Purification of synthetic all-E lycophyll (ψ,ψ-carotene-16,16′-diol)

An efficient purification of synthetic all-trans (all-E) lycophyll is described. The synthetic preparation of the rare xanthophyll lycophyll produces a mixture of geometric isomers. Purification by HPLC using reverse-phase C30 silica affords milligram quantities of the desired all-trans isomer in >95% purity, as confirmed by 1H NMR and LC/MS. Most recently, a facile work-up of the geometric mixture formed during total synthesis was found to provide multigrams of the targeted all-E geometric isomer of lycophyll. The acquisition of modest quantities of this specific lycopene analog allows its therapeutic potential to be explored.