• dysregulations enzymatic activity
• fluorescent molecular probes
• glycoconjugates
• stereoselective synthesis
• tumoral metabolism

Enzymes play a fundamental role in the regulation of cellular metabolism. Many pathologies are closely related to an enzyme pool malfunction, such as Lysosomal Storage Diseases (related to the reduced or absent activity of specific enzymes) and many tumoral processes which sustain their dysregulated growth from the increased activity of some enzymes. In both cases, of considerable interest are α- and β-glucosidases. The evaluation of enzymatic activity, by means of quantitative assays, is therefore of a wide interest both for diagnostic and therapeutic purposes. The use of fluorogenic substrates in determination and quantification of enzymatic activity is considered one of the most reliable approaches both in the clinical and research fields, as these substrates can be easily synthesized and the developed assays are highly reproducible and sensitive. However, most of the analytical methods can’t be adapted in vitro and in vivo mainly due to the photophysical and chemical issues of commonly used fluorogenic substrates (i.e. poor solubility, lack of cell internalization, photobleaching). In particular, assays that use coumarin-based scaffolds as fluorophore provide a basification step at pH (up to 10) not compatible with a quantification of fluorescence in living cells (neutral/acidic pH). This problem places severe limitations on the possibility of generating maps of enzymatic activity spatially or temporally resolved by taking advantage of widely used microscopy techniques. Therefore, the development of new fluorescent sensors capable of signalling with high spatio-temporal precision dysregulations of enzymatic activity could allow to evaluate more accurately both the metabolic state of individual cells and the therapeutic effect in drug screening techniques. In order to meet these requirements, this thesis work focused on development and stereoselective synthesis of innovative fluorescent glycoconjugates. These molecular probes are constituted by a sugar unit, necessary for direction and cellular uptake of the probe, and by a coumarin-based fluorogenic moiety potentially capable of allowing the development of direct diagnostic techniques (diagnostic imaging) and precision medicine especially in tumoral field (surgery removed tissues by means of Fluorescence-Guided Surgery techniques).