Research
Current Research Projects
« Why Nature Chose Phosphates » is the title of a Science classic article published by Westheimer.[ Science 1987, 235, 1173] The initial statement « phosphate esters and anhydrides dominate the living world […] » spotlights the prominent importance of this type of modification. It is for this reason that our group has defined the chemistry and biology of phosphates and its conjugates a central research topic. Below you will find a brief overview of current research interests within our laboratory.
Inositol Pyrophosphates
Inositol Pyrophosphates are essential second messengers in eukaryotes. Their stereoselective synthesis and the generation of analogues for studies into their biology is a central topic in the Jessen laboratory. The chemical biology of inositol pyrophosphates and the lower inositol phosphates holds great potential to understand this important and understudied class of molecules. Potential applications of the knowledge generated are in drug development with a particular focus on metabolic diseases, such as diabetes and obesity.
Magic Spot Nucleotides
Magic Spot Nucleotides are bacterial and plant alarmones, that signal stress. In bacteria, they are involved in the stringent response, a condition that eventually leads to metabolic shutdown and persistence towards antibiotics. Research in this area will help us to understand how bacteria (and plants) adjust to stresses and how this could be exploited for antibiotics development.
Analytical Chemistry of Polar Metabolites
Analytical Chemistry of Polar Metabolites is essential for our efforts to understand charged metabolites and messengers. We are focusing our research on 31P NMR spectroscopy in combination with electrophoretic methods, in particular capillary electrophoresis mass spectrometry (CE-MS) and gel electrophoresis.
Photo-Cages, Switches, and Cleaver
Photo-Cages, Switches, and Cleaver are developed to enable light controlled manipulation of small organic molecules, in particular second messengers. Moreover, the light-controlled inhibition of enzyme function is another aspect we are working on. The development of new photcages and switches that respond to diverse wavelengths with defined kinetics is critically required to obtain the next generation of chemical biology tools. These will be required to fully appreciate the biological functions of second messengers with spatiotemporal control.
Condensed Phosphates
Condensed Phosphates are an important family of molecules. Their synthesis and study on a fundamental level will help us to understand the rich biology of inorganic polyphosphates and the related cyclic metaphosphates. Moreover, reagent development based on condensed phosphate analogues can contribute significantly to a sustainable use of phosphate resources and can unlock efficient synthetic approaches towards densely phosphorylated metabolites.
Reactive Oxygen Species
Reactive Oxygen Species (ROS) are essential in biological signalling but can also cause cell damage. Molecular design enables us to store and release oxygen and ROS on demand to fulfill different functions. For example, singlet oxygen (1O2 ) is a high-energy species derived from ground-state triplet oxygen. Singlet oxygen can damage cellular membranes and can be used for example to kill bacteria. The controlled intramembrane release of singlet-oxygen from aromatic endoperoxides is thus an appealing approach to develop new antibiotics. Another application is the reversible storage of oxygen is materials science.
Individual Research Projects
Some Recent Key References:
- C. Popp, P. Moser, X. Liu, J. Freitag, P. Sarmah, I. Prucker, R. Zscherp, X. Wang, P. Klahn, H.-G. Koch, G. Bange, H. J. Jessen “Controlled Delivery and Light-Induced Release of Magic Spot Nucleotides in Escherichia coli.” Angew. Chem. Int. Ed. 2026, 0:e23307 https://doi.org/10.1002/anie.202523307
- G. M. Häner, G. Liu, E. Lange, N. Jork, K. Ditrich, R. Greiner, G. Schaaf, H. J. Jessen ” Stereoselective chemoenzymatic phytate transformations provide access to diverse inositol phosphate derivatives.” Chem. Sci. 2025, 16, 13459.
- K. Ritter, A.-S. C. Braun, G. Liu, M. Lu, V. Gaugler, G. Schaaf, H. J. Jessen ” Expanding the Inositol Pyrophosphate Toolbox: Stereoselective Synthesis and Application of PP-InsP4 Isomers in Plant Signaling ” Angew. Chem. Int. Ed. 2025, e202507058
- S. Moser, G. Hans, A. Shukla, A. Saiardi, S. Bru, A. Aras Taskin, C. Meisinger, H. J. Jessen “A Screening Approach Unveils an Unknown Mn2+-dependent Endopolyphosphatase Activity in Yeast” Chem. Sci. 2025, 16,13760
- G. Kim, G. Liu, D. Qiu, N. Gopaldass, G. De Leo, J. Hermes, J. Timmer, A. Saiardi, A. Mayer, H. J. Jessen “Pools of independently cycling inositol phosphates revealed by pulse labeling with 18O-water.” J. Am. Chem. Soc. 2025, 147,17626
- A. Ripp, M. Krämer, V. Barth, P. Moser, T. M. Haas, J. Singh, T. Huck, L. Gleue, K. Friedland, M. Helm, H. J. Jessen “The P(III)-amidite based synthesis of stable isotope labeled mRNA-cap-structures enables their sensitive quantitation from brain tissue” Angew. Chem. Int. Ed. 2025, 64, e202414537
- V. B. Eisenbeis, D. Qiu, O. Gorka, L. Strotmann, G. Liu, I. Prucker, K. Ritter, C. Loenarz, O. Gross, A. Saiardi, H. J. Jessen “β-Lapachone Regulates Inositol Pyrophosphate Levels in an NQO1 and Oxygen-dependent Manner.” Proc. Natl. Acad. Sci. USA 2023, 120, e2306868120.
- D. Qiu, E. Riemer, T. M. Haas, I. Prucker, S. Masuda, Y. L. Wang, G. Felix, G. Schaaf, H. J. Jessen “Bacterial Pathogen Infection Triggers Magic Spot Nucleotide Signaling in Arabidopsis thaliana Chloroplasts Through Specific RelA/SpoT Homologs” J. Am. Chem. Soc. 2023,145, 16081–16089.
- N. Qin, L. Li, X. Ji, R. Pereira, Y. Chen, S. Yin, C. Li, X. Wan, D. Qiu, H. Luo, Y. Zhang, G. Dong, Y. Zhang, S. Shi, H. J. Jessen, J. Xia, Y. Chen, C. Larsson, T. Tan, Z. Liu, J. Nielsen “Flux Regulation through Glycolysis and Respiration is Balanced by Inositol Pyrophosphates” Cell 2023, 186, 748–763.
- G. Liu, E. Riemer, R. Schneider, D. Cabuzu, O. Bonny, C. A. Wagner, D. Qiu, A. Saiardi, A. Strauss, T. Lahaye, G. Schaaf, T. Knoll, J. P. Jessen, H. J. Jessen “The phytase RipBL1 enables the assignment of a specific inositol phosphate isomer as a structural component of human kidney stones” RSC Chem. Biol. 2023, 4, 300-309.
- T. M. Haas, B.-J. Laventie, S. Lagies, C. Harter, I. Prucker, D. Ritz, R. Saleem-Batcha, D. Qiu, W. Hüttel, J. Andexer, B. Kammerer, U. Jenal, H. J. Jessen “Photoaffinity capture compounds to profile the Magic Spot Nucleotide interactomes ” Angew. Chem. Int. Ed. 2022,61, e2022017
- T. M. Haas, S. Mundinger, D. Qiu, N. Jork, K. Ritter, T. Dürr-Mayer, A. Ripp, A. Saiardi, G. Schaaf, H. J. Jessen “Stable isotope phosphate labelling of diverse metabolites is enabled by a family of 18O-phosphoramidites” Angew. Chem. Int. Ed. 2022, 61,e202112457