Isolation and structural elucidation of (13Z,13'Z,3R,3'R,6'R)-lutein from marigold flowers, kale, and human plasma.
(13Z,13'Z,3R,3'R,6'R)-Lutein has been isolated and purified from extracts of marigold flowers, fresh raw kale (Brassica oleracea var. Acephala), and human plasma and fully characterized by (1)H and (13)C NMR, UV/vis, and MS. While the concentration of (13Z, 13'Z)-lutein in kale and human plasma compared to (all-E,3R,3'R, 6'R)-lutein was found to be quite low, this compound was readily isolated by fractional crystallization of lutein from marigold extracts. Thus, the mother liquors from two consecutive crystallizations of lutein from a saponified extract of marigold flowers were enriched in (13Z,13'Z)-lutein (8.7% of total carotenoids) and employed for the isolation of this compound by HPLC. The identity of the di-Z-lutein in kale and human plasma has been established by comparison of the HPLC-UV/vis-MS profiles of the purified compounds with those of a fully characterized sample, isolated from marigolds. 3-Hydroxy-beta,epsilon-caroten-3'-one and 3'-epilutein have also been identified in extracts from marigolds.
Khachik
F
F
Department of Chemistry and Biochemistry, Joint Institute for Food Safety and Applied Nutrition (JIFSAN), University of Maryland, College Park 20742, USA. fk17@umail.umd.edu
Steck
A
A
Pfander
H
H
D001937:Brassica / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D014975:Lutein / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000032:analysis; D010946:Plants, Medicinal / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
D010936:Plant Extracts; D014975:Lutein