School of Molecular Sciences, The University of Western Australia, Crawley, WA 6009, Australia.
CNRS, Sorbonne Université, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074 Roscoff, Bretagne, France.
J Org Chem. 2020 Dec 18;85(24):16182-16195. doi: 10.1021/acs.joc.0c02339. Epub 2020 Nov 12.
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--equatorial α-linkage. Using the late stage ring closure approach, an -linked analogue of methyl neo-β-carrabioside was also realized. These compounds have applications in the identification and characterization of marine bacterial -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 -α-3,6-anhydro-d-galactosidase GH129 demonstrates that the minimum substrate unit for the enzyme is neo-β-carrabiose.
甲基新β-卡拉胶苷首次被合成，采用后期环合来安装所需的 3,6-脱水桥，或采用合适的 3,6-脱水半乳糖供体来形成不受欢迎的 1,2--赤道α-键。采用后期环合方法，还实现了甲基新β-卡拉胶苷的 -连接类似物。这些化合物可用于鉴定和表征对红藻新卡拉胶低聚糖具有特异性活性的海洋细菌 -α-3,6-脱水-d-半乳糖苷酶，例如糖苷水解酶家族 127 和 129 中发现的那些。此外，使用合成的甲基新β-卡拉胶苷和海洋细菌 -α-3,6-脱水-d-半乳糖苷酶 GH129 的生化测定表明，该酶的最小底物单位是新β-卡拉双糖。
