Bacterioruberin

The cyclization inhibitor nicotine prevents formation of the C50 carotenoid bacterioruberin [2,2 -bis-(3-hydroxy-3-methylbutyl)-3,4,3, 4 -tetradehydro-... 

None associated with photochemistry None - Bacterioruberins (Qv,) retinal - direct photochemistry (not involved in lightharvesting)... 

Isoprenylated Carotenoids.—Details of the revised structure of bacterioruberin (38) have been published. Anhydro- and bisanhydro-bacterioruberin [(39) and (40)] were also isolated from Halobacterium salinarium. The latter carotenoid was also... 

In the C50 series, the absolute configuration of bacterioruberin [(25,2 5)-2, 2 -bis-(3-hydroxy-3-methylbutyl)-3,4,3, 4 -tetrahydro-l,2,T,2 -tetrahydro- /, />-carotene-l,T-diol (32)] has been determined by synthesis of the derivative (2S,2 5)-tetra-anhydrobacterioruberin (33) from (-)-(i )-lavandulol (36). Samples of (33) obtained by synthesis and prepared from natural bacterioruberin or bisanhydrobacterioruberin [2,2 -bis-(3-methylbut-2-enyl)-3,4,3, 4 -tetradehydro-l,2,T,2 -tetrahydro- /, j/ -carotene-l,T-diol (34)] had the same c.d. properties. That c.d. data for carotenoids must be interpreted with caution was indicated by the fact that a direct comparison of the c.d. properties of (32) and (34) with those of a synthetic octahydro model (35) led to the erroneous opposite conclusion. In a similar... 

The synthesis of racemic bacterioruberin (248), reported in 1979, was the first synthesis of a Cso-carotenoid [102]. 

Isoprenylated Carotenoids.—The bacterial C50 carotenoids bacterioruberin (10) and anhydrobacterioruberin (11) have the same absolute stereochemistry. Both mono- and di-glycosides of bacterioruberin are present with 80% glucose and 20% mannose attached to the additional C5 unit. The stereochemistry of decaprenaxanthin (9) has been discussed above. It too occurs as mono- and di-glucosides. ... 

The synthesis of racemic bacterioruberin (456), reported in 1979, was the first synthesis of a Cso-carotenoid [28,30]. Oxidation of lavandulol (150) with chromic anhydride and pyridine gave lavandulal (151) which was elongated with the Cs-phosphonate 28 in a Horner-Emmons reaction to provide the ester 152. The regioselective diepoxidation with MCPBA resulted in the ester 153. Opening of both epoxides and simultaneous reduction of the ester group with LiAlH4 led to the triol 154 which was converted, with triphenylphosphine hydrobromide, into... 

In bacteria, polyterpenols stabilize the cell walls and also perform other physiological functions. Violet bacterioruberin (C50H76O4) and sarcinaxanthin (C50H72O2) from Flavobacterium dehydrogenatus serving as sun protection for halophilic bacteria in salt lakes are examples. 

ScHWiETER, U., R. Ruegg, and O. Isler Synthesen in der Carotinoid-Reihe 21. Synthese von 2,2 -Diketo-spirilloxanthin (P518) und 2,2 -Diketo-bacterioruberin. Helv. Chim. Acta 49, 992 (1966). 

Tetraanhydrobacteriorubin (67), synthesized either from (/ )-lavandulol or by dehydration of natural bacterioruberin (37) or bisanhydrobacterioruberin (68), had identical CD properties 104, 107). The total synthesis of (67) consequently permitted configurational assignment of the aliphatic Cso carotenoids (37) and (68). 

Total synthesis of bacterioruberin derivatives. Absolute configuration of bacterio-... 

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