Laatsch, Hartmut G.

[["dc.bibliographiccitation.firstpage","251"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Pineal Research"],["dc.bibliographiccitation.lastpage","260"],["dc.bibliographiccitation.volume","39"],["dc.contributor.author","Guenther, A. L."],["dc.contributor.author","Schmidt, S. I."],["dc.contributor.author","Laatsch, Hartmut"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Ness, H."],["dc.contributor.author","Ressmeyer, A. R."],["dc.contributor.author","Poeggeler, Burkhard"],["dc.contributor.author","Hardeland, Ruediger"],["dc.date.accessioned","2018-11-07T10:55:28Z"],["dc.date.available","2018-11-07T10:55:28Z"],["dc.date.issued","2005"],["dc.description.abstract","The melatonin metabolite N-1-acetyl-5-methoxykynuramine (AMK) was found to be unstable in air when adsorbed on a thin-layer silica gel chromatography plate, a result that is in good agreement with the relatively high reactivity of this compound. Three novel main products were separated from the reaction mixture and identified by mass spectrometry and nuclear magnetic resonance data as: (i) 3-acetamidomethyl-6-methoxycinnolinone (AMMC), (ii) 3-nitro-AMK (AMNK, N-1-acetyl-5-methoxy-3-nitrokynuramine), and (iii) N-[2-(6-methoxyquinazolin-4-yl)-ethyl]-acetamide (MQA). AMMC and AMNK are shown to be nonenzymatically formed also in solution, by nitric oxide (NO) in the first case, and by a mixture of peroxynitrite and hydrogen carbonate, in the second one. The use of three different NO donors, PAPA-NONOate, S-nitroso-N-acetylpenicillamine and sodium nitroprussiate led to essentially the same results, with regard to a highly preferential formation of AMMC; AMNK was not detected in these reaction systems. Competition experiments with the NO scavenger N-acetylcysteine indicate a somewhat lower reactivity compared with the competitor. Peroxynitrite led to AMNK formation in the presence of physiological concentrations of hydrogen carbonate at pH 7.4, but not in its absence, indicating that nitration involves a mixture of carbonate radicals and NO2, formed from the peroxynitrite-CO2 adduct. No AMMC was detected after AMK exposure to peroxynitrite. Both AMNK and AMMC exhibited a much lower reactivity toward 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) cation radicals than did AMK. In a competition assay for hydroxyl radicals, AMMC showed prooxidant properties, whereas AMNK was a moderate antioxidant. AMMC and AMNK should represent relatively stable physiological products, although their rates of synthesis are still unknown and may be low. Formation of these compounds may contribute to the disappearance of AMK from tissues and body fluids."],["dc.identifier.doi","10.1111/j.1600-079X.2005.00242.x"],["dc.identifier.isi","000231621600006"],["dc.identifier.pmid","16150105"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49793"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1600-079X"],["dc.relation.issn","0742-3098"],["dc.title","Reactions of the melatonin metabolite AMK (N-1-acetyl-5-methoxykynuramine) with reactive nitrogen species: Formation of novel compounds, 3-acetamidomethyl-6-methoxycinnolinone and 3-nitro-AMK"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3"],["dc.bibliographiccitation.lastpage","74"],["dc.contributor.author","Laatsch, Hartmut"],["dc.contributor.author","Fotso, Serge"],["dc.date.accessioned","2018-11-07T11:19:24Z"],["dc.date.available","2018-11-07T11:19:24Z"],["dc.date.issued","2008"],["dc.description.abstract","The present article gives an overview of the natural occurring anthracyclines and anthracyclinones reported from microorganisms. A general description, discussion of their physicochemical properties, including NMR increments, and their structural classification are reported. In addition to a compilation of their sugar moieties, an exhaustive list of naturally occurring anthracyclines and anthracyclinones has been added."],["dc.identifier.doi","10.1007/128_2008_5"],["dc.identifier.isi","000258827500001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55266"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.publisher.place","Berlin"],["dc.relation.isbn","978-3-540-75814-3"],["dc.relation.ispartof","ANTHRACYCLINE CHEMISTRY AND BIOLOGY I: BIOLOGICAL OCCURENCE AND BIOSYNTHESIS, SYNTHESIS AND CHEMISTRY: BIOLOGICAL OCCURENCE AND BIOSYNTHESIS, SYNTHESIS AND CHEMISTRY"],["dc.relation.ispartofseries","Topics in Current Chemistry; 282"],["dc.title","Naturally occurring anthracyclines"],["dc.type","book_chapter"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1129"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Natural Product Research"],["dc.bibliographiccitation.lastpage","1135"],["dc.bibliographiccitation.volume","20"],["dc.contributor.author","Jin, Yulan"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Yongtang, Z."],["dc.contributor.author","Sevvana, Madhumati"],["dc.contributor.author","Laatsch, Hartmut"],["dc.contributor.author","Zhang, W."],["dc.date.accessioned","2018-11-07T09:12:05Z"],["dc.date.available","2018-11-07T09:12:05Z"],["dc.date.issued","2006"],["dc.description.abstract","A new sulfur-containing guanidino derivative, halichondria sulfonic acid (1) showing anti-HIV-1 activity, and halistanol trisulfate (2) with anti-tumor activity have been isolated from the marine sponge Halichondria rugosa Ridley & Dendy collected in the Chinese Southern Sea. The structure of 1 was elucidated by analysis of spectroscopic and crystal data."],["dc.identifier.doi","10.1080/14786410600879748"],["dc.identifier.isi","000242898600016"],["dc.identifier.pmid","17127667"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26868"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Taylor & Francis Ltd"],["dc.relation.issn","1478-6419"],["dc.title","Halichondria sulfonic acid, a new HIV-1 inhibitory guanidino-sulflonic acid, and halistanol sulfate isolated from the marine sponge Halichondria rugosa Ridley & Dendy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","27"],["dc.bibliographiccitation.journal","ChemInform"],["dc.bibliographiccitation.volume","36"],["dc.contributor.author","Than, Ni Ni"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Sevvana, Madhumati"],["dc.contributor.author","Sheldrick, George M."],["dc.contributor.author","Fiebig, Heinz H."],["dc.contributor.author","Kelter, Gerhard"],["dc.contributor.author","Laatsch, Hartmut"],["dc.date.accessioned","2021-12-08T12:29:22Z"],["dc.date.available","2021-12-08T12:29:22Z"],["dc.date.issued","2005"],["dc.identifier.doi","10.1002/chin.200527176"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/96053"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-476"],["dc.relation.eissn","1522-2667"],["dc.relation.issn","0931-7597"],["dc.rights.uri","http://doi.wiley.com/10.1002/tdm_license_1.1"],["dc.title","Sesquiterpene Lactones from Elephantopus scaber."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","303"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","The Journal of Antibiotics"],["dc.bibliographiccitation.lastpage","308"],["dc.bibliographiccitation.volume","63"],["dc.contributor.author","Yao, Clarisse B. Fotso-Fondja"],["dc.contributor.author","Al Zereini, Wael"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Anke, Heidrun"],["dc.contributor.author","Laatsch, Hartmut"],["dc.date.accessioned","2018-11-07T08:42:47Z"],["dc.date.available","2018-11-07T08:42:47Z"],["dc.date.issued","2010"],["dc.description.abstract","The structures of secondary metabolites with antibacterial and cytotoxic activities produced by a marine Vibrio strain from the Red Sea were elucidated. Aqabamycin A (1a) and seven further nitro-substituted maleimide derivates named aqabamycins B-G (1b-f and 2) were obtained together with 12 known metabolites, 3-nitro-1H-indazole (3), indazole-3-carbaldehyde (4), 3-nitro-4-hydroxycinnamic acid, 4-hydroxycinnamic acid, 3-nitro-4-hydroxybenzaldehyde, phenyl-2-bis-indolylmethane (5a), turbomycin B (5b), vibrindole A (6), phenylacetic acid, 3-hydroxybenzoic acid, benzoic acid and 1,4-dithiane (7). Some of the known metabolites (for example, 3, 4 and 7) are described in this study for the first time as natural products. Their structures were elucidated based on 1D and 2D NMR, MS spectra and by comparison with synthetic material. The Journal of Antibiotics (2010) 63, 303-308; doi:10.1038/ja.2010.35; published online 30 April 2010"],["dc.description.sponsorship","German Ministry of Education and Research (BMBF) [03F0348A]"],["dc.identifier.doi","10.1038/ja.2010.35"],["dc.identifier.isi","000279418800005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19785"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Japan Antibiotics Research Assoc"],["dc.relation.issn","0021-8820"],["dc.title","Aqabamycins A-G: novel nitro maleimides from a marine Vibrio species: II. Structure elucidation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","304"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Journal of Natural Products"],["dc.bibliographiccitation.lastpage","306"],["dc.bibliographiccitation.volume","70"],["dc.contributor.author","Wu, Shao Jie"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Li, Fuchao"],["dc.contributor.author","Qin, Song"],["dc.contributor.author","Laatsch, Hartmut"],["dc.date.accessioned","2018-11-07T11:05:25Z"],["dc.date.available","2018-11-07T11:05:25Z"],["dc.date.issued","2007"],["dc.description.abstract","The chemical investigation of the crude extract of the marine-derived Streptomyces sp. M491 yielded three new sesquiterpenes, namely, 10 alpha,11-dihydroxyamorph-4-ene (4), 10 alpha,15-dihydroxyamorph-4-en-3-one (6), and 5 alpha,10 alpha,11-trihydroxyamorphan-3-one (7). In addition, the known compounds 10 alpha-hydroxyamorph-4-en-3-one (2), o-hydroxyacetanilide, genistein, prunetin, and indole-3-carbaldehyde and the macrolide antibiotic chalcomycin A were identified. The structures were determined on the basis of spectroscopic analysis, especially 1D and 2D NMR data. This is the first report of these sesquiterpenes from bacteria."],["dc.identifier.doi","10.1021/np050358e"],["dc.identifier.isi","000244390900029"],["dc.identifier.pmid","17315965"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52065"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0163-3864"],["dc.title","Amorphane sesquiterpenes from a marine Streptomyces sp."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","42"],["dc.bibliographiccitation.journal","ChemInform"],["dc.bibliographiccitation.volume","41"],["dc.contributor.author","Fotso Fondja Yao, Clarisse Blandine"],["dc.contributor.author","Al Zereini, Wael"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Anke, Heidrun"],["dc.contributor.author","Laatsch, Hartmut"],["dc.date.accessioned","2021-12-08T12:29:52Z"],["dc.date.available","2021-12-08T12:29:52Z"],["dc.date.issued","2010"],["dc.identifier.doi","10.1002/chin.201042218"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/96237"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-476"],["dc.relation.issn","0931-7597"],["dc.rights.uri","http://doi.wiley.com/10.1002/tdm_license_1.1"],["dc.title","ChemInform Abstract: Marine Bacteria. Part 42. Aqabamycins A-G: Novel Nitro Maleimides from a Marine Vibrio Species. Part 2. Structure Elucidation."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1242"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Zeitschrift für Naturforschung B"],["dc.bibliographiccitation.lastpage","1246"],["dc.bibliographiccitation.volume","58"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Maskey, Rajendra P."],["dc.contributor.author","Grun-Wollny, I."],["dc.contributor.author","Laatsch, Hartmut"],["dc.date.accessioned","2018-11-07T10:34:36Z"],["dc.date.available","2018-11-07T10:34:36Z"],["dc.date.issued","2003"],["dc.description.abstract","The red coloured ethyl acetate extract of the Streptomyces sp. isolate GW37/3236 delivered the two new antibiotics 13-O-acetyl-bisanhydro-13-dihydrodaunomycinone (3c) and 4,13-O-diacetyl-bisanhydro-4-O-demethyl-13-dihydrodaunomycinone (3d) and additionally several known compounds. The quinones 3c and 3d are the first naturally occurring quinone acetates. Their structures were derived by comparison of the NMR data with those of bisanhydro-13-dihydrodaunomycinone (3b) and by interpretation of the 2D NMR data accompanied by the molecular weight and formula. 2-Acetamido-3-hydroxybenzamide (5) was also isolated from the extract and was identified by comparison of the NMR data with those of 2-acetamidobenzamide and by 2D NMR correlations. 6,9,11 Trihydroxy-4-methoxy-5,12-naphthacenedione (4) is isolated for the first time as a natural product."],["dc.identifier.isi","000188214300015"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/44913"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Verlag Z Naturforsch"],["dc.relation.issn","0932-0776"],["dc.title","Isolation, structure elucidation and activity of anthracycline acetates from a terrestrial Streptomyces sp."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","736"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","The Journal of Antibiotics"],["dc.bibliographiccitation.lastpage","746"],["dc.bibliographiccitation.volume","61"],["dc.contributor.author","Shaaban, Khaled Attia"],["dc.contributor.author","Shaaban, Mohamed"],["dc.contributor.author","Facey, Petrea"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Frauendorf, Holm"],["dc.contributor.author","Helmke, Elisabeth"],["dc.contributor.author","Maier, Armin"],["dc.contributor.author","Fiebig, Heinz-Herbert"],["dc.contributor.author","Laatsch, Hartmut"],["dc.date.accessioned","2018-11-07T11:08:35Z"],["dc.date.available","2018-11-07T11:08:35Z"],["dc.date.issued","2008"],["dc.description.abstract","Chemical investigation of the marine-derived Streptomyces sp. Act8015 led to the isolation of two cyclic peptide antibiotics, piperazimycins A and B (1a, 1b). Their structures were confirmed on the basis of a detailed HRESI-MS/MS analysis. Additionally, a new butanolide, 4,10-dihydroxy-10-methyl-dodecan-4-olide (2), and the respective acid, 4,10-dihydroxy-10-methyl-dodecanoic acid (3a) were identified. Further isolated compounds were staurosporin, adenine, indole-3-carboxylic acid, ferulic acid, tryptophol, and three gamma-butyrolactones: virginiae butanolide E (4e) and Graefe's Factors I (4f) and III (4g). The structures of 2 and 3a were confirmed by detailed 1 D and 2D NMR studies and MS spectra and by comparison with related structures. A full signal assignment of virginiae butanolide E (4e) is reported here for the first time."],["dc.description.sponsorship","Alexander von Humboldt Foundation (AvH); BMBF [03F0415A]"],["dc.identifier.isi","000263144400003"],["dc.identifier.pmid","19194032"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/52819"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Japan Antibiotics Research Assoc"],["dc.relation.issn","0021-8820"],["dc.title","Electrospray Ionization Mass Spectra of Piperazimycins A and B and gamma-Butyrolactones from a Marine-derived Streptomyces sp."],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","629"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Zeitschrift für Naturforschung B"],["dc.bibliographiccitation.lastpage","634"],["dc.bibliographiccitation.volume","66"],["dc.contributor.author","Fotso, Serge"],["dc.contributor.author","Yao, Clarisse B. Fotso-Fondja"],["dc.contributor.author","Helmke, Elisabeth"],["dc.contributor.author","Laatsch, Hartmut"],["dc.date.accessioned","2018-11-07T08:55:12Z"],["dc.date.available","2018-11-07T08:55:12Z"],["dc.date.issued","2011"],["dc.description.abstract","In addition to luisol A (1a), luisol B (2), and aloesaponarin II, the marine streptomycete B7617 produced a new derivative of la, 2-hydroxy-luisol A (1b). In an attempt to increase the biological activity, luisol A (1a) was oxidized and delivered with Jones reagent or by Swern oxidation the derivatives 3a/3b and 4a/4b, respectively, but none of these compounds showed antimicrobial or cytotoxic activities. All structure elucidations are based on 2D NMR analyses or were derived by comparison with published data."],["dc.description.sponsorship","Bundesministerium fur Bildung und Forschung (BMBF) [03FO233A]"],["dc.identifier.isi","000294097700011"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22849"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Verlag Z Naturforsch"],["dc.relation.issn","0932-0776"],["dc.title","2-Hydroxy-luisol A, a New Quinone-derived Tetraol from a Marine Streptomyces sp and Oxidation Products of Luisol A"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]