Our in-house human skin equivalents contain all stratum corneum (SC) barrier lipid classes, but have a reduced level of free fatty acids (FAs), of which a part is mono-unsaturated. These differences lead to an altered SC lipid organization and thereby a reduced barrier function compared to human skin.…

Research training projects in the MCBIM group - Bachelor and master students of all chemistry related studies are more than welcome to take part in our research activities. We have various research projects, all in one way or another involving transition metal ions. Daily supervision in the laboratory…

Pseudomonas Aeruginosa is a Gram-negative bacterium which can form biofilms, increasing its resistance against antibiotics and the host immune system. Polysaccharides are an integral part of this biofilm, one of these polysaccharides is called Psl. PslG is a glycosidase, able to cleave this polysaccharide,…

Promotor: G.A. van der Marel, Co-promotor: D.C. Codée

Growing public backlash against international organizations (IOs) and attacks of national political elites on the rule of law increasingly challenge governance by IOs.

Biological chemist Nathaniel Martin is going to test an alternative antibiotic that can combat common resistant bacteria such as MRSA. For this purpose, he will receive 350,000 euros from the NWO's NACTAR programme. ‘We want to know how safe and effective our antibiotic is in a realistic situation.’

Antibiotic resistance, caused by widespread use of antibiotics, leads to bacterial infections that are difficult, if not impossible, to treat and is a major worldwide health concern.

This Thesis describes a strategy to synthesize 1,2-cis-oligosaccharides modulated by additives, such as dimethylformamide (DMF), triphenylphosphine oxide (Ph3P=O) and N-methyl(phenyl)formamide (MPF), using building blocks that carry solely benzyl type protecting groups and are therefore of uniform r…

This thesis describes the design and synthesis of fragments of various cell wall carbohydrates of the Streptococcus species, including the branched Group B-specific antigen (GBC) of Group B Streptococcus, glycerol phosphate (GroP) modified group A carbohydrate (GAC), and the O-acetylated type 1 capsular…

Schistosomiasis is an acute and chronic disease caused by blood dwelling parasitic trematodes of the genus Schistosoma, and it is classified as the second most socioeconomically devastating parasitic disease, second only to malaria.

This work has described synthetic strategies towards well-defined structures resembling capsular polysaccharide (CPS) fragments, CPS mimics, teichoic acid (TA) fragments as well as a third-generation ring-closing tandem metathesis (RCM) linker to better exploit the potential of automated synthesis.

Promotor: G.A. van der Marel, Co-promotor: J.D.C. Codée

This dissertation presents the synthesis and evaluation of antibody recognition for various capsular polysaccharide (CP) fragments of Staphylococcus aureus (S. aureus).

Synthetic methodlogy is described, aiding in the synthetic preparation of putative inhibitors of retaining and inverting glycosidases and glycosyl transferases. All constructs are cyclophellitol-based cyclitols.

The chemical synthesis of inhibitors and probes targeting endo-glycosidases.

Design and synthesis of two 3-substituted swainsonine derivatives with the aim to improve the potency and selectivity towards Golgi alpha-mannosidase II.

hotocatalysis has emerged as a powerful tool for enabling challenging transformations in organic synthesis. This thesis explores the development of several photocatalytic reactions designed to form carbon-heteroatom bonds from less-functionalized precursors.

Regenerative medicine is a new way of treatment that helps impaired cells, tissues, and organs work well again. We do this by repairing, replacing, or restoring cells, tissues, and organs after damage from illness or injury. This includes treating long-term diseases such as diabetes, kidney diseases,…

Solar energy is used by photosynthetic organisms to drive energy required cellular processes. Is absorbed by two groups of pigments, located in the LHCs.

Solar energy harnessed by plants and algae has great potential to be converted into biofuels for future generations.

In the search for sustainable energy solutions, the idea of artificial photosynthesis has been proposed as an approach with which to use water and sunlight to produce hydrogen.

Inspired by natural photosynthesis, perovskite-based photoelectrochemical (PEC) systems are being developed for artificial photosynthesis, aiming to enhance solar-to-hydrogen conversion for green energy.

This thesis is concerned with the constitution of chiral responsive matrix assemblies that may undergo light-driven conformational changes and self-select vibrations to develop vibronic states for driving semi-classical coherent transfer with nearly 100% yield in a lossless NCAP process.

The long-held desire - to link structure directly to function and to explain molecular mechanisms based on basic chemical or physical principles - is finally coming closer, satisfying not only our scientific curiosity but also offering new solutions to the many challenges in the field of health, energy…

Although it is often assumed that the stereochemistry in Ugi multicomponent reactions is determined in the final Mumm rearrangement step, experimental and computational evidence that Ugi reactions on hydroxylated pyrrolines proceed under kinetic control is reported.

With Sylvestre Bonnet, Jeroen Codée and Remus Dame, the Leiden Institute of Chemistry (LIC) will be getting no less than three new professors. Bonnet will become professor in Bioinorganic Chemistry, Codée professor in Organic Chemistry and Dame professor in Molecular and Cellular Biochemistry.

Mechanical forces are known to play an important role in bacterial colonies. In this dissertation, we study the self-organization at various stages of growing bacterial colonies, and focus on the mechanical effects of cell growth.

Organic amendments applied to agricultural fields can partially offset our carbon emissions to the atmosphere and improve the resilience of agriculture to the effects of climate change. Driving these benefits, however, are complex and poorly understood interactions between organic amendment properties,…

Multicopper oxidase, laccase, can efficiently reduce oxygen to water and are mostly used in the enzymatic biofuel cells.

The glycosylation reaction is a pivotal reaction in creating new and complex oligosaccharides.

Glycoconjugate vaccines are composed of microbial poly- or oligosaccharides covalently linked to a carrier protein.

Glycosidases are essential in fundamental biological processes and are responsible for the degradation of most (oligo)saccharides, glycolipids and glycoproteins.

Sphingolipids are important membrane compounds with a variety of functions. In mammalian cells, different enzymes are involved in the metabolism of sphingolipids, but interruption of this metabolism process leads to different diseases.

The research described in this Thesis was aimed at designing and synthesizing nature-inspired compounds as part of TB vaccine discovery.

The primary goal of this research is to deepen our understanding of substrate-enzyme interactions in Glycoside hydrolases. For this purpose, Bacillus circulans xylanase (BcX) has been selected as a well-established model to examine the Michaelis complex and glycosyl-enzyme adduct.

To this day, all cyclophellitol-based inhibitors and ABPs have been close analogues of their natural substrate counterparts. As a result, these probes showed high selectivity towards their target glycosidases.

Neuraminidases are enzymes that cleave glycosidic linkages of sialic acid. These enzymes are involved in influenza infections as well as in many cellular processes in mammals and micro-organisms.

Nicotinamide adenine dinucleotide (NAD+) is the substrate used for the introduction of the ubiquitous and highly dynamic PTM in which either one or multiple adenosine diphosphate ribose (ADPr) moieties are covalently attached to a nucleophilic side chain of an specific amino acid in the target protein…

As a virtually inexhaustible source, solar energy plays a major role in future global energy scenarios.

Climate change is a challenge for both current and future generations. New biological resources have to be developed in order to meet the demand for energy as well as the demand for food.

Decentralized plug and play systems for energy production are the future picture of our society. Artificial photosynthetic systems are used for this purpose.

Promotor: H.J.M. de Groot, Co-Promotor: A. Alia

Promotores: Prof.dr. H.J.M. de Groot, Prof.dr. J. Matysik (Universitaet Leipzig)

Promotor: H.J.M. de Groot, Co-Promotor: A. Alia

Promotor: Huub J.M. de Groot, Co-promotor: Francesco Buda

The Future of Multilateralism addresses current challenges and future perspectives of international and regional organizations. It aims to uncover how stable the foundations of global cooperation really are, particularly in the light of the latest unilateral and protectionist practices of international…

How can we understand the material instability of photographic (mixed media) artworks (1960s - present) from an integrated approach of Art History, Conservation Science and Chemistry in order to preserve these works for the future?

In this thesis, bioorthogonal chemistry is combined with correlative light-electron microscopy to selectively label and study pathogenic intracellular bacteria within the host immune cell.