Professor Hermen Overkleeft has received the esteemed Roy L. Whistler International Award in Carbohydrate Chemistry for 2024 by the International Carbohydrate Organization. The award recognises Overkleeft’s outstanding contributions to the field of carbohydrate chemistry and biochemistry.

Promotores: Prof.dr. H.S. Overkleeft, Prof.dr. G.A. van der Marel

This thesis focuses on the design and synthesis of activity-based probes and inhibitors targeting enzymes involved in the degradation of specific plant glycans.

Peptides are routinely synthesized in the range of 5-80 amino acids, in an amount of 1-200 µmol (smaller and larger amounts are also possible).

This Thesis focuses on the design and synthesis of ADP-ribosylated compounds that can be applied in biological studies.

Climate change is one of the largest challenges faced by humanity. To combat this research into alternatives to fossil fuels is ongoing. Dihydrogen is considered a good alternative fuel, since its burning only forms water.

The central theme of the NWO-project ‘The Promise of Organization’ is the evolution of political organization during the 19th century. We focus on the enthusiasm, arguments and concrete activities of the organizers as well as the criticism offered by opponents of modern political organization.

Petra van der Bekerom, Joris van der Voet, and Johan Christensen, three assistant professors at Leiden University, conducted a large-scale survey experiment about whether citizens are more negative about failing service delivery than private organizations.

Cyclic peptides are investigated as a platform to induce different orientations between various ligands.

Netherton Syndrome (NTS) is a rare genetic skin disease caused by mutations in the serine protease inhibitor Kazal-type 5 gene, which encodes the lympho-epithelial Kazal-type-related inhibitor. NTS patients have a profound impaired skin barrier function. Because SC lipids play a crucial role in the…

Alzheimer's disease (AD) is the most frequent neurodegenerative disorder and the primary cause of dementia. The neuropathological features of AD include the occurrence of senile plaques, neurofibrillary tangles, decreased synaptic density, and loss of neurons. An obstacle in the study and treatment…

This work describes the use of click-to-release chemistry to get spatiotemporal control over immunocytokine activity. Until now, immunocytokines (cytokines coupled to a tumor-targeting-moiety) remained active throughout the body, being able to bind their respective receptors, causing mild to severe…

The research described in this thesis focused on the preparation of S/N functionalized carbene ligands and their transition metal complexes, and the exploration of their application as electrocatalysts for proton reduction.

Glycoside hydrolases (glycosidases/GHs) are widely abundant enzymes in all kingdoms of life and are important biocatalysts that catalyze the hydrolysis of glycosidic linkages in oligo/polysaccharides, glycoproteins and glycolipids with tremendous efficiency

It is the aim of this project to better understand how the physical properties of lipids influences the structure and overall barrier function of the skin.

Do recent developments in the European security architecture signal the end of multilateral cooperation, or the beginning of a new era with emerging forms of international security collaboration?

In the hunt for a vaccine against cervical cancer, fundamental knowledge about the immune system and organic chemistry have been brought together and have already resulted in a vaccine that is now being tested in clinical trials. Scientists are now working hard on an improved variant.

This thesis has described novel synthetic methods to produce a variety of (glyco)peptides and their application in the study of various immunological processes.

A dense region of a gaseous and dusty cloud collapses to form a protostar surrounded by a disk and an envelope. This thesis uses both observations and models to study physical and chemical conditions of these protostellar systems which are likely where planets start to form.

Promotores: H.S. Overkleeft, G.A. van der Marel, Co-promotor: B.I. Florea

This thesis describes the use of a combined approach of computational and experimental techniques to gain novel insights to understand the glycosylation reaction and its reactive intermediates.

Public management scholars have long debated public and private sector differences. However, the generalizability of empirical results has been limited due to the shortage of cross-national studies.

Reducing greenhouse gas emissions is one of the most pressing challenges that humanity faces in the coming decades.

Zebrafish is an excellent model organism for studying various human diseases. Due to opaqueness of the adult phase, in vivo studies are restricted to early embryonic stages. This raises the need for rapid sensitive and non-invasive in vivo imaging methods to follow developmental processes, not only…

Advanced UHF MRI techniques provide powerful tools for studying the zebrafish brain, an emerging model in neurological research. In this work, various MRI and localized MRS methods are optimized and employed for UHF strength for studying the zebrafish brain.

Dr. at the Department of organic chemistry, Wageningen University - the Nederlands

This dissertation explores new chemical strategies for the synthesis of self-adjuvanting peptide conjugates and immunomodulatory ligands aimed at targeted activation of the immune system.

A key step in the synthesis of oligosaccharides and glycoconjugates is the formation of the glycosidic bond.

Contact Bio-organic Synthesis

This paper describes two synthetic lipid models designed to replace human stratum corneum (SC) in studies of the impact of volatile organic chemicals on the molecular organization of the skin barrier lipids.

The lipids in the uppermost layer of the skin, the stratum corneum (SC), play an important role in the skin barrier function. The three main SC lipid classes are ceramides (CER), cholesterol and free fatty acids.

The lipid matrix in the stratum corneum (SC), the upper layer of the skin, plays a critical role in the skin barrier. The matrix consists of ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs).

The aim of this research was to develop an effective, generative, and practical approach to enhance students’ structure-property reasoning (SPR).

Promotor: H.J.M. de Groot

Chapter 2 describes a post-synthetic methodology to introduce a fluorescent label in highly lipophilic, Pam3Cys based conjugates.

An attractive feature of the MSc Chemistry programme at Leiden University is the great flexibility of the study programme, allowing students to put together a tailor-made programme following their personal interests. Within the limits set by the programme, students can make their own choices and adjust…

With defending his thesis ‘Applications of topology to Weyl semimetals and quantum computing’, the Leiden theoretical physicist Tom O'Brien has gained the rare 'cum laude' qualification. The freshly minted PhD has started a five year research programme on quantum algorithms for quantum chemistry, funded…

Physicians and researchers of the Leiden University Medical Center (LUMC) and Leiden University are working on therapies for restoring damaged organs such as hearts and kidneys. They are even trying to construct tailor-made organs. Read more on this topic in the new science dossier on Vascular and Regenerative…

Molecular Physiology is a research group at the Leiden Institute of Chemistry dedicated to the design, synthesis and application of chemical tools to study important biological and biomedical questions. The group is headed by Prof. Dr. Mario van der Stelt and includes the research lines of Assistant…

Professor Craig M. Crews of Yale University (USA) is the recipient of the 2025 Havinga Medal.

Promotores: Prof.dr. H.S. Overkleeft, Prof.dr. G.A. van der Marel

Promotores: H.S. Overkleeft; G.A. van der Marel Co-Promotor: B.I. Florea

Phosphorylation affects all four major biomolecules – proteins, lipids, carbohydrates and nucleic acids – and plays a pivotal role in the most fundamental cellular functions.

In this Ph.D. thesis we study the interaction of low energy electrons with thin materials, namely layered materials (graphene, hexagonal boron nitride, molybdenum disulfide) and organic films. At these low energies the quantum mechanical wavelength of the electron wave function is in the order of a…

Beyond Empires explores the complexity of empire building from the point of view of self-organized networks, rather than from the point of view of the central state.