Red Algal Molecules - Synthesis of Methyl Neo-β-carrabioside and Its S-Linked Variant via Two Synthetic Routes: A Late Stage Ring Closure and Using a 3,6-Anhydro-d-galactosyl Donor

Michael D Wallace (1) , Elizabeth Ficko-Blean (2) , Keith A Stubbs (1)

1 UWA - The University of Western Australia
2 LBI2M - Laboratoire de Biologie Intégrative des Modèles Marins

Methyl neo-β-carrabioside has been synthesized for the first time, employing either a late stage ring closure to install the required 3,6-anhydro-bridge or a suitable 3,6-anhydro-galactosyl donor to form the unfavored 1,2-cis-equatorial α-linkage. Using the late stage ring closure approach, an S-linked analogue of methyl neo-β-carrabioside was also realized. These compounds have applications in the identification and characterization of marine bacterial exo-α-3,6-anhydro-d-galactosidases that have specific activity on red algal neo-carrageenan oligosaccharides, such as those found in both family 127 and 129 of the glycoside hydrolases. In addition a biochemical assay using the synthesized methyl neo-β-carrabioside and the marine bacterial exo-α-3,6-anhydro-d-galactosidase ZgGH129 demonstrates that the minimum substrate unit for the enzyme is neo-β-carrabiose.

Mots clés: Column chromatography; Peptides and proteins; Free radicals; Alkyls; Post-translational modification

Domaines: Chimie

Michael D Wallace, Elizabeth Ficko-Blean, Keith A Stubbs. Red Algal Molecules - Synthesis of Methyl Neo-β-carrabioside and Its S-Linked Variant via Two Synthetic Routes: A Late Stage Ring Closure and Using a 3,6-Anhydro-d-galactosyl Donor. Journal of Organic Chemistry, 2020, 85 (24), pp.16182-16195. ⟨10.1021/acs.joc.0c02339⟩. ⟨hal-03471275⟩