Further evidence for detection of short-lived transient hypomanganate(V) and manganate(VI) intermediates during oxidation of some sulfated polysaccharides by alkaline permanganate using conventional spectrophotometric techniques

Spectrophotometric evidence for the formation of hypomanganate(V), [CAR-MnVO43-], and manganate(VI), [CAR-MnVIO42-], intermediate complexes has been confirmed during the oxidation of iota- and lambda-carrageenan-sulfated polysaccharides (CAR) by alkaline permanganate at pHs ⩾12 using a conventional spectrophotometer. These short-lived intermediate complexes were identified and characterized. A reaction mechanism in good consistence with the experimental results is suggested.

Graphical abstractThe kinetics of oxidation of iota- and lambda-carrageenan polysaccharides by alkaline permanganate have been investigated spectrophotometrically. A kinetic evidence for the formation of 1:1 intermediate complexes is revealed. The products were keto-acid oxidation derivative and were identified by IR spectra and elemental analysis.Figure optionsDownload full-size imageDownload as PowerPoint slide