Stereochemical investigation of carotenoids in the antarctic krill Euphausia superba.

“…Natural astaxanthin monoester (AM) from different sources has been studied [11]. Due to the lack of standard and difficulty to synthesize AM, the determination of AM basically falls into two categories.…”

Section: Introductionmentioning

confidence: 99%

Preparation of (3R, 3′R)-astaxanthin monoester and (3R, 3′R)-astaxanthin from Antarctic krill (Euphausia superba Dana)

Zhang

Sun

Liu

2014

Eur Food Res Technol

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“…Moreover, eyestalks contain large amounts of astaxanthin (Maoka et al, 1985;Funk and Hobson, 1991). In addition, the stomach of (feeding) summer krill most probably contains more ingested pigments than that of non-feeding winter krill.…”

Section: Astaxanthin Contentmentioning

confidence: 99%

Physiological and morphological colour change in Antarctic krill, Euphausia superba: a field study in the Lazarev Sea

Auerswald¹,

Freier

Lopata

et al. 2008

Journal of Experimental Biology

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SUMMARYAntarctic krill, Euphausia superba, is very susceptible to harmful solar radiation because of its unique genetic setup. Exposure occurs in spring to autumn during vertical diel migration and during occasional daytime surface-swarming. We have investigated colour change in Antarctic krill, Euphausia superba, during summer and winter in the Lazarev Sea in response to ultraviolet radiation (UVR) and photosynthetically active radiation (PAR). Short-term physiological colour change and long-term (seasonal) morphological colour change are present. Both are facilitated by a single type of monochromatic red chromatophore, i.e. erythrophores, of 20-450 μm diameter. Superficial erythrophores cover large dorsal areas, especially above vital organs (brain, sinus glands), additional ʻprofoundʼ erythrophores cover internal organs (heart, gut, nerve cords). Short-term change in light regime causes rapid physiological colour change along dense bundles of microtubules: pigment disperses into chromorhizae upon exposure to PAR and UVA and to a lesser extent to UVB. Darkness leads to aggregation of pigment in the centre and hence blanching. There is no circadian rhythm in the dispersal state of erythrophores present in winter. Physiological colour change in adult krill is two to three times more rapid in summer than in winter. Furthermore, seasonal changes in light regime also result in a profound morphological colour change: in summer animals, abdominal astaxanthin concentration is 450% and erythrophore count is 250-480% higher than in winter krill. We conclude from our results, that pigmentation of E. superba serves in the protection from harmful solar radiation and is adapted to the varying diel and seasonal light conditions.

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“…The greatest carotenoid concentration was found in the cephalothorax and the carapace (71.3 and 59.8 lg/g) [13]. Maoka et al [14] separated the two enantiomers (3S,39S-/3R,39R-) and the meso-astaxanthin (3S,39R/3R,39S), finding 3R,39R-to be the most abundant (62-71%). They found up to 908 lg/g in krill eyes.…”

Section: Introductionmentioning

confidence: 99%

Unambiguous detection of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana)

Grynbaum

Hentschel

Putzbach

et al. 2005

J of Separation Science

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HPLC atmospheric pressure chemical ionization (APCI)/MS, GC MS, HPLC diode array detection (DAD), and NMR were used for the identification of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana). Matrix solid phase dispersion was applied for the extraction of the carotenoids. This gentle and expeditious extraction technique for solid and viscous samples leads to distinct higher enrichment rates than the conventional liquid-liquid extraction. The chromatographic separation was achieved employing a C30 RP column that allows the separation of shape-constrained geometrical isomers. A methanol/tert-butylmethyl ether/water gradient was applied. (all-E) Astaxanthin and the geometrical isomers were identified by HPLC APCI/MS, by coelution with isomerized authentical standard, by UV spectroscopy (DAD), and three isomers were unambiguously assigned by microcoil NMR spectroscopy. In this method, microcoils are transversally aligned to the magnetic field and have an increased sensitivity compared to the conventional double-saddle Helmholtz coils, thus enabling the measurement on small samples. The carotenol fatty acid esters were saponified enzymatically with Lipase type VII from Candida rugosa. The fatty acids were detected by GC MS after transesterification, but also without previous derivatization by HPLC APCI/MS. C14:0, C16:0, C16:1, C18:1, C20:0, C20:5, and C22:6 were found in astaxanthin monoesters and in astaxanthin diesters. (all-E) Astaxanthin was identified as the main isomer in six fatty acid ester fractions by NMR. Quantitation was carried out by the method of internal standard. (13-cis) Astaxanthin (70 microg/g), 542 microg/g (all-E) astaxanthin, 36 microg/g unidentified astaxanthin isomer, 62 microg/g (9-cis) astaxanthin, and 7842 microg/g astaxanthin fatty acid esters were found.

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Stereochemical investigation of carotenoids in the antarctic krill Euphausia superba.

Cited by 33 publications

References 1 publication

Preparation of (3R, 3′R)-astaxanthin monoester and (3R, 3′R)-astaxanthin from Antarctic krill (Euphausia superba Dana)

Preparation of (3R, 3′R)-astaxanthin monoester and (3R, 3′R)-astaxanthin from Antarctic krill (Euphausia superba Dana)

Physiological and morphological colour change in Antarctic krill, Euphausia superba: a field study in the Lazarev Sea

Unambiguous detection of astaxanthin and astaxanthin fatty acid esters in krill (Euphausia superba Dana)

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