Astaxanthin Diester Research Articles

Determination of astaxanthin and astaxanthin esters in three samples of shrimp waste (Parapenaeus longirostris) by high performance liquid chromatography coupled photo-diode array and mass spectrometry detection

The present study aimed to identify the content of astaxanthin and its esterified forms using high-performance liquid chromatography coupled with diode array and atmospheric pressure chemical ionisation mass spectrometry detection in three samples of shrimp waste. The analyses revealed twenty-one astaxanthin derivatives, including astaxanthin in free form, across all three extracts with the highest number of derivatives observed in the head extract. The shell extract had a lower content of astaxanthin and its esterified forms, with monoesterified astaxanthins being the major components, with contents ranging from 0.5–1 mg g−1. On the other hand, in both global waste and head extracts, astaxanthin diesters were found to be the dominant bioactive compounds, with contents ranging from 0.7–5.2 mg g−1 and 10.2–18.2 mg g−1, respectively. Notably, the astaxanthin content extracted from head was significantly higher compared to other extracts, indicating its potential as a valuable source of bioactive compounds.

Astaxanthin- Enriched Fraction from the Microalga Haematococcus pluvialis Mitigates Kidney Injury via Modulation of Nrf2/Keap1 and MAPK/ERK Pathways in Rats

Acute kidney injury is a complication of using gentamicin in high doses and is associated with severe morbidity and mortality. Astaxanthin, the red xanthophyll carotenoid pigment, has an antioxidant power higher than 100 times that of vitamin E and 10 times more than that of β-carotene, making it one of the strongest bioactive carotenoids. Haematococcus pluvialis, Haematococcaceae, microalga produces high amounts of astaxanthin in the form of astaxanthin esters besides adequate amounts of free astaxanthin. We attempted to explore the potential therapeutic effects of astaxanthin- and astaxanthin ester–enriched fractions from H. pluvialis against acute kidney injury induced by gentamicin and their mechanisms of action in rats. Adult male Wister albino rats were injected with gentamicin (100 mg/kg, i.p.) for seven consecutive days to induce acute kidney injury, and these rats were treated daily with astaxanthin ester–enriched fractions (30 mg/kg; p.o.) for 14 days. LC/ESI–MS analysis revealed the presence of different isomers of free astaxanthin, astaxanthin monoesters, and astaxanthin diesters in the astaxanthin- and astaxanthin ester–enriched fractions. Astaxanthin and its esters ameliorated kidney dysfunction, modulated nuclear factor erythroid 2 related factor 2/Kelch-like erythroid associated protein 1/hypoxia-inducible factor-alpha, and suppressed mitogen-activated protein kinases/extracellular signal-regulated kinases/renin-angiotensin system expression. Astaxanthin and its ester improved early acute kidney injury via modulation of the Nrf2/Keap1 antioxidant defense pathway and MAPK/ERK signaling cascade.Graphical

Optimization of Pigment Extraction from Aristeus alcocki Shell Wastes via Different Solvent Systems

ABSTRACT Arabian deep-sea red shrimp Aristeus alcocki is considered to be an ideal source of pigments, especially astaxanthin, and its analogs. Extraction of pigments from exoskeleton discards of A. alcocki was analyzed by using organic solvents, namely, n-hexane, acetone, ethyl acetate, methanol, and ethanol under cold and hot conditions. A significantly greater pigments yield was obtained using acetone: methanol (1:1 v/v) (10.4-10.9%) and ethanol (9.3-9.7%) extractions compared with conventional acetone extract (7.4-8.1%) (p < 0.05). Chromatographic experiments with the pigment extracts showed the presence of free astaxanthin, astaxanthin mono-ester, and astaxanthin di-ester.

Comprehensive biorefinery of invasive European green crab (Carcinus maenas) into multiple high-value biomolecules

European green crab (Carcinus maenas) is an invasive species globally and is considered marine waste that needs to be eliminated. In this study, the green crab was biorefined via a clean enzymes-assisted bioprocess into multiple value-added bioproducts, i.e., crab oil, minerals, carotenoprotein, and chitin. The recovered crab oil was rich in unsaturated fatty acids such as EPA and DHA as per GC-MS analysis. Citric acid, as a replacement for conventional hash acids, was found to optimally demineralize the crab powder at 1 M and 4 °C for 18 h, where the recovered crab minerals identified using ICP-MS showed a high level of calcium, in form of nutritious calcium citrate. Crab carotenoprotein recovered using trypsin exhibited antioxidant properties. It contained 139.26 μg/g of carotenoids pigment, mainly astaxanthin and astaxanthin diester, as verified by thin layer chromatography, and the protein component in the carotenoprotein was rich in essential amino acids such as leucine via UPLC-MS. The produced crab chitin from papain-assisted deproteinization showed characteristic physicochemical properties following FTIR and XRD analysis. These biomolecules biorefined from the green crab possess wide applications in food, pharmaceutical, biomaterials, etc. This new biorefinery strategy enhances the sustainability for biowaste utilization.

İskenderun Körfezi’nden avlanan derin su pembe karidesi (Parapenaeus longirostris)’nin atıklarından elde edilen astaksantinin ekstraksiyonu ve karakterizasyonu

The aim of this study is to purpose a simple and effective method for the isolation of high-value pigment astaxanthin from shrimp waste, a low-value raw material. In this study, acetone was used as an extraction solvent. Mobile phase for TLC was acetone:hexane in the ratio 3:7 (v/v). The samples used in the study belong to the Parapenaeus longirostris species and were obtained from local fishermen operating in the Iskenderun Bay / Turkey. Shrimp waste was transported to the laboratory in a sterile container filled with ice. The wastes used in shrimp are the cephalothorax, abdominal shell and tail portion. Adhering meat from the cephalothorax was removed and the waste was washed under water and samples were dried at 50 °C with drying oven. Packed in polyethylene bags and stored at -18 °C until use. In this study, astaxanthin was extracted from shrimp shell waste using organic solvents (petroleum ether and acetone). Characterization of Astaxanthin pigment was performed with TLC buy comparing the Retardation Factor (Rf) as indicated in the Lorenz Todd standard chromatogram, in which three bands of Astaxanthin (Rf=0.36), Astaxanthin monoester (Rf=0.60) and Astaxanthin diester (Rf=0.75) were detected.

Identification and Content of Astaxanthin and Its Esters from Microalgae Haematococcus pluvialis by HPLC-DAD and LC-QTOF-MS after Extraction with Various Solvents.

Haematococcus pluvialis, a unicellular green microalga that produces a secondary metabolite under stress conditions, bears one of the most potent antioxidants, namely xanthophyll astaxanthin. The aim of our study was to determine the content of astaxanthin and its esterified forms using three different solvents—methyl tert-butyl ether (MTBE), hexane isopropanol (HEX -IPA) and acetone (ACE)—and to identify them by using high performance liquid chromatography coupled with diode array detection and the quadrupole time-of-flight mass spectrometry (HPLC-DAD and LC-QTOF-MS) technique. We identified eleven astaxanthin monoesters, which accounted for 78.8% of the total astaxanthin pool, six astaxanthin diesters (20.5% of total), while free astaxanthin represented the smallest fraction (0.7%). Astaxanthin monoesters (C16:2, C16:1, C16:0), which were the major bioactive compounds in the H. pluvialis samples studied, ranged from 10.2 to 11.8 mg g−1 DW. Astaxanthin diesters (C18:4/C18:3, C18:1/C18:3) were detected in the range between 2.3 and 2.6 mg g−1 DW. All three solvents were found to be effective for extraction, but MTBE and hexane-isopropanol extracted the greatest amount of free bioactive astaxanthin. Furthermore, MTBE extracted more low-chain astaxanthin monoesters (C16), and hexane-isopropanol extracted more long-chain monoesters (C18 and above) and more diesters. We can conclude that MTBE is the solvent of choice for the extraction of monoesters and hexane-isopropanol for diesters.

Spatial and Temporal Variations in Pigment and Species Compositions of Snow Algae on Mt. Tateyama in Toyama Prefecture, Japan.

Snow algae are photosynthetic microbes that inhabit the melting snow surface in alpine and polar regions. We analyzed the pigment and species composition of colored snow collected on Mt. Tateyama in Japan during the melting seasons of 2015 and 2016. High-performance liquid chromatographic analyses of the pigments extracted from the colored snow showed that their composition varied within the study area and were classified into four types: Type A (astaxanthin-monoester dominant), Type B (medium astaxanthin-monoester content), Type C (abundant primary carotenoids and free-astaxanthin), and Type D (abundant primary carotenoids and astaxanthin diesters). Types A and B were most commonly observed in the study area, whereas Types C and D appeared only at specific sites. Analysis of the 18S ribosomal RNA (18S rRNA) gene revealed six major amplicon sequence variants (ASVs) of snow algae, belonging to the Sanguina, Chloromonas, and Chlainomonas groups. The relative abundance of the algal ASVs showed that Sanguina was dominant (>48%) in both Types A and B, suggesting that the difference in astaxanthin abundance between the two types was caused by the production of pigments in the algal cells. The algal community structures of Types C and D differed from those of Types A and B, indicating that the primary carotenoids and astaxanthin diesters were derived from certain algal species in these types. Therefore, astaxanthin-rich Sanguina algae mostly induced the red snow that appeared widely in this alpine area; however, they were partially dominated by Chloromonas or Chlainomonas algae, causing different pigment compositions.

Molecular Composition, Digestion and Absorption Characteristics of Astaxanthin in Antarctic Krill Oil

The extraction of Antarctic krill oil enrich astaxanthins using n-hexane-ethanol solvent systems was studied, taking the total astaxanthin content, phospholipid content and yield of Antarctic krill oil as the investigation indexes. Meanwhile, the molecular species composition of astaxanthins in Antarctic krill oil which extracted under the optimized conditions were characterized and analyzed. Then the digestion process and bioaccessibility of astaxanthins in Antarctic krill oil were investigated by single-dose oral gavage with different doses of Antarctic krill oil, using ICR mice as model animals. Furthermore, the bioacceptability of astaxanthin from Antarctic krill oil and Haematococcus pluvialis were compared. The results showed that the 60%(V/V) n-hexane-ethanol solution was selected as the best solvent to extract Antarctic krill oil enrich astaxanthins. The astaxanthins in krill oil were mainly present as fatty acid esters, the relative percentages of astaxanthin diesters, monoesters, and free astaxanthin were 73.5%, 24.8%, and 1.62%. The astaxanthin diesters were hydrolyzed to monoesters or free from in the gastrointestinal tract. After 24 hours of gavage, the bioaccessibility of astaxanthin in low, middle and high dose groups was not significant, and the bioaccessibility of astaxanthin in Antarctic krill oil was about 74%. In addition, the bioaccessibility of astaxanthin in Antarctic krill oil was about 1.25 times of that in Haematococcus pluvialis oil. These results could provide a scientific basis for the rational production and the evaluation of dietary nutritional of Antarctic krill oil.

Haematococcus pluvialis Carotenoids Enrich Fractions Ameliorate Liver Fibrosis Induced by Thioacetamide in Rats: Modulation of Metalloproteinase and Its Inhibitor.

Hepatic fibrosis is a consequence of chronic liver diseases. Metalloproteinase and its inhibitor have crucial roles in the resolution of liver fibrosis. The current relevant study is aimed to evaluate the therapeutic effect of Haematococcus pluvialis (H. pluvialis) extract, astaxanthin-rich fraction, astaxanthin ester-rich fraction, and β-carotene-rich fraction as well as their mechanisms of action in curing hepatic fibrosis induced by thioacetamide (TAA). Liver fibrosis was induced using TAA (intraperitoneal injection, two times a week for 6 weeks), in a rat model and H. pluvialis extract (200 mg/kg), and other fractions (30 mg/kg) were orally administered daily for 4 weeks after the last TAA injection. Based on HPLC analysis, H. pluvialis extract contains β-carotene (12.95 mg/g, extract) and free astaxanthin (10.85 mg/g, extract), while HPLC/ESI-MS analysis revealed that H. pluvialis extract contains 28 carotenoid compounds including three isomers of free astaxanthin, α or β-carotene, lutein, 14 astaxanthin mono-esters, 5 astaxanthin di-esters, and other carotenoids. H. pluvialis and its fractions reduced liver enzymes, nitric oxide, collagen 1, alpha-smooth muscle actin, and transforming growth factor-beta as well as elevated catalase antioxidant activity compared to the TAA group. Also, H. pluvialis extract and its fractions exceedingly controlled the balance between metalloproteinase and its inhibitor, activated Kupffer cells proliferation, and suppressed liver apoptosis, necrobiosis, and fibrosis. These findings conclude that H. pluvialis extract and its fractions have an antifibrotic effect against TAA-induced liver fibrosis by regulating the oxidative stress and proinflammatory mediators, suppressing multiple profibrogenic factors, and modulating the metalloproteinase and its inhibitor pathway, recommending H. pluvialis extract and its fractions for the development of new effective medicine for treating hepatic fibrosis disorders.

Preparation, characterization and antioxidant activity of astaxanthin esters with different molecular structures.

Astaxanthin (Asta) is widely used in the nutraceutical and food industry because of its strong antioxidant properties. However, natural Asta mainly exists in the esterified form with various fatty acid chains, making it difficult to understand the particular molecular structure of astaxanthin esters (Asta-Es) that have better antioxidant capacity. In this study, Asta-Es with different molecular structures was systematically prepared, and identified by using thin-layer chromatography (TLC), ultraviolet-visible (UV-visible), high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), and proton nuclear magnetic resonance (1 H-NMR). In addition, their antioxidant properties were evaluated by 2,2'-diphenylpicrylhydrazyl (DPPH) and ABTS scavenging activity. Fourteen Asta-Es with different molecular structures were systematically synthesized. This study used a simple and efficient method for the separation and purification of astaxanthin monoester (Asta-ME) and astaxanthin diester (Asta-DE) with high purity (86%-94%) by silica gel column chromatography. 13-cis-Asta-E and 9-cis-Asta-E were firstly identified from Asta-E. The DPPH clearance rates and ABTS scavenging rates of Asta-C4:0, Asta-C8:0, Asta-C12:0, and Asta-C18:0 were relatively close, but the DPPH and ABTS scavenging rates of Asta-C18:0, Asta-C18:1, Asta-C18:2, and Asta-C22:6 increased gradually. Among all Asta-Es, Asta-C22:6/C22:6 showed the highest antioxidant capacity, with the DPPH and ABTS scavenging rates of 77.22 ± 3.29% and 51.84 ± 1.65%, respectively. In this study, it was concluded that chemically synthesized Asta-Es contained cis-astaxanthin ester and polyunsaturated fatty acid chain increased the antioxidant activity of Asta, showing less effect of the length of fatty acid chain. These results provide useful information for the production and use of highly efficient Asta-E as functional food and pharmaceutical ingredients. © 2020 Society of Chemical Industry.

Influence of molecular structure of astaxanthin esters on their stability and bioavailability

The stability and bioavailability of fourteen astaxanthin esters (Asta-Es) with different molecular structures were investigated using in vitro and in vivo digestion models. The results demonstrated that Asta-E with long-chain and saturated fatty acids were more stable than other types of Asta-E. Astaxanthin diester (Asta-DE) was better than astaxanthin monoester (Asta-ME) and free astaxanthin (F-Asta), as determined based on the degradation rate constant at 60 °C. The absorbability of Asta-Es with different molecular structures was evaluated through the serum concentrations of astaxanthin (Asta). The results indicated that Asta-E with short-chain fatty acids had higher bioavailability than Asta-Es with long-chain fatty acids, whereas Asta-E with high-unsaturation fatty acids had higher bioavailability than Asta-E with low-unsaturation fatty acids. Asta-ME had significantly increased bioavailability compared with Asta-DE. We concluded that the molecular structure of Asta-E could significantly affect their stability and bioavailability.

Analysis of Carotenoids in Grass Prawn Heads by High Performance Liquid Chromatography

The carotenoid composition in grass prawn ( Penaeus monodon ) heads was studied in this investigation to obtain basic information for any future application of the natural colorants from grass prawn heads. The red oily pigment in grass prawn heads was extracted with acetone, followed by petroleum ether (b.p. 30- 50 degrees centigrade) which was dissolved in acetone and stored overnight at minus 10 degrees centigrade. Next, the crude pigment was obtained by removal of precipitates from the cold acetone, then finally, removal of the acetone. The crude pigment was analyzed by HPLC with Sumipax OA-2000 column (5 um, 0.46 cm i.d. x 25 cm) and n-hexane/dichloromethane/ethanol(l20:17:1, v/v/v)as a mobile phase. Flow rate was set at 1.5 ml/min and the dectector was set at 470 nm. The main results are shown as follows: 1.The main carotenoids in the grass heads are composed of astaxanthin, astaxanthin monoester, astaxanthin diester, and some unidentified pigments. The relative amounts of these pigments are 36.1%, 31.5%, 17.5%, and 14.9% respectively. 2. The astaxanthin fraction was separated in to its three optical isomers: (3R, 3'R)-astaxanthin, (3R, 3'S)-astaxanthin, and (3S, 3'S)-astaxanthin. The relative amounts are 15%, 43.7%, and 41.3%, respectively, as determined by HPLC.

Effects of Drying Methods on the Content, Structural Isomers, and Composition of Astaxanthin in Antarctic Krill.

Antarctic krill (Euphausia superba) is one of the important bioresources in Antarctic waters, containing many bioactives (e.g., astaxanthin), which have a highly potential value for commercial exploitation. In this study, the effects of processing methods on the content, structural isomers, and composition of astaxanthins (free astaxanthin and astaxanthin esters) were studied. Three drying methods, comprising freeze-drying, microwave drying, and hot-air drying, were used. Free astaxanthin (Ast), astaxanthin monoesters (AM), and astaxanthin diesters (AD) in boiled krill (control) and dried krill were extracted and analyzed using high-resolution mass spectrometry with ultraviolet detection. After the three processes, total astaxanthin loss ranged from 8.6 to 64.9%, and the AM and AD contents ranged from 78.3 to 16.6 and 168.7 to 90.5 μg/g, respectively. Compared to other kinds of astaxanthin esters, astaxanthin esters, which linked to eicosapentaenoic acid and docosahexaenoic acid, as well as the Ast, were more easily degraded, and AM was more susceptible to degradation than AD. All-E-astaxanthin easily transformed to the 13Z-astaxanthin than to the 9Z-astaxanthin during the drying process, but the proportions of optical isomers changed due to drying by no more than 5%. The results suggested that freeze-drying, low-power microwave drying (≤1 kW), and low-temperature hot-air drying (≤60 °C) are optimal drying methods for ensuring the quality of krill products.

Impact of pulsed electric field pretreatment on yield and quality of lipid extracted from cephalothorax of Pacific white shrimp (Litopenaeus vannamei) by ultrasound‐assisted process

SummaryPacific white shrimp cephalothorax was subjected to pulsed electric field (PEF) pretreatment at different electric field strengths (4, 8, 12 and 16 kV cm−1) and pulse numbers (120, 160, 200 and 240) to enhance the extraction yield of lipids. PEF‐treated samples were subsequently subjected to lipid extraction using ultrasound‐assisted extraction (UAE) process at ultrasound amplitude of 80% for 25 min in continuous mode. PEF‐pretreated samples subjected to UAE rendered the highest lipid yield (30.34 g 100 g−1 solids). PEF pretreatment resulted in reduced lipid oxidation as evidenced by the decreases in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Lipids from PEF‐pretreated samples extracted using UAE had higher content of PUFAs and carotenoids, including astaxanthin, astaxanthin monoester, astaxanthin diester, canthaxanthin and β‐carotene. Overall, PEF pretreatment helped in enhancing the extraction yield of lipids and carotenoids from shrimp cephalothorax and reduce lipid oxidation to some extent.

Yield and chemical composition of lipids extracted from solid residues of protein hydrolysis of Pacific white shrimp cephalothorax using ultrasound-assisted extraction

The yield of lipids extracted from the lipid-containing solid residue (LSR) obtained from the protein hydrolysis of shrimp cephalothorax using ultrasonic-assisted extraction (UAE), and their chemical compositions were determined. When UAE with different amplitudes (60%–100%) was used, the highest lipid yield (10–11 g/100 g) and carotenoids (8.6–8.8 mg/g lipid) were obtained at 80% amplitude (P < 0.05), regardless of the sample/solvent ratio. However, UAE contributed to higher lipid oxidation and hydrolysis as shown by increased peroxide (PV) and thiobarbituric acid reactive substances (TBARS) values, as well as a higher free fatty acid (FFA) content. When continuous and pulse modes of UAE were compared at various ultrasonic times (5–30 min), the time longer than 10 min showed a similar lipid yield (P ≥ 0.05), irrespective of the ultrasound mode, and at the same ultrasonic times, no differences in lipid yield were found between the two modes (P ≥ 0.05). Furthermore, the PV and TBARS values of the lipids extracted using UAE with both modes increased with increasing ultrasonic time (5–30 min), whereas the FFA content of the lipids increased when the ultrasonic time was longer than 10 min. The lipids extracted from all the treatments contained docosahexaenoic acid (DHA) as the most abundant n-3 fatty acid, followed by eicosapentaenoic acid (EPA) and they also contained the carotenoids, astaxanthin, astaxanthin monoester, astaxanthin diester and canthaxanthin. Therefore, UAE with appropriate conditions could be used as a potential method for the extraction of lipids from the LSR.

Effect of pre-treatments on yield and properties of lipid extracted from cephalothorax of Pacific white shrimp (Litopenaeus vannamei) by ultrasonic assisted process

Impacts of different pre-treatments of cephalothorax from Pacific white shrimp before ultrasound assisted extraction (UAE) on yield and characteristics of lipids were studied. Autolysis at 50 °C for 3 h in the absence and presence of 0.1% tannic acid (TA), a lipase inhibitor, was implemented. Pre-heating of cephalothorax containing 0.1% TA at 95 °C for different times (15–45 min) was also carried out. When UAE was used to extract the lipids at the ultrasonic amplitude of 80% for 25 min in continuous mode, samples with pre-heating rendered the highest lipid yield (13.3g-14.1 g/100 g sample). Pre-heating along with TA addition resulted in suppression of lipid oxidation as evidenced by decrease in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Free fatty acid (FFA) content was also found to be lower, whereas the control (without pre-treatment) had higher FFA. Fourier transform infrared (FTIR) spectra confirmed lower oxidation in lipid from pre-heated samples added with TA. Lipid contained astaxanthin, astaxanthin monoester, astaxanthin diester, canthaxanthin and β-carotene. Overall, the combination of pre-heating and addition of TA was a promising means to increase the yield and maintain the quality of lipid from cephalothorax using UAE.

Effects of Astaxanthin and Docosahexaenoic-Acid-Acylated Astaxanthin on Alzheimer's Disease in APP/PS1 Double-Transgenic Mice.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with the characteristics of senile plaques, neuroinflammation, neurofibrillary tangles, and destruction of synapse structure stability. Previous studies have verified the protective effects of astaxanthin (AST). However, whether synthesized docosahexaenoic-acid-acylated AST diesters (AST-DHA) could delay AD pathogenesis remains unclear. In the present study, APP/PSEN1 (APP/PS1) double-transgenic mice were administrated with AST and AST-DHA for 2 months. The results of radial 8-arm maze and Morris water maze tests showed that AST-DHA exerted more significant effects than AST in enhancing learning and memory levels of APP/PS1 mice. Further mechanical studies suggested that AST-DHA was superior to AST in regulating the parameters of oxidative stress, reducing tau hyperphosphorylation, suppressing neuroinflammation, and regulating inflammasome expression and activation in APP/PS1 mice. The findings suggested that AST-DHA attenuated cognitive disorders by reducing pathological features in APP/PS1 mice, suggesting that AST-DHA might be a potential therapeutic agent for AD.

Structures of Yellow Xanthophylls and Metabolism of Astaxanthin in the Prawn &lt;i&gt;P&lt;/i&gt;&lt;i&gt;enaeus japonicus&lt;/i&gt;

The dried powder of Paracoccus carotinifaciens (PANAFERD-AX®) contains (3S,3'S)-astaxanthin as a major carotenoid. Administration of PANAFERD-AX® for pigmentation of the prawn Penaeus japonicus was examined. Total carotenoid contents in the carapace, muscle, and head of the prawn were dose-dependently increased depending on the amount of PANAFERD-AX® administered. Furthermore, not only the amounts of astaxanthins (astaxanthin diester, astaxanthin monoester, and free astaxanthin) but also the amounts of yellow xanthophylls, isoastaxanthin (1), 5,6-dihydropenaeusxanthin (2), penaeusxanthin (3), tetrahydroxypirardixanthin (4), and curstaxanthin (5), were dose-dependently increased with the administration of PANAFERD-AX®. 5,6-Dihydropenaeusxanthin (2) and penaeusxanthin (3) are new carotenoids isolated from the prawn P. japonicus. These structures were determined to be (3R,4S,5R,6R,6'S)-5,6-dihydro-3,4,4'- trihydroxy-β,ε-caroten-3'-one (2) and (3R,4S,6'S)-3,4,4'-trihydroxy-β,ε-caroten-3'-one (3) by UV/vis, ESI TOF MS, 1H NMR, and CD spectral data. The metabolism of astaxanthin to these yellow xanthophylls in the prawn was discussed.

Carotenoids of Red, Brown, and Black Specimens of Plectropomus leopardus, the Coral Trout (Suziara in Japanese).

This study investigated the carotenoids occurring in the integument of Plectropomus leopardus, the coral trout. For a red specimen, the major carotenoids included astaxanthin diester and monoester, as well as α-cryptoxanthin ester, tunaxanthin diester, adonixanthin diester, adonirubin ester, and adonirubin; for brown and black specimens, tunaxanthin diester was the main carotenoid. 1H-NMR and MS spectral analyses showed that docosahexaenoic acid was the sole fatty acid esterified with xanthophylls in the coral trout.

Characterization and storage stability of astaxanthin esters, fatty acid profile and α-tocopherol of lipid extract from shrimp (L. vannamei) waste with potential applications as food ingredient

In this work a lipid extract from shrimp waste was obtained and characterized. The most abundant fatty acids found were C16:0, C18:2n6c, C18:1n9c, C22:6n3, and C20:5n3. The extract contained all-trans-astaxanthin, two cis-astaxanthin isomers, 5 astaxanthin monoesters, and 10 astaxanthin diesters (7±1mg astaxanthin/g). C22:6n3 and C20:5n3 were the most frequent fatty acids in the esterified forms. Appreciable amounts of α-tocopherol and cholesterol were also found (126±11mg/g and 65±1mg/g, respectively). Little lipid oxidation was observed after 120days of storage at room temperature, revealed by a slight reduction of ω-3 fatty acids, but neither accumulation of TBARS nor formation of oxidized cholesterol forms was found. This is attributed to the antioxidant effect of astaxanthin and α-tocopherol, as their concentrations decreased as storage continued. The lipid extract obtained has interesting applications as food ingredient, owing to the coloring capacity and the presence of healthy components.