A5042442059- RNA and protein synthesis mechanisms
- DNA and Nucleic Acid Chemistry
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Chemical Synthesis and Analysis
- Advanced biosensing and bioanalysis techniques
- Crystallography and molecular interactions
- Energetic Materials and Combustion
- RNA Interference and Gene Delivery
- Asymmetric Synthesis and Catalysis
- Click Chemistry and Applications
- Chemical Reaction Mechanisms
- Molecular spectroscopy and chirality
- Electron Spin Resonance Studies
- Inorganic Fluorides and Related Compounds
- Advanced Battery Materials and Technologies
- Axial and Atropisomeric Chirality Synthesis
- Carbohydrate Chemistry and Synthesis
- Chemical Reactions and Mechanisms
- Advancements in Battery Materials
- Molecular Sensors and Ion Detection
- RNA modifications and cancer
- Thermal and Kinetic Analysis
- Structural Analysis of Composite Materials
- Lanthanide and Transition Metal Complexes
Goethe University Frankfurt
2014-2025
Leibniz Institute of Polymer Research
2014-2024
Robert Bosch (Germany)
2017
Leibniz Institute for Neurobiology
2014
Ludwig-Maximilians-Universität München
2006-2013
University of Maryland, College Park
2010
Energy Concepts (United States)
2010
Institut für Urheber- und Medienrecht
2009
Bauhaus-Universität Weimar
2009
University of Cambridge
2008
The first anionic tetrazole-2N-oxide has been prepared by mild aqueous oxidation of easily 5-nitrotetrazole with commercially available oxone in high yields. result protonating 5-nitrotetrazolate-2N-oxide identified as a hydroxytetrazole, and the nitrogen-rich salts including ammonium, hydroxylammonium, guanidinium, aminoguanidinum, diaminoguanidinium, triaminoguanidinium have characterized. When compared to nitrotetrazole, nitrotetrazole-2N-oxide show superior energetic performance...
Abstract The development of new energetic materials is an emerging area chemistry facilitated by a worldwide need to replace used at present, due environmental considerations and safety requirements, while the same time securing high performance. such complex, owing fact that several different apparently mutually exclusive material properties have be met in order for become widely accepted. In turn, understanding basic principles structure property relationships highly desirable, as would...
Coordination or local environments (e.g., tetrahedra and octahedra) are powerful descriptors of the crystalline structure materials. These structural essential to understanding crystal chemistry design new However, extensive statistics on occurrence environment not available even common chemistries such as oxides. Here, we present first large-scale statistical analysis coordination cations in oxides using a large set experimentally observed compounds (about 8000). Using newly developed...
The correct target: cell division cycle protein 37 (Cdc37) and the heat shock (Hsp90) are molecular chaperones crucial for folding stabilization of kinases including oncogenic kinases. NMR studies show that celastrol, a recently identified triterpene targeting Hsp90, in fact binds to Cdc37 disrupts Cdc37–Hsp90 complex. Celastrol inactivates through thiol-mediated mechanism. Detailed facts importance specialist readers published as "Supporting Information". Such documents peer-reviewed, but...
SARS-CoV-2 contains a positive single-stranded RNA genome of approximately 30 000 nucleotides. Within this genome, 15 elements were identified as conserved between SARS-CoV and SARS-CoV-2. By nuclear magnetic resonance (NMR) spectroscopy, we previously determined that these fold independently, in line with data from vivo ex-vivo structural probing experiments. These contain non-base-paired regions potentially harbor ligand-binding pockets. Here, performed an NMR-based screening poised...
Why Pentose‐And Not Hexose‐Nucleic Acids? Part III. Oligo(2′,3′‐dideoxy‐β‐ D ‐glucopyranosyl)nucleotides. (‘Homo‐DNA’): Base‐Pairing Properties Summary in collaboration with Prof. Dr. C. E. Wintner , Haverford College, Haverford, PA 19041‐1392. The paper presents results of a comprehensive investigation on the pairing properties homo‐DNA oligonucleotides, preparation which has been described II this series [2]. was carried out by using established methods literature for characterization...
Abstract 1,1‐Diamino‐2,2‐dinitroethene, C 2 H 4 N O (FOX‐7), is a novel high energy density material with low friction and impact sensitivity activation barrier to detonation. In this study, the previously unknown crystal structure of γ‐polymorph trimorphic FOX‐7 reported. γ‐FOX‐7 stable from ∼435 K until compound decomposes just above 504 K. A single α‐FOX‐7 ( P 1 /n, Z =4, =694.67(7) pm, b =668.87(9) c =1135.1(1) β=90.14(1)°, T =373 K) was first transformed into β‐FOX‐7 , =698.6(1)...
Lithium–sulfur (Li–S) batteries hold a promising position as candidates for next-generation high-energy storage systems. Here, we combine inverse vulcanization of sulfur with multiwalled carbon nanotubes (MWCNTs) to increase the conductivity cathode materials Li–S batteries. The mixing process inversely vulcanized copolymer networks MWCNTs is aided by shear in two-roll mill take advantage soft nature copolymer. high-throughput method demands source conductive that can be intimately mixed S...
2-aminopyridine and 2-aminobenzimidazole were chosen as structural analogues to substitute guanidinium groups in receptor molecules designed phosphoryl transfer catalysts. Shifting the pKa of toward 7 was expected raise catalytic activities aqueous buffer. Although pKa's both heterocycles are similar (6.2 7.0), only led active RNA cleavers. All cleavage assays run with fluorescently labeled substrates a DNA sequencer. RNase contaminations would degrade enantioselectively. In contrast,...
[reaction: see text] Enantioselective catalysis of Diels-Alder reactions is mostly achieved by coordinating the dienophile to relatively strong chiral Lewis acids. Here we report on a novel approach employing hydrogen-bond-mediated association dienophiles host molecules. In reaction forming steroid skeleton norgestrel, amidinium ions induce 5:ent-5 ratios up 2.5:1. Improved and simplified catalysts may become interesting candidates perform stereoselective transformations.
Why Pentose and Not Hexose Nucleic Acids? Part II . Preparation of Oligonucleotides Containing 2′,3′‐Dideoxy‐β‐ D ‐glucopyranosyl Building Blocks (7) This paper describes the preparation 2′,3′‐dideoxy‐β‐ ‐glucopyranosyl‐( = ‐ erythro ‐hexopyranosyl)‐derived nucleosides five bases adenine, cytosine, guanine, thymine, uracil ( ‘homo‐de‐oxyribonucleosides’) as well synthesis oligonucleotides derived from them. The methods used for both nucleoside oligonucleotide closely follow known in...
Abstract Energetic salts containing the nitroformate (trinitromethanide) anion with several nitrogen‐rich cations were investigated, including ammonium (ANF), melaminium (MNF), guanidinium monohydrate (GNFH), aminoguanidinium (AGNF), diaminoguanidinium (DAGNF) as well triaminoguanidinium (TAGNF). All characterized using vibrational spectroscopy (IR, Raman), mass spectrometry, multinuclear NMR and elemental analysis. The thermal decomposition of was monitored differential scanning...
Hydrazoic acid (HN(3))--potentially explosive, highly toxic, and very hygroscopic--is the simplest covalent azide contains 97.7 wt % nitrogen. Although its molecular structure was established decades ago, crystal has now been solved by X-ray diffraction for first time. Molecules of HN(3) are connected to each other hydrogen bonds in nearly planar layers parallel (001) with stacking sequence A, B, ... The layer distance, at 2.950(1) Å, is shorter than that 2H-graphite [3.355(2) Å]. N-H···N...
Proximity effects and electrophilic activation combined account for the accelerated ring-opening in transesterification of 1 with amidinium alcohol 2. The spatial proximity arise a contact ion-pair Electrophilic causes 9000-fold rate enhancement reaction 2 relative to phenylalcohol; addition phenyl form 3 caused 25-fold increase.
RNA cleaving tris(2-aminobenzimidazoles) have been attached to DNA oligonucleotides via disulfide or amide bonds. The resulting conjugates are effective organocatalytic nucleases showing substrate and site selectivity as well saturation kinetics. benzimidazole also degrade enantiomeric RNA. This observation rules out contamination effects an alternative explanation of degradation. pH dependency shows that the catalyst is most active in deprotonated state. Typical half-lifes substrates range...
The heptapeptide H-Iva-Api-Iva-ATANP-Iva-Api-Iva-NHCH 3 (P1a), where Iva is (S)-isovaline, Api 4-amino-4-carboxypiperidine, and ATANP (S)-2-amino-3-[1-(1,4,7-triazacyclononane)]propanoic acid, has been synthesized. Its conformation in aqueous solution essentially that of a 10 -helix. By connecting three copies P1a to functionalized Tris(2-aminoethyl)amine (Tren) platform new peptide template, [T(P1) ], was obtained. This molecule able bind up four metal ions (Cu II or Zn ): one the Tren...
Spin labeling of oligonucleotides with nitroxides is hampered by their intrinsic instability under conditions solid‐phase synthesis and enzymatic ligation. Although nitroxide decomposition can be avoided in some cases postsynthetic introduction or special reaction conditions, a more general solution would reversible protection the radical. We have recently developed such method based on photolabile groups for DNA demonstrated application EPR spectroscopy. Here, we extend this to RNA...
Rates never before achieved for the hydrolysis of amides are attained by Cu2(O2) complex 1, which converts dimethylformamide into formate ion in seconds (half-lives water often several years!). The interacting Cu ions play an important role. Such simple model systems can provide insights structure–activity relationships enzymes and even lead to development highly active catalysts.
Amidines and guanidines are important functional groups in molecular recognition host-guest chemistry. Here it is shown that lipophilic amidinium ions catalyze a cycloaddition reaction representing the key step of Quinkert-Dane estrone synthesis. Hydrogen-bond-mediated association with organic cation leads to an electrophilic activation dienophile enhanced rates Diels-Alder reaction. The observed effects similar those expected from mild Lewis acids. In competition experiments, catalysis...
We describe in full the first synthesis of potent insect antifeedant azadirachtin through a highly convergent approach. An O-alkylation reaction is used to unite decalin ketone and propargylic mesylate fragments, after which Claisen rearrangement constructs central C8-C14 bond stereoselective fashion. The allene results from this sequence then enables second critical carbon-carbon forming event whereby [3.2.1] bicyclic system, present natural product, generated via 5-exo-radical cyclisation...
Starting from Dane's diene and methylcyclopentenedione, (+)-estrone is synthesized along the Quinkert−Dane route in 24% total yield. The key step an enantioselective Diels−Alder reaction promoted by amidinium catalyst as efficiently a traditional Ti-TADDOLate Lewis acid.