SPDS Meeting Book

4.  3’‐Epilutein

o (3R,3’S,6’R)‐lutein o Not dietary— no biological or commercial role o Significant epimer product and loss of lutein o Occurs in aqueous acid o Reaction likely proceeds by S N 1 and S N 2, but mostly S N

2 since 

conversion exceeds 50% 

o Structure

General Analytical Needs

Method should  – Quantitatively de‐esterify all analyte forms – Separate and accurately quantify relevant free analytes • Lutein • Zeaxanthin • β‐Cryptoxanthin • 3’ Epilutein (principal lutein metabolite) ‐ – Determine the above in • Raw materials used in dietary supplement formulations • Finished products?