Carbohydrates, glycans, and their conjugates play critical roles in a very broad spectrum of biological processes, many of which are central to human health, development and disease states. The diversity of glycan-dependent biological processes is reflected by the even-more diverse spectrum and complexity of the implicated glycans and glycoconjugates, collectively known as the glycome. The study of glycan dependent biological processes and their eventual regulation and/or exploitation in human medicine is enormously hampered by difficulties in isolating and structurally characterizing meaningful quantities of pure unique glycans, known as homogeneous glycoforms, from biological sources. It is imperative therefore that simple practical technologies for glycan synthesis be developed that combine robustness with ease of operation such that specialist and non-specialists alike will be able to access glycans with relative ease. This proposal aims to develop exactly the kind of scalable robust methodology that is required to address the chemical synthesis of a broad cross section of the glycome. The focus is on the development of direct photochemical methods without the need for external additives thereby reducing the system to its essentials – a glycosyl donor and glycosyl acceptor – and eliminating complexity to the greatest extent possible. The technologies to be developed are designed to employ light-emitting diodes (LEDs) as light sources and ultimately to be applicable under flow conditions so as to enable practical scaled-up syntheses of biologically important glycans.

The state-of-the-art in practical efficient and stereocontrolled preparation of glycosidic bonds lags far behind that for peptide and oligonucleotide synthesis and consequently seriously hinders the study of the biology of oligosaccharides and their conjugates. This proposal sets out two develop two new photochemical technologies for glycosidic bond formation, with the emphasis on simplicity and ease of operation such as will be required if synthetic glycans are to be made routinely available to the Glycoscience community.