Beta-Carotene → 9-Cis-Beta-Carotene

Participants

Reaction Conditions

Reaction Steps

High purity beta-carotene from Example I was dissolved in a minimal amount of warm (about 40°-50° C.) hexane to achieve saturation. The solution was then chilled, typically to about -20° C., which caused the preferential crystallization of the trans-isomer of beta-carotene. The crystals were then separated from the supernatant solution by filtration through a hydrophobic 0.22 μ nylon membrane filter (Micron Separations, Inc., Cambridge, MA). Chromatograms of representative preparations of the supernatant enriched in the 9-cis isomer (approximately 75-80% 9-cis and 15-20% all-trans) and of the crystals containing the all-trans isomer (approximately 80-85% all-trans and 10-15% 9-cis) are shown in FIGS. 2B and 2C, respectively.

Provenance & Evidence