The Botryococcenes—hydrocarbons of novel structure from the alga Botryococcus braunii, Kützing

The hydrocarbon fraction of Botryococcus braunii, growing in its natural environment, has been isolated and examined. Surprisingly this fraction was found to comprise 76 per cent of the dry weight of the alga. Furthermore, two unsaturated isomeric hydrocarbons of formula C34H58, termed botryococcene and isobotryococcene, constitute the bulk of the hydrocarbons. No saturated hydrocarbons were detected. Approaches to the structural elucidation of the botryococcenes are described and the significance of their occurrence, in terms of the diagenetic fate of B. braunii, is discussed. Possible biogenetic routes are considered.