The determination of the geometrical configurations of several mono-cis carotenoids is reported. The method of combining controlled alkaline permanganate oxidation and '3C NMR spectroscopy has provided evidence for the 9-mono-cis structure of violeoxanthin and neoxanthin, as well as for the configurational assignments of neozeaxanthin A, neozeaxanthin B, neocapsorubin A, neocapsorhbin B and neolutein B. The stereoisomeric sets of capsanthin and those of lutein epoxide are considered, and

more »

... o. their new mono-cis members are reported. Some configurational assignments based on ultraviolet and light absorption properties are proposed. An attempt to study the kinetics of cis-trans rearrangements in the field of carotenoids was made, and the cis-trans isomerism of the lutein epoxide±neolutein epoxide A system is commented on.