Spectrophotometric evidence for the formation of a short-lived Mn(VI) intermediate has been confirmed during the oxidation of pectin polysaccharide, a natural polymer, as well as poly (vinyl alcohol) [PVA], a synthetic polymer, by potassium permanganate in alkaline medium at pH's > 12. This Mn(VI) intermediate was characterized by a band at a wavelength of 606 nm an absorption maximum, with a molar extinction coefficient of 1200 ± 50 dm3mol−1cm−1