a carotenoid chi-end derivative + 2 AH2 => a carotenoid beta-end derivative + 2 A
a carotenoid chi-end derivative + 2 ah2 => a carotenoid beta-end derivative + 2 a
a carotenoid chi-end derivative + 2 AH2 => a carotenoid beta-end derivative + 2 A
a carotenoid chi-end derivative + 2 ah2 => a carotenoid beta-end derivative + 2 a