@article{AltmannMutWolfetal.2021,
  author    = {Altmann, Stephan and Mut, J{\"u}rgen and Wolf, Natalia and Meißner-Weigl, Jutta and Rudert, Maximilian and Jakob, Franz and Gutmann, Marcus and L{\"u}hmann, Tessa and Seibel, J{\"u}rgen and Ebert, Regina},
  title     = {Metabolic glycoengineering in hMSC-TERT as a model for skeletal precursors by using modified azide/alkyne monosaccharides},
  series = {International Journal of Molecular Sciences},
  volume    = {22},
  journal   = {International Journal of Molecular Sciences},
  number    = {6},
  issn      = {1422-0067},
  doi       = {10.3390/ijms22062820},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259247},
  year      = {2021},
  abstract  = {Metabolic glycoengineering enables a directed modification of cell surfaces by introducing target molecules to surface proteins displaying new features. Biochemical pathways involving glycans differ in dependence on the cell type; therefore, this technique should be tailored for the best results. We characterized metabolic glycoengineering in telomerase-immortalized human mesenchymal stromal cells (hMSC-TERT) as a model for primary hMSC, to investigate its applicability in TERT-modified cell lines. The metabolic incorporation of N-azidoacetylmannosamine (Ac\(_4\)ManNAz) and N-alkyneacetylmannosamine (Ac\(_4\)ManNAl) into the glycocalyx as a first step in the glycoengineering process revealed no adverse effects on cell viability or gene expression, and the in vitro multipotency (osteogenic and adipogenic differentiation potential) was maintained under these adapted culture conditions. In the second step, glycoengineered cells were modified with fluorescent dyes using Cu-mediated click chemistry. In these analyses, the two mannose derivatives showed superior incorporation efficiencies compared to glucose and galactose isomers. In time-dependent experiments, the incorporation of Ac\(_4\)ManNAz was detectable for up to six days while Ac\(_4\)ManNAl-derived metabolites were absent after two days. Taken together, these findings demonstrate the successful metabolic glycoengineering of immortalized hMSC resulting in transient cell surface modifications, and thus present a useful model to address different scientific questions regarding glycosylation processes in skeletal precursors.},
  language  = {en}
}
@article{EltamanyAbdelmohsenHaletal.2021,
  author    = {Eltamany, Enas E. and Abdelmohsen, Usama Ramadan and Hal, Dina M. and Ibrahim, Amany K. and Hassanean, Hashim A. and Abdelhameed, Reda F. A. and Temraz, Tarek A. and Hajjar, Dina and Makki, Arwa A. and Hendawy, Omnia Magdy and AboulMagd, Asmaa M. and Youssif, Khayrya A. and Bringmann, Gerhard and Ahmed, Safwat A.},
  title     = {Holospiniferoside: A New Antitumor Cerebroside from The Red Sea Cucumber Holothuria spinifera: In Vitro and In Silico Studies},
  series = {Molecules},
  volume    = {26},
  journal   = {Molecules},
  number    = {6},
  issn      = {1420-3049},
  doi       = {10.3390/molecules26061555},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234058},
  year      = {2021},
  abstract  = {Chemical investigation of the methanolic extract of the Red Sea cucumber Holothuria spinifera led to the isolation of a new cerebroside, holospiniferoside (1), together with thymidine (2), methyl-α-d-glucopyranoside (3), a new triacylglycerol (4), and cholesterol (5). Their chemical structures were established by NMR and mass spectrometric analysis, including gas chromatography-mass spectrometry (GC-MS) and high-resolution mass spectrometry (HRMS). All the isolated compounds are reported in this species for the first time. Moreover, compound 1 exhibited promising in vitro antiproliferative effect on the human breast cancer cell line (MCF-7) with IC\(_{50}\) of 20.6 µM compared to the IC50 of 15.3 µM for the drug cisplatin. To predict the possible mechanism underlying the cytotoxicity of compound 1, a docking study was performed to elucidate its binding interactions with the active site of the protein Mdm2-p53. Compound 1 displayed an apoptotic activity via strong interaction with the active site of the target protein. This study highlights the importance of marine natural products in the design of new anticancer agents.},
  language  = {en}
}
@article{FullPanchalGoetzetal.2021,
  author    = {Full, Julian and Panchal, Santosh P. and G{\"o}tz, Julian and Krause, Ana-Maria and Nowak-Kr{\´o}l, Agnieszka},
  title     = {Modulare Synthese helikal-chiraler Organobor-Verbindungen: Ausschnitte verl{\"a}ngerter Helices},
  series = {Angewandte Chemie},
  volume    = {133},
  journal   = {Angewandte Chemie},
  number    = {8},
  doi       = {10.1002/ange.202014138},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224385},
  pages     = {4396 -- 4403},
  year      = {2021},
  abstract  = {Zwei Arten helikal-chiraler Verbindungen mit einem oder zwei Boratomen wurden nach einem modularen Ansatz synthetisiert. Die Bildung der helikalen Strukturen erfolgte durch Einf{\"u}hrung von Bor in flexible Biaryl- bzw. Triaryl-Vorstufen, hergestellt aus kleinen achiralen Bausteinen. Die durchgehend ortho-fusionierten Azabora[7]helicene zeichnen sich dabei durch außergew{\"o}hnliche Konfigurationsstabilit{\"a}t, blaue oder gr{\"u}ne Fluoreszenz in L{\"o}sung mit Quantenausbeuten (Φ\(_{fl}\)) von 18-24 \%, gr{\"u}ne oder gelbe Emission im Festk{\"o}rper (Φ\(_{fl}\) bis zu 23 \%) und starke chiroptische Resonanz mit großen Anisotropiefaktoren von bis zu 1.12×10\(^{-2}\) aus. Azabora[9]helicene, aufgebaut aus winkelf{\"o}rmig sowie linear angeordneten Ringen, sind blaue Emitter mit Φ\(_{fl}\) von bis zu 47 \% in CH\(_{2}\)Cl\(_{2}\) und 25 \% im Festk{\"o}rper. DFT-Rechnungen zeigen, dass ihre P-M-Interkonversion {\"u}ber einen komplexeren Weg verl{\"a}uft als im Fall von H1. R{\"o}ntgenstrukturanalyse von Einkristallen zeigt deutliche Unterschiede in der Packungsanordnung von Methyl- und Phenylderivaten auf. Die Molek{\"u}le werden als Prim{\"a}rstrukturen verl{\"a}ngerter Helices vorgeschlagen.},
  language  = {de}
}
@phdthesis{Hecht2021,
  author    = {Hecht, Markus},
  title     = {Liquid-Crystalline Perylene Bisimide and Diketopyrrolopyrrole Assemblies},
  doi       = {10.25972/OPUS-21698},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216987},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The research presented in this thesis illustrates that self-assembly of organic molecules guided by intermolecular forces is a versatile bottom-up approach towards functional materials. Through the specific design of the monomers, supramolecular architectures with distinct spatial arrangement of the individual building blocks can be realized. Particularly intriguing materials can be achieved when applying the supramolecular approach to molecules forming liquid-crystalline phases as these arrange in ordered, yet mobile structures. Therefore, they exhibit anisotropic properties on a macroscopic level. It is pivotal to precisely control the interchromophoric arrangement as functions originate in the complex structures that are formed upon self-assembly. Consequently, the aim of this thesis was the synthesis and characterization of liquid-crystalline phases with defined supramolecular arrangements as well as the investigation of the structure-property relationship. For this purpose, perylene bisimide and diketopyrrolopyrrole chromophores were used as they constitute ideal building blocks towards functional supramolecular materials due to their thermal stability, lightfastness, as well as excellent optical and electronic features desirable for the application in, e.g., organic electronics.},
  subject      = {Selbstorganisation},
  language  = {en}
}
@article{IvanovaKoesterHolsteinetal.2021,
  author    = {Ivanova, Svetlana and K{\"o}ster, Eva and Holstein, Julian J. and Keller, Niklas and Clever, Guido H. and Bein, Thomas and Beuerle, Florian},
  title     = {Isoreticular crystallization of highly porous cubic covalent organic cage compounds},
  series = {Angewandte Chemie International Edition},
  volume    = {60},
  journal   = {Angewandte Chemie International Edition},
  number    = {32},
  doi       = {10.1002/anie.202102982},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256462},
  pages     = {17455-17463},
  year      = {2021},
  abstract  = {Modular frameworks featuring well-defined pore structures in microscale domains establish tailor-made porous materials. For open molecular solids however, maintaining long-range order after desolvation is inherently challenging, since packing is usually governed by only a few supramolecular interactions. Here we report on two series of nanocubes obtained by co-condensation of two different hexahydroxy tribenzotriquinacenes (TBTQs) and benzene-1,4-diboronic acids (BDBAs) with varying linear alkyl chains in 2,5-position. n-Butyl groups at the apical position of the TBTQ vertices yielded soluble model compounds, which were analyzed by mass spectrometry and NMR spectroscopy. In contrast, methyl-substituted cages spontaneously crystallized as isostructural and highly porous solids with BET surface areas and pore volumes of up to 3426 m\(^2\) g\(^{-1}\) and 1.84 cm\(^3\) g\(^{-1}\). Single crystal X-ray diffraction and sorption measurements revealed an intricate cubic arrangement of alternating micro- and mesopores in the range of 0.97-2.2 nm that are fine-tuned by the alkyl substituents at the BDBA linker.},
  language  = {en}
}
@article{KabingerStillerSchmitzovaetal.2021,
  author    = {Kabinger, Florian and Stiller, Carina and Schmitzov{\´a}, Jana and Dienemann, Christian and Kokic, Goran and Hillen, Hauke S. and H{\"o}bartner, Claudia and Cramer, Patrick},
  title     = {Mechanism of molnupiravir-induced SARS-CoV-2 mutagenesis},
  series = {Nature Structural \& Molecular Biology},
  volume    = {28},
  journal   = {Nature Structural \& Molecular Biology},
  doi       = {10.1038/s41594-021-00651-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254603},
  pages     = {740-746},
  year      = {2021},
  abstract  = {Molnupiravir is an orally available antiviral drug candidate currently in phase III trials for the treatment of patients with COVID-19. Molnupiravir increases the frequency of viral RNA mutations and impairs SARS-CoV-2 replication in animal models and in humans. Here, we establish the molecular mechanisms underlying molnupiravir-induced RNA mutagenesis by the viral RNA-dependent RNA polymerase (RdRp). Biochemical assays show that the RdRp uses the active form of molnupiravir, β-d-\(N^4\)-hydroxycytidine (NHC) triphosphate, as a substrate instead of cytidine triphosphate or uridine triphosphate. When the RdRp uses the resulting RNA as a template, NHC directs incorporation of either G or A, leading to mutated RNA products. Structural analysis of RdRp-RNA complexes that contain mutagenesis products shows that NHC can form stable base pairs with either G or A in the RdRp active center, explaining how the polymerase escapes proofreading and synthesizes mutated RNA. This two-step mutagenesis mechanism probably applies to various viral polymerases and can explain the broad-spectrum antiviral activity of molnupiravir.},
  language  = {en}
}
@article{KimLiessStolteetal.2021,
  author    = {Kim, Jin Hong and Liess, Andreas and Stolte, Matthias and Krause, Ana-Maria and Stepanenko, Vladimir and Zhong, Chuwei and Bialas, David and Spano, Frank and W{\"u}rthner, Frank},
  title     = {An Efficient Narrowband Near-Infrared at 1040 nm Organic Photodetector Realized by Intermolecular Charge Transfer Mediated Coupling Based on a Squaraine Dye},
  series = {Advanced Materials},
  volume    = {33},
  journal   = {Advanced Materials},
  number    = {26},
  doi       = {10.1002/adma.202100582},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256374},
  year      = {2021},
  abstract  = {A highly sensitive short-wave infrared (SWIR, λ > 1000 nm) organic photodiode (OPD) is described based on a well-organized nanocrystalline bulk-heterojunction (BHJ) active layer composed of a dicyanovinyl-functionalized squaraine dye (SQ-H) donor material in combination with PC\(_{61}\)BM. Through thermal annealing, dipolar SQ-H chromophores self-assemble in a nanoscale structure with intermolecular charge transfer mediated coupling, resulting in a redshifted and narrow absorption band at 1040 nm as well as enhanced charge carrier mobility. The optimized OPD exhibits an external quantum efficiency (EQE) of 12.3\% and a full-width at half-maximum of only 85 nm (815 cm\(^{-1}\)) at 1050 nm under 0 V, which is the first efficient SWIR OPD based on J-type aggregates. Photoplethysmography application for heart-rate monitoring is successfully demonstrated on flexible substrates without applying reverse bias, indicating the potential of OPDs based on short-range coupled dye aggregates for low-power operating wearable applications.},
  language  = {en}
}
@phdthesis{KimbadiLombe2021,
  author    = {Kimbadi Lombe, Blaise},
  title     = {Novel-Type Dimeric Naphthylisoquinoline Alkaloids from Congolese Ancistrocladus Lianas: Isolation, Structural Elucidation, and Antiprotozoal and Anti-Tumoral Activities},
  doi       = {10.25972/OPUS-19178},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191789},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Herein described is the discovery of three novel types of dimeric naphthylisoquinoline alkaloids, named mbandakamines, cyclombandakamines, and spirombandakamines. They were found in the leaves of a botanically as yet unidentified, potentially new Ancistrocladus species, collected in the rainforest of the Democratic Republic of the Congo (DRC). Mbandakamines showed an exceptional 6′,1′′-coupling, in the peri-position neighboring one of the outer axes, leading to an extremely high steric hindrance at the central axis, and to U-turn-like molecular shape, which - different from all other dimeric NIQs, whose basic structures are all quite linear - brings three of the four bicyclic ring systems in close proximity to each other. This created an unprecedented follow-up chemistry, involving ring closure reactions, leading to two further, structurally even more intriguing subclasses, the cyclo- and the spirombandakamines, displaying eight stereogenic elements (the highest total number ever found in naphthylisoquinoline alkaloids). The metabolites exhibited pronounced antiplasmodial and antitrypanosomal activities. Likewise reported in this doctoral thesis are the isolation and structural elucidation of naphthylisoquinoline alkaloids from two further potentially new Ancistrocladus species from DRC. Some of these metabolites have shown pronounced antiausterity activities against human pancreatic cancer PANC-1 cells.},
  subject      = {Naphthylisochinolinalkaloide},
  language  = {en}
}
@article{KokicHillenTegunovetal.2021,
  author    = {Kokic, Goran and Hillen, Hauke S. and Tegunov, Dimitry and Dienermann, Christian and Seitz, Florian and Schmitzova, Jana and Farnung, Lucas and Siewert, Aaron and H{\"o}bartner, Claudia and Cramer, Patrick},
  title     = {Mechanism of SARS-CoV-2 polymerase stalling by remdesivir},
  series = {Nature Communications},
  volume    = {12},
  journal   = {Nature Communications},
  doi       = {10.1038/s41467-020-20542-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-220979},
  year      = {2021},
  abstract  = {Remdesivir is the only FDA-approved drug for the treatment of COVID-19 patients. The active form of remdesivir acts as a nucleoside analog and inhibits the RNA-dependent RNA polymerase (RdRp) of coronaviruses including SARS-CoV-2. Remdesivir is incorporated by the RdRp into the growing RNA product and allows for addition of three more nucleotides before RNA synthesis stalls. Here we use synthetic RNA chemistry, biochemistry and cryoelectron microscopy to establish the molecular mechanism of remdesivir-induced RdRp stalling. We show that addition of the fourth nucleotide following remdesivir incorporation into the RNA product is impaired by a barrier to further RNA translocation. This translocation barrier causes retention of the RNA 3ʹ-nucleotide in the substrate-binding site of the RdRp and interferes with entry of the next nucleoside triphosphate, thereby stalling RdRp. In the structure of the remdesivir-stalled state, the 3ʹ-nucleotide of the RNA product is matched and located with the template base in the active center, and this may impair proofreading by the viral 3ʹ-exonuclease. These mechanistic insights should facilitate the quest for improved antivirals that target coronavirus replication.},
  language  = {en}
}
@article{LehmannBaumannLambovetal.2021,
  author    = {Lehmann, Matthias and Baumann, Maximilian and Lambov, Martin and Eremin, Alexey},
  title     = {Parallel polar dimers in the columnar self-assembly of umbrella-shaped subphthalocyanine mesogens},
  series = {Advanced Functional Materials},
  volume    = {31},
  journal   = {Advanced Functional Materials},
  number    = {38},
  doi       = {10.1002/adfm.202104217},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256343},
  year      = {2021},
  abstract  = {The self-assembly of umbrella-shaped mesogens is explored with subphthalocyanine cores and oligo(thienyl) arms with different lengths in the light of their application as light-harvesting and photoconducting materials. While the shortest arm derivatives self-assemble in a conventional columnar phase with a single mesogen as a repeating unit, the more extended derivatives generate dimers that pile up into liquid crystalline columns. In contrast to the antiparallel arrangement known from single crystals, the present mesogens align as parallel dimers in polar columnar phases as confirmed by X-ray scattering, experimental densities, dielectric spectroscopy, second harmonic generation, alignment, and conductivity studies. UV-vis and fluorescence spectroscopies reveal a broad absorption in the visible range and only weak emission of the Q-band. Thus, these light-collecting molecules forming strongly polar columnar mesophases are attractive for application in the area of photoconductive materials.},
  language  = {en}
}
@article{LiaqatSednevStilleretal.2021,
  author    = {Liaqat, Anam and Sednev, Maksim V. and Stiller, Carina and H{\"o}bartner, Claudia},
  title     = {RNA-cleaving deoxyribozymes differentiate methylated cytidine isomers in RNA},
  series = {Angewandte Chemie International Edition},
  volume    = {60},
  journal   = {Angewandte Chemie International Edition},
  doi       = {10.1002/anie.202106517},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256519},
  pages     = {19058-19062},
  year      = {2021},
  abstract  = {Deoxyribozymes are emerging as modification-specific endonucleases for the analysis of epigenetic RNA modifications. Here, we report RNA-cleaving deoxyribozymes that differentially respond to the presence of natural methylated cytidines, 3-methylcytidine (m\(^3\)C), N\(^4\)-methylcytidine (m\(^4\)C), and 5-methylcytidine (m\(^5\)C), respectively. Using in vitro selection, we found several DNA catalysts, which are selectively activated by only one of the three cytidine isomers, and display 10- to 30-fold accelerated cleavage of their target m\(^3\)C-, m\(^4\)C- or m\(^5\)C-modified RNA. An additional deoxyribozyme is strongly inhibited by any of the three methylcytidines, but effectively cleaves unmodified RNA. The mXC-detecting deoxyribozymes are programmable for the interrogation of natural RNAs of interest, as demonstrated for human mitochondrial tRNAs containing known m\(^3\)C and m\(^5\)C sites. The results underline the potential of synthetic functional DNA to shape highly selective active sites.},
  language  = {en}
}
@article{LiaqatSednevStilleretal.2021,
  author    = {Liaqat, Anam and Sednev, Maksim V. and Stiller, Carina and H{\"o}bartner, Claudia},
  title     = {RNA-Cleaving Deoxyribozymes Differentiate Methylated Cytidine Isomers in RNA},
  series = {Angewandte Chemie International Edition},
  volume    = {60},
  journal   = {Angewandte Chemie International Edition},
  number    = {35},
  doi       = {10.1002/anie.202106517},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254544},
  pages     = {19058-19062},
  year      = {2021},
  abstract  = {Deoxyribozymes are emerging as modification-specific endonucleases for the analysis of epigenetic RNA modifications. Here, we report RNA-cleaving deoxyribozymes that differentially respond to the presence of natural methylated cytidines, 3-methylcytidine (m\(^3\)C), N\(^4\)-methylcytidine (m\(^4\)C), and 5-methylcytidine (m\(^5\)C), respectively. Using in vitro selection, we found several DNA catalysts, which are selectively activated by only one of the three cytidine isomers, and display 10- to 30-fold accelerated cleavage of their target m\(^3\)C-, m\(^4\)C- or m\(^5\)C-modified RNA. An additional deoxyribozyme is strongly inhibited by any of the three methylcytidines, but effectively cleaves unmodified RNA. The m\(^X\)C-detecting deoxyribozymes are programmable for the interrogation of natural RNAs of interest, as demonstrated for human mitochondrial tRNAs containing known m\(^3\)C and m\(^5\)C sites. The results underline the potential of synthetic functional DNA to shape highly selective active sites.},
  language  = {en}
}
@article{MerzMerzKirchneretal.2021,
  author    = {Merz, Viktor and Merz, Julia and Kirchner, Maximilian and Lenhart, Julian and Marder, Todd B. and Krueger, Anke},
  title     = {Pyrene-Based "Turn-Off" Probe with Broad Detection Range for Cu\(^{2+}\), Pb\(^{2+}\) and Hg\(^{2+}\) Ions},
  series = {Chemistry—A European Journal},
  volume    = {27},
  journal   = {Chemistry—A European Journal},
  number    = {31},
  doi       = {10.1002/chem.202100594},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256803},
  pages     = {8118-8126},
  year      = {2021},
  abstract  = {Detection of metals in different environments with high selectivity and specificity is one of the prerequisites of the fight against environmental pollution with these elements. Pyrenes are well suited for the fluorescence sensing in different media. The applied sensing principle typically relies on the formation of intra- and intermolecular excimers, which is however limiting the sensitivity range due to masking of e. g. quenching effects by the excimer emission. Herein we report a highly selective, structurally rigid chemical sensor based on the monomer fluorescence of pyrene moieties bearing triazole groups. This sensor can quantitatively detect Cu\(^{2+}\), Pb\(^{2+}\) and Hg\(^{2+}\) in organic solvents over a broad concentrations range, even in the presence of ubiquitous ions such as Na\(^{+}\), K\(^{+}\), Ca\(^{2+}\) and Mg\(^{2+}\). The strongly emissive sensor's fluorescence with a long lifetime of 165 ns is quenched by a 1 : 1 complex formation upon addition of metal ions in acetonitrile. Upon addition of a tenfold excess of the metal ion to the sensor, agglomerates with a diameter of about 3 nm are formed. Due to complex interactions in the system, conventional linear correlations are not observed for all concentrations. Therefore, a critical comparison between the conventional Job plot interpretation, the method of Benesi-Hildebrand, and a non-linear fit is presented. The reported system enables the specific and robust sensing of medically and environmentally relevant ions in the health-relevant nM range and could be used e. g. for the monitoring of the respective ions in waste streams.},
  language  = {en}
}
@phdthesis{MezaChincha2021,
  author    = {Meza Chincha, Ana Lucia},
  title     = {Catalytic Water Oxidation with Functionalized Ruthenium Macrocycles},
  doi       = {10.25972/OPUS-20962},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-209620},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {In light of the rapidly increasing global demand of energy and the negative effects of climate change, innovative solutions that allow an efficient transition to a carbon-neutral economy are urgently needed. In this context, artificial photosynthesis is emerging as a promising technology to enable the storage of the fluctuating energy of sunlight in chemical bonds of transportable "solar fuels". Thus, in recent years much efforts have been devoted to the development of robust water oxidation catalysts (WOCs) leading to the discovery of the highly reactive Ru(bda) (bda: 2,2'-bipyridine-6,6'-dicarboxylic acid) catalyst family. The aim of this thesis was the study of chemical and photocatalytic water oxidation with functionalized Ruthenium macrocycles to explore the impact of substituents on molecular properties and catalytic activities of trinuclear macrocyclic Ru(bda) catalysts. A further objective of this thesis comprises the elucidation of factors that influence the light-driven water oxidation process with this novel class of supramolecular WOCs.},
  subject      = {Rutheniumkomplexe},
  language  = {en}
}
@phdthesis{Michail2021,
  author    = {Michail, Evripidis},
  title     = {Design and Development of a Two-Photon Absorption Induced Fluorescence Spectrometer and the Investigation of Nonlinear Optical Properties of Organic Chromophores},
  doi       = {10.25972/OPUS-24218},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242185},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Main objectives of the present dissertation can be divided in two parts. The first part deals with setting up a spectroscopic technique for reliable and accurate measurements of the two-photon absorption (2PA) cross section spectra. In the second part, this firmly established experimental technique together with conventional spectroscopic characterization, quantum-chemical computations and theoretical modelling calculations was combined and therefore used as a tool to gain information for the so-called structure-property relationship through several molecular compounds.},
  subject      = {Nonlinear Optical Properties of Organic Materials},
  language  = {en}
}
@article{MieczkowskiSteinmetzgerBessietal.2021,
  author    = {Mieczkowski, Mateusz and Steinmetzger, Christian and Bessi, Irene and Lenz, Ann-Kathrin and Schmiedel, Alexander and Holzapfel, Marco and Lambert, Christoph and Pena, Vladimir and H{\"o}bartner, Claudia},
  title     = {Large Stokes shift fluorescence activation in an RNA aptamer by intermolecular proton transfer to guanine},
  series = {Nature Communications},
  volume    = {12},
  journal   = {Nature Communications},
  doi       = {10.1038/s41467-021-23932-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254527},
  pages     = {3549},
  year      = {2021},
  abstract  = {Fluorogenic RNA aptamers are synthetic functional RNAs that specifically bind and activate conditional fluorophores. The Chili RNA aptamer mimics large Stokes shift fluorescent proteins and exhibits high affinity for 3,5-dimethoxy-4-hydroxybenzylidene imidazolone (DMHBI) derivatives to elicit green or red fluorescence emission. Here, we elucidate the structural and mechanistic basis of fluorescence activation by crystallography and time-resolved optical spectroscopy. Two co-crystal structures of the Chili RNA with positively charged DMHBO+ and DMHBI+ ligands revealed a G-quadruplex and a trans-sugar-sugar edge G:G base pair that immobilize the ligand by π-π stacking. A Watson-Crick G:C base pair in the fluorophore binding site establishes a short hydrogen bond between the N7 of guanine and the phenolic OH of the ligand. Ultrafast excited state proton transfer (ESPT) from the neutral chromophore to the RNA was found with a time constant of 130 fs and revealed the mode of action of the large Stokes shift fluorogenic RNA aptamer.},
  language  = {en}
}
@article{MieczkowskiSteinmetzgerBessietal.2021,
  author    = {Mieczkowski, Mateusz and Steinmetzger, Christian and Bessi, Irene and Lenz, Ann-Kathrin and Schmiedel, Alexander and Holzapfel, Marco and Lambert, Christoph and Pena, Vladimir and H{\"o}bartner, Claudia},
  title     = {Large Stokes shift fluorescence activation in an RNA aptamer by intermolecular proton transfer to guanine},
  series = {Nature Communications},
  volume    = {12},
  journal   = {Nature Communications},
  doi       = {10.1038/s41467-021-23932-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270274},
  year      = {2021},
  abstract  = {Fluorogenic RNA aptamers are synthetic functional RNAs that specifically bind and activate conditional fluorophores. The Chili RNA aptamer mimics large Stokes shift fluorescent proteins and exhibits high affinity for 3,5-dimethoxy-4-hydroxybenzylidene imidazolone (DMHBI) derivatives to elicit green or red fluorescence emission. Here, we elucidate the structural and mechanistic basis of fluorescence activation by crystallography and time-resolved optical spectroscopy. Two co-crystal structures of the Chili RNA with positively charged DMHBO+ and DMHBI+ ligands revealed a G-quadruplex and a trans-sugar-sugar edge G:G base pair that immobilize the ligand by π-π stacking. A Watson-Crick G:C base pair in the fluorophore binding site establishes a short hydrogen bond between the N7 of guanine and the phenolic OH of the ligand. Ultrafast excited state proton transfer (ESPT) from the neutral chromophore to the RNA was found with a time constant of 130 fs and revealed the mode of action of the large Stokes shift fluorogenic RNA aptamer.},
  language  = {en}
}
@article{MuellerBessiRichteretal.2021,
  author    = {M{\"u}ller, Diana and Bessi, Irene and Richter, Christian and Schwalbe, Harald},
  title     = {The Folding Landscapes of Human Telomeric RNA and DNA G-Quadruplexes are Markedly Different},
  series = {Angewandte Chemie International Edition},
  volume    = {60},
  journal   = {Angewandte Chemie International Edition},
  number    = {19},
  doi       = {10.1002/anie.202100280},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238917},
  pages     = {10895 -- 10901},
  year      = {2021},
  abstract  = {We investigated the folding kinetics of G-quadruplex (G4) structures by comparing the K\(^{+}\)-induced folding of an RNA G4 derived from the human telomeric repeat-containing RNA (TERRA25) with a sequence homologous DNA G4 (wtTel25) using CD spectroscopy and real-time NMR spectroscopy. While DNA G4 folding is biphasic, reveals kinetic partitioning and involves kinetically favoured off-pathway intermediates, RNA G4 folding is faster and monophasic. The differences in kinetics are correlated to the differences in the folded conformations of RNA vs. DNA G4s, in particular with regard to the conformation around the glycosidic torsion angle χ that uniformly adopts anti conformations for RNA G4s and both, syn and anti conformation for DNA G4s. Modified DNA G4s with \(^{19}\)F bound to C2′ in arabino configuration adopt exclusively anti conformations for χ. These fluoro-modified DNA (antiTel25) reveal faster folding kinetics and monomorphic conformations similar to RNA G4s, suggesting the correlation between folding kinetics and pathways with differences in χ angle preferences in DNA and RNA, respectively.},
  language  = {en}
}
@phdthesis{PeethambaranNairSyamala2021,
  author    = {Peethambaran Nair Syamala, Pradeep},
  title     = {Bolaamphiphilic Rylene Bisimides: Thermodynamics of Self-assembly and Stimuli-responsive Properties in Water},
  doi       = {10.25972/OPUS-21342},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-213424},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The present thesis demonstrates how different thermodynamic aspects of self-assembly and stimuli-responsive properties in water can be encoded on the structure of π-amphiphiles, consisting of perylene or naphthalene bisimide cores. Initially, quantitative thermodynamic insights into the entropically-driven self-assembly was studied for a series of naphthalene bisimides with UV/Vis and ITC measurements, which demonstrated that their thermodynamic profile of aggregation is heavily influenced by the OEG side chains. Subsequently, a control over the bifurcated thermal response of entropically driven and commonly observed enthalpically driven self-assembly was achieved by the modulation of glycol chain orientation. Finally, Lower Critical Solution Temperature (LCST) phenomenon observed for these dyes was investigated as a precise control of this behavior is quintessential for self-assembly studies as well as to generate 'smart' materials. It could be shown that the onset of phase separation for these molecules can be encoded in their imide substituents, and they are primarily determined by the supramolecular packing, rather than the hydrophobicity of individual monomers.},
  subject      = {Supramolekulare Chemie},
  language  = {en}
}
@article{PetersKaiserFinketal.2021,
  author    = {Peters, Simon and Kaiser, Lena and Fink, Julian and Schumacher, Fabian and Perschin, Veronika and Schlegel, Jan and Sauer, Markus and Stigloher, Christian and Kleuser, Burkhard and Seibel, Juergen and Schubert-Unkmeir, Alexandra},
  title     = {Click-correlative light and electron microscopy (click-AT-CLEM) for imaging and tracking azido-functionalized sphingolipids in bacteria},
  series = {Scientific Reports},
  volume    = {11},
  journal   = {Scientific Reports},
  number    = {1},
  doi       = {10.1038/s41598-021-83813-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259147},
  pages     = {4300},
  year      = {2021},
  abstract  = {Sphingolipids, including ceramides, are a diverse group of structurally related lipids composed of a sphingoid base backbone coupled to a fatty acid side chain and modified terminal hydroxyl group. Recently, it has been shown that sphingolipids show antimicrobial activity against a broad range of pathogenic microorganisms. The antimicrobial mechanism, however, remains so far elusive. Here, we introduce 'click-AT-CLEM', a labeling technique for correlated light and electron microscopy (CLEM) based on the super-resolution array tomography (srAT) approach and bio-orthogonal click chemistry for imaging of azido-tagged sphingolipids to directly visualize their interaction with the model Gram-negative bacterium Neisseria meningitidis at subcellular level. We observed ultrastructural damage of bacteria and disruption of the bacterial outer membrane induced by two azido-modified sphingolipids by scanning electron microscopy and transmission electron microscopy. Click-AT-CLEM imaging and mass spectrometry clearly revealed efficient incorporation of azido-tagged sphingolipids into the outer membrane of Gram-negative bacteria as underlying cause of their antimicrobial activity.},
  language  = {en}
}