LONG-TERM DEGRADATION OF TERPENES FROM A 20-MILLION YEARS OLD TAXODIOXYLON GYPSACEUM

The comparison of the steam distillate from a 20 million years old Tax odioxylon gypsaceum with that of a corresponding 1.5 million years old sample has permitted the description of the last steps of terpene deg radation of this species. The main feature is the reduced number of co mponents in the older sample which contains over 97% of alpha-phyllocl adane and traces of other components present, by contrast, in the youn ger one. The lack of new compounds, related to the lost components, su ggests leaching to be the cause of the losses. This seems to be confir med by the analysis of the inner part of a trunk of one of the younger samples presently subjected to a sort of natural leaching. Analyses i ndicate an increase in alpha-phyllocladane and a severe reduction in s imonellite as well as other terpenes, together with the formation of t wo new compounds of 164 and 222 MWs. The occurrence of alpha-phyllocla dane in other European lignites suggests the choice of this compound a s a biomarker of the species Taxodioxylon gypsaceum.