Reisolation of carotenoid 3,6-epoxides from red paprika (Capsicum annuum)

Cucurbitaxanthin A (=(3S,5R,6R,3'R)-3,6-epoxy-5,6-dihydro-beta,beta-carotene-5,3'-diol; 5), cucurbitaxanthin B (=(3S,5R,6R,3'S,5'R,6'S)-3,6,5',6'-diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene-5,3'-diol; 6), the epimeric cucurbitachromes 1 and 2 (=(3S,5R,6R,3'S,5'R,8'S)- and (3S,5R,6R,3'S,5'R,8'R)-3,6,5',8'-diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene-5,5'-diol, resp.; 9/10), cycloviolaxanthin (=(3S,5R,6R,3'S,5'R,6'R)-3,6,3',6'-diepoxy-5,6,5',6'-tetrahydro-beta,beta-carotene-5,5'-diol; 8), and capsanthin 3,6-epoxide (=(3S,5R,6R,3'S,5'R)-3,6-epoxy-5,6-dihydro-5,3'-dihydroxy-beta,kappa-caroten-6'-one; 7) were isolated from red spice paprika (Capsicum annuum var. longum) and characterized by their H-1- and C-13-NMR, mass, and CD spectra.