Extraction and identification of antioxidant polyhydroxynaphthoquinone pigments from the sea urchin, Psammechinus miliaris

Sea Urchin Food Waste into Bioactives: Collagen and Polyhydroxynaphtoquinones from P. lividus and S. granularis

Approximately 75,000 tons of different sea urchin species are globally harvested for their edible gonads. Applying a circular economy approach, we have recently demonstrated that non-edible parts of the Mediterranean Sea urchin Paracentrotus lividus can be fully valorized into high-value products: antioxidant pigments (polyhydroxynaphthoquinones-PHNQs) and fibrillar collagen can be extracted to produce innovative biomaterials for biomedical applications. Can waste from other edible sea urchin species (e.g., Sphaerechinus granularis) be similarly valorised? A comparative study on PHNQs and collagen extraction was conducted. PHNQ extraction yields were compared, pigments were quantified and identified, and antioxidant activities were assessed (by ABTS assay) and correlated to specific PHNQ presence (i.e., spinochrome E). Similarly, collagen extraction yields were evaluated, and the resulting collagen-based biomaterials were compared in terms of their ultrastructure, degradation kinetics, and resistance to compression. Results showed a partially similar PHNQ profile in both species, with significantly higher yield in P. lividus, while S. granularis exhibited better antioxidant activity. P. lividus samples showed higher collagen extraction yield, but S. granularis scaffolds showed higher stability. In conclusion, waste from different species can be successfully valorised through PHNQ and collagen extraction, offering diverse applications in the biomedical field, according to specific technical requirements.

Dimeric (Poly)Hydroxynaphthazarins, Metabolites of Echinoderms and Lichens: The History of the Synthesis and Structure Elucidation

This review provides information on the synthesis and revision of the structures of natural dimeric (poly)hydroxynaphthazarins, metabolites of echinoderms and lichens, and on the refinement of the direction and mechanism of reactions in the synthesis of some of these compounds.

Therapeutic Potential of Polyphenols and Other Micronutrients of Marine Origin

Polyphenols are compounds found in various plants and foods, known for their antioxidant and anti-inflammatory properties. Recently, researchers have been exploring the therapeutic potential of marine polyphenols and other minor nutrients that are found in algae, fish and crustaceans. These compounds have unique chemical structures and exhibit diverse biological properties, including anti-inflammatory, antioxidant, antimicrobial and antitumor action. Due to these properties, marine polyphenols are being investigated as possible therapeutic agents for the treatment of a wide variety of conditions, such as cardiovascular disease, diabetes, neurodegenerative diseases and cancer. This review focuses on the therapeutic potential of marine polyphenols and their applications in human health, and also, in marine phenolic classes, the extraction methods, purification techniques and future applications of marine phenolic compounds.

Assessment of trace element contamination and effects on Paracentrotus lividus using several approaches: Pollution indices, accumulation factors and biochemical tools

Among the most common contaminants in marine ecosystems, trace elements are recognized as serious pollutants. In Corsica (NW Mediterranean Sea), near the old asbestos mine at Canari, trace elements from the leaching of mine residues have been discharged into the sea for several decades. The aim of this study was to assess the levels of contamination in this area and the potential effects on Paracentrotus lividus (Lamarck, 1816) using pollution indices, accumulation factors and biochemical tools. For this purpose, the concentration of 24 trace elements was measured in sea urchins (gonads and gut content), macroalgae, seawater column and sediment collected at 12 stations nearby the old asbestos mine and at a reference site. The bioaccumulation of trace elements occurs as follows: macroalgae > gut > gonads. TEPI contribute to highlight contamination gradients which are mainly due to the dominant marine currents allowing the migration of mining waste along the coastline. This hypothesis was supported by TESVI, which identified characteristic trace elements in the southern area of the mine. High hydrogen peroxide content, associated with elevated catalase and glutathione-S-transferase enzyme activities, were also identified at these sites and at the reference site. Trace elements contamination as well as several abiotic factors could explain these results (e.g. microbiological contamination, hydrodynamic events, etc.). The results obtained in this study suggest that oxidative stress induced by contamination does not affect the health of Paracentrotus lividus. This work has provided a useful dataset allowing better use of sea urchins and various tools for assessing trace element contamination in coastal ecosystems.

In Vitro Anti-Inflammatory and Vasculoprotective Effects of Red Cell Extract from the Black Sea Urchin Arbacia lixula

Sea urchins have emerged as an important source of bioactive compounds with anti-inflammatory and antioxidant properties relevant to human health. Since inflammation is a crucial pathogenic process in the development and progression of atherosclerosis, we here assessed the potential anti-inflammatory and vasculoprotective effects of coelomic red-cell methanolic extract of the black sea urchin Arbacia lixula in an in vitro model of endothelial cell dysfunction. Human microvascular endothelial cells (HMEC-1) were pretreated with A. lixula red-cell extract (10 and 100 μg/mL) before exposure to the pro-inflammatory cytokine tumor necrosis factor (TNF)-α. The extract was non-toxic after 24 h cell treatment and was characterized by antioxidant power and phenol content. The TNF-α-stimulated expression of adhesion molecules (VCAM-1, ICAM-1) and cytokines/chemokines (MCP-1, CCL-5, IL-6, IL-8, M-CSF) was significantly attenuated by A. lixula red-cell extract. This was functionally accompanied by a reduction in monocyte adhesion and chemotaxis towards activated endothelial cells. At the molecular level, the tested extract significantly counteracted the TNF-α-stimulated activation of the pro-inflammatory transcription factor NF-κB. These results provide evidence of potential anti-atherosclerotic properties of A. lixula red-cell extract, and open avenues in the discovery and development of dietary supplements and/or drugs for the prevention or treatment of cardiovascular diseases.

Quinoid Pigments of Sea Urchins Scaphechinus mirabilis and Strongylocentrotus intermedius: Biological Activity and Potential Applications

This review presents literature data: the history of the discovery of quinoid compounds, their biosynthesis and biological activity. Special attention is paid to the description of the quinoid pigments of the sea urchins Scaphechinus mirabilis (from the family Scutellidae) and Strongylocentrotus intermedius (from the family Strongylocentrotidae). The marine environment is considered one of the most important sources of natural bioactive compounds with extremely rich biodiversity. Primary- and some secondary-mouthed animals contain very high concentrations of new biologically active substances, many of which are of significant potential interest for medical purposes. The quinone pigments are products of the secondary metabolism of marine animals, can have complex structures and become the basis for the development of new natural products in echinoids that are modulators of chemical interactions and possible active ingredients in medicinal preparations. More than 5000 chemical compounds with high pharmacological potential have been isolated and described from marine organisms. There are three well known ways of naphthoquinone biosynthesis-polyketide, shikimate and mevalonate. The polyketide pathway is the biosynthesis pathway of various quinones. The shikimate pathway is the main pathway in the biosynthesis of naphthoquinones. It should be noted that all quinoid compounds in plants and animals can be synthesized by various ways of biosynthesis.

Coelomic fluid of Echinometra mathaei: The new prospects for medicinal antioxidants

Echinoid pigments have various biological properties such as antioxidant, cytotoxic, and antibacterial activities. We aimed to evaluate the extraction of cell-free coelomic fluid (CFCF) and coelomocyte lysate (CL) as well as qualitatively and quantitatively identify the coelomic fluid of Echinometra mathaei as a new source of polyhydroxylatednaphthoquinone (PHNQ) antioxidant pigments. Based on the High Performance liquid chromatography-electrospray mass spectrometry (HPLC-MS) analysis in negative mode, the main quinonoid (PHNQ) pigments were identified and quantified. This study also illustrated the total ion current chromatograms and related mass spectra of Spinochrome A, Spinochrome B, Spinochrome C, and Echinochrome A in CL and SpinochromeC in CFCF samples. The ions at 221, 279, 265 and 263 m/z correspond to the pseudo-molecular [M - H] ions of Spinochrome B, Spinochrome C, Echinochrome A, and Spinochrome A, respectively. These components have previously been noted from the shells and spines of sea urchins but identification of PHNQs pigments in CL and CFCF of E. mathaei using LC-MS was introduced for the first time. The results also showed that, the highest DPPH radical scavenging activity of CFCF (88.12 DPPH% scavenging at 70 μg/mL, IC₅₀ = <10 μg/mL). The findings clearly suggest that the coelomic fluid of E. mathaei could be served as the promising as well as potential natural antioxidants in the medical and pharmaceutical industries and could replace the increasing prices of the commercial antioxidants products.

Green Extraction Strategies for Sea Urchin Waste Valorization

Commonly known as “purple sea urchin,” Paracentrotus lividus occurs in the Mediterranean Sea and the eastern Atlantic Ocean. This species is a highly appreciated food resource and Italy is the main consumer among the European countries. Gonads are the edible part of the animal but they represent only a small fraction (10–30%) of the entire sea urchin mass, therefore, the majority ends up as waste. Recently, an innovative methodology was successfully developed to obtain high-value collagen from sea urchin by-products to be used for tissue engineering. However, tissues used for the collagen extraction are still a small portion of the sea urchin waste (<20%) and the remaining part, mainly the carbonate-rich test and spines, are discarded. Residual cell tissues, tests, and spines contain polyunsaturated fatty acids, carotenoids, and a class of small polyphenols, called polyhydroxynaphthoquinones (PHNQ). PHNQ, due to their polyhydroxylated quinonoid nature, show remarkable pharmacologic effects, and have high economic significance and widespread application in several cosmetic and pharmaceuticals applications. A green extraction strategy aimed to obtain compounds of interest from the wastes of sea urchins was developed. The core strategy was the supercritical CO₂ technique, characterized by low environmental impacts. Fatty acids and carotenoids were successfully and selectively extracted and identified depending on the physical parameters of the supercritical CO₂ extraction. Finally, the exhausted powder was extracted by solvent-based procedures to yield PHNQ. The presence of Spinochrome A and Spinochrome B was confirmed and extracts were characterized by a remarkably high antioxidant activity, measured through the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. Overall, the selective and successive extraction methods were validated for the valorization of waste from sea urchins, demonstrating the feasibility of the techniques targeting added-value compounds.

In vitro characterization of bioactive compounds extracted from sea urchin (Stomopneustes variolaris) using green and conventional techniques

This study investigated the in vitro bioactivities of extracts obtained from viscera, spines, shells, and gonads of Stomopneustes variolaris using subcritical water extraction (SWE) at 110 °C, 150 °C, 190 °C, and 230 °C and Soxhlet extraction. The highest amounts of phenolics (22.68 ± 0.05 mg GAE/g), flavonoids (27.11 ± 0.10 mg RE/g), and proteins (40.25 ± 0.84 mg BSA/g) were recorded from gonads at 230 °C, whereas maximum sugar content (23.38 ± 1.30 mg glucose/g) was in viscera at 150 °C. Gonads at 230 °C exhibited the highest DPPH activity (78.68 ± 0.18%), whereas viscera at 150 °C exhibited the highest ABTS⁺ (98.92 ± 1.27%) and protein denaturation inhibition activity (37.13 ± 9.94%). Viscera at 110 °C claimed the highest amylase inhibition (42.46 ± 0.83%), and spines at 150 °C had the highest anticancer activity (IC₅₀ = 767.47 μg/mL). SWE achieved superior results in bioactive compound recovery and detected higher levels of bioactivities (p < 0.05). Results suggest processing sea urchin extracts via SWE has potential application to the food and pharmaceutical industries.

Spinochrome Identification and Quantification in Pacific Sea Urchin Shells, Coelomic Fluid and Eggs Using HPLC-DAD-MS

The high-performance liquid chromatography method coupled with diode array and mass spectrometric detector (HPLC-DAD-MS) method for quinonoid pigment identification and quantification in sea urchin samples was developed and validated. The composition and quantitative ratio of the quinonoid pigments of the shells of 16 species of sea urchins, collected in the temperate (Sea of Japan) and tropical (South-China Sea) climatic zones of the Pacific Ocean over several years, were studied. The compositions of the quinonoid pigments of sea urchins Maretia planulata, Scaphechinus griseus, Laganum decagonale and Phyllacanthus imperialis were studied for the first time. A study of the composition of the quinonoid pigments of the coelomic fluid of ten species of sea urchins was conducted. The composition of quinonoid pigments of Echinarachnius parma jelly-like egg membrane, of Scaphechinus mirabilis developing embryos and pluteus, was reported for the first time. In the case of Scaphechinus mirabilis, we have shown that the compositions of pigment granules of the shell epidermis, coelomic fluid, egg membrane, developing embryos and pluteus are different, which should enable a fuller understanding of the functions of pigments at different stages of life.

Polyhydroxynaphthoquinone Pigment From Vietnam Sea Urchins as a Potential Bioactive Ingredient in Cosmeceuticals

In this study, valuable polyhydroxynaphthoquinone (PHNQ) pigments were recovered from sea urchin food waste and were investigated as a potential bioactive ingredient for cosmeceuticals. The crude PHNQ pigment extract from 4 Vietnam sea urchins, Diadema setosum, Diadema savignyi, Stomopneustes variolaris, and Tripneustes gratilla, exhibited effective 2,2-diphenyl-1-picryl-hydrazyl-hydrate scavenging activity, tyrosinase inhibitory activity, and antibacterial activity. The moisturizing cream with 0.5% of PHNQ pigments from D. setosum and Tripneustes gratilla sea urchins showed no dermal irritation over 14 days of mouse skin test. Four major active components in PHNQ were identified via high-performance liquid chromatography coupled with diode array detector and mass spectrometry. Echinochrome A contributed considerably to the antioxidant activity of the extracts while those containing echinochrome A and spinochrome E were significantly active against various bacteria. The promising results laid the foundation for establishing a novel process from food waste to innovative biomaterial and formulating eco-friendly skincare products with PHNQ components from sea urchins as precious ingredient.

Antiviral Potential of Sea Urchin Aminated Spinochromes against Herpes Simplex Virus Type 1

Herpes simplex virus type 1 (HSV-1) is one of the most prevalent pathogens worldwide requiring the search for new candidates for the creation of antiherpetic drugs. The ability of sea urchin spinochromes-echinochrome A (EchA) and its aminated analogues, echinamines A (EamA) and B (EamB)-to inhibit different stages of HSV-1 infection in Vero cells and to reduce the virus-induced production of reactive oxygen species (ROS) was studied. We found that spinochromes exhibited maximum antiviral activity when HSV-1 was pretreated with these compounds, which indicated the direct effect of spinochromes on HSV-1 particles. EamB and EamA both showed the highest virucidal activity by inhibiting the HSV-1 plaque formation, with a selectivity index (SI) of 80.6 and 50.3, respectively, and a reduction in HSV-1 attachment to cells (SI of 8.5 and 5.8, respectively). EamA and EamB considerably suppressed the early induction of ROS due to the virus infection. The ability of the tested compounds to directly bind to the surface glycoprotein, gD, of HSV-1 was established in silico. The dock score of EchA, EamA, and EamB was -4.75, -5.09, and -5.19 kcal/mol, respectively, which correlated with the SI of the virucidal action of these compounds and explained their ability to suppress the attachment and penetration of the virus into the cells.

PHNQ from Evechinus chloroticus Sea Urchin Supplemented with Calcium Promotes Mineralization in Saos-2 Human Bone Cell Line

Polyhydroxylated naphthoquinones (PHNQs), known as spinochromes that can be extracted from sea urchins, are bioactive compounds reported to have medicinal properties and antioxidant activity. The MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay showed that pure echinochrome A exhibited a cytotoxic effect on Saos-2 cells in a dose-dependent manner within the test concentration range (15.625-65.5 µg/mL). The PHNQ extract from New Zealand sea urchin Evechinus chloroticus did not induce any cytotoxicity within the same concentration range after 21 days of incubation. Adding calcium chloride (CaCl2) with echinochrome A increased the number of viable cells, but when CaCl2 was added with the PHNQs, cell viability decreased. The effect of PHNQs extracted on mineralized nodule formation in Saos-2 cells was investigated using xylenol orange and von Kossa staining methods. Echinochrome A decreased the mineralized nodule formation significantly (p < 0.05), while nodule formation was not affected in the PHNQ treatment group. A significant (p < 0.05) increase in mineralization was observed in the presence of PHNQs (62.5 µg/mL) supplemented with 1.5 mM CaCl2. In conclusion, the results indicate that PHNQs have the potential to improve the formation of bone mineral phase in vitro, and future research in an animal model is warranted.

Autofluorescence mediated red spherulocyte sorting provides insights into the source of spinochromes in sea urchins

Red spherule cells (RSCs) are considered one of the prime immune cells of sea urchins, but their detailed biological role during immune responses is not well elucidated. Lack of pure populations accounts for one of the major challenges of studying these cells. In this study, we have demonstrated that live RSCs exhibit strong, multi-colour autofluorescence distinct from other coelomocytes, and with the help of fluorescence-activated cell sorting (FACS), a pure population of live RSCs was successfully separated from other coelomocytes in the green sea urchin, Strongylocentrotus droebachiensis. This newly developed RSCs isolation method has allowed profiling of the naphthoquinone content in these cells. With the use of ultra high-performance liquid chromatography, UV absorption spectra, and high-resolution tandem mass spectrometry, it was possible to identify sulphated derivatives of spinochrome C, D, E and spinochrome dimers, which suggests that the RSCs may play an important biological role in the biogenesis of naphthoquinone compounds and regulating their bioactivity.

MITF: an evolutionarily conserved transcription factor in the sea urchin Paracentrotus lividus

Microphthalmia-associated transcription factor (MITF) is a member of MYC superfamily, associated with melanocyte cells, as it was discovered in depigmented mice. However, over the last years it was found to be involved in many cellular signaling pathways, among which oncogenesis, osteoclast differentiation, and stress response. In mammals, Mitf gene mutations can cause diverse syndromes affecting pigmentation of eyes or skin, bone defects and melanomas. As MITF protein homologs were also found in some invertebrates, we have isolated and characterized the MITF cDNAs from the sea urchin Paracentrotus lividus, referred to as Pl-Mitf. The in silico study of the secondary and tertiary structure of Pl-Mitf protein showed high conserved regions mostly lying in the DNA binding domain. To understand the degree of evolutionary conservation of MITF, a phylogenetic analysis was performed comparing the Pl-Mitf deduced protein with proteins from different animal species. Moreover, the analysis of temporal and spatial expression pattern of Pl-Mitf mRNA showed that it was expressed from the onset of gastrulation of the sea urchin embryo to the pluteus larva, specifically in primary mesenchymes cells (PMCs), the sea urchin skeletogenic cells, and in the forming archenteron, the larval gut precursor. In silico protein-protein interactions analysis was used to understand the association of MITF with other proteins. Our results put in evidence the conservation of the MITF protein among vertebrates and invertebrates and may provide new perspectives on the pathways underlying sea urchin development, even if further functional analyses are needed.

In vitro study of the scolicidal effects of Echinometra mathaei spine and shell extracts on hydatid cyst protoscolices

Hydatid cyst is a zoonotic parasitic infection caused by the tapeworm Echinococcus granulosus. Such infections are of considerable public health and economic concern, and new effective treatments are intensely sought. Sea urchin (Salmacis virgulata) shell extracts have potent antimicrobial and antioxidant activity, and spines of several species of echinoderms also show antimicrobial activity. In the present in vitro study, we investigated the scolicidal effect of spines and shells extractions from Echinometra mathaei obtained from the Persian Gulf. Spines and shells from the sea urchin, Echinometra mathaei were used in the tests. Spines and shells from 800 specimens were extracted with dibasic sodium phosphate buffer (pH 7.5). Procedures used protoscolices of E. granulosus were obtained aseptically from hydatid cyst in naturally infected sheep's liver and goats and viable protoscolices exposed with spine and shell extractions. The apoptosis was assessed by measuring the caspase 3 activity of the extract-treated protoscolices, using ELISA-based commercial kits to determine caspase activity. The scolicidal effects of shells were also showed, 20 μg/ml of shell extracts after 60 min exposure, the viability of protoscolices were 21.99 ± 0.01. The results showed that 20 μg/ml of spines gave maximum scolicidal activity (p < 0.05). This study represents the first attempt at combatting echinoid parasites by natural compounds with high efficiency, and may provide a base for future treatment of hydatid cysts.

Echinometra mathaei and its ectocommensal shrimps: the role of sea urchin spinochrome pigments in the symbiotic association

Tuleariocaris holthuisi and Arete indicus are two ectocommensal shrimps closely associated with the tropical sea urchin Echinometra mathaei. This study provides a comparison of these two E. mathaei symbiotic crustaceans and particularly focuses on the relationship between T. holthuisi and its host's pigments (i.e. spinochromes), and its dependency on its host. While all the analyses underline a close association between A. indicus and E. mathaei, they reveal a particularly close interaction between T. holthuisi and its host. Chemical analyses reveal that these shrimps present the same spinochrome composition as E. mathaei, and have similar colouration, allowing camouflage. Isotopic composition and pigment loss after host separation suggest that these pigments are certainly assimilated upon feeding on the urchin. Moreover, symbiont isolation experiments demonstrate the high dependency of T. holthuisi on its host and the importance of the host's pigments on their survival capacity. Finally, some host recognition mechanisms are investigated for T. holthuisi and show the probable implication of spinochromes in host selection, through chemical recognition. Hence, all the results suggest the essential roles of spinochromes for T. holthuisi, which, in turn, suggests the potential implication of these pigments in the shrimps' metabolism.

Mapping of Spinochromes in the Body of Three Tropical Shallow Water Sea Urchins

Sea urchin pigments, also known as spinochromes or polyhydroxynaphthoquinones (PHNQ) have been well studied for their bioactive properties like anti-bacterial, fungicidal, antioxidant and pro-inflammatory effects. Moreover, many studies have analyzed and identified these pigments in sea urchin tests and spines but, and to the best of our knowledge, never in their body compartments or in a quantitative manner. The aim of this work was to investigate the diversity and concentration of pigments in three sea urchins localized in the same coral reef in Madagascar ( Diadema savignyi, Tripneustes gratilla and Toxopneustes pileolus). Their pigment distribution patterns were compared and linked to their behavior in order to understand better the implication of spinochromes in a sea urchin's life. Analyses and quantifications by LC-MS showed the presence of 11 different spinochromes with principally two kinds of patterns. First, D. savignyi showed a high concentration in all its body compartments with a predominance for Echinochrome A and Spinochrome D – Iso 3, a pattern close to the E. mathaei distribution found in our previous study. The presence of these pigments has been linked to their bioactive properties and suggested their implications in UV radiation protection, in reproduction, in feeding as well as in their immune systems. Secondly, T. gratilla and T. pileolus presented few spinochromes, which could explain their restricted diet and their covering behavior facing sunlight. Moreover, the absence of pigments in their gonads could be explained by their seasonal spawning occurring before our collection period. Nevertheless, the near absence of spinochromes may be counterbalanced by other bioactive compounds like their toxic proteins, which may act as either a defense mechanism or immune agents, or like carotenoid pigments already shown in sea urchin and acting as defense agents. In conclusion, spinochromes, and pigments in general, seem to play many roles in sea urchin ecology. Their highly reactive structures confer them with strong bioactive properties involved in most parts of their metabolic system and clearly participate in the survival of the sea urchins.

Naphthoquinones of the spinochrome class: occurrence, isolation, biosynthesis and biomedical applications

Quinones are widespread in nature and have been found in plants, fungi and bacteria, as well as in members of the animal kingdom. More than forty closely related naphthoquinones have been found in echinoderms, mainly in sea urchins but occasionally in brittle stars, sea stars and starfish. This review aims to examine controversial issues on the chemistry, biosynthesis, functions, stability and application aspects of the spinochrome class, a prominent group of secondary metabolites found in sea urchins. The emphasis of this review is on the isolation and structure of these compounds, together with evaluation of their relevant biological activities, source organisms, the location of origin and methods used for isolation and identification. In addition, the studies of their biosynthesis and ecological function, stability and chemical synthesis have been highlighted. This review aims to establish a focus for future spinochrome research and its potential for benefiting human health and well-being.

Marine Waste Utilization as a Source of Functional and Health Compounds

Consumer demand for convenience has led to large quantities of seafood being value-added processed before marketing, resulting in large amounts of marine by-products being generated by processing industries. Several bioconversion processes have been proposed to transform some of these by-products. In addition to their relatively low value conventional use as animal feed and fertilizers, several investigations have been reported that have demonstrated the potential to add value to viscera, heads, skins, fins, trimmings, and crab and shrimp shells by extraction of lipids, bioactive peptides, enzymes, and other functional proteins and chitin that can be used in food and pharmaceutical applications. This chapter is focused on reviewing the opportunities for utilization of these marine by-products. The chapter discusses the various products and bioactive compounds that can be obtained from seafood waste and describes various methods that can be used to produce these products with the aim of highlighting opportunities to add value to these marine waste streams.

Extraction, structural characterization and stability of polyhydroxylated naphthoquinones from shell and spine of New Zealand sea urchin (Evechinus chloroticus)

The extraction of polyhydroxylated naphthoquinone (PHNQ) pigments from the shell and spines of the New Zealand sea urchin Evechinus chloroticus was evaluated using six different macroporous resins as an alternative to using organic solvent extraction alone. Four of the resins evaluated in this study (D4006, D4020, D101 and NKA-9) provided the best extraction of PHNQ pigments in terms of the overall adsorption and desorption of E. chloroticus PHNQ pigments from the resins. Organic solvents alone had a higher yield of PHNQs than the resins. The PHNQ composition was characterised by high-performance liquid chromatography (HPLC) with diode-array detection and mass spectrometry. Five PHNQ compounds (spinochromes E, B, C, A and echinochrome A), and three aminated PHNQ compounds (spinamine E, echinamines A and B) were identified. The pigments were found to be prone to degradation on exposure to light, with the aminated PHNQ pigments being the least stable.

Identification and quantification of spinochromes in body compartments of Echinometra mathaei's coloured types

Sea urchin pigmentation is mainly due to polyhydroxy-1,4-naphthoquinones called spinochromes. If their molecular structures are well known in test and spines of many species, their abundance and distribution in other body compartments remain unstudied. The aim of this study is to analyse the pigment composition in four body compartments (test/spines, digestive system, gonads and coelomic fluid) of four coloured types of the sea urchin Echinometra mathaei. Qualitative and quantitative measurements by mass spectrometry highlight the existence of 13 different pigments; among which are five isomers of known spinochromes as well as three potentially new ones. The composition comparison shows the largest spinochrome diversity in 'test/spines' body compartments. The spinochrome concentrations vary from 48 to 1279 mg kg-1 of dried body compartment. It is the highest in the digestive system, although it is also important in the organic fraction of the 'test/spines' body compartment. This observation may be explained by higher exposures of some body compartments to external environments and by the protective role fulfilled by spinochromes against microorganisms, ultraviolet radiation and reactive oxygen species. The 'black' type-the most common coloured type in coral reefs-has the highest concentration of spinochromes indicating their importance in Echinoids' fitness by acting as a protective agent.

Synthesis of Polyhydroxylated Aminonaphthazarins Related to Natural Pigments

Amino analogs of echinochrome and ethylmompain, metabolites of sea urchins Scaphechinus mirabilis and Echinothrix diadema, and amino analogs of cristazarin, a metabolite of lichen Cladonia cristatella, were synthesized.

Chemical Profiling and Bioactivity of Body Wall Lipids from Strongylocentrotus droebachiensis

The lipids from gonads and polyhydroxynaphthoquinone pigments from body walls of sea urchins are intensively studied. However, little is known about the body wall (BW) lipids. Ethanol extract (55 °C) contained about equal amounts of saturated (SaFA) and monounsaturated fatty acids (MUFA) representing 60% of total fatty acids, with myristic, palmitic and eicosenoic acids as major SaFAs and MUFAs, respectively. Non-methylene-interrupted dienes (13%) were composed of eicosadienoic and docosadienoic acids. Long-chain polyunsaturated fatty acids (LC-PUFA) included two main components, n6 arachidonic and n3 eicosapentaenoic acids, even with equal concentrations (15 μg/mg) and a balanced n6/n3 PUFA ratio (0.86). The UPLC-ELSD analysis showed that a great majority of the lipids (80%) in the ethanolic extract were phosphatidylcholine (60 μg/mg) and phosphatidylethanolamine (40 μg/mg), while the proportion of neutral lipids remained lower than 20%. In addition, alkoxyglycerol derivatives-chimyl, selachyl, and batyl alcohols-were quantified. We have assumed that the mechanism of action of body wall lipids in the present study is via the inhibition of MAPK p38, COX-1, and COX-2. Our findings open the prospective to utilize this lipid fraction as a source for the development of drugs with anti-inflammatory activity.

Seasonal antioxidant responses in the sea urchin Paracentrotus lividus (Lamarck 1816) used as a bioindicator of the environmental contamination in the South-East Mediterranean

In this study, sea urchin Paracentrotus lividus were sampled seasonally at three stations during 2012 in the coastal areas of the Gulf of Annaba (southeast Mediterranean). For all sea urchins, the gonad index was calculated to determine sea urchin reproductive status. Moreover, a set of biochemical parameters, including biomarkers and oxidative stress parameters, was measured in gonads. The pesticides and physiochemical parameters were measured and dosed in sea water. The results obtained highlighted that the levels of pesticide were generally low and below those commonly applied by environmental quality standards (EQS), indicating that no alarm state is currently present in the Gulf of Annaba. In addition to pollution, seasonal change is an important factor influencing biomarker activity, and the significant increases in biomarker levels in spring are a major observed trend. This activity may also be related to reproductive status. Seasonal variability was confirmed by the significant results of the Kruskal-Wallis test and by the high degree of divergence between seasons in PCA, with a total of 83.83% of variance explained. These results indicate that environmental factors that vary seasonally may affect the antioxidant status of the sea urchin Paracentrotus lividus.

The Roles of Spinochromes in Four Shallow Water Tropical Sea Urchins and Their Potential as Bioactive Pharmacological Agents

Spinochromes are principally known to be involved in sea urchin pigmentation as well as for their potentially interesting pharmacological properties. To assess their biological role in sea urchin physiology, experiments are undertaken on crude extracts from four species and on four isolated spinochromes in order to test their antibacterial, antioxidant, inflammatory and cytotoxic activities. First, the antibacterial assays show that the use of crude extracts as representatives of antibacterial effects of spinochromes are inaccurate. The assays on purified spinochromes showed a decrease in the growth of four strains with an intensity depending on the spinochromes/bacteria system, revealing the participation of spinochromes in the defense system against microorganisms. Secondly, in the 2,2-diphenyl-1-picrylhydrazyl antioxidant assays, spinochromes show an enhanced activity compared to the positive control. This latter observation suggests their involvement in ultraviolet radiation protection. Third, spinochromes present a pro-inflammatory effect on lipopolysaccharide-stimulated macrophages, highlighting their possible implication in the sea urchin immune system. Finally, cytotoxicity assays based on Trypan blue exclusion, performed in view of their possible future applications as drugs, show a weak cytotoxicity of these compounds against human cells. In conclusion, all results confirm the implication of spinochromes in sea urchin defense mechanisms against their external environment and reveal their potential for pharmacological and agronomical industries.

GC-MS, FTIR and Raman Analysis of Antioxidant Components of Red Pigments from Stemphylium lycopersici

Many microorganisms can generate pigments with different colours and structures during the growth process. In this study, an endophytic fungus producing red pigments was isolated from Cynanchum auriculatum Royle ex Wight tissue. PCR amplification sequencing was conducted, and phylogenetic analysis was performed on the ITS region sequences. Combined with morphological observation, the fungus was identified as Stemphylium lycopersici. The antioxidant activities of the pigments were evaluated in vitro and showed good antioxidant properties. Ultraviolet (UV), Raman, and Fourier transform infrared (FTIR) spectroscopy and gas chromatography-mass spectroscopy (GC-MS) were used to analyse the pigments' components, which were shown to contain phenolics and anthraquinones. Most of these components have not been previously reported in Stemphylium lycopersici, especially physcione. This study is the first report of Stemphylium lycopersici secondary metabolites and their potential use as red pigments and antioxidants. Further optimisation of the culture conditions of this fungal strain might permit its application for pigment production.

New Aminonaphthoquinone from the Sea Urchins Strongylocentrotus pallidus and Mesocentrotus nudus

The aminonaphthoquinone, spinamine E (5), was isolated for the first time from the sea urchins Strongylocentrotus pallidus (Sars G.O., 1872) and Mesocentrotus nudus (A. Agassiz, 1864). The structure of 5 was elucidated as 2-amino-3,5,6,7,8-pentahydroxy-l,4-naphthoquinone using 1D 1H-, 13C- and 2D NMR procedures, and HR-ESI mass-spectrometric data of 5 and its trimethyl ether. Spinamine E, as well as two other aminonaphthoquinones of sea urchins, echinamines A (2) and B (3), along with their hydroxylated analogues, spinochrome E (4) and echinochrome A (1), were tested for their ability to scavenge the stable DPPH radical and to inhibit lipid peroxidation. All investigated naphthoquinones obtained from the sea urchins showed a high antiradical activity, which was up to 1.5 times higher than that of α-tocopherol. Echinamine B showed the highest scavenging effect (EC50 = 6.5-10−6 M); this effect decreases in the series 3>5>1>2>4>α-tocopherol. In a lipid peroxidation inhibition testing model, echinamine B and spinamine E showed the highest inhibitory effect. The stability of compounds 1-5 in weakly alkaline solutions was evaluated.