Carotenoid Glucoside Esters Research Articles

Novel carotenoid glucoside esters from alkaliphilic heliobacteria

Novel carotenoid glucoside esters from alkaliphilic heliobacteria

Novel carotenoid glucoside esters from alkaliphilic heliobacteria.

Pigments of three species of alkaliphilic heliobacteria of the genus Heliorestis, H. daurensis, H. baculata and an undescribed species Heliorestis strain HH, were identified using spectroscopic methods. In these species, bacteriochlorophyll g esterified with farnesol was present, as for other heliobacteria. The carotenoids consisted of 4,4'-diaponeurosporene, also found in other heliobacteria, plus the novel pigments OH-diaponeurosporene glucoside esters (C16:0 and C16:1). In addition, trace amounts of biosynthetic intermediates, OH-diaponeurosporene and OH-diaponeurosporene glucoside, were found. Trace amounts of a carotenoid with 20 carbon atoms, 8,8'-diapo-zeta-carotene, were also found in these species as well as in the non-alkaliphilic heliobacteria. The non-alkaliphilic species Heliophilum fasciatum also contained trace amounts of the two OH-diaponeurosporene glucoside esters. The results are used to predict the pathway of carotenoid biosynthesis in heliobacteria.

Dihydroxylycopene diglucoside diesters: a novel class of carotenoids from the phototrophic purple sulfur bacteria Halorhodospira abdelmalekii and Halorhodospira halochloris.

The carotenoids in Halorhodospira abdelmalekii and Halorhodospira halochloris were analyzed by spectroscopic methods. The carotenoid composition of the two species was almost the same. Both species contained substantial amounts of unusual carotenoid glycoside fatty acid esters, which have been found for the first time in phototrophic purple bacteria. Methoxy-hydroxylycopene glucoside was a major component, and dihydroxylycopene diglucoside and dihydroxylycopene diglucoside diester were also found. Lycopene, rhodopin, and 3,4,3',4'-tetrahydrospirilloxanthin were present in very small amounts. Methoxy, glucosyl, and glucosyl ester groups were observed as substituents at the positions of the two original hydroxyl groups of dihydroxylycopene and made up approximately 20, 50, and 20%, respectively, of the total end groups (100%). The fatty acid components of the three carotenoid glucoside esters were the same (C12:0 and C14:1) and were rare in the cellular lipids of the two species.

Stabilization of liposomal membranes by thermozeaxanthins: carotenoid-glucoside esters

Thermozeaxanthins (TZS) are novel carotenoid-glucoside esters existing in the cell membranes of the thermophilic bacterium, Thermus thermophilus. The effect of TZS on membrane permeability was studied by measuring the leakage of the fluorescent dye from calcein-entrapped large unilamellar liposomes (LUVs). The LUVs were composed of a small portion (0.2-1.0 mol%) of TZS and phosphatidylcholine (PC) of various length and saturation degree of hydrocarbon chains. Incorporation of TZS in egg PC LUVs stabilized the liposomes in the temperature range from 30 to 80 degrees C, as only 2.6% of the entrapped calcein leaked out in contrast to 10% release from the egg PC liposomes without TZS. LUVs composed of dipalmitoylphosphatidylcholine (DPPC) or dioleoylphosphatidylcholine (DOPC) were stabilized by the incorporation of TZS at a temperature below 30 degrees C. Inclusion of TZS in LUVs composed of dimyristoylphosphatidylcholine, whose hydrocarbon chains are shorter than both DPPC and DOPC, did not stabilize the liposomes. About 90% of the entrapped dye was lost indicating defects of the liposomal membranes. Matching of the lipid bilayer thickness with the molecular length of TZS in the bilayers is discussed.

Pigment Composition in the Reaction Center Complex from the Thermophilic Green Sulfur Bacterium, Chlorobium tepidum: Carotenoid Glucoside Esters, Menaquinone and Chlorophylls

Distribution of pigments in the reaction center (RC) complex, chlorosomes and chlorosome-free membranes prepared from the green sulfur bacterium, Chlorobium tepidum, was analyzed. The RC complex contained approximately 40 molecules of bacteriochlor ophyll (BChl) a per P840, half of which are estimated to be in the Fenna-Matthews-Olson (FMO) protein. Carotenes (2 molecules per P840) occupied only one third of the total carotenoids. The remaining carotenoids (4 to 5 molecules per P840) were OH-chlorobactene glucoside ester and OH-/-carotene glucoside ester. Dihydrochlorobactene was decreased compared with cellular carotenes. Furthermore, approximately 9 C670 and 1 menaquinone-7 per P840 were also found. BChl c and carotenes, whose major component is chlorobactene, were found mainly in chlorosomes, and two kinds of carotenoid glucoside esters were observed in chlorosome-free membranes.

Carotenoids of the Fruiting Gliding Myxobacterium,Myxococcussp. MY-18, Isolated from Lake Sediment: Accumulation of Phytoene and Keto-myxocoxanthin Glucoside Ester

The precise chemical structures of two carotenoid glucoside esters, keto-myxocoxanthin glucoside ester isolated from Myxococcus sp. MY-18 and dehydrorhodopin glucoside ester from cells cultured in a nicotinecontaining medium, were determined as 1′-[(6-O-acyl-β-D-glucopyranosyl)oxy]-3′,4′-didehydro-l′,2′-dihydro-β,ψ-caroten-4-one and 1-[(6-O-acyl-β-D-glucopyranosyl)oxy]-3,4-didehydro-1,2-dihydro-ψ,ψ-carotene, respectively. They had β-D-glucoside, whose C-6 hydroxyl group was esterified. The major fatty acid was 11-methyldodecanoate with minor components of n-dodecanoate, n-tetradecanoate, and 13-methyltetradecanoate. This composition is different from that of cellular lipids, and the unusual accumulation of phytoene (more than 70% of total carotenoids) is characteristic of this strain. The possible biosynthetic pathway for the carotenoid glucoside ester starts with lycopene being cyclized to γ-carotene, from which myxocoxanthin is produced by hydration and desaturation. β-D-Glucose was attached to the carotenoid, and the fatty acid ester was next. The pathway for the introduction of a keto group to the carotenoid moiety was not clear, however. The final product was keto-myxocoxanthin glucoside ester. Cyclization was completely inhibited by 6.0mM nicotine in the medium, in which case, the final product was dehydrorhodopin glucoside ester.

Influence of Growth Temperature on Compositions of Carotenoids and Fatty Acids from Carotenoid Glucoside Ester and from Cellular Lipids inRhodococcus rhodochrousRNMSI

The influence of growth temperature (21–41°C) and light intensity on compositions of four carotenoids, and of fatty acids from carotenoid glucoside ester (carotenoid K-G-FA) and from the cellular lipids in Rhodococcus rhodochrous RNMS1 were quantitatively investigated. Lowering the temperature increased the total carotenoid content and the proportion of carotenoid K-G-FA. It increased the proportion of unsaturated fatty acids in both carotenoid K-G-FA and the cellular lipids, decreased that of saturated ones, and slightly decreased that of branched-chain ones. This bacterium adapted itself to low temperature by desaturating its fatty acids. The light intensity affected neither the content and the composition of carotenoids nor the composition of the fatty acids in carotenoid K-G-FA and the cellular lipids. This bacterium was a scotochromogenic strain.

Heterogeneous position of the double bonds of unsaturated fatty acids in carotenoid glucoside esters from Rhodococcus rhodochrous RNMS1.

Rhodococcus rhodochrous RNMS1 has been found to contain four kinds of carotenoid pigments.1) The major one was fatty acid esters of a carotenoid glucoside, and their structure was 1 '-[(6-0-acyl-/?-D-glucopyranosyl)oxy]r^-dihydro-jft^-caroten^-one. The fatty acid moiety comprised nine major types, which were four saturated (C16:0-C19:0), four mono-unsaturated (C18:l-C21:l) and one branched-chain (10-methyl C19:0) acid, including odd-numbered ones. On the other hand, the major fatty acids in cellular lipids were hexadecanoic, hexadecenoic, octadecenoic and 10-methyloctadecanoic acids.2) Profiles of the double bond location in cellular unsaturated fatty acids are very useful for the taxonomic characterization of corynebacteria with a Type I fatty acid 2139

On the utilization in vivo of lycopene and phytoene as precursors for the formation of carotenoid glucoside ester and on the regulation of carotenoid biosynthesis in Myxococcus fulvus.

During th logarithmic phase of growth of the myxobacterium Myxococcus fulvus the specific carotenoid content and the molar ratio of the two main carotenoids keto-torulene (3',4'-didehydro-beta,psi-caroten-4-one, 15%) and myxobacton ester (1'-glucosyloxy-3',4'-didehydro-1',2'-dihydro-beta,psi-caroten-4-one ester, 80%) are highly constant. When the formation of these carotenoids was prevented by an inhibitory block at the level of phytoene desaturation, the normal specific content is rapidly reached after release of this block by a two-three-fold enhanced rate of synthesis. The experimentally accumulated phytoene molecules however, are not used as a precursor pool for the formation of the coloured carotenoids. The absolute amount of phytoene does not decrease, although a considerable molecule exchange between this pool and the pathway occurs. Furthermore, experimentally accumulated lycopene is only converted into myxobacton ester when the carotenogenic pathway is blocked at an earlier step, at the level of phytoene desaturation. Without this blockage the lycopene pool remains unaffected. The results are discussed in terms of arrangement of the carotenogenic enzymes in a sort of assembly line in association with the cytoplasmic membrane. Four sites of control are suggested in this pathway.

A new carotenoid glucoside ester from Chondromyces apiculatus

Abstract The carotenoid composition of the myxobacterium Chondromyces apiculatus is reported. A new acyclic carotenoid glucoside ester was isolated and its structure determined as 1′-glucosyloxy-3′,4′-didehydro-1′,2′-dihydro-ψ,ψ-carotene monoester.

Biosynthesis of carotenoid glucoside esters in Myxococcus fulvus (Myxobacterales): Inhibition by nicotine and carotenoid turnover

1. The inhibitory effects of nicotine at various concentrations (0,02 to 8.00 mM) on carotenogenesis in Myxococcus fulvus were investigated. 2. Nicotine inhibited the cyclization of carotenoid glucoside esters at low concentration (<1 mM). A new acyclic carotenoid glucoside ester accumulated. When the inhibitor was removed, a monocyclic carbonylated glucoside ester was synthesized at the expense of the acyclic glucoside ester. 3. A second intermediate, a monocyclic non-carbonylated glucoside ester, was accumulated when cells were reincubated anaerobically after removal of nicotine. Further aerobic incubation resulted in the carbonylation of this monocyclic intermediate. 4. At higher concentration (>1 mM), nicotine inhibited the introduction of the hydroxyl group at 1' position of carotenes (inhibition of hydration across the 1',2'-double bond). Lycopene accumulated under such conditions. 5. Three further effects of nicotine on cell growth are discussed. 6. Virtually no turnover or degradation of carotenoids were found during a time range of 22 h (about four generation times).

Carotenoid pigments of Sorangium compositum (Myxobacterales) including two new carotenoid glucoside esters and two new carotenoid rhamnosides.

The carotenoid pigments of the myxobacterium Sorangium compositum were analyzed by chromatographical and chemical techniques and by visible, infra red, and mass spectroscopy. Besides γ-carotene, neurosporene, torulene, lycopene, and 1′,2′-dihydro-1′-hydroxy-γ-carotene, four new carotenoid glycosides were found. These pigments were identified as 1′,2′-dihydro-1′-hydroxy-torulene glucoside ester (I), 1′,2′-dihydro-3,1′-dihydroxy-torulene glucoside ester (III), 1′,2′-dihydro-1′-hydroxy-torulene rhamnoside (II), and 1′,2′-dihydro-3,1′-dihydroxytorulene rhamnoside (IV).