Figure 5

MALDI ToF MS spectra of oxime functionalized oligosaccharides. The structure of a functionalized tetramer is shown above the spectra. The upper spectrum shows bi-functionalized oligosaccharides obtained from a product mixture generated by NcLPMO9A from PASC. The spectrum shows clear signals for a trimeric, tetrameric, and pentameric double-funtionalized compound and a lower signal for the hexameric product (m/z 641, 803, 965 and 1,127, respectively; all sodium adducts). There are also peaks corresponding to proton and potassium adducts denoted [M+H]⁺ and [M+K]⁺. The lower panel shows functionalization of LPMO-generated C4-oxidized products that were C1-protected through oxidation by CDH (m/z values are 42 lower compared to panel (A); sodium adducts). The latter spectrum also shows peaks corresponding to [M−H+2Na]⁺ and [M−H+K+Na]⁺ adducts, which are formed due to the presence of an (CDH-generated) aldonic acid group. The spectra were generated with Flex analysis 3.4, https://www.bruker.com.