Introduction:

Quesnoin, a Novel Pentacyclic ent-Diterpene from 55 Million Years Old Oise Amber

“…A new amber fossil deposit was discovered, in 1997, at the Quesnoy locality in the Oise River area of the Paris basin (France). The deposit is exceptionally rich in diversity with flora, fauna, and especially amber fossils and by an excellent state of preservation. , The earliest Eocene age, about 53−55 million years ago, of the deposit was assessed by stratigraphy and confirmed by the presence of fossil remains of Condylarthra (primitive ongulet), Perissodactyla (small equidae), and Teihardina (minuscule primate) as the mammalian layer reference (Figure ) and angiosperm-like pollens and woody remains mainly belonging to dicotyledon. ,, It is noteworthy that London Clay is also very rich in diverse flora fossils aged the same (early lower Eocene). , Generally, it is very difficult to identify the tree producer of resin that eventually becomes amber, which contains numerous ditepene isomers.…”