Carotenoids in fish. XXIV. Sardina pilchardus Walb. (Clupeidae)

The author investigated the presence of various carotenoids in Sardina pilchardus Walb. from the coast of Southern Europe.The presence of the following carotenoids has been stated: -carotene, -carotene epoxide, -cryptoxanthin, canthaxanthin, lutein epoxide, zeaxanthin, astaxanthin (free and ester form) and mutatochrome. The dominant carotenoid in all the parts of the body was astaxanthin, especially its ester form. The total content of carotenoid ranged from 10.537 (skin and muscles) to 116.309 µg/g fresh weight (liver).     

Presence of carotenoids in Gordius aquaticus (Nematomorpha,Nemathelminthes) specimens from deep wells

By means of columnar and thin-layer chromatography, the presence of carotenoids in Gordius aquaticus L. (Nematomorpha, Nemathelminthes) from deep wells was studied.The investigations revealed the presence of the following carotenoids: -carotene, mutatochrome, -cryptoxanthin, ,-carotene epoxide,lutein, zeaxanthin and astaxanthin ester.     

Investigations of carotenoids in some faunal elements of the Adriatic Sea. IV-molluscs

The carotenoids in the molluscsClanculus cruciatus, Patella coerulea, Mytilus galloprovincialis, Sepia officinalis andLoligo vulgaris from the Adriatic sea were investigated. Their presence was determined by means of columnar and thin-layer chromatography. The following carotenoids were found inC. cruciatus; mytiloxanthin-like, lutein, lutein ester, zeaxanthin and astaxanthin-like; inP. coerulea: mytiloxanthin-like, lutein, lutein ester, lutein-5,6-epoxide, zeaxanthin and astaxanthin-like; inM. galloprovincialis: -carotene, mytiloxanthin-like, lutein, lutein ester, lutein-5,6-epoxide and zeaxanthin; inS. officinalis: -carotene, lutein, lutein ester, tunaxanthin and zeaxanthin; inL. vulgaris: -carotene, -carotene, -carotene, -cryptoxanthin, isocryptoxanthin, isorenieratene, capsanthin, capsorubin, mutatochrome, triophaxanthin, zeaxanthin, 4-hydroxy--carotene and 4-keto--carotene     

Production of deuterated β-carotene by metabolic labelling of Spirulina platensis

Method for production of deuterated -carotene for the bioavailability studies of vitamin A has been developed using Spirulina platensis in culture. Suspension cultures of Spirulina in heavy water (99.4% D₂O) medium produced maximum biomass and -carotene in 28 to 30 days. Of the total carotenoids, lutein constituted 30 to 35% while -carotene was about 24%. MS showed that 60 to 65% H atoms in -carotene were deuterated. 100% replacement of H atom with deuterium was achieved by preventing exchange with atmospheric moisture. The medium could be used in several cycles for metabolic labelling of carotenoids whereby the cost of production is reduced.     

Carotenoids in fish. XXIII. Syngnathidae family

The author investigated the presence of various carotenoids in three species of the Syngnathidae family by means of columnar and thin-layer chromatography. The investigations revealed the presence of the following carotenoids: canthaxanthin, lutein, lutein epoxide, zeaxanthin, astaxanthin (free and ester form) and 4-hydroxy-4-keto--carotene. Ketocarotenoids (astaxanthin and canthaxanthin) comprised the greatest part     

American Cockroach (Periplaneta americana) Synthesizes Carotenoids from the Precursor [14C]Mevalonic Acid Pyrophosphate

The level of an important carotenoid (-carotene) in the gut of Periplaneta americana depends on the content of the carotenoid in food: a carotenoid-fortified diet causes accumulation of -carotene up to 10 g/g wet weight, while on a carotenoid-deficient diet the level of this substance is low (0.7 g/g wet weight). In the eye, in contrast to the gut, a constant level of -carotene (1.3-1.4 g/g wet weight) is found regardless of the diet. This phenomenon remained unchanged over three years of feeding of the cockroaches with the carotenoid-deficient diet, suggesting that P. americana produces carotenoids by de novo biosynthesis. This suggestion was confirmed in experiments using intraperitoneal injection of the exogenous carotenoid biosynthesis precursor [¹⁴C]mevalonic acid pyrophosphate followed by extraction of carotenoid and chromatographic purification of the labeled product. Injection of 3.4 nmoles [¹⁴C]mevalonic acid pyrophosphate transiently increased the -carotene content in eyes on days 2 and 4 after injection of the label. Purification of radiolabeled carotenoids from eye and gut by the transfer of carotenoids into a less polar solvent, alkaline hydrolysis (saponification), and chromatography on alumina and cellulose columns decreased the specific radioactivity to a constant level that cannot be further decreased by repeated chromatography. The elution profile of these purified preparations of -carotene after chromatography is characterized by coincidence of symmetric peaks of count and absorption. We suggest that to create the optimal carotenoid concentration in the eye, P. americana uses two biochemical mechanism: 1) it accumulates carotenoids in reserve in the gut when abundant supplies of carotenoids are available in the diet; 2) it synthesizes carotenoids de novo when its food is deficient in these compounds.     

Evidence of β-carotene 7,8(7′,8′) oxygenase (β-cyclocitral,crocetindial generating) in Microcystis

A -carotene oxygenase is described which occurs in the Cyanobacterium Microcystis. It cleaves -carotene and zeaxanthin specifically at the positions 7,8 and 7,8, while echinenone and myxoxanthophyll are not affected. The oxidative cleavage of -carotene leads to the formation of -cyclocitral and crocetindial and that of zeaxanthin to hydroxy--cyclocitral and crocetindial in nearly stoichiometric amounts. Oxidant is dioxygen as has been demonstrated by high incroporation (86%) of ¹⁸O₂ into -cyclocitral. -Carotene oxygenase is membrane bound, sensitive to sulfhydryl reagents, antioxidants and chelating agents. Iron seems to be an essential part of the enzyme activity. Cofactors necessary for the reaction could not be detected.Abbreviations TLC thin layer-chromatography - PIPES piperazine-N,N-bis-(2-ethanesulfonate) Na - TES 2{[tris-(hydroxymethyl)-methyl]-amino} ethanesulfonic acid Dedicated to Professor G. Drews on occasion of his 60th birthday     

Carotenoid pigments of Stigmatella aurantiaca (Myxobacterales)

Summary In this first article on the carotenoids of Myxobacterales we report on the minor carotenoids of Stigmatella aurantiaca: phytoene, phytofluene, lycopene, -carotene, 4-keto--carotene, 1,2-dihydro-1-hydroxy--carotene, 4-keto-1,2-dihydro-1-hydroxy--carotene, 4-keto-1,2-dihydro-1-hydroxy-torulene, and 1,2,1,2-tetrahydro-1,1-dihydroxy-lycopene. These pigments account for about 10% of total carotenoids.     

The neutral carotenoids of wild-type and mutant strains of Neurospora crassa

The neutral carotenoids of wild-type Neurospora crassa and of carotenoid mutants at four discrete genetic loci were isolated using gradient elution chromatography on deactivated alumina columns. Carotenoids were identified by absorption spectrophotometry and thin layer cochromatography with carotenoid standards. Phytoene, phytofluene, -carotene, -carotene, neurosporene, torulene, lycopene, and 3,4-dehydrolycopene were isolated from wild type. Phytoene, phytofluene, -carotene, -carotene, neurosporene, -carotene, lycopene, and one unknown carotenoid, tentatively identified as 15,15-cis--carotene, were isolated from a yellow mutant, ylo-1. ylo-1 also contained residual carotenoids having similar absorption spectra to, but very different chromatographic behavior from, phytofluene, -carotene, -carotene, and lycopene. Albino and colored al-1 mutants contained large amounts of phytoene and only traces of other neutral carotenoids. Albino al-2 and al-3 mutants contained only traces of neutral carotenoids.     

Carotenoid composition in milo (Sorghum vulgare) shoots as affected by phytochrome and chlorophyll

The composition of coloured carotenoids in the milo shoot was investigated quantitatively (high performance liquid chromatography) during light-mediated plastidogenesis, including the time span of photodelay as caused by medium and high light fluxes. It was found that as long as only the far-red-absorbing form of phytochrome operates, the carotenoid pattern remains virtually the same as in complete darkness (violaxanthin and lutein as major constituents, traces of -carotene). On the other hand, the pattern changes dramatically in white or red light with increasing amounts of chlorophyll (lutein and -carotene dominate, -carotene showing the strongest relative increase). Photodelay during the early phase of plastidogenesis affects the carotenoid composition strongly. Increase of neoxanthin, violaxanthin and -carotene contents are diminished while lutein accumulation proves resistant towards chlorophyll-mediated photoinhibition. The photodelay can be diminished by an appropriate light pretreatment. The data indicate that light-mediated control over carotenoid accumulation is exerted at three levels: i) a coarse control through phytochrome, ii) fine tuning in connection with chlorophyll accumulation, iii) stabilization of holocomplexes against photodecomposition.Abbreviations GG14 high fluence rate green-yellow light - HPLC high-performance liquid chromatography - Chl chlorophyll - WL_w weak white light (1200 lx) - WL_m medium flux white light (12000 lx)     

Antisense inhibition of the beta-carotene hydroxylase enzyme in Arabidopsis and the implications for carotenoid accumulation,photoprotection and antenna assembly

The xanthophylls are oxygenated carotenoids and are important structural components of the photosynthetic apparatus. Xanthophylls contribute to the assembly and stability of light-harvesting complex apoproteins (LHC) and contribute to photoprotection via non-photochemical quenching of chlorophyll fluorescence (NPQ) in oxygenic photosynthetic organisms. Previously, mutations have been described that disrupt many steps in the xanthophyll biosynthetic pathway. However, there are no definitive reports of a lesion that effects the -hydroxylase enzyme, which catalyzes hydroxylation of the -rings of -carotene and -carotene, and is thus necessary for synthesis of essentially all xanthophylls of higher plant chloroplasts. We have utilized an antisense approach to effectively reduce levels of -hydroxylase in Arabidopsis thaliana in order to examine how a reduction in this enzyme impacts carotenoid biosynthesis and plant viability. Expression of the antisense -hydroxylase transgene resulted in a maximal reduction in violaxanthin of 64% and a maximal reduction in neoxanthin of 41%. This reduction was reflected in a 22% increase in -carotene and a reduction in the total carotenoid pool, whereas lutein levels were relatively unaltered. Despite the reduction in violaxanthin and neoxanthin, the antisense -hydroxylase plants had a wild-type complement of chlorophylls and LHCs on a fresh weight basis. Under high light stress, the unconverted pool of violaxanthin was the same size as in wild type and thus there was an even greater proportional reduction in zeaxanthin of 75%. Despite this marked decrease in zeaxanthin, NPQ only declined by 16%.This revised version was published online in October 2005 with corrections to the Cover Date.     

A quantitative method for separating reaction components of CMP-sialic acid: Lactosylceramide sialyltransferase using Sep Pak C18 cartridges

A rapid procedure is described for the separation of CMP-sialic acid:lactosylceramide sialyltransferase reaction components using Sep Pak C₁₈ cartridges. The quantitative separation of the more polar nucleotide sugar, CMP-sialic acid, and its free acid from the less polar G_M3-ganglioside is simple and rapid relative to previously described methods. Recovery of G_M3 is optimized by the addition of phosphatidylcholine to the reaction mixture prior to the chromatographic step. Using rat liver Golgi membranes as a source of CMP-sialic acid: lactosylceramide sialyltransferase activity (G_M3 synthase; ST-1), the transfer of [¹⁴C] sialic acid from CMP-[¹⁴C] sialic acid to lactosylceramide can be quantified by this assay. The procedure is reliable and may be applicable to the isolation of ganglioside products in otherin vitro glycosyltransferase assays.Abbreviations G_M3 G_M3-ganglioside - II³NeuAc-LacCer NeuAc2-3Gal1-4Glc1-1Cer - G_D1a G_D1a-ganglioside, IV³NeuAc, II³NeuAc-GgOse₄Cer, NeuAc2-3Gal1-3GalNac1-4(NeuAc2-3)Gal1-4Glc1-1Cer - G_D3 G_D3-ganglioside, II³(NeuAc)₂LacCer, NeuAc2-8NeuAc2-3Gal1-4Glc1-1Cer - GgOse₄Cer asialo-G_M1 Gal1-3GalNAc1-4Gal1-4Glc1-1Cer - FucG_MI fucosyl-G_MI-ganglioside, Fuc1-2Gal1-3GalNAc1-4Gal1-4 Glc1-1Cer - ST-1 G_M3 synthase, CMP-sialic acid:lactosylceramide sialyltransferase - LacCer lactosylceramide, Gal1-4Glc1-1Cer - CMP-NeuAc cytidine 5-monophospho-N-acetylneuraminic acid - PC phosphatidylcholine - PMSF phenylmethylsulfonyl fluoride     

Ganglioside-cholera toxin interactions: a binding and lipid monolayer study

Summary On t.l.c. plates ¹²⁵I-cholera toxin binds to a disialoganglioside tentatively identified as GD_lb with about 10 times less capacity than to ganglioside GM₁. Binding of labeled toxin to both gangliosides was abolished in presence of excess amounts of unlabeled B subunit. Ganglioside extracts from human or pig intestinal mucosa showed toxin binding to gangliosides GM₁ and GD_1b. In ganglioside-containing lipid monolayers the penetration of the toxin was independent of the ganglioside binding capacity.Abbreviations GM₂ Gal-NAc14Gal(3-2NeuAc)14G1c1Cer - GM₁ Gal3Ga1-NAc14Gal(32NeuAc)14G1c11Cer - GD_1a NeuAc23Ga113Gal-NAc14Gal(32NeuAc)14G1c11Cer - GD1b Gall3Gal-NAcl4Gal(32NeuAc82NeuAc)14Glc11Cer - GT_1b NeuAc23Ga113Ga1-NAcal4Gal(3-2NeuAc82NeuAc)14G1c11Cer - dpPC 1,2-hexadecanoyl-sn-glycero-3-phosphocholine - dpPE 1,2-hexadecanoyl-sn-glycero-3-phosphoethanolamine     

Chlorophylle und Carotinoide der Chaetophorineae (Chlorophyceae,Ulotrichales)

Zusammenfassung Bei der Untersuchung der Pigmente und des Stoffwechsels der Chaetophorineen wurden drei Stämme der Chaetophoracee Microthamnion kuetzingianum Naegeli näher analysiert. Neben den üblichen Chloroplastenpigmenten: Chlorophyll a und b, - und -Carotin, -Cryptoxanthin, Lutein, Zeaxanthin, Antheraxanthin, Violaxanthin, Neoxanthin und Neoxanthin Neo A konnte Siphonaxanthin identifiziert werden (ca. 30–40% der Gesamtcarotinoide). Es war nicht in den Chaetophoraceen Draparnaldia glomerata, Chaetophora elegans und Stigeoclonium helveticum var. maius zu finden. Dieses für viele Gattungen der Bryopsidales (= Siphonales) typische Keto-Carotinoid wurde damit auch außerhalb dieser Ordnung nachgewiesen. Seine Bedeutung als Leitcarotinoid wird diskutiert.

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Chlorophylls and carotenoids of the Chaetophorineae (Chlorophycea, Ulotrichales) 1. Siphonaxanthin in Microthamnion kuetzingianum Naegeli

Summary In the forthcoming series of papers we are going to investigate the chlorophylls and carotenoids of the members of the subordo Chaetophorineae (ordo: Ulotrichales). Three strains of Microthamnion kuetzingianum Naegeli have already been studied. In addition to the usual chloroplast pigments: chlorophyll a and b, -and -carotene, -cryptoxanthin, lutein, zeaxanthin, antheraxanthin, violaxanthin, neoxanthin, and neoxanthin neo A—siphonaxanthin was found (approx. 30–40% of total carotenoids). This keto-carotenoid does not occur in Chaetophora elegans, Draparnaldia glomerata, and in Stigeoclonium helveticum var. maius. Since Siphonaxanthin is typical for many genera of the Bryopsidales (= Siphonales) the chemotaxonomical significance of its occurrence outside this order is discussed.

     

Some carotenoids in Chironomus annularius Meig. larvae (Diptera : Chironomidae)

Summary The author investigated the presence of various carotenoids in the body of the larvae of the Chironomus annularius MEIG. moquito (Diptera: Chironomidae) by means of columnar and thin-layer chromatography.The investigations revealed the presence of the following carotenoids in the larvae: -carotene, -carotene, canthaxanthin, cryptoxanthin, lutein, astacene and a kind of xanthophyl which was not possible to identify more closely.     

Heterogeneity of the hemoglobin of the Ohrid trout (Salmo L. typicus)

We have analyzed the hemoglobins of five individual trout from the Ohrid Lake (Salmo L. typicus) by electrophoretic methods, by reversed-phase high-performance liquid chromatography, and by limited structural analyses. The two major classes of hemoglobin are type I (35% of total) and type IV (65%). Type IV is the major oxygen-transporting hemoglobin; it consists of three types of chain (in about equal quantities) and three types of chain (one major and two minor types). Several structural differences have been observed between these three (IV) chains and between the three (IV) chains, suggesting a complex genetic system governing the synthesis of these proteins. Moreover, a few amino acid substitutions occur at positions involved in contacts between chains, which suggests that differences in oxygen affinity may exist between these various type IV hemoglobins. Type I hemoglobin is less complex because it contains one type of chain and two chains; the latter two differ in numerous positions, suggesting duplications of the (I)-globin gene. The and chains of type I hemoglobin differ considerably from the and chains of type IV hemoglobin, indicating the existence of (I)- and (I)-globin genes separate from the (IV)- and (IV)- globin genes.This study was supported in part by the Yugoslav-American Joint Funds, pp 812 (to G.D.E.), and by United States Public Health Service Research Grant HLB-05168 (to T.H.J.H.).     

β-Carotene producing mutants of Phaffia rhodozyma

Like other carotenoid-producing organisms, Phaffia rhodozyma, a red astaxanthin-producing yeast, is supposed to synthesize carotenoids by the following steps: formation of phytoene from geranylgeranyl pyrophosphate, dehydrogenation of phytoene to lycopene, cyclization of lycopene to -carotene and oxidation of the latter to astaxanthin. Mutagenic treatments generated in P. rhodozyma a wide diversity of colour variants ranging from white to dark red. The identification of the corresponding carotenoid compounds revealed the occurrence of -carotene-accumulating strains, phytoene-accumulating strains, and strains lacking any carotenoid compound. These classes of strains are likely to result from alterations in, respectively, the oxidation of -carotene, phytoene dehydrogenation and the phytoene synthetase step. Except for the cyclization of lycopene to -carotene, all the steps of carotenogenesis in P. rhodozyma are represented by the above mutants. Furthermore, astaxanthin-overproducing mutants were also selected; they are likely to be affected in some upstream step, and certainly before -carotene, as after an additional mutagenesis they generated oxidaseless strains that, in this case, overproduce -carotene. The latter strains appear very promising for biotechnological production of natural -carotene.     

13Cα and 13Cβ chemical shifts as a tool to delineate β-hairpin structures in peptides

Unravelling the factors that contribute to the formation and the stability of -sheet structure in peptides is a subject of great current interest. A -hairpin, the smallest -sheet motif, consists of two antiparallel hydrogen-bonded -strands linked by a loop region. We have performed a statistical analysis on protein -hairpins showing that the most abundant types of -hairpins, 2:2, 3:5 and 4:4, have characteristic patterns of ¹³C and ¹³C conformational shifts, as expected on the basis of their and angles. This fact strongly supports the potential value of ¹³C and ¹³C conformational shifts as a means to identify -hairpin motifs in peptides. Their usefulness was confirmed by analysing the patterns of ¹³C and ¹³C conformational shifts in 13 short peptides, 10–15 residues long, that adopt -hairpin structures in aqueous solution. Furthermore, we have investigated their potential as a method to quantify -hairpin populations in peptides.     

Carotenogenesis and asparagine inLeptosphaeria michotii (West) Sacc.

Summary InLeptosphaeria michotii U¹⁴C-asparagine was incorporated into the coloured carotenoids, the synthesis of which carried on till day 8. The pigment turnover, obvious from day 6, was not modified by the light conditions used.Nicotine (0.25 to 4.5 mM) has been used to study carotenogenesis and sporulation rhythm regulation inL. michotii fed with asparagine 2.6 mM. Control cultures contained in darkness -carotene only and in continuous light -carotene 98% and lycopene 2%. The mold receiving nicotine 0.25 mM in darkness contained -carotene 98% and lycopene 2%. For nicotine 0.5 mM and upwards -carotene decreased, lycopene increased and -carotene appeared, the balance between these pigments also depending on the light conditions. Whereas period length () of the sporulation rhythm increased from one cycle to the next in control cultures in darkness, it was stabilized either by continuous light ( 27 h) or by nicotine 0.25 mM ( 30 h). For nicotine 0.5 mM sporulation was uniform in darkness or in light.     

Carotenoids in fish. XXVIII. Carotenoids in Micropterus salmoides (Lalépéde) Centrarchidae

The occurrence and contents of carotenoids in different body parts were investigated by column chromatography and TLC in Micropterus salmoides (Lalép).The following carotenoids were found: -carotene, -cryptoxanthin, -cryptoxanthin, echinenone, canthaxanthin, lutein, zeaxanthin, neothxanthin, tunaxanthin, -doradexanthin, -doradexanthin, idoxanthin, astaxanthin, astaxanthin ester, mutatochrome and mutatoxanthin.Their total contents varied within the range of 0.071–1.691 µg/g wet weight.