ISOLATION AND IDENTIFICATION OF CAROTENOIDS FROM THE PETALS OF RAPE (BRASSICA NAPUS)

摘要

From the yellow petals of rape flowers (Brassica napus), the carotenoids have been extracted and some compounds were identified. A HPLC analysis of the whole extract showed at least 80 different carotenoids, ranging from hydrocarbons to highly oxygenated species, including naturally occurring E/Z-isomers. The most polar part of the extract was further investigated by HPLC and UV-vis photodiodearray detection. The major carotenoids were isolated and identified, from UV-vis, CD, 400 MHz H-1-NMR, and mass spectra, as (8'R)- and (8'S)-luteoxanthin, (13Z,8'R)-luteoxanthin, flavoxantkin/chrysanthemaxanthin, taraxanthin, and (all-E)-, (9Z)-, and (13Z)-violaxanthin. This shows the existence of different E/Z-isomers in nature. It was shown that luteoxanthin is found as an 8'-epimeric mixture, whereas there were no epimers found for violaxanthin.