Mini Reviews in Medicinal Chemistry - Volume 25, Issue 11, 2025

O-GlcNAcylation is a non-canonical form of protein glycosylation that occurs in nuclear, cytoplasmic, and mitochondrial proteins among all multicellular eukaryotes. There are only two enzymes that regulate this post-translational modification, one of which is O-GlcNAcase, a glycoside hydrolase that catalyzes the hydrolytic cleavage of O-GlcNAc from protein substrates. Related studies have shown that the reduction of O-GlcNAc levels is closely related to Alzheimer's disease, which is maintained by reducing the aggregation of tau via inhibiting O-GlcNAcase. Various small-molecule O-GlcNAcase inhibitors with different chemical structures have been developed and used as chemical probes to explore the O-GlcNAc pathway. Although many reported inhibitors have shown that O-GlcNAcase activity has single-digit nmol IC50 values in binding assays, and molecules, such as LY-3372689, have entered phase II clinical studies, further exploration of novel O-GlcNAcase inhibitors with higher inhibitory activity and specificity is still worthy of attention. This article reviews the pathogenesis and therapeutic role of O-GlcNAcase in Alzheimer's disease, as well as the recent progress of O-GlcNAcase small molecule inhibitors, including sugar-derived or non-sugar scaffolds, and summarizes the clinical progress and potential prospects of O-GlcNAcase inhibitors.

Currently, the synthesis of bioactive sulfonamides using amino acid as a starting reagent has become an area of research interest in organic chemistry. Over the years, an amine-sulfonyl chloride reaction has been adopted as a common step in traditional sulfonamide synthetic methods. However, recent developments have shown amino acids to be better precursors than amines in the synthesis of sulfonamides. Although amines and amino acids have some structural similarities, using amino acids rather than amines in the synthesis of sulfonamides minimizes several drawbacks. Comparatively, amino acids are preferred to amines as starting reagents in sulfonamide synthesis due to their biological relevance, chirality, stereochemistry, diversity of side chains, orthogonality in functional group manipulation, the potential for peptide and protein synthesis, mild reaction conditions, alignment with green chemistry principles, diverse synthetic applications, easy availability, and economic viability. Amino acids, having the aforementioned properties, offer a versatile platform for the synthesis of sulfonamides with tailored structures. The reaction mechanism of the synthesis of amino acid-derived sulfonamides involves a nucleophilic attack by the amino group on the activated sulfonyl species to produce a sulfonamide functional group. Amino acid-based sulfonamides have numerous pharmacological activities, including antibacterial, antiviral, anticancer, antioxidant, anti-inflammatory, anti-plasmodial, antimalarial, anti-trypanosomal, and insect growth regulatory properties. This review discusses several synthetic processes, emphasizing established ways, cutting-edge techniques, and novel approaches that emphasize the significance of amino acids in the synthesis of sulfonamides. The structure-activity relationship of amino acid-derived sulfonamides and their pharmacological activities are also highlighted.