recrystallization of the mixture afforded ancistrocladidine, which was identical in all respects to the reported data.

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Ancistroguineines A and B as well as ancistrotectorine-naphthylisoquinoline alkaloids from Ancistrocladus guineënsis

Cited by 29 publications

References 17 publications

Anthraquinones and Betaenone Derivatives from the Sponge-Associated Fungus Microsphaeropsis Species: Novel Inhibitors of Protein Kinases

Anthraquinones and Betaenone Derivatives from the Sponge-Associated Fungus Microsphaeropsis Species: Novel Inhibitors of Protein Kinases

Determination of the Absolute Configurations of γ-Rubromycin and Related Spiro Compounds by Quantum Chemical CD Calculations

Total Synthesis of the 7,3‘-Linked Naphthylisoquinoline Alkaloid Ancistrocladidine

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