The natural product biomarkers in succinite, glessite and stantienite ambers from Bitterfeld, Germany

The biomarker compositions of six ambers (two glessites, two succinites, goitschite, and stantienite) from the Upper Oligocene of the Bitterfeld deposit in Germany were analyzed by gas chromatography–mass spectrometry (GC-MS) to determine their botanical origin. The extracts of the two glessites have similar compositions comprised of sesquiterpenoids of the cadinane and bisabolane classes and triterpenoids of the oleanane, ursane, lupane, and allobetulane classes. These triterpenoids are common in angiosperms. The botanical origin of the glessite ambers is proposed to be Betula, because allobetulane triterpenoids are the specific biomarkers for that genus. The constituents of two succinites and goitschite are similar, mainly consisting of succinic acid, borneol monoterpenoids, cadinane sesquiterpenoids, isopimarane, pimarane, and abietane type diterpenoids, with a predominance of dehydroabietic acid. Monoterpanyl succinates and monoterpanyl diterpenoates are also present. Monoterpanyl esters are one notable characteristic of succinite type ambers. The terpenoid compositions of these ambers indicate Pinaceae as the botanical source. Furthermore, the detailed examination of our results suggests that the ambers are derived from resins of Pinus or Picea (Pinaceae). The stantienite yielded an unresolved complex mixture (UCM) of branched and cyclic compounds, C12–C32 methyl alkanoates (maximizing at C25) and C12–C27 dimethyl alkanedioates (maximizing at C18), with minor amounts of aromatic diterpenoids and triterpenoids including hopanes. The series of methyl esters are regarded to be derived from leaf waxes and suberins of higher plants. The carbon preference indices (CPI) of the methyl alkanoates and alkanedioates indicate full diagenetic/catagenetic maturity of the amber. Unknown compounds A and B (MW = 400) are major components in the amber and also occur in the Miocene resin of Cupressospermum saxonicum. Thus the botanical source of stantienite may be in part the same as the Miocene resin. The amber is also admixed with microbial triterpenoids, leaf wax and biopolymer products indicating mixed sources.