摘要
A series of novel tetracyclic triterpanes based on the lanostane skeleton, ranging in cars-bon number from C_(30) to C_(32), were identified for the first time in Eocene lacustrine depo-its of Biyang Depression, China. These compounds have been identified by GC, GC- MS, andcoinjection with authentic standard, as 8β(H), 9α(H)- lanostane (C_(30)), 24-methyl- lanostane(C_(31)) and 24- ethyl- lanostane (C_(32)). Mechanisms are proposed for the origin and geologicalfate of these compounds. To the best of our knowledge, this is the first confirmed occur-rence of lanostanes in the sedimentary record.
A series of novel tetracyclic triterpanes based on the lanostane skeleton, ranging in cars-bon number from C<sub>30</sub> to C<sub>32</sub>, were identified for the first time in Eocene lacustrine depo-its of Biyang Depression, China. These compounds have been identified by GC, GC- MS, andcoinjection with authentic standard, as 8β（H）, 9α（H）- lanostane (C<sub>30</sub>), 24-methyl- lanostane(C<sub>31</sub>) and 24- ethyl- lanostane (C<sub>32</sub>). Mechanisms are proposed for the origin and geologicalfate of these compounds. To the best of our knowledge, this is the first confirmed occur-rence of lanostanes in the sedimentary record.
