Exploring the Chemical Properties and Medicinal Applications of Tetramethylthiocycloheptyne Sulfoximine Used in Strain-Promoted Azide-Alkyne Cycloaddition Reactions

• Main Authors: Matt Timmers (Author), Andi Kipper (Author), Raphael Frey (Author), Stef Notermans (Author), Maksym Voievudskyi (Author), Claire Wilson (Author), Nina Hentzen (Author), Michael Ringle (Author), Clara Bovino (Author), Bernhard Stump (Author), Cristianne J. F. Rijcken (Author), Tina Vermonden (Author), Ingrid Dijkgraaf (Author), Rob Liskamp (Author)
• Format: Book
• Published: MDPI AG, 2023-08-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/ph16081155; 1424-8247
• Keywords: SPAAC; click chemistry; stability; bio-orthogonal chemistry; bioconjugation; Medicine; R; Pharmacy and materia medica; RS1-441
• Source: Pharmaceuticals, Vol 16, Iss 8, p 1155 (2023)

The recently developed compound, tetramethylthiocycloheptyne sulfoximine (TMTHSI), has shown to be a promising strained alkyne for strain-promoted azide-alkyne cycloaddition (SPAAC), metal-free click chemistry. This research explores the properties of TMTHSI-based compounds via three aspects: (1) large-scale production, (2) unique stability in acidic conditions and its subsequent use in peptide synthesis, and (3) the functionalization of antibodies. Here, it is shown that (1) scale-up is achieved on a scale of up to 100 g. (2) TMTHSI is remarkably stable against TFA allowing for the site-specific functionalization of peptides on resin. Finally, (3) the functionalization of an antibody with a model payload is very efficient, with antibody conjugation demonstrating more beneficial features such as a high yield and limited hydrophobicity as compared to other alkyne reagent conjugates. These results illustrate the high potential of TMTHSI for diverse bioconjugation applications, with production already being GMP-compatible and a highly efficient conversion resulting in attractive costs of goods.