Eine Suche nach 3′‐Epilutein ( = (3R,3′S,6′R)‐β,ε‐Carotin‐3,3′‐diol) und 3′, O‐Didehydrolutein (=(3R, 6′R)‐3‐Hydroxy‐β,ε‐carotin‐3′‐on) in Eigelb, in Blüten von Caltha palustris und in Herbstblättern

Search for the Presence in Egg Yolk, in Flowers of Caltha palustris and in Autumn Leaves of 3′‐Epilutein ( =(3 R ,3′ S ,6′ R )‐β,ε‐Carotene‐3,3′‐diol) and 3′, O ‐Didehydrolutein ( =(3 R ,6′ R )‐3‐Hydroxy‐β,ε‐carotene‐3′‐one) 3′. O ‐Didehydrolutein ( =(3 R , 6′ R )‐3‐hydroxy‐β,ε‐carotene‐3′‐one; 2) has been detected in egg yolk and in flowers of Caltha palustris . This is the first record for its occurrence in a plant. The compound shows a remarkable lability towards base; therefore, it may have been overlooked til now, because it is destroyed under the usual conditions of saponification of the carotenoid‐esters. One of the many products formed from 2 with 1% KOH in methanol has been purified and identified as the diketone 3 ( =(3 R )‐3‐hydroxy‐4′, 12′‐ retro ‐β,β‐carotene‐3′,12′‐dione). The identification of this transformation product from lutein might throw a new light on the metabolism of this important carotenoid in green plants. 3′‐Epilutein ( =(3 R ,3′ S ,6′ R )‐β,ε‐carotene‐3,3′‐diol; 1) was not detected in egg yolk, but is present besides lutein in flowers of C. palustris , thus confirming an earlier report of the occurrence of an isomeric (possibly epimeric) lutein (‘calthaxanthin’) in that plant [21]. We were not able to detect even traces of 1 or 2 in the carotenoid fraction from autumn leaves of Prunus avium (cherry), Parrotia persica, Acer montanum (maple) and yellow needles of Larix europaea (larch). α‐Cryptoxanthin (4) , a very rare carotenoid, was isolated in considerable quantity for the first time from flowers of C. palustris .