Isoshowacene, A C31 hydrocarbon from Botryococcus braunii var. showa

Abstract -Two C 31 acyclic hydrocarbons, showacene and isoshowacene, were obtained from a 16-day-old air-lift culture of Botryococcus braunii var. showa . The compounds were isolated as a 17:10 mixture by reversed-phase HPLC. Upon analysis by GC-MS and by 1 H and 13 C NMR, the compounds were found to be 1′–3 fused triterpenes of the botryococcene type bearing a single additional methyl at opposite ends of the isoprenoid chains.