Wolkenstein, Klaus

[["dc.bibliographiccitation.artnumber","e0223552"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","PLoS One"],["dc.bibliographiccitation.volume","14"],["dc.contributor.author","Affenzeller, Susanne"],["dc.contributor.author","Frauendorf, Holm"],["dc.contributor.author","Licha, Tobias"],["dc.contributor.author","Jackson, Daniel J."],["dc.contributor.author","Wolkenstein, Klaus"],["dc.date.accessioned","2020-08-04T08:32:28Z"],["dc.date.available","2020-08-04T08:32:28Z"],["dc.date.issued","2019"],["dc.description.abstract","Eumelanin and pheomelanin are well known and common pigments found in nature. However, their complex polymer structure and high thermostability complicate their direct chemical identification. A widely used analytical method is indirect determination using HPLC with UV detection of both types of melanin by their most abundant oxidation products: pyrrole-2,3-dicarboxylic acid (PDCA), pyrrole-2,3,5-tricarboxylic acid (PTCA), thiazole-4,5-dicarboxylic acid (TDCA), and thiazole-2,4,5-tricarboxylic acid (TTCA). An increasing interest in pigmentation in biological research led us to develop a highly sensitive and selective method to identify and quantify these melanin markers in diverse biological samples with complex matrices. By introducing solid-phase extraction (SPE, reversed-phase) following alkaline oxidation we could significantly decrease background signals while maintaining recoveries greater than 70%. Our HPLC-UV-MS method allows for confident peak identification via exact mass information in corresponding UV signals used for quantitation. In addition to synthetic melanin and Sepia officinalis ink as reference compounds eumelanin markers were detected in brown human hair and a brown bivalve shell (Mytilus edulis). Brown feathers from the common chicken (Gallus g. domesticus) yielded all four eumelanin and pheomelanin markers. The present method can be easily adapted for a wide range of future studies on biological samples with unknown melanin content."],["dc.identifier.doi","10.1371/journal.pone.0223552"],["dc.identifier.pmid","31622353"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16606"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/67513"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1932-6203"],["dc.relation.orgunit","Abteilung Geobiologie"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Quantitation of eumelanin and pheomelanin markers in diverse biological samples by HPLC-UV-MS following solid-phase extraction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e12625"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Palaeontology"],["dc.bibliographiccitation.volume","65"],["dc.contributor.affiliation","Wolkenstein, Klaus; 1\r\nDepartment of Geobiology, Geoscience Centre\r\nUniversity of Göttingen\r\nGoldschmidtstraße 3 37077 Göttingen Germany"],["dc.contributor.author","Wolkenstein, Klaus"],["dc.contributor.editor","Hautmann, Michael"],["dc.date.accessioned","2022-12-01T08:31:14Z"],["dc.date.available","2022-12-01T08:31:14Z"],["dc.date.issued","2022"],["dc.date.updated","2022-11-27T10:10:55Z"],["dc.description.abstract","Abstract\r\nUV light‐induced fluorescence is widely used as a key to reveal residual shell colour patterns of Neogene and Palaeogene molluscs. However, only few examples of fluorescent colour patterns are known from Mesozoic marine shells and little is known about the nature of fluorescence in fossils. Here, UV light‐induced fluorescence reveals previously unseen abundance and diversity in the colour patterns of the basal pectinid Pleuronectites laevigatus from the Middle Triassic Muschelkalk of Central Europe. In addition to known variations of radial bands, a multitude of zigzag and zigzag‐related patterns was found. The diversity of colour patterns is comparable to modern pectinids and is interpreted as colour pattern polymorphism. Raman spectra of the colour patterns indicated the preservation of residual organic pigments with aromatic moieties. The fluorescence properties of P. laevigatus and other basal pectinids from the Muschelkalk of Germany and France are described in detail, suggesting that colour pattern fluorescence is due to colourless diagenetic products of the pigments, not to the fossil pigments themselves. A remarkable feature of the colour patterns of P. laevigatus is the presence of different fluorescence colours. Because a gradual shift of the fluorescence colour from yellow to red with decreasing intensity to finally non‐fluorescent is observed, which correlates with the provenance of the specimens, the fluorescence properties are interpreted to reflect differences in diagenetic history. The results show that the fluorescence colour of fossil molluscs, especially of Mesozoic molluscs, may be affected by diagenesis and should only be used with caution for taxonomic purposes."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659"],["dc.identifier.doi","10.1111/pala.12625"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/118116"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-621"],["dc.relation.eissn","1475-4983"],["dc.relation.issn","0031-0239"],["dc.relation.orgunit","Abteilung Geobiologie"],["dc.rights","This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited."],["dc.title","Fluorescent colour patterns in the basal pectinid\r\n Pleuronectites\r\n from the Middle Triassic of Central Europe: origin, fate and taxonomic implications of fluorescence"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","476"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Nature Communications"],["dc.bibliographiccitation.volume","10"],["dc.contributor.author","van Maldegem, Lennart M."],["dc.contributor.author","Sansjofre, Pierre"],["dc.contributor.author","Weijers, Johan W. H."],["dc.contributor.author","Wolkenstein, Klaus"],["dc.contributor.author","Strother, Paul K."],["dc.contributor.author","Wörmer, Lars"],["dc.contributor.author","Hefter, Jens"],["dc.contributor.author","Nettersheim, Benjamin J."],["dc.contributor.author","Hoshino, Yosuke"],["dc.contributor.author","Schouten, Stefan"],["dc.contributor.author","Sinninghe Damsté, Jaap S."],["dc.contributor.author","Nath, Nilamoni"],["dc.contributor.author","Griesinger, Christian"],["dc.contributor.author","Kuznetsov, Nikolay B."],["dc.contributor.author","Elie, Marcel"],["dc.contributor.author","Elvert, Marcus"],["dc.contributor.author","Tegelaar, Erik"],["dc.contributor.author","Gleixner, Gerd"],["dc.contributor.author","Hallmann, Christian"],["dc.date.accessioned","2019-07-09T11:51:05Z"],["dc.date.available","2019-07-09T11:51:05Z"],["dc.date.issued","2019"],["dc.description.abstract","Eukaryotic algae rose to ecological relevance after the Neoproterozoic Snowball Earth glaciations, but the causes for this consequential evolutionary transition remain enigmatic. Cap carbonates were globally deposited directly after these glaciations, but they are usually organic barren or thermally overprinted. Here we show that uniquely-preserved cap dolostones of the Araras Group contain exceptional abundances of a newly identified biomarker: 25,28-bisnorgammacerane. Its secular occurrence, carbon isotope systematics and co-occurrence with other demethylated terpenoids suggest a mechanistic connection to extensive microbial degradation of ciliate-derived biomass in bacterially dominated ecosystems. Declining 25,28-bisnorgammacerane concentrations, and a parallel rise of steranes over hopanes, indicate the transition from a bacterial to eukaryotic dominated ecosystem after the Marinoan deglaciation. Nutrient levels already increased during the Cryogenian and were a prerequisite, but not the ultimate driver for the algal rise. Intense predatory pressure by bacterivorous protists may have irrevocably cleared self-sustaining cyanobacterial ecosystems, thereby creating the ecological opportunity that allowed for the persistent rise of eukaryotic algae to global importance."],["dc.identifier.doi","10.1038/s41467-019-08306-x"],["dc.identifier.pmid","30696819"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16045"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59872"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.orgunit","Abteilung Geobiologie"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.subject.ddc","550"],["dc.title","Bisnorgammacerane traces predatory pressure and the persistent rise of algal ecosystems after Snowball Earth"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","103892"],["dc.bibliographiccitation.journal","Organic Geochemistry"],["dc.bibliographiccitation.volume","136"],["dc.contributor.author","Wolkenstein, Klaus"],["dc.date.accessioned","2020-08-04T08:42:12Z"],["dc.date.available","2020-08-04T08:42:12Z"],["dc.date.issued","2019"],["dc.description.abstract","The distribution and origin of diagenetic products of polycyclic quinone pigments in fossil crinoids was investigated using high-performance liquid chromatography–diode array detection–atmospheric pressure photoionization mass spectrometry (HPLC–DAD–APPI-MS). A number of characteristic higher-molecular-weight polycyclic aromatic hydrocarbons (PAHs) were identified in toluene extracts of diverse crinoid samples, with 1,2,3,4,5,6-hexahydrophenanthro[1,10,9,8-opqra]perylene as the main compound. Moreover, phenanthro[1,10,9,8-opqra]perylene-7,14-dione (PPQ) and further derivatives were detected for the first time in the fossil record, representing intermediates between hydroxylated phenanthroperylene quinone pigments such as fringelite F and phenanthroperylene PAHs. The widespread presence of PPQ, its derivatives and related PAHs in fossil crinoids which contain phenanthroperylene quinone pigments confirms the diagenetic formation of specific PAHs by reductive degradation of quinone pigments."],["dc.identifier.doi","10.1016/j.orggeochem.2019.07.001"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16471"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/67515"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","0146-6380"],["dc.relation.orgunit","Abteilung Geobiologie"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Characterization of polycyclic aromatic hydrocarbons and their phenanthroperylene quinone precursors in fossil crinoids using liquid chromatography–atmospheric pressure photoionization mass spectrometry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","47"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Frontiers in Zoology"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Affenzeller, Susanne"],["dc.contributor.author","Wolkenstein, Klaus"],["dc.contributor.author","Frauendorf, Holm"],["dc.contributor.author","Jackson, Daniel J."],["dc.date.accessioned","2020-08-04T07:39:30Z"],["dc.date.available","2020-08-04T07:39:30Z"],["dc.date.issued","2019"],["dc.description.abstract","The geometric patterns that adorn the shells of many phylogenetically disparate molluscan species are comprised of pigments that span the visible spectrum. Although early chemical studies implicated melanin as a commonly employed pigment, surprisingly little evidence generated with more recent and sensitive techniques exists to support these observations."],["dc.identifier.doi","10.1186/s12983-019-0346-5"],["dc.identifier.pmid","31889966"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/17046"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/67512"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1742-9994"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0/"],["dc.title","Eumelanin and pheomelanin pigmentation in mollusc shells may be less common than expected: insights from mass spectrometry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","445"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Marine Drugs"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Vemulapalli, Sahithya Phani Babu"],["dc.contributor.author","Fuentes-Monteverde, Juan Carlos"],["dc.contributor.author","Karschin, Niels"],["dc.contributor.author","Oji, Tatsuo"],["dc.contributor.author","Griesinger, Christian"],["dc.contributor.author","Wolkenstein, Klaus"],["dc.date.accessioned","2021-10-01T09:58:28Z"],["dc.date.available","2021-10-01T09:58:28Z"],["dc.date.issued","2021"],["dc.description.abstract","Two new water-soluble phenanthroperylene quinones, gymnochrome H (2) and monosulfated gymnochrome A (3), as well as the known compounds gymnochrome A (4) and monosulfated gymnochrome D (5) were isolated from the deep-sea crinoid Hypalocrinus naresianus, which had been collected in the deep sea of Japan. The structures of the compounds were elucidated by spectroscopic analysis including HRMS, 1D 1H and 13C NMR, and 2D NMR. The absolute configuration was determined by ECD spectroscopy, analysis of J-couplings and ROE contacts, and DFT calculations. The configuration of the axial chirality of all isolated phenanthroperylene quinones (2–5) was determined to be (P). For gymnochrome H (2) and monosulfated gymnochrome A (3), a (2′S,2″R) configuration was determined, whereas for monosulfated gymnochrome D (5) a (2′R,2″R), configuration was determined. Acetylated quinones are unusual among natural products from an echinoderm and gymnochrome H (2) together with the recently reported gymnochrome G (1) represent the first isolated acetylated phenanthroperylene quinones."],["dc.description.abstract","Two new water-soluble phenanthroperylene quinones, gymnochrome H (2) and monosulfated gymnochrome A (3), as well as the known compounds gymnochrome A (4) and monosulfated gymnochrome D (5) were isolated from the deep-sea crinoid Hypalocrinus naresianus, which had been collected in the deep sea of Japan. The structures of the compounds were elucidated by spectroscopic analysis including HRMS, 1D 1H and 13C NMR, and 2D NMR. The absolute configuration was determined by ECD spectroscopy, analysis of J-couplings and ROE contacts, and DFT calculations. The configuration of the axial chirality of all isolated phenanthroperylene quinones (2–5) was determined to be (P). For gymnochrome H (2) and monosulfated gymnochrome A (3), a (2′S,2″R) configuration was determined, whereas for monosulfated gymnochrome D (5) a (2′R,2″R), configuration was determined. Acetylated quinones are unusual among natural products from an echinoderm and gymnochrome H (2) together with the recently reported gymnochrome G (1) represent the first isolated acetylated phenanthroperylene quinones."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft"],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft-CAPES Collaborative Research Initiative"],["dc.identifier.doi","10.3390/md19080445"],["dc.identifier.pii","md19080445"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/90069"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-469"],["dc.publisher","MDPI"],["dc.relation.eissn","1660-3397"],["dc.relation.orgunit","Abteilung Geobiologie"],["dc.rights","https://creativecommons.org/licenses/by/4.0/"],["dc.title","Structure and Absolute Configuration of Phenanthro-perylene Quinone Pigments from the Deep-Sea Crinoid Hypalocrinus naresianus"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]