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1.
Merete Grung Frances M. L. D'Souza Michael Borowitzka Synnøve Liaaen-Jensen 《Journal of applied phycology》1992,4(2):165-171
Aplanospores ofHaematococcus pluvialis MUR 145 contained 0.7% carotenoids (dry wt. basis) consisting of β,β-carotene (5% of total carotenoid), echinenone (4%),
canthaxanthin (4%), (3S,3′S)-astaxanthin diester (34%), (3S,3′S)-astaxanthin monoester (46%), (3S,3′S)-astaxanthin (1%) and (3R,3′R,6′R)-lutein (6%).
The astaxanthin esters were examined by TLC and HPLC and VIS,1H NMR and mass spectra recorded. Their chirality was determined by the camphanate method (Vecchi & Müller, 1979) after anaerobic
hydrolysis.
The tough cell wall of the aplanospores required enzymatic treatment prior to pigment extraction. The potential use of this
microalga as a feed ingredient in aquaculture is discussed briefly. 相似文献
2.
Summary The isolation, morphology and growth chracteristics of pure cultures of a Thiothece, Lamprocystis and Thiodictyon strain are described.Their carotenoid composition is reported. The Thiothece strain produced in addition to okenone (1), several related ketocarotenoids, among which a demethylated okenone (6) was identified by a small scale total synthesis. Thiodictyon and Lamprocystis produced carotenoids of the rhodopinal (previously warmingone) series, the latter organism contained as major carotenoids a lycopenol (4), not previously found in Nature, and a cross-conjugated lycopenal (2), previously called anhydro-warmingone.Part 7. Acta chem. scand. 21, 2185 (1967). 相似文献
3.
Merete Grung Georg Kreimer Michael Calenberg Michael Melkonian Synnøve Liaaen-Jensen 《Planta》1994,193(1):38-43
Isolated intact eyespot apparatuses, the photoreceptive organelles involved in blue-light-mediated photoresponses of flagellate green algae, were analyzed regarding their carotenoid composition. Carotenoids from the eyespot apparatuses of Spermatozopsis similis were identified by high-performance liquid chromatography, visible-light absorption spectra, mass spectroscopy and by 1H-nuclear magnetic resonance spectroscopy (carotenes), and compared with those of whole-cell extracts. Both extracts contained ,-carotene, ,-carotene (formerly -carotene), lycopene, lutein, zeaxanthin, violaxanthin and all-E-and 9-Z-neoxanthin. The relative carotenoid compositions, however, differed significantly. A twofold relative increase in the total carotene level was evident in the fraction enriched in eyespot apparatuses. This was mainly due to an increase in the monocyclic ,-carotene and the aliphatic lycopene, whereas the relative content of ,-carotene remained unchanged. On the other hand a relative decrease in the total xanthophyll content, especially of lutein and the epoxidic carotenoid neoxanthin, was observed in the eyespot apparatuses compared with the whole-cell extracts. The decrease of the latter resulted almost solely from a reduction of the 9-Z-rather than the all-E-isomer. The bulk of the carotenes is thought to be localized in the highly organized eyespot lipid globules, which act as a combined quarter-wave interference reflector and absorption screen for the photoreceptor in green algae. The enrichment of ,-carotene and lycopene in the eyespot apparatuses, extending the range of visible light absorption to longer wavelengths, represents an adaptation of the screen to the retinal-based photoreceptor of flagellate green algae and is one of the prerequisites for maximal directional sensitivity of the eyespot apparatus.Abbreviations
1H-NMR
nuclear magnetic resonance
- IUPAC
International Union of Pure and Applied Chemistry
- VIS
visible absorption spectra
This work was supported by the Deutsche Forschungsgemeinschaft (G.K. and M.M.). M.G. was supported by a fellowship from the Norwegian Research Council of Science and Humanities. 相似文献
4.
The absolute configurations of heteroxanthin ((3S,5S,6S,3′R)- 7′,8′-didehydro-5,6-dihydro-β,β-carotene-3,5,3′,6′-tetrol) ex Euglena gracilis and of diadinoxanthin ((3S,5R,6S,3′R)-5,6-epoxy-7′,8′-didehydro-5,6-dihydro-β,β-carotene-3,3′-diol) from the same source have been established by chemical reactions, hydrogen bonding studies, 1H NMR and CD. Two previously unknown carotenoids (artefacts?) from Trollius europaeus, assigned the structures (3S,5S,6S,3′S,5′R,6′R)-6,7-didehydro-5,6,5′,6′-tetrahydro-β,β -carotene-3,5,6,3′,5′-pentol and its 5R epimer, served as useful models. 相似文献
5.
In marine fish larviculture the live feed organisms are often enriched in order to enhance their nutritional value. One of the challenges is to enhance the phospholipids (PL) content, and another is to enhance the content of specific water soluble nutrients, like free amino acids (FAA). There are a few studies where this has been achieved by the use of liposomes. The aim of this study was to develop a simple method for mass-production of liposomes within a size range of 1–5 μm a size range suitable to feed live food organisms. Furthermore, the liposomes should have a high FAA concentration and be stable under conditions typical for short-time enrichment of live feed organisms. The method used in the present study is based on a combination of a reverse-phase evaporation method for preparing liposomes and re-hydration of freeze-dried, empty liposomes. The liposomal membrane was made of soy phosphatydilcholine and was loaded with a highly concentrated free amino acids solution. Most of the liposomes produced were 2–8 μm in diameter and the FAA encapsulation efficiency was 42.6%. Two experiments simulating 2 hr of live food enrichment were used to evaluate the liposomes. The results showed the liposome did not disintegrate or aggregate when suspended in seawater and that only 9% of the FAA content of the liposomes was lost after 2 hr suspension. The developed method was easy and reliable, producing tens of grams of liposomes per batch. 相似文献
6.
Toril Synnøve Jenssen 《Visual Anthropology: Published in cooperation with the Commission on Visual Anthropology》2013,26(4):291-308
ABSTRACT The use of film as a tool in anthropological fieldwork is a challenge to traditional ways of thinking about scientific research. Nevertheless, documentary filming of the informants in their own context has proved to be an interesting supplement in the exploration of what the anthropological research field actually covers. Furthermore, film work confronts the researchers with aesthetic aspects of mediation that have not been epistemically well attended to within social science. This article highlights pivotal problems in the professional no-man's-land where visual culture studies take place, as exemplified by the film Cool and Crazy. 相似文献
7.
Marte Synnøve Lilleeng Stein Joar Hegland Knut Rydgren Stein R. Moe 《Ecological Research》2016,31(6):777-784
Selective herbivory can influence both spatial and temporal vegetation heterogeneity. For example, many northern European populations of free-ranging ungulates have reached unprecedented levels, which can influence plant species turnover, long-term maintenance of biodiversity and the subsequent stability of boreal ecosystems. However, the mechanisms by which large herbivores affect spatial and temporal vegetation heterogeneity remain poorly understood. Here, we combined a 10-year exclusion experiment with a herbivore intensity gradient to investigate how red deer (Cervus elaphus) acts as a driver of temporal and spatial heterogeneity in the understory of a boreal forest. We measured the two dimensions of heterogeneity as temporal and spatial species turnover. We found that temporal heterogeneity was positively related to herbivory intensity, and we found a similar trend for spatial heterogeneity. Removing red deer (exclosure) from our study system caused a distinct shift in species composition, both spatially (slow response) and temporally (quick response). Vegetation from which red deer had been excluded for 10 years showed the highest spatial heterogeneity, suggesting that the most stable forest understory will occur where there are no large herbivores. However, excluding red deer resulted in lower species diversity and greater dominance by a low number of plant species. If both stable but species rich ecosystems are the management goal, these findings suggest that naturally fluctuating, but moderate red deer densities should be sustained. 相似文献
8.
Ylioja S Pertovaara A Koivisto J Korvenoja A Artchakov D Carlson S 《Somatosensory & motor research》2004,21(1):3-7
Somatosensory point localization is a clinical test evaluating spatial accuracy of the somatosensory system. Possible effects of the interstimulus interval (ISI) on point localization threshold have not been previously examined. In the present set of experiments the effect of time delay on somatosensory point localization was studied using ISIs of 1, 3, 5, 7, and 9 s, and applying a newly developed computer-controlled application method of a Semmes-Weinstein monofilament. It was found that the point localization threshold was not significantly affected by the ISI length. However, the response time was shorter and response accuracy better at the shorter (1 and 3 s) than at the longer (5, 7, and 9 s) ISIs, suggesting a change in the mechanism underlying point localization decision criteria in ISIs longer than 3 s. 相似文献
9.
Chin SL Johnson SA Quinn J Mirosavljevic D Price JT Dudley AC Thomas DM 《Biochemical and biophysical research communications》2003,307(4):1051-1058
TGF-beta increases bone resorption in vivo and greatly increases osteoclast formation stimulated by receptor activator of NF-kappaB ligand (RANKL) in vitro. TGF-beta does not independently affect the differentiation state of RAW264.7 preosteoclasts, but increases cell attachment to vitronectin. This effect is mediated by increased expression of alphaV integrin subunit mRNA and protein. Concomitant with induction of osteoclast differentiation, RANKL causes relocation of alphaV to focal sites in the cell. This effect is potentiated by TGF-beta. Integrin blockade disrupts both attachment to vitronectin and RANKL-induced osteoclast formation, but culture on vitronectin has little effect. Ectopic expression of alphaV stimulates multinucleation of RAW264.7 cells and increases the number of osteoclasts formed in the presence of RANKL. These data suggest that TGF-beta potentiates RANKL-induced osteoclast formation, in part by increased expression of the alphaV integrin subunit, which may contribute to cell fusion. 相似文献
10.