Characterization and antioxidative activities of rare C(50) carotenoids-sarcinaxanthin, sarcinaxanthin monoglucoside, and sarcinaxanthin diglucoside-obtained from Micrococcus yunnanensis.

While screening for antioxidative carotenoids from marine bacteria, we isolated and identified sarcinaxanthin and its glucosylated compounds (sarcinaxanthin monoglucoside and sarcinaxanthin diglucoside) from a moderately halophilic bacterium-Micrococcus yunnanensis strain AOY-1. In the singlet oxygen ((¹O2) quenching model, the IC(50) values of the antioxidative activities of these carotenoids were as follows: sarcinaxanthin , 57 µM; sarcinaxanthin monoglucoside, 54 µM; and sarcinaxanthin diglucoside, 74 µM. In addition, the complete proton nuclear magnetic resonance (¹H NMR) assignments of sarcinaxanthin monoglucoside pentaacetate and sarcinaxanthin diglucoside octaacetate, and fast atom bombardment mass spectrometry/mass spectrometry (FAB-MS/MS) analyses of sarcinaxanthin and sarcinaxanthin monoglucoside are reported for the first time.

5-Hydroxy-5,6-dihydro-apo-4,4'-lycopene and methyl 5-hydroxy-5,6-dihydro-apo-4,4'-lycopenoate, novel C(30)-carotenoids produced by a mutant of marine bacterium Halobacillus halophilus [corrected].

We performed the chemical mutagenesis of Halobacillus halophilus (the producer of a C(30) carotenoid, methyl glucosyl-3,4-dehydro-apo-8'-lycopenoate) to isolate novel carotenoids that are biosynthetic intermediates of methyl glucosyl-3,4-dehydro-apo-8'-lycopenoate. As a result, we isolated two novel C(30) carotenoids, hydroxy-3,4-dehydro-apo-8'-lycopene and methyl hydroxy-3,4-dehydro-apo-8'-lycopenoate, which were biosynthesized through a novel 8'-apo C(30) pathway. These carotenoids showed antioxidative activity in the (1)O(2) suppression model.