canthaxanthin + 2 A + 3 H2O => echinenone + 2 AH2 + 2 O2
canthaxanthin + 2 a + 3 h2o => echinenone + 2 ah2 + 2 o2
canthaxanthin + 2 A + 3 H2O => echinenone + 2 AH2 + 2 O2
canthaxanthin + 2 a + 3 h2o => echinenone + 2 ah2 + 2 o2