SYNTHESIS OF PROTODIOSCIN

Abstract

Glycosylation is a fundamental reaction in organic chemistry that involves the attachment of a sugar moiety to a non-sugar molecule, such as a steroid or a protein. This ubiquitous biological process is observed across all living organisms and performs vital functions such as facilitating cell-cell recognition, signal transduction, and immune responses. Additionally, glycosylation can modulate the properties of biomolecules, such as their solubility, stability, and bioactivity making it a valuable tool for drug discovery and development. Protodioscin is a natural steroid saponin that has attracted attention for its pharmacological properties, which include anti-inflammatory, anticancer, and anti-diabetic effects. However, its isolation from natural sources is complex and inefficient, making chemical synthesis an attractive alternative. In this study, I developed a gold-catalyzed glycosylation approach for synthesising protodioscin from readily available starting materials. The synthesis involved using a gold(I) catalyst and a glycosyl donor to selectively activate the C-3 position of a steroid precursor, followed by regio- and stereoselective glycosylation at the C-26 position. The reaction was optimised using a range of reaction conditions. My results demonstrate an elementary, proficient, and scalable approach for the synthesis of protodioscin, which has the potential to facilitate its further investigation as a therapeutic agent.