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  • 1
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 130 (1981), S. 223-227 
    ISSN: 1432-072X
    Schlagwort(e): Antibiotics ; Basidiomycetes ; Pleurotellus hypnophilus ; Galerina cephalotricha ; Hypnophilin ; Pleurotellol ; Pleurotellic acid ; Complicatic acid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Three new antibiotically active metabolites were isolated from cultures of the fungus Pleurotellus hypnophilus. The structures which are closely related to the coriolins were elucidated by spectroscopic methods. Hypnophilin (1) has a hirsutane sceleton whereas pleurotellol (2) and pleurotellic acid (3) are sesquiterpenoids with novel hirsutane skeletons. The common structural feature of all three metabolites is an α-methylene ketone moiety. The antibiotics inhibited the growth of several bacteria as well as of some fungi. In cells of the ascitic form of Ehrlich carcinoma RNA and DNA syntheses were more affected than protein synthesis. The mode of action was compared with the antimicrobial and cytotoxic effects of complicatic acid (4) and other α-methylene ketones and lactones from higher plants. All the compounds tested reacted rapidly with cysteine to form adducts which were almost devoid of biological activity.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 1432-1955
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Natural and synthetic anthranoid compounds were subjected to an evaluation against asexual erythrocytic stages of the human malaria parasite Plasmodium falciparum in vitro. Stimulated by the good activities of Vismia guineënsis extracts, a more detailed investigation of the active principles revealed the prenylated preanthraquinone vismione H (1) to be a potent antimalarial [50% growth-inhibitory concentration (IC50) 0.088 μg/ml]. On the basis of this finding a series of chemically related phlegmacins (2–5), flavomannins (6–8), and rufoolivacins (9–11) isolated from several species of Cortinarius, a genus of higher fungi, and 5 synthetic vismione-like anthranoids (12–16) were evaluated as well. Although these compounds displayed weaker antiplasmodial effects than did vismione H (1) itself, considerable levels of activity were obtained with phlegmacin B1 (2), flavomannin-6,6′-di-O-methyl ether A1 (6), trans-4-hydroxy-flavomannin-6,6′-di-O-methyl ether A (8), and rufoolivacin B (10). Initial preconditions for activity within the vismiones and related anthranoids were established.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Chemistry - A European Journal 3 (1997), S. 1254-1268 
    ISSN: 0947-6539
    Schlagwort(e): peptide bundles ; peptides ; pseudo-peptides ; template synthesis ; tripodal ligands ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The stereochemical course of the formation of the two diastereomers of trimethyl 2,2′,2″-nitrilotris[2-(benzoylamino)acetate], 2a and 2b, is described. The structures of both isomers were confirmed by X-ray diffraction studies. Diastereomer 2b could be obtained in larger quantities by epimerisation of 2 a to 2 b with catalytical amounts of NaOMe. The (RRR/SSS)-triester 2 b is a suitable template for the synthesis of tripodal peptide bundles. Saponification of 2 b yielded the C3-symmetrical racemic triacid 4 b, which was coupled with amino acid methyl esters and dipeptide esters to give pseudo-hexapeptides and pseudo-nonapeptides, respectively. The resulting mixtures of diastereomers were easily separated by crystallisation. Their absolute configuration at the template unit (RRR or SSS) was established by means of the CD spectra. The pseudo-hexapeptide (SSS)N(BzGly*ValOMe)3 (14) was saponified to yield the optically pure triacid (SSS)N(BzGly*ValOH)3 (23). Compound 23 is an ideally preorganised template for the production of longer tripodal peptides. This was illustrated by the synthesis of two pseudo-pentadecapeptides. Peptide bundles with polar side chains (histidine and serine) or end groups (catechol or hydroxamate units) were synthesised by using the templates 4 b, 22 and 23 as anchors.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
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  • 4
    ISSN: 0951-4198
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Physik
    Notizen: The application of Fourier-transform laser microprobe mass spectrometry to lichens is described. The in situ detection of a new perylene quinone in samples of the tropical species Laurera sanguinaria Malme and Graphis haematites Fée was achieved with minimal specimen preparation. The high mass resolution and mass accuracy of the instrument eliminates the need for additional characterization of the isolated substances by high resolution electron impact mass spectrometry and direct introduction probe.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 5
    ISSN: 0947-6539
    Schlagwort(e): alkaloids ; Heck reactions ; heterocycles ; indoles ; total syntheses ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Arcyriacyanin A (1) has been synthesized by three different routes. In the first synthesis the bisbromomagnesium salt of 2,4′-biindole (5) was treated with dibromomaleimide (6) to yield arcyriacyanin A (1). The second approach used an intramolecular Heck reaction for the cyclization of a 4-(triflyloxy)arcyriarubin 8 to N-methylarcyriacyanin A (2). Thirdly, compound 2 was obtained by a domino Heck reaction between 3-bromo-4-[1-(tert-butoxycarbonyl)indol-3-yl]-1-methylmaleimide (9) and 4-bromoindole (10). The N-methyl derivative 2 could be transformed into arcyriacyanin A (1) by standard methods.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    ISSN: 1434-193X
    Schlagwort(e): Macrocystidia cucumis ; Cucumins ; Hirsutanes ; Sesquiterpenoids ; Antibiotics ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Arthrosporone (1) and eight new triquinane-type sesquiterpenoids have been isolated from mycelial cultures of the agaric Macrocystidia cucumis. The cucumins A-D (2, 4-6) are highly unsaturated hirsutane derivatives, whereas the cucumins E-G (7-9) represent a new type of linear triquinanes. Cucumin H (10) is a new member of the ceratopicane group. The absolute configuration of cucumin F (8) was assigned by 1H-NMR analysis of the corresponding Mosher esters. Two further metabolites were identified as cyclo(phenylalanylprolyl) (12) and cyclo(leucylprolyl) (13). Cucumin A (2) exhibits antibacterial and cytotoxic activities.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 255-260 
    ISSN: 1434-193X
    Schlagwort(e): Triterpenoids ; Sodagnitins ; Chromogens ; Toadstools ; Natural Products ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: -Fruit-bodies of the toadstools Cortinarius sodagnitus,C. fulvoincarnatus, C. arcuatorum(Agaricales) show a remarkable ink-red colour reaction when treated with aqueous base. We isolated six chromogens, named the sodagnitins A-F, from the toadstools and elucidated their structures by spectroscopic techniques. The sodagnitins are triterpenoids of the malabaricane type with a highly modified side chain. A mechanism for the colour reaction is proposed.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 1051-1055 
    ISSN: 1434-193X
    Schlagwort(e): Fungus ; Dihydroxybenzoic acids ; Benzoquinones ; Spirodiones ; Natural products ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: -Fruit bodies of the wood-rotting North American fungus Hapalopilusmutans produce a mixture of dihydroxybenzoic acids 1, dihydroxybenzoquinones 2 and a novel type of spirodiones, e.g. mutadione A (4a). All compounds carry long alkyl chains, which may be partially unsaturated. The structures of the metabolites were established by spectroscopic methods.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1434-193X
    Schlagwort(e): Benzopyranones ; (E)-2-Nonenal ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: ---The bright orange-red color of the toadstool Tricholoma aurantium is due to the benzotropolone pigment aurantricholone (1). The compound is at least partially present as the calcium salt. Minor pigments are the yellow 2H-furo[3,2-b]benzopyran-2-one derivatives aurantricholides A (7a) and B (7b), which exhibit strong green fluorescences. Their structures have been established by total syntheses.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1434-1948
    Schlagwort(e): 2-Phenyl-4-R-5(4H)-oxazolones ; Iridium ; Palladium ; Platinum ; Iron ; Chromium ; C-o,N-Bridging 2-phenyloxazolone ; Peptide labelling ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Reactions of 2-phenyl-4-R-5(4H)-oxazolones (R = Me, CH2Ph, CHMeEt) with [(η5-C5Me5)IrCl2]2 afforded the cyclometallated complexes (η5-C5Me5)(Cl)Ir(L) (1-3) [L = 2-phenyl-4-R-5(4H)-oxazolone(C-o,N)]. 2-Phenyl-5(4H)-oxazolone reacts with [(η5-C5Me5)IrCl2]2 and palladium(II) acetate to give complexes with a C-o,N-bridging oxazolone [(η5-C5Me5)(Cl)Ir]2(μ-Cl)(μ-L-H+) (4) and Pd3(μ-ac)5(μ-L-H+) (5). 2-Phenyloxazolone anions were added to the π ligands of [(η5-C6H7)Fe(CO)3]+ and [(η7-C7H7)Cr(CO)3]+ to give the adducts 6-11. Dipeptide derivatives 12-18 were obtained by reaction of 1, 2 and by reaction of the adduct 6 from [(η5-C6H7)Fe(CO)3]+; and the anion of 2-phenyloxazolone with α-amino acid esters. These reactions may be used for the labelling of peptides. Saponification of 15-18 yields the organometallic substituted peptide acids 19-22. Their dianions (deprotonation of COOH and peptide amide) were used as ligands towards (Ph3P)2PtCl2 to yield the bimetallic complexes 23-25. The structures of 4, 5, 9 and 10 were determined by X-ray diffraction.
    Materialart: Digitale Medien
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