LINDOW MAN, TOLLUND MAN AND OTHER PEAT-BOG BODIES - THE PRESERVATIVE AND ANTIMICROBIAL ACTION OF SPHAGNAM, A REACTIVE GLYCURONOGLYCAN WITH TANNING AND SEQUESTERING PROPERTIES

The tanning reaction that contributes to the preservation of animal tissues by peat consists of a Maillard reaction between the free amino-groups of collagen and reactive carbonyl groups in a soluble glycuronoglycan ('sphagnan') containing residues of D-lyxo-5-hexosulopyranuronic acid. Sphagnan is a complex, pectin-like material which is covalently linked to cellulosic and amyloid-like chains in living Sphagnum moss, but slowly liberated by autohydrolysis into the ambient water as the dead moss is converted into peat. It is a precursor of aquatic humus from Sphagnum peat, and the tanning of adventitious collagen in animal remains is only one manifestation of the continuous incorporation of ammonia, amino-acids and polypeptides from a wide variety of sources into the structure of the humic acid molecule. Sphagnan can also suppress microbial activity by reacting with exo-enzymes and sequestering essential, multivalent metal cations.