当前位置：
X-MOL 学术
›
Org. Geochem.
›
论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Two novel decamethyl henicosanes (C31H64) identified in a Maoming Basin shale, China
Organic Geochemistry ( IF 3 ) Pub Date : 2018-11-01 , DOI: 10.1016/j.orggeochem.2018.09.012 Jing Liao , Hong Lu , Qiao Feng , Youping Zhou , Quan Shi , Ping'an Peng , Guoying Sheng
Organic Geochemistry ( IF 3 ) Pub Date : 2018-11-01 , DOI: 10.1016/j.orggeochem.2018.09.012 Jing Liao , Hong Lu , Qiao Feng , Youping Zhou , Quan Shi , Ping'an Peng , Guoying Sheng
Abstract Two new C31 branched alkanes (botryococcanes) presumably produced by the B race of Botryococcus braunii were isolated and purified from the Maoming Basin shales using column chromatography and preparative gas chromatography and structurally characterized with HR-EI-MS and 1D and 2D NMR. Interpretation of their EI mass spectral and 1D and 2D NMR (HMBC and HSQC) data led to the firm assignments of the two alkanes as diastereoisomeric 2,3,6,7,10,12,15,16,19,20-decamethylhenicosanes (DMHs). The structural assignments were further confirmed by the close match of the measured 13C NMR chemical shifts with those predicted by Lindeman-Adams 13C chemical shift modeling. The skeletons of these two DMHs are virtually identical to that of the recently identified C33 botryococcane/botryococcanone in the same sample. It is proposed that these two DMHs share a precursor C33 botryococcene biochemically formed by condensing two farnesyl diphosphates involving an unusual cyclobutanation, a retro-Prins reaction and a tetramethylation. A photo-mediated geochemical oxidation of the double bond in the ethenyl group connected to the sole quaternary carbon C-10 is also proposed to be responsible for the formation of the co-occurring DMHs and C33 botryococcane/botryococcanone.
更新日期：2018-11-01
京公网安备 11010802027423号