Braunicetals: Acetals from condensation of macrocyclic aldehydes and terpene diols in Botryococcus braunii

Two series of braunicetals were isolated from the green microalga Botryococcus braunii. Based on spectroscopic data and chemical evidence, their structures were determined to be acetals formed by the condensation of C32 and C34 aldehydes with C33 and C34 methylated squalene diols (series I), or a C40 lycopaene diol (series II).