GEL-PERMEATION CHROMATOGRAPHIC STUDY OF THE MOLECULAR-WEIGHT DISTRIBUTION OF TANNINS IN THE WOOD, BARK AND LEAVES OF EUCALYPTUS SPP

The molecular weight distribution of tannins from the wood, bark and l eaves of Eucalyptus camaldulensis, E. globulus and E. rudis from two d ifferent Spanish provenances has been studied by high performance gel permeation chromatography, using the compounds' acetylated derivatives . The MW distribution profiles showed important variability depending on the type of vegetal tissue, the species and, in some cases, on the geographical provenance of the samples. Bark was the vegetal tissue th at yielded tannins with the highest molecular weight, followed by wood and leaves. Tannins from wood and bark of E. camaldulensis were of hi gher molecular size than those from E. globulus and E. rudis; those in the leaves of E. globulus and E. camaldulensis were similar in molecu lar size and larger than those in the leaves of E. rudis.