Manganese is also used in portland cement mixtures. Manganese is an important element for human health, essential for development, metabolism, and the antioxidant system. Nevertheless, excessive exposure or intake may lead to a condition known as manganism, a neurodegenerative disorder that causes dopaminergic neuronal death and symptoms similar to Parkinson's disease. The classes of enzymes that have manganese cofactors is large and includes oxidoreductases, transferases, hydrolases, lyases, isomerases, ligases, lectins, and integrins. The reverse transcriptases of many retroviruses (though not lentiviruses such as HIV) contain manganese. The best-known manganese-containing polypeptides may be arginase, the diphtheria toxin, and Mn-containing superoxide dismutase (Mn-SOD).
Manganese Manganese compounds where manganese is in oxidation state +7, which are mostly restricted to the unstable oxide MnO, compounds of the intensely purple permanganate anion MnO, and a few oxyhalides (MnOF and MnOCl), are powerful oxidizing agents. Compounds with oxidation states +5 (blue) and +6 (green) are strong oxidizing agents and are vulnerable to disproportionation. The most stable oxidation state for manganese is +2, which has a pale pink color, and many manganese(II) compounds are known, such as manganese(II) sulfate (MnSO) and manganese(II) chloride (MnCl). This oxidation state is also seen in the mineral rhodochrosite (manganese(II) carbonate). Manganese(II) most commonly