Isolation and Structure Elucidation of Anhydroluteins from Cooked Sorrel ( Rumex rugosus C ampd .)

Anhydrolutein I (=(all‐ E ,3 R ,6′ R )‐3′,4′‐didehydro‐ β , γ ‐caroten‐3‐ol; 2 ) and anhydrolutein II (=(all‐ E , 3 R ,6′ S )‐2′,3′‐didehydro‐ β , ε ‐caroten‐3‐ol; 3 ) have been isolated and characterized from the extract of steam‐cooked sorrel. The presence of these compounds in cooked vegetable is postulated to be due to acid‐catalyzed dehydration of lutein ( 1 ; Scheme ). The structures of the isolated anhydroluteins were established by UV/VIS, CD, and 1 H‐NMR spectroscopy, and mass spectrometry.