Analysis of lignin and proanthocyanidin polymers the most abundant pol
yphenols in the biosphere, heavily relies on chemical degradation meth
ods. The most recent development of acid-catalysed degradations in the
presence of cn nucleophilic thiol are presented: identification of no
vel monomeric units, determination of frequency and nature of monomer
units and intermonomeric linkages, determination of polymer refit;ent
in plant materials.