Synthesis, Isolation, and NMR‐Spectroscopic Characterization of Fourteen (<i>Z</i>)‐Isomers of Lycopene and of Some Acetylenic Didehydro‐ and Tetradehydrolycopenes

Hengartner, Urs; Bernhard, Kurt; Meyer, Karl; Englert, Gerhard; Glinz, Ernst

doi:10.1002/hlca.19920750611

Cited by 129 publications

(130 citation statements)

References 36 publications

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“…The incorporation of carotenes into the lipid bilayer was assessed by extracting the carotenes from the liposomes formed with chloroform/methanol 2:1 (v/v) followed by spectrophotometric estimation (Shimadzu, UV-2501PC) using for 9-cis-lycopene, ⑀ 444 nm ϭ 115,000 liters mol Ϫ1 cm Ϫ1 for 7,9-di-cis-lycopene. The extinction coefficient for 9-cis-lycopene was also used for the "unknown" peak (e) since they share similar spectra with a trans-like fine structure (25).…”

Section: Methodsmentioning

confidence: 99%

“…The organic phases containing substrate and products were combined and dried under reduced pressure. The residue was dissolved in chloroform and analyzed by HPLC-System 1 (Waters, Alliance 2695) on a C 30 reversed phase column (YMC-Europe) as detailed earlier (20) or dissolved in hexane and analyzed by HPLC-System 2 (UFLC, Shimadzu, Prominence) using a direct phase column (Nucleosil 300 -5, Macherey & Nagel) with dry hexane/N-ethyldiisopropylamine 2000:1 (v/v) as the mobile phase at a flow-rate of 1.5 ml/min (25). Equilibration of this direct phase system can take several days.…”

Section: Methodsmentioning

confidence: 99%

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Plant Carotene Cis-Trans Isomerase CRTISO

Ghisla

Hirschberg

et al. 2011

Journal of Biological Chemistry

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The carotene cis-trans isomerase CRTISO is a constituent of the carotene desaturation pathway as evolved in cyanobacteria and prevailing in plants, in which a tetra-cis-lycopene species, termed prolycopene, is formed. CRTISO, an evolutionary descendant of the bacterial carotene desaturase CRTI, catalyzes the cis-to-trans isomerization reactions leading to all-trans-lycopene, the substrate for the subsequent lycopene cyclization to form all-trans-␣/␤-carotene. CRTISO and CRTI share a dinucleotide binding motif at the N terminus. Here we report that this site is occupied by FAD in CRTISO. The reduced form of this cofactor catalyzes a reaction not involving net redox changes. Results obtained with C(1)-and C(5)-deaza-FAD suggest mechanistic similarities with type II isopentenyl diphosphate: dimethylallyl diphosphate isomerase (IDI-2). CRTISO, together with lycopene cyclase CRTY and IDI-2, thus represents the third enzyme in isoprenoid metabolism belonging to the class of non-redox enzymes depending on reduced flavin for activity. The regional specificity and the kinetics of the isomerization reaction were investigated in vitro using purified enzyme and biphasic liposome-based systems carrying specific cis-configured lycopene species as substrates. The reaction proceeded from cis to trans, recognizing half-sides of the symmetrical prolycopene and was accompanied by one trans-to-cis isomerization step specific for the C(5)-C(6) double bond. Rice lycopene ␤-cyclase (OsLCY-b), when additionally introduced into the biphasic in vitro system used, was found to be stereospecific for all-trans-lycopene and allowed the CRTISO reaction to proceed toward completion by modifying the thermodynamics of the overall reaction.Carotenoids belong to a large isoprenoid family, some members of which are indispensible in all photosynthetic organisms; however, they can also be formed by some heterotrophic bacteria and fungi. In photosynthesis, carotenoids play an important role in light harvesting and in the protection of cells from photo damage caused by reactive oxygen species. In addition, some carotenoids are precursors of phytohormones such as abscisic acid (1) and the strigolactones (2, 3). In human nutrition, carotenoids containing at least one unsubstituted ␤-ionone ring serve as provitamin A carotenoids (for review, see Ref. 4). In recent years, a wealth of molecular information on carotenogenesis in plants and microorganisms has become available (see Refs. 5, 6 for reviews on plant carotenogenesis), however, information on the enzymology and biochemistry of the involved reactions is comparatively scarce.In the carotenoid biosynthetic pathway, phytoene is the first carotene formed. Phytoene is a colorless C 40 triene prenyl hydrocarbon, which undergoes four desaturation steps during which double bonds are introduced to finally form the fully conjugated undecaene chromophore of the red-colored lycopene (Fig. 1). There are two divergent classes of carotene desaturases catalyzing the formation of the identical product (all-trans-lyc...

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Plant Carotene Cis-Trans Isomerase CRTISO

Ghisla

Hirschberg

et al. 2011

Journal of Biological Chemistry

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“…The configuration has been determined as Z for the double bonds at C-10/ C-11 and C-12/C-13, on the basis of the coupling constants for H-10/ H-11 (J¼7.4 Hz (2), 5.6 Hz (3), 9.7 Hz (4) and 5.8 Hz (5)), and for H-12/H-13 (J¼11.2 Hz (2-5)), as shown in Table 2. In addition, the geometry of the C-8/C-9 double bonds of compounds 2, 3 and 5 was assigned as E on the basis of the chemical shifts of a related system, 4 and the configuration of compound 4 was assigned as E on the basis of the coupling constant for H-8/H-9 (J¼15.2 Hz). The NOESY spectrum of compound 2 showed correlations for H-20 to H-13 and H-18, H-11 showed correlations to H-15 and H-10 showed correlations to H 3 -25.…”

Section: Structural Elucidationmentioning

confidence: 99%

Gombapyrones, new α-pyrone metabolites produced by Streptomyces griseoruber Acta 3662

et al. 2009

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Gombapyrones A-D, new members of the a-pyrone family of secondary metabolites, were produced by Streptomyces griseoruber Acta 3662, which was isolated from bamboo tree rhizosphere. The strain was characterized by its morphological and chemotaxonomical features and by 16S rDNA sequencing as S. griseobuber. The gombapyrone structures were determined by mass spectrometry and by NMR experiments, and were found to have an inhibitory activity against protein tyrosine phosphatase 1B and glycogen synthase kinase 3b. The Journal Antibiotics ( Keywords: fermentation; isolation; a-pyrone; protein-tyrosine phosphatase inhibitor; Streptomyces; structure elucidation INTRODUCTION In our screening program to detect novel secondary metabolites from actinomycetes for pharmaceutical applications (http://www. actapha rm.org) freshly isolated strains from selected European and Malaysian ecosystems were included. The strains were grown as submerged cultures in different complex media, extracts were prepared from mycelia and from culture filtrates at various fermentation times and were screened by HPLC-diode array analysis to determine their chemical diversity. Evaluation of chromatograms was performed using our in-house developed HPLC-UV-Vis database, which contains 933 entries, most of them being antibiotics. 2 Strain Acta 3662, which was isolated from soil collected from the rhizosphere of bamboo trees in the tropical rainforest of the University of Malaya Field Station at Gombak, Selangor, Malaysia, was of interest because of the presence of a family of metabolites in the mycelium extract having nearly congruent UV-Vis spectra, which were unlike those of all reference compounds of the database. This study describes the taxonomy of the producing strain, the fermentation, isolation, structural elucidation and biological activity of the new family of metabolites from strain Acta 3662, which were named gombapyrones, composed from the collection site Gombak and the a-pyrone scaffold of their structures, which are shown in Figure 1.

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“…Moreover, from the 1 H-NMR spectrum patterns at the low field region (Fig. 4), these carotenoids were presumed to be lycopene (1a), phytofluene (1b), and phytoene (1c), comparing the spectra with those of the literature [6][7][8], although the chemical shifts were slightly different because of the different solvents. Structural assignment was further confirmed by comparing their spectra with those of the pure standards.…”

Section: Lc-nmrmentioning

confidence: 81%

Application of LC‐NMR to analysis of carotenoids in foods

Tode

Maoka

Sugiura

2009

J of Separation Science

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LC‐NMR has been applied to componential analysis of carotenoids in several foods, specifically, tomato juice, palm oil, and satsuma mandarin orange juice. The crude carotenoids extracted with organic solvent from these foodstuffs were analyzed after simple pre‐processing. Three, four, and two kinds of carotenoids were identified for tomato juice, palm oil, and satsuma mandarin orange, respectively, primarily by comparing their NMR spectra with those of pure standard.

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Synthesis, Isolation, and NMR‐Spectroscopic Characterization of Fourteen (Z)‐Isomers of Lycopene and of Some Acetylenic Didehydro‐ and Tetradehydrolycopenes

Abstract: Eight (Z)-isomers of lycopene were prepared by stereocontrolled syntheses and fully characterized by '€1-NMR, "C-NMR, mass, and UVjVIS spectroscopy: (5Z)-, (72)

Cited by 129 publications

References 36 publications

Plant Carotene Cis-Trans Isomerase CRTISO

Plant Carotene Cis-Trans Isomerase CRTISO

Gombapyrones, new α-pyrone metabolites produced by Streptomyces griseoruber Acta 3662

Application of LC‐NMR to analysis of carotenoids in foods

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