Design and Synthesis of Boronic Acid-Based Sensors for Microarray Analysis and FRET-detection to study Carbohydrates

Carbohydrates play significant roles in various biological and pathological processes such as cancer metastasis and inflammation. They participate in various signaling pathways and are able to bind to a litany of biological receptors such as proteins and viruses. Biologists have known for decades that the structure of glycans changes with the onset of cancer and inflammation. Due to these important activities, carbohydrate sensing has long been a focus of research. One example of such a carbohydrate sensor is boronic acid-based sensors. Boronic acid-based sensors are of particular interest due to their selectivity for 1,2- or 1,3-diols. A variety of techniques have been employed for detection. Two techniques that have rarely been applied are high-throughput microarray analysis and FRET detection. In this thesis, we present work based on the development of a boronic acid-based carbohydrate sensor that will be used for microarray analysis and the development of various fluorophore-tagged boronic acids as donor/acceptor pairs for FRET detection. The receptor design includes a phenylboronic acid for carbohydrate recognition, an amine in close proximity to the boron center to enhance binding, and a terminal amine for attachment to the epoxysilane microarray slide. In FRET detection, it is a requirement that the emission spectrum of the donor overlaps with the absorption/ emission spectrum of the acceptor. A FRET pair used in this thesis is coumarin/NBD-tagged boronic acid. These compounds will be used to study the detection of saccharides by boronic acids