TETRACYCLIC DITERPANES OF CARBONIFEROUS AND PERMIAN HUMIC COALS IN NORTH CHINA

Diterpenoid biomarkers were evidently detected by GC and GC/MS analysis in the saturated hydrocarbon fractions of arboniferous and Permian humic coals in five coal mines in the western and Southern North China. Based on the characteristics of mass spectra, kovats indices as well as the comparison with literature ， their major conipcTnents were determined as five tetracyclic diterpanes with kaurane-typc skeletons, i.e., ent-beyerane, 16α(H) -and 16β(H) -phyllocladanes, 16α(H) -and 16β(H) -Kauraaes as well as atricyclic isopimarane, The discovery of a complete series of tetracyclic diterpanes in the Carboniferous and Permian coals in North China probably is the first case in the northern hemisphere. The differences of diterpenoid inner composition of humic coals trom different periods and positions in North China may reflect the variation of evolution and distribution of the palaeobotanic assemblages. The stereochemical configurations of phyllocladanes and kauranes could provide some information on the itiaturity of organic matter.