Fig. 2

Scheme of oxidative cleavage reaction by LPMOs [18]. Possible products by C1 oxidation are aldonic acid (M+16, where M indicates the mass of native oligosaccharides), sodium adduct of aldonic acid (M+16-H+Na), and 1,5 δ-lactone (M−2), and those by C4 oxidation are 4-ketoaldose (M−2) and gemdiol (M+16). A product that contains both aldonic acid and gemdiol (M+32), 1,5 δ-lactone and gemdiol (M+14), or aldonic acid and 4-ketoaldose (M+14) is an evidence of double (C1/C4) oxidation