Carotenoid biosynthesis in a Flavobacterium sp.: stereochemistry of hydrogen elimination in the desaturation of phytoene to lycopene, rubixanthin and zeaxanthin (Short Communication)

Abstract

[2-14C,(2R)-2-3H1]- and [2-14C,(2S)-2-3H1]-Mevalonates were rapidly incorporated into phytoene, lycopene, rubixanthin and zeaxanthin in a Flavobacterium system obtained by disruption of the bacterial cells by shaking with glass beads. Four hydrogen atoms arising from the 2-pro-S-hydrogen atoms of mevalonate were lost in the desaturation of phytoene to lycopene, rubixanthin and zeaxanthin. The desaturation of phytoene involves trans-elimination of hydrogen in the introduction of the double bonds at C-7, C-11, C-7′ and C-11′.