Retention of the 4-pro-R hydrogen atom of mevalonate at C-2,2' of bacterioruberin in Halobacterium halobium.

Intact cells of Halobacterium halobium fed with (3R,4R)-[2-14C,4-3H1]mevalonic acid were found to incorporate label into acyclic C40 and C50 carotenoids, of which bacterioruberin was the most abundant. The 14C/3H ratios of the isolated carotenoids demonstrated that the 4-pro-R hydrogen atom of mevalonic acid was retained at the C-2 and C-2' positions of bacterioruberin. Diphenylamine was found to inhibit the production of bacterioruberin.