Publications by authors named "J Lehn"

The hypoxic microenvironment is crucial for tumour cell growth and invasiveness. Tumour tissue results from adaptation to reduced oxygen availability. Hypoxia first activates pro-angiogenic signals for alleviation.

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Molecular recognition and detection of small bioactive molecules, like neurotransmitters, remain a challenge for chemists, whereas nature found an elegant solution in form of protein receptors. Here, we introduce a concept of a dynamic artificial receptor that synergically combines molecular recognition with dynamic imine bond formation inside a lipid nanoreactor, inducing a fluorescence response. The designed supramolecular system combines a lipophilic recognition ligand derived from a boronic acid, a fluorescent aldehyde based on push-pull styryl pyridine and a phenol-based catalyst.

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SAr reactions were remarkably accelerated using a pretargeting and activating unit based on dynamic covalent chemistry (DCvC). A Cys attack at the C-F bond on the aromatic ring of salicylaldehyde derivatives was only observed upon iminium formation with a neighboring Lys residue of model small peptides. Such self-activation was ascribed to the stronger electron-withdrawing capability of the iminium bond with respect to that of the parent aldehyde that stabilized the transition state of the reaction, together with the higher preorganization of the reactive groups in the cationic aldiminium species.

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Developing visible-light-driven fluorescent photoswitches in the solid state remains an enormous challenge in smart materials. Such photoswitches are obtained from salicylaldimines through excited-state intramolecular proton transfer (ESIPT) and subsequent cis-trans isomerization strategies. By incorporating a bulky naphthalimide fluorophore into a Schiff base, three photoswitches achieve dual-mode changes (both in color and fluorescence) in the solid state.

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Sea urchin eggs are covered with layers of extracellular matrix, namely, the vitelline layer (VL) and jelly coat (JC). It has been shown that sea urchin eggs' JC components serve as chemoattractants or ligands for the receptor on the fertilizing sperm to promote the acrosome reaction. Moreover, the egg's VL provides receptors for conspecific sperm to bind, and, to date, at least two sperm receptors have been identified on the surface of sea urchin eggs.

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