An efficient conversion of (3R,3'R,6'R)-lutein to (3R,3'S,6'R)-lutein (3'-epilutein) and (3R,3'R)-zeaxanthin

J Nat Prod. 2003 Jan;66(1):67-72. doi: 10.1021/np020376l.

Abstract

Two dietary carotenoids, (3R,3'R,6'R)-lutein (1) and (3R,3'R)-zeaxanthin (2), and their metabolite (3R,3'S,6'R)-lutein (3'-epilutein) (3) accumulate in human serum, milk, and ocular tissues. There is increasing evidence that compounds 1 and 2 play an important role in the prevention of age-related macular degeneration. Therefore, the availability of these carotenoids for metabolic studies and clinical trials is essential. Compound 1 is isolated from extracts of marigold flowers (Tagete erecta) and is commercially available, whereas 2 is only accessible by a lengthy total synthesis, and a viable method for synthesis of 3 has not yet been developed. This report describes an efficient conversion of technical grade 1 to 2 via 3. Acid-catalyzed epimerization of 1 yields an equimolar mixture of diastereomers 1 and 3. The mixture was separated by enzyme-mediated acylation with lipase AK from Pseudomonas fluorescens that preferentially esterified 3 and after alkaline hydrolysis yielded this carotenoid in 90% diastereomeric excess (de). Compound 3 was also separated from 1 in 56-88% de by solvent extraction and low-temperature crystallization, Soxhlet extraction, or supercritical fluid extraction. Base-catalyzed isomerization of 3 gave 2 in excellent yield, providing a convenient alternative to the total synthesis of this important dietary carotenoid.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biotransformation
  • Carotenoids / analysis
  • Carotenoids / chemistry
  • Carotenoids / metabolism*
  • Chromatography, High Pressure Liquid
  • Dietary Supplements
  • Flowers
  • Humans
  • Lipase / metabolism
  • Lutein / analogs & derivatives
  • Lutein / analysis
  • Lutein / chemistry*
  • Lutein / metabolism*
  • Macular Degeneration / prevention & control
  • Mass Spectrometry
  • Milk, Human / chemistry
  • Molecular Structure
  • Plants, Medicinal / chemistry*
  • Plasma / chemistry
  • Pseudomonas fluorescens / enzymology
  • Spectrophotometry, Ultraviolet
  • Stereoisomerism
  • Tagetes / chemistry*
  • Xanthophylls
  • Zeaxanthins
  • beta Carotene / analogs & derivatives*
  • beta Carotene / metabolism

Substances

  • (3R,3'S,6'R)-lutein
  • Xanthophylls
  • Zeaxanthins
  • beta Carotene
  • Carotenoids
  • Lipase
  • Lutein