Isolation and Characterization of Cyclic C₃₃ Botryococcenes and a Trimethylsqualene Isomer from <i>Botryococcus braunii</i> Race B

Three cyclic C₃₃ botryococcenes and one new trimethylsqualene isomer were isolated from the B race, Showa (Berkeley) strain of <i>Botryococcus braunii</i>, which is known to produce large amounts of isoprenoid hydrocarbons ranging in carbon number from 30 to 34. Their purity was determined by GC-MS, and structures were characterized by 1D and 2D NMR. One of these molecules, cyclic C₃₃-1 botryococcene (<b>5</b>), has an unusual connection of a methylenecyclohexane ring to the molecule backbone not seen before in botryococcenes. This report further adds to our knowledge of the wide range of isoprenoid hydrocarbon structures produced by <i>B. braunii