TY - JOUR A1 - Bringmann, Gerhard A1 - Zagst, Rainer A1 - Schöner, Bernd A1 - Busse, Holger A1 - Hemmerling, Martin A1 - Burschka, Christian T1 - Acetogenic Isoquinoline Alkaloids. XXIII. Structure of the Naphthyl Isoquinoline Alkaloid Dioncophylline A N2 - No abstract available KW - Chemie Y1 - 1991 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31331 ER - TY - CHAP A1 - Burschka, Christian A1 - Bringmann, Gerhard A1 - Busse, Holger A1 - Guessregen, Stefan A1 - Schoener, Bernd A1 - Zagst, Rainer T1 - Structure and dynamics of free and metallated benzonaphthopyranones and -pyrans N2 - First calculations of the structures of metal-free and complexed biaryl lactones and their confrrmation by X-ray crystaIlography, the search for the transition states of their heIimerization processes, and the spectroscopic determination of the heIimerization barriers of related cyclic ethers by DNMR are reported. Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46858 ER - TY - JOUR A1 - Bringmann, Gerhard A1 - Hartung, Thomas A1 - Goebel, Lothar A1 - Schupp, Olaf A1 - Ewers, Christian L. J. A1 - Schoener, Bernd A1 - Zagst, Rainer A1 - Peters, Karl A1 - Von Schnering, Hans Georg A1 - Burschka, Christian T1 - Novel concepts in directed biaryl synthesis, IX: Synthesis and structure of benzonaphthopyranones, useful bridged model precursors for stereoselective biaryl syntheses N2 - A practicable two-step procedure for the preparation of a series of lactone-type bridged biaryls 7 as favorable substrates for subsequent atropisomer-selective ring-opening reactions is described. Due to the efficiency of the coupling step, which tolerates even a telt·butyl group next to the biaryl axis and avoids problems of regioselectivity, a variety of differently substituted representatives is prepared. These cover a broad range of steric hindrance and thus molecular distortion. The structures are investigated mainly by NMR spectroscopy and X-ray diffraction, showing the lactones 7 to be helically distorted, depending on the size of the residues R. KW - Chemie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46635 ER - TY - JOUR A1 - Bringmann, Gerhard A1 - Ortmann, Thomas A1 - Zagst, Rainer A1 - Schoener, Bernd A1 - Assi, Laurent Ake A1 - Burschka, Christian T1 - +/- Dioncophyllacine A, a naphthylisoquinoline alkaloid with a 4-methoxy substituent from the leaves of Triphyophyllum peltatum N2 - The isolation and structure elucidation of rac-dioncophyllacine A from the leaves of Triphyophyllun peltatum, is described. Unlike all other naphthylisoquinoline alkaloids, this fully dehydrogenated representative has an additional methoxy group at C-4, the position of which is deduced from NOE results. Dioncophyllacine A has a 7,1' site of the biaryl axis, as in dioncophylline A. Its constitution is confirmed by an X-ray structure analysis, which shows that the crystalline form of this new alkaloid is racemic. KW - Dioncophyllaceae KW - Triphyophyllum peltaturn KW - Dioncophyllaceae leaves KW - (± )-dioncophyllacine A KW - naphthylisoquinoline alkaloids KW - structure elucidation Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31873 ER - TY - JOUR A1 - Pimentel-Elardo, Sheila M. A1 - Buback, Verena A1 - Gulder, Tobias A. M. A1 - Bugni, Tim S. A1 - Reppart, Jason A1 - Bringmann, Gerhard A1 - Ireland, Chris M. A1 - Schirmeister, Tanja A1 - Hentschel, Ute T1 - New Tetromycin Derivatives with Anti-Trypanosomal and Protease Inhibitory Activities JF - Marine drugs N2 - Four new tetromycin derivatives, tetromycins 1-4 and a previously known one, tetromycin B (5) were isolated from Streptomyces axinellae Pol001(T) cultivated from the Mediterranean sponge Axinella polypoides. Structures were assigned using extensive 1D and 2D NMR spectroscopy as well as HRESIMS analysis. The compounds were tested for antiparasitic activities against Leishmania major and Trypanosoma brucei, and for protease inhibition against several cysteine proteases such as falcipain, rhodesain, cathepsin L, cathepsin B, and viral proteases SARS-CoV M(pro), and PL(pro). The compounds showed antiparasitic activities against T. brucei and time-dependent inhibition of cathepsin L-like proteases with K(i) values in the low micromolar range. KW - cysteine protease KW - drugs KW - streptomyces KW - discovery KW - anti-trypanosomal KW - protease inhibition KW - Streptomyces axinellae KW - marine sponge KW - tetromycin Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-141171 VL - 9 IS - 10 ER - TY - JOUR A1 - Pimentel-Elardo, Sheila M. A1 - Buback, Verena A1 - Gulder, Tobias A. M. A1 - Bugni, Tim S. A1 - Reppart, Jason A1 - Bringmann, Gerhard A1 - Ireland, Chris M. A1 - Schirmeister, Tanja A1 - Hentschel, Ute T1 - New Tetromycin Derivatives with Anti-Trypanosomal and Protease Inhibitory Activities N2 - Four new tetromycin derivatives, tetromycins 1–4 and a previously known one, tetromycin B (5) were isolated from Streptomyces axinellae Pol001T cultivated from the Mediterranean sponge Axinella polypoides. Structures were assigned using extensive 1D and 2D NMR spectroscopy as well as HRESIMS analysis. The compounds were tested for antiparasitic activities against Leishmania major and Trypanosoma brucei, and for protease inhibition against several cysteine proteases such as falcipain, rhodesain, cathepsin L, cathepsin B, and viral proteases SARS-CoV Mpro, and PLpro. The compounds showed antiparasitic activities against T. brucei and time-dependent inhibition of cathepsin L-like proteases with Ki values in the low micromolar range. KW - Biologie KW - tetromycin KW - anti-trypanosomal KW - protease inhibition KW - Streptomyces axinellae KW - marine sponge Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75465 ER - TY - JOUR A1 - Messi, Bernadette Biloa A1 - Ndjoko-Ioset, Karine A1 - Hertlein-Amslinger, Barbara A1 - Lannang, Alain Meli A1 - Nkengfack, Augustin E. A1 - Wolfender, Jean-Luc A1 - Hostettmann, Kurt A1 - Bringmann, Gerhard T1 - Preussianone, a New Flavanone-Chromone Biflavonoid from Garcinia preussii Engl. JF - Molecules N2 - A new flavanone-chromone biflavonoid, preussianone (1), has been isolated from the leaves of Garcinia preussii, along with four known biflavonoids. The absolute stereostructures were elucidated by chemical, spectroscopic, and chiroptical methods. The biological properties of the new biflavonoid against several bacterial strains were evaluated. KW - multiflora KW - minimal inhibitory concentration KW - absolute configuration KW - circular dichroism KW - C-13 NMR KW - guttiferae KW - flavenoids KW - extractives KW - biflavanoids KW - livingstonei KW - high-temperature NMR KW - antibacterial activity KW - Garcinia biflavonoids Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130881 VL - 17 IS - 5 ER - TY - JOUR A1 - Jansen, Nils A1 - Ohlendorf, Birgit A1 - Erhard, Arlette A1 - Bruhn, Torsten A1 - Bringmann, Gerhard A1 - Imhoff, Johannes F. T1 - Helicusin E, Isochromophilone X and Isochromophilone XI: New Chloroazaphilones Produced by the Fungus Bartalinia robillardoides Strain LF550 JF - Marine Drugs N2 - Microbial studies of the Mediterranean sponge Tethya aurantium led to the isolation of the fungus Bartalinia robillardoides strain LF550. The strain produced a number of secondary metabolites belonging to the chloroazaphilones. This is the first report on the isolation of chloroazaphilones of a fungal strain belonging to the genus Bartalinia. Besides some known compounds (helicusin A (1) and deacetylsclerotiorin (2)), three new chloroazaphilones (helicusin E (3); isochromophilone X (4) and isochromophilone XI (5)) and one new pentaketide (bartanolide (6)) were isolated. The structure elucidations were based on spectroscopic analyses. All isolated compounds revealed different biological activity spectra against a test panel of four bacteria: three fungi; two tumor cell lines and two enzymes. KW - tethya aurantium KW - marine natural product KW - azaphilone KW - pentaketide KW - bartalinia robillardoides Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-129649 VL - 11 IS - 3 ER - TY - JOUR A1 - Brixner, Tobias A1 - Koch, Federico A1 - Kullmann, Martin A1 - Selig, Ulrike A1 - Nuernberger, Patrick A1 - Götz, Daniel C. G. A1 - Bringmann, Gerhard T1 - Coherent two-dimensional electronic spectroscopy in the Soret band of a chiral porphyrin dimer JF - New Journal of Physics N2 - Using coherent two-dimensional (2D) electronic spectroscopy in fully noncollinear geometry, we observe the excitonic coupling of β,β'-linked bis[tetraphenylporphyrinato-zinc(II)] on an ultrafast timescale in the excited state. The results for two states in the Soret band originating from an excitonic splitting are explained by population transfer with approximately 100 fs from the energetically higher to the lower excitonic state. This interpretation is consistent with exemplary calculations of 2D spectra for a model four-level system with coupling. KW - optics KW - quantum optics KW - laser Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96139 ER - TY - JOUR A1 - Wang, Hui A1 - Li, Min-Yi A1 - Katele, Félix Zongwe A1 - Satyanandamurty, Tirumani A1 - Wu, Jun A1 - Bringmann, Gerhard T1 - Decandrinin, an unprecedented \(C_9\)-spiro-fused 7,8-\( seco-ent\)-abietane from the Godavari mangrove \(Ceriops\ decandra\) JF - Beilstein Journal of Organic Chemistry N2 - Decandrinin (1), an unprecedented \(C_9\)-spiro-fused 7,8-\(seco-ent\)-abietane, was obtained from the bark of an Indian mangrove, \(Ceriops\ decandra\), collected in the estuary of Godavari, Andhra Pradesh. The constitution and the relative configuration of 1 were determined by HRMS (ESI) and extensive NMR investigations, and the absolute configuration by circular dichroism (CD) and optical-rotatory dispersion (ORD) spectroscopy in combination with quantum-chemical calculations. Decandrinin is the first 7,8-\(seco-ent\)-abietane. KW - ceriops decandra KW - abietane KW - absolute configuration KW - circular dichroism KW - decandrinin KW - rhizophoraceae Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119983 SN - 1860-5397 VL - 10 ER -