A5102012634- Spectroscopy and Laser Applications
- Advanced Chemical Physics Studies
- Atomic and Molecular Physics
- Cold Atom Physics and Bose-Einstein Condensates
- Laser Design and Applications
- Glycosylation and Glycoproteins Research
- Quantum, superfluid, helium dynamics
- Photochemistry and Electron Transfer Studies
- Carbohydrate Chemistry and Synthesis
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
- Laser-induced spectroscopy and plasma
- Photochromic and Fluorescence Chemistry
- Quantum Mechanics and Non-Hermitian Physics
- Enzyme Production and Characterization
- Genomics and Phylogenetic Studies
- Molecular Spectroscopy and Structure
- Analytical Chemistry and Chromatography
- Scientific Measurement and Uncertainty Evaluation
- Marine Sponges and Natural Products
- Atomic and Subatomic Physics Research
- Microbial Natural Products and Biosynthesis
- Laser-Matter Interactions and Applications
- Photodynamic Therapy Research Studies
- Analytical Chemistry and Sensors
Max Planck Institute of Colloids and Interfaces
2018-2022
Freie Universität Berlin
2019-2021
Universidad Nacional de Colombia
2014
Universidad Autónoma de Madrid
1994-2005
Universidad Politécnica de Madrid
1997
Consejo Superior de Investigaciones Científicas
1980
Polysaccharides are the most abundant biopolymers on earth that serve various structural and modulatory functions. Pure, completely defined linear branched polysaccharides essential to understand carbohydrate structure function. Polysaccharide isolation provides heterogeneous mixtures, while heroic efforts were required complete chemical and/or enzymatic syntheses of as long 92-mers. Here, we show automated glycan assembly (AGA) enables access a 100-mer polysaccharide via 201-step synthesis...
The stereoselective formation of 1,2-cis-glycosidic bonds is challenging. However, 1,2-cis-selectivity can be induced by remote participation C4 or C6 ester groups. Reactions involving are believed to proceed via a key ionic intermediate, the glycosyl cation. Although mechanistic pathways were postulated many years ago, structure reaction intermediates remained elusive owing their short-lived nature. Herein, we unravel cations involved in reactions cryogenic vibrational spectroscopy and...
Automated glycan assembly (AGA) aims at accelerating access to synthetic oligosaccharides meet the demand for defined glycans as tools molecular glycobiology. The linkers used connect growing chain solid support play a pivotal role in synthesis strategy they determine all chemical conditions during and form of obtained end it. Here, we describe traceless photolabile linker prepare carbohydrates with free reducing end. Modification o-nitrobenzyl scaffold is key high yields compatibility AGA...
Cell surfaces are often decorated with glycoconjugates that contain linear and more complex symmetrically asymmetrically branched carbohydrates essential for cellular recognition communication processes. Mannose is one of the fundamental building blocks glycans in many biological membranes. Moreover, oligomannoses commonly found on surface pathogens such as bacteria viruses both glycolipids glycoproteins. However, their mechanism action not well understood, even though this great potential...
The marine brown alga Dictyota pfaffii from Atol das Rocas, in Northeast Brazil is a rich source of dolabellane diterpene, which has the potential to be used future antiviral drugs by inhibiting reverse transcriptase (RT) HIV-1. Reexamination minor diterpene constituents yielded three new diterpenes, (1R*,2E,4R*,7S,10S*,11S*,12R*)10,18-diacetoxy-7-hydroxy-2,8(17)-dolabelladiene (1), (1R*,2E,4R*,7R*,10S*,11S*,12R*)10,18-diacetoxy-7-hydroxy-2,8(17)-dolabelladiene (2),...
The connection between monosaccharides influences the structure, solubility, and biological function of carbohydrates. Although tandem mass spectrometry (MS/MS) often enables compositional identification carbohydrates, traditional MS/MS fragmentation methods fail to generate abundant cross-ring fragments intrachain that could reveal carbohydrate connectivity. We examined potential helium-charge transfer dissociation (He-CTD) as a method decipher connectivity β-1,4- β-1,3-linked...
Carbohydrates, such as oligo- and polysaccharides, are highly abundant biopolymers that involved in numerous processes. The study of their structure functions is commonly based on a material isolated from complex natural sources. However, more precise analysis requires pure compounds with well-defined structures can be obtained chemical or enzymatic syntheses. Novel synthetic strategies have increased the accessibility larger monodisperse posing challenge to analytical methods used for...
Abstract Microbial glycan degradation is essential to global carbon cycling. The marine bacterium Salegentibacter sp. Hel_I_6 (Bacteroidota) isolated from seawater off Helgoland island (North Sea) contains an α-mannan inducible gene cluster with a GH76 family endo-α-1,6-mannanase (ShGH76). This related genetic loci employed by human gut bacteria digest fungal α-mannan. Metagenomes the isolation site revealed increasing frequencies in free-living during microalgae blooms, suggesting of...
Excited-state reactions involved in the fluorescence of norharman have been investigated different binary mixtures acetic acid with dichloromethane, dioxane, and benzene. Time-resolved measurements revealed existence a new species which has not observed from steady-state spectra. The complex decay kinetics interactions surrounding environment are discussed detail.
It has been reported that fragments produced by glycosidic bond breakage in mass spectrometry-based experiments can retain a memory of their anomeric configuration, which major implications for glycan sequencing. Herein, we use cryogenic vibrational spectroscopy and ion mobility-mass spectrometry to study the structure B-type protected galactosides. Cationic were generated from glycosyl donors carrying trichloroacetimidate or thioethyl leaving groups different configuration. The obtained...
Abstract Die stereoselektive Bildung von 1,2‐ cis ‐glykosidischen Bindungen ist bislang sehr anspruchsvoll. Häufig wird diese ‐Selektivität durch Fernpartizipation (remote participation) C4‐ oder C6‐Estergruppen herbeigeführt. Hierbei davon ausgegangen, dass ein ionisches Schlüsselintermediat, das Glykosylkation, gebildet wird. Obwohl derartige Mechanismen bereits vor Jahrzehnten postuliert wurden, konnte die exakte Struktur dieses Intermediats aufgrund seiner Kurzlebigkeit bisher nicht...
Arabinomannan (AM) polysaccharides are clinical biomarkers for Mycobacterium tuberculosis (MTB) infections due to their roles in the interaction with host cells and interference macrophage activation. Collections of defined AM oligosaccharides can help improve understanding these development novel therapeutical diagnostic agents. Automated glycan assembly (AGA) was employed prepare core structure from MTB, containing α-(1,6)-Man, α-(1,5)-Ara, α-(1,2)-Man linkages. The introduction a capping...
We report here an analysis of the B1Πu → X1Σ+g band system sodium dimer. The body data includes laser-induced emission Na2 consisting discrete molecular fluorescence (107 series) excited by visible lines from argon ion laser and rotational relaxation for strong transitions. In order to enlarge set transitions within this system, which cover both states up dissociation, results were combined with spectroscopic experimental available in literature. obtained Dunham coefficients used derive...