Β-carotene Isomers Research Articles

Use of carotenoids in the characterization of octadecylsilane bonded columns and mechanism of retention of carotenoids on monomeric and polymeric stationary phases

Different analyses were performed with 29 commercial octadecylsilane bonded columns in HPLC and subcritical fluid chromatography (SbFC) in order to evaluate the characteristics of stationary phases. Two types of test molecules were used, carotenoids and polycyclic aromatic hydrocarbons. The use of the cis-trans isomers of β-carotene allowed the characterization of the stationary phase (monomeric versus polymeric) and of the carbon content. The separation of luteine and zeaxanthine depends on the nature of the stationary phase and, in addition, allows the evaluation of the extent of accessibility of residual silanol groups. These results, and those of a study on the effect of temperature, allow a better understanding of the separation mechanisms in the retention of planar and non-planar compounds, and emphasize the similarity between HPLC and SbFC.

EFFECT OF GAMMA IRRADIATION ON ISOMERIZATION OF ?-CAROTENE IN SWEET POTATO

Cured Georgia Reds, sweet potato roots, were irradiated using 60Co source for 500 Krad dose. HPLC analyses of tissue extracts indicated that irradiation did not lead to isomerization of all-trans-β-carotene. Greater than 97% of the total β-carotene was in the all-trans form. Cis isomers of β-carotene have lower provitamin A activities than all-trans-β-carotene. Since they were not produced with γ-irradiation, this process did not decrease provitamin A due to isomerization. Thus, irradiation of sweet potatoes can be used without significant changes in the provitamin A content.

Cis-trans isomers of lycopene and β-carotene in human serum and tissues

Since cis or trans isomers of carotenoids may have different biological reactivities, the isomeric composition of lycopene and β-carotene was measured in serum and seven human tissues. In addition to all- trans lycopene, at least three cis-isomers (9-, 13-, and 15-cis) were present, accounting for more than 50% of total lycopene. 13-and 15- cis-β-carotene, however, were present at only 5% of the all- trans isomer. In addition, 9- cis-β-carotene was present in tissue samples but not in serum. There were interindividual differences in carotenoid levels of the different tissue types, but liver, adrenal gland, and testes always contained significantly higher amounts of the carotenoids than kidney, ovary, and fat; carotenoids in brain stem tissue were below the detection limit. β-Carotene was the major carotenoid in liver, adrenal gland, kidney, ovary, and fat, whereas lycopene was the predominant carotenoid in testes.

Fluorescence of carotenoids. Effect of oxygenation and cis/trans isomerization

C 40 carotenoids fall, with respect to fluorescence in homogeneous solution, into two distinct groups depending on the presence of a CO group in the molecule. Excitation spectra agree with absorption spectra for the carbonyl derivatives astaxanthin and canthaxanthin. In contrast, zeaxanthin and isomers of β-carotene have a twentyfold increase in fluorescence quantum yield for excitation around 350 nm compared to excitation near the absorption maximum (at approximatively 430 nm). These differences are interpreted in terms of the role of non-emitting 1(n, π*) states related to the CO group in facilitating non-radiative deactivation of higher 1(π, π*) states.

ChemInform Abstract: Triplet‐Sensitized and Thermal Isomerization of all‐trans, 7‐cis, 9‐ cis, 13‐cis, and 15‐cis Isomers of β‐Carotene: Configurational Dependence of the Quantum Yield of Isomerization via the T1 State.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Comparison of Liquid Chromatographic Methods for Determination of Cis-Trans Isomers of β-Carotene

Abstract Four liquid chromatographic columns and various solvent systems were evaluated for their ability to resolve and quantitate cls-trans Isomers of β-carotene. The Vydac C18 201 TP and Ca(OH)2 columns were most effective in resolving alltrans-, 13-cls-, and 9-cls-β-carotenes. Additionally, the 15- c18 Isomer was separated using the method employing a Ca(OH)2 column. Peak Identification was based on absorption spectra (obtained from photodlode array data), retention times, and coelutlon in comparison to authentic standards. A quantitative analysis of vegetable extracts using both the Vydac and Ca(OH)2 columns showed comparable results. However, both procedures lacked complete resolution of 2 minor clsβ-carotenes, tentatively identified as dl-cis Isomers. High selectivity for carotene Isomers as well as fewer interferences were observed with the Ca(OH)2 procedure for analysis of plant tissue extracts and thus, It is preferred for determination of β-carotene cis-isomer content In these samples.

Time-resolved absorption spectroscopy of the triplet state produced from the all-trans, 7-cis, 9-cis, 13-cis, and 15-cis isomers of β-carotene

Time-resolved absorption spectroscopy was applied to the triplet species produced by anthracene-sensitized flash photolysis of the all-trans, 7-cis, 9-cis, 13-cis, and 15-cis isomers of β-carotene. Upon triplet excitation, the all-trans and 15-cis isomers produced an identical triplet species showing the same spectrum and decay constant, while the other isomers produced different triplet species of their own. Concerning the initial and final ground-state isomers, excitation from and subsequent relaxation to the original isomer were seen for the all-trans, 7-cis, and 9-cis isomers, while isomerization into the all-trans isomer was seen for the 13-cis and 15-cis isomers.

ChemInform Abstract: 1H NMR Spectra of the all‐trans (I), 7‐cis, 9‐cis, 13‐cis and 15‐cis Isomers of β‐Carotene: Elongation of the Double Bond and Shortening of the Single Bond Toward the Center of the Conjugated Chain as Revealed by Vicinal Coupling Constants.

ChemInformVolume 20, Issue 22 Physical Organic Chemistry ChemInform Abstract: 1H NMR Spectra of the all-trans (I), 7-cis, 9-cis, 13-cis and 15-cis Isomers of β-Carotene: Elongation of the Double Bond and Shortening of the Single Bond Toward the Center of the Conjugated Chain as Revealed by Vicinal Coupling Constants. Y. KOYAMA, Y. KOYAMA Fac. Sci., Kwansei Gakuin Univ., Nishinomiya 662, Jap.Search for more papers by this authorM. HOSOMI, M. HOSOMI Fac. Sci., Kwansei Gakuin Univ., Nishinomiya 662, Jap.Search for more papers by this authorH. HASHIMOTO, H. HASHIMOTO Fac. Sci., Kwansei Gakuin Univ., Nishinomiya 662, Jap.Search for more papers by this authorT. SHIMAMURA, T. SHIMAMURA Fac. Sci., Kwansei Gakuin Univ., Nishinomiya 662, Jap.Search for more papers by this author Y. KOYAMA, Y. KOYAMA Fac. Sci., Kwansei Gakuin Univ., Nishinomiya 662, Jap.Search for more papers by this authorM. HOSOMI, M. HOSOMI Fac. Sci., Kwansei Gakuin Univ., Nishinomiya 662, Jap.Search for more papers by this authorH. HASHIMOTO, H. HASHIMOTO Fac. Sci., Kwansei Gakuin Univ., Nishinomiya 662, Jap.Search for more papers by this authorT. SHIMAMURA, T. SHIMAMURA Fac. Sci., Kwansei Gakuin Univ., Nishinomiya 662, Jap.Search for more papers by this author First published: May 30, 1989 https://doi.org/10.1002/chin.198922064Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume20, Issue22May 30, 1989 RelatedInformation

1H NMR spectra of the all- trans, 7- cis, 9- cis, 13- cis and 15- cis isomers of β-carotene: elongation of the double bond and shortening of the single bond toward the center of the conjugated chain as revealed by vicinal coupling constants

400 MHz 1H-NMR spectra of the all- trans, 7- cis, 9- cis, 13- cis and 15- cis isomers of β-carotene have been recorded in benzene and chloroform solutions. A set of coupling constants for olefinic 1Hs has been obtained from the spectra of the two different kind of solutions, in which the chemical shifts and the overlap of the signals are different. Assignment of the signals newly made for the benzene solution is based on 1H 1H and 1H 13C chemical shift-correlated and 1H J-resolved spectra as well as the empirical rule of isomerization shifts. Comparison of the coupling constants for the cis-trans isomers reveals: (1) the vicinal coupling constant of the trans CC bond decreases, while that of the ( trans) CC bond increases, from the end toward the center of an extended conjugated chain; (2) the vicinal coupling constant of the cis CC bond in the center is smaller than that at the end. The changes in the coupling constants are ascribed to elongation of the double bond and shortening of the single bond, toward the center of the conjugated chain.

The CC stretching Raman lines of [β-carotene isomers in the S 1 state as detected by pump-probe resonance Raman spectroscopy

A Raman line due to the S 1 state of isomeric β-carotene (at 1777 cm −1 for all-trans and at 1760 cm −1 for 15-cis) has been detected by means of transient, resonance Raman spectroscopy using < 100 ps, 355 nm pump and 532 nm probe pulses, the latter being rigorously resonant with the S n ← S 1 absorption. The Raman line is assigned to a CC stretching vibration in the 2 1A g − state by inference based on shorter polyenes.

Distribution of cis-trans-β-Carotene in Pigment-Protein Fractions of Photosystem I and II

The distribution of isomers of β-carotene is reported in the CP-47 pigment-protein complex of photosystem II and photosystem I (PS I) from barley. The distribution of carotenoids from light harvester complex I I is reported. CP-47 lacks 9,9′-rá-carotene, but contains 9,13′-cis-carotene; PS I lacks 9,13′-cis but contains 9,9′-eis. More 9-cis, 9,13-cis, 9,15-cis, and epoxide is observed in CP-47 than in PS I.

Laser-Induced Intrinsic and Dye-Sensitized Photoconductivity in β-Carotene Glass

Photoconductivity is studied in thin films of β-carotenc glass, an amorphous mixture of β-carotene isomers. Photocurrents are produced by a pulsed dye laser and are on the order of microamperes. The mechanism for production of photocurrent is believed to be two-photon internal photoemission. Photoconduction is also investigated in a variety of organic dyes. These dyes and chlorophyll a are then used to sensitize the photoconduction of β-carotene glass to longer wavelengths than it would normally photoconduct. It is believed that chlorophyll and phthalocyanine donate holes to the carotene after photoexcitation, while the other dyes undergo an energy transfer process. The voltage, laser intensity, and wavelength dependences of the photocurrents are examined and compared with results from earlier studies.

Supplementary and revised assignment of the peaks of the 7,9-, 9,9′-, 13,13′-, 9,13′-di- cis and 9,9′,13-tri- cis isomers of β-carotene in high-performance liquid chromatography using a column of calcium hydroxide

Supplementary and revised assignment of the peaks of the 7,9-, 9,9′-, 13,13′-, 9,13′-di- cis and 9,9′,13-tri- cis isomers of β-carotene in high-performance liquid chromatography using a column of calcium hydroxide

Picosecond transient absorption spectroscopy on isomeric retinoid and carotenoid.

Deca-picosecond to nanosecond time-resolved, absorption spectroscopy applied to a set of cis-trans isomers of retinal, retinylideneacetaldehyde and β-carotene is summarized. No configurational changes have been detected in the singlet excited-state (S1) of either retinylideneacetaldehyde or β-carotene. Configurational changes (isomerization) have been detected in the triplet excited-state (T1) of retinal, retinylidene acetaldehyde and β-carotene. The rate of triplet isomerization was dependent on the starting ground-state configuration; it is the highest for the central-bent, unmethylated-cis configuration, and it is the lowest for the all-trans configuration.

Configuration of the carotenoid in the reaction centers of photosynthetic bacteria. (2) Comparison of the resonance Raman lines of the reaction centers with those of the 14 different cis-trans isomers of β-carotene

Configuration of the carotenoid in the reaction centers of photosynthetic bacteria. (2) Comparison of the resonance Raman lines of the reaction centers with those of the 14 different cis-trans isomers of β-carotene

Configuration of the carotenoid in the reaction centers of photosynthetic bacteria. Comparison of the resonance Raman spectrum of the reaction center of Rhodopseudomonas sphaeroides G1C with those of cis-trans isomers of β-carotene

The resonance Raman spectrum of the reaction center of Rhodopseudomonas sphaeroides G1C as well as those of the cis-trans isomers of β-carotene (all- trans, 9- cis, 13- cis, 15- cis and 9- cis, 13- cis- (or 9- cis, 13′- cis)) have been recorded at liquid N 2 temperature by use of the 457.9, 488.0 and 514.5 nm excitation lines. Comparison of the spectra indicated that the carotenoid in the reaction center takes the 15- cis configuration.

Carotenoids and pteridines in the skin of interspecific hybrids of Xiphophorus

1. 1. Certain interspecific hybrids of Xiphophorus segregate in Mendalian ratios into red and orange fish. Their coloration is due to carotenoids and pteridines in the skin. The main carotenoid compounds were identified as two keto-carotenoids, two isomers of zeaxanthin, zeaxanthin, lutein and β-carotene and the main pteridine compounds as neodrosopterin, drosopterin, isodrosopterin, sepiapterin, isoxanthopterin, ranachrome-3 and biopterin. 2. 2. The carotenoids form a yellow background upon which the red and orange coloration are caused by neodrosopterin, drosopterin, isodrosopterin and sepiapterin, depending on their quantities. 3. 3. The red coloration is apparently dependent on a gene which intensifies pigment cell differentiation, whereas the orange coloration presumably is determined by the lack of this gene.

Thermal reaction of β-carotene. Part 1

β-Carotene has ben heated under vacuum at temperatures ranging from 200 to 350°C for 24 h as a model of geothermal reaction of carotenoids in sediments and of a thermal reaction of highly conjugated polyene. Compounds with molecular weights of 138, 240, 346 and 444 and isomers of β-carotene were obtained in addition to toluene, xylene, ionene and 2,6-dimethylnaphthalene, which have been reported previously as pyrolysis products of β-carotene. Possible reaction mechanisms for the formation of the pyrolysis products are given.

Carotenoids in Cyclops strenuus strenuus Fischer (Crustacea, copepoda)

1. 1. The presence of carotenoids in Copepoda of an intense pink colour— Cyclops strenuus strenuus Fischer—was studied. 2. 2. In extracts separated by means of column and thin-layer chromatography, the following carotenoids were identified: β-carotene, echinenone, canthaxanthin, astaxanthin, lutein, one unknown carotene and unknown xanthophyll. Carotenoids identified only in young specimens: α-carotene, β-carotene isomer (?) and cryptoxanthin.

Correlation of spectroscopic observations on polyenes with ripening of tomato fruits

Absorption spectra of tomato fruit purees supplemented spectroscopic studies of carotene fractions in hexane solution to trace development of polyenes in ripening fruits, from very green to fully ripe. Genetic types of great diversity ranged from yellow through orange and red in ripe fruit color. Purees indicated early appearance of proneurosporene in all types, while extract data indicated first the appearance of α- or β-carotene isomers. Phytoene, phytofluene, and ζ-carotene varied with different strains. cis-Isomers appear before all- trans isomers in some cases. 3,4,3′,4′-Dehydrolycopene was apparent in all red and some orange fruit purees. Considerable support is given to the theory of ring closure before lycopene formation in polyene synthesis, but paths may differ greatly among genetic types. The spectroscopic study of purees appears a promising tool in studies of polyene analysis.