Seaweeds as Source of Bioactive Pigments with Neuroprotective and/or Anti-Neurodegenerative Activities: Astaxanthin and Fucoxanthin.

The marine kingdom is an important source of a huge variety of scaffolds inspiring the design of new drugs. The complex molecules found in the oceans present a great challenge to organic and medicinal chemists. However, the wide variety of biological activities they can display is worth the effort. In this article, we present an overview of different seaweeds as potential sources of bioactive pigments with activity against neurodegenerative diseases, especially due to their neuroprotective effects. Along with a broad introduction to seaweed as a source of bioactive pigments, this review is especially focused on astaxanthin and fucoxanthin as potential neuroprotective and/or anti-neurodegenerative agents. PubMed and SciFinder were used as the main sources to search and select the most relevant scientific articles within the field.

Antibacterial activity of pigment extracted from bacteria isolated from soil samples.

The purpose of this study was to evaluate antibacterial activity of pigment extracted from bacteria, isolated from soil samples. During the study, 20 soil samples were collected from different areas (forest, agriculture fields, river sides and dumping sites) of Kathmandu and Lalitpur districts which were processed for isolation of pigment producing bacteria by spread plate technique. The pigmented bacterial isolates were identified and enriched in nutrient broth. Then, pigment was extracted in 95% methanol as solvent, which was further characterized using UV-Vis Spectrophotometric and TLC analysis. The obtained crude pigment extract was processed to carry out the antimicrobial susceptibility assay using agar well diffusion method. Out of 13 total pigmented bacteria isolates, four different colored pigmented bacterial isolates (S4O, S11Y, S14P and S17G) which produced efficient pigment on nutrient agar were chosen and they were further processed. Among these isolates, S4O was identified as Staphylococcus aureus, S11Y was identified as Micrococcus luteus, S14P was identified as Micrococcus roseus and S17G was identified as Pseudomonas aeruginosa respectively. On characterization using UV-Vis Spectrophotometric and TLC analysis, the pigment extracted from isolates S4O, S11Y and S14P were found to be Carotenoids and from isolate S17G was found to be Pyocyanin in nature. The maximum antibacterial activity was shown against Staphylococcus aureus from all the four pigments extracts. The green color pigment extract from isolate S17G was found to be most effective against all the Gram-positive and Gram-negative test bacteria. This study suggests that these pigment extracts from pigmented bacteria may have beneficial antibacterial roles that can be exploited in controlling unwanted bacterial growth.

Proangiogenic Azaphilones from the Marine-Derived Fungus Neopestalotiopsis sp. HN-1-6.

Developing novel, safe, and efficient proangiogenic drugs is an important approach for the prevention and treatment of cardiovascular diseases. In this study, 4 new compounds, including 3 azaphilones (1-3) and 1 dihydroisocoumarin (4), as well as 13 known compounds (5-17), were isolated from the sea-mud-derived fungus Neopestalotiopsis sp. HN-1-6 from the Beibu Gulf of China. The structures of the new compounds were determined by NMR, MS, ECD, and NMR calculations. Compounds 3, 5, and 7 exhibited noteworthy proangiogenic activities in a zebrafish model at a concentration of 40 µM, without displaying cytotoxicity toward five human cell lines. In addition, some compounds demonstrated antibacterial effects against Staphylococcus aureus, Escherichia coli, and Candida albicans, with MIC values ranging from 64 µg/mL to 256 µg/mL.

Purified Pyropia yezoensis Pigment Extract-Based Tandem Dye Synthesis.

Red phycoerythrin (R-PE) is a highly valuable protein found in an edible seaweed, Pyropia yezoensis. It is used extensively in biotechnological applications due to its strong fluorescence and stability in diverse environments. However, the current methods for extracting and purifying R-PE are costly and unsustainable. The aim of the present study was to enhance the financial viability of the process by improving the extraction and purification of R-PE from dried P. yezoensis and to further enhance R-PE value by incorporating it into a tandem dye for molecular biology applications. A combination of ultrafiltration, ion exchange chromatography, and gel filtration yielded concentrated (1 mg·mL-1) R-PE at 99% purity. Using purified PE and Cyanine5 (Cy5), an organic tandem dye, phycoerythrin-Cy5 (PE-Cy5), was subsequently established. In comparison to a commercially available tandem dye, PE-Cy5 exhibited 202.3% stronger fluorescence, rendering it suitable for imaging and analyzes that require high sensitivity, enhanced signal-to-noise ratio, broad dynamic range, or shorter exposure times to minimize potential damage to samples. The techno-economic analysis confirmed the financial feasibility of the innovative technique for the extraction and purification of R-PE and PE-Cy5 production.

[Research progress in chemical constituents and pigment extraction process of Carthami Flos].

Carthami Flos(flowers of Carthamus tinctorius) with the effects of activating blood, dredging meridians, dissipating stasis, and relieving pain is one of the commonly used traditional Chinese medicines for promoting blood circulation and resolving stasis in clinical practice. So far, more than 210 compounds in Carthami Flos have been isolated and reported, including quinochalcones(safflower yellow pigments and red pigments), flavonoids, spermidines, alkaloids, polyacetylenes, and organic acids. Safflower yellow pigments, as the main water-soluble active components of Carthami Flos, is commonly obtained by the water extraction method, while red pigments are commonly obtained by the alkali extraction and acid precipitation method. In recent years, natural deep eutectic solvents as green solvents have demonstrated promising application prospects in the extraction and separation of pigments from Carthami Flos. This review systematically summarizes the chemical constituents of Carthami Flos and analyzes the extraction process of pigment components from Carthami Flos, aiming to provide a reference for further utilization of Carthami Flos resources.

Azaphilone pigments from the marine-derived Penicillium sclerotium UJNMF 0503 and their neuroprotective potential against H2O2-induced cell apoptosis through modulating PI3K/Akt pathway.

Azaphilones represent a particular group of fascinating pigments from fungal source, with easier industrialization and lower cost than the traditional plant-derived pigments, and they also display a wide range of pharmacological activities. Herein, 28 azaphilone analogs, including 12 new ones, were obtained from the fermentation culture of a marine fungus Penicillium sclerotium UJNMF 0503. Their structures were elucidated by MS, NMR and ECD analyses, together with NMR and ECD calculations and biogenetic considerations. Among them, compounds 1 and 2 feature an unusual natural benzo[d][1,3]dioxepine ring embedded with an orthoformate unit, while 3 and 4 represent the first azaphilone examples incorporating a novel rearranged 5/6 bicyclic core and a tetrahydropyran ring on the side chain, respectively. Our bioassays revealed that half of the isolates exhibited neuroprotective potential against H2O2-induced injury on RSC96 cells, while compound 13 displayed the best rescuing capacity toward the cell viability by blocking cellular apoptosis, which was likely achieved by upregulating the PI3K/Akt signaling pathway.

Neuroprotective azaphilones from a deep-sea derived fungus Penicillium sp. SCSIO41030.

Ten azaphilones including one pair of new epimers and three new ones, penineulones A-E (1-5) with the same structural core of angular deflectin, were obtained from a deep-sea derived Penicillium sp. SCSIO41030 fermented on a liquid medium. Their structures including absolute configurations were elucidated using chiral-phase HPLC analysis, extensive NMR spectroscopic and HRESIMS data, ECD and NMR calculations, and by comparing NMR data with literature data. Biological assays showed that the azaphilones possessed no antitumor and anti-viral (HSV-1/2) activities at concentrations of 5.0 µM and 20 µM, respectively. In addition, azaphilones 8 and 9 showed neuroprotective effects against Aß25-35-induced neurotoxicity in primary cultured cortical neurons at a concentration of 10 µM. Azaphilones 8 and 9 dramatically promoted axonal regrowth against Aß25-35-induced axonal atrophy. Our study indicated that azaphilones could be promising lead compounds for neuroprotection.

Pulvinic Acid Derivative Pigments in Lanmaoa asiatica and L. macrocarpa.

Lanmaoa asiatica G. Wu & Zhu L. Yang and L. macrocarpa N. K. Zeng, H. Chai & S. Jiang are two important gourmet bolete in China, and locally named "Jian Shou Qing" meaning their fruiting bodies turn blue after bruising. The genus represents a distinct lineage in Boletaceae. The pigment(s) associated with the discoloration in Lanmaoa has not been identified. The aim of this study was to determine the pigment(s) underpinning the bluing reaction of L. asiatica and L. macrocarpa when bruised. Potential compounds were isolated by HPLC and identified by LC-HRMS and NMR. In total five to six pigments of hydroxylated pulvinic acid derivatives were detected with similar distribution patterns in both L. asiatica and L. macrocarpa, which by abundance were variegatic acid, variegatorubin, xerocomic acid (and/or isoxerocomic acid), xerocomorubin, and atromentic acid. Variegatic acid, the most abundant pigment, was isolated by HPLC, and the structure was further characterized by NMR. The amount of variegatic acid increased after regular cooking, which may suggest its enhanced health benefit as human diet. The types of pigments that cause bluing reactions often differ among families of Boletales. Our results showed that the pigments in Lanmaoa belong to the category of hydroxylated pulvinic acid derivatives, the major bluing compounds in Boletaceae.

Progress on the Extraction, Separation, Biological Activity, and Delivery of Natural Plant Pigments.

Natural plant pigments are safe and have low toxicity, with various nutrients and biological activities. However, the extraction, preservation, and application of pigments are limited due to the instability of natural pigments. Therefore, it is necessary to examine the extraction and application processes of natural plant pigments in detail. This review discusses the classification, extraction methods, biological activities, and modification methods that could improve the stability of various pigments from plants, providing a reference for applying natural plant pigments in the industry and the cosmetics, food, and pharmaceutical industries.

Purification of Natural Pigments Violacein and Deoxyviolacein Produced by Fermentation Using Yarrowia lipolytica.

Violacein and deoxyviolacein are bis-indole pigments synthesized by a number of microorganisms. The present study describes the biosynthesis of a mixture of violacein and deoxyviolacein using a genetically modified Y. lipolytica strain as a production chassis, the subsequent extraction of the intracellular pigments, and ultimately their purification using column chromatography. The results show that the optimal separation between the pigments occurs using an ethyl acetate/cyclohexane mixture with different ratios, first 65:35 until both pigments were clearly visible and distinguishable, then 40:60 to create a noticeable separation between them and recover the deoxyviolacein, and finally 80:20, which allows the recovery of the violacein. The purified pigments were then analyzed by thin-layer chromatography and nuclear magnetic resonance.

Naturally Occurring Partially Reduced Perylenequinones from Fungi.

This Review provides a critical analysis of the literature covering the naturally occurring partially reduced perylenequinones (PQs) from fungi without carbon substituents (which can be named class A perylenequinones) and discusses their structures, stereochemistry, biosynthesis, and biological activities as appropriate. Perylenequinones are natural pigments with a perylene skeleton produced by certain fungi, aphids, some plants, and animal species. These compounds display several biological activities, e.g., antimicrobial, anti-HIV, photosensitizers, cytotoxic, and phytotoxic. It describes 36 fungal PQs and cites 81 references, covering from 1956 to August 2022.

Using mass spectrometry to investigate fluorescent compounds in squirrel fur.

While an array of taxa are capable of producing fluorescent pigments, fluorescence in mammals is a novel and poorly understood phenomenon. A first step towards understanding the potential adaptive functions of fluorescence in mammals is to develop an understanding of fluorescent compounds, or fluorophores, that are present in fluorescent tissue. Here we use Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) of flying squirrel fur known to fluoresce under ultraviolet (UV) light to identify potentially fluorescent compounds in squirrel fur. All of the potentially fluorescent compounds we identified were either present in non-fluorescent fur or were not present in all species of fluorescent flying squirrel. Therefore, we suggest that the compounds responsible for fluorescence in flying squirrels may also be present in non-fluorescent mammal fur. Some currently unexplained factor likely leads to excitation of fluorophores in flying squirrel fur. A recently suggested hypothesis that fluorescence in mammals is widely caused by porphyrins is consistent with our findings.

Bioprospecting of Microalgae Isolated from the Adriatic Sea: Characterization of Biomass, Pigment, Lipid and Fatty Acid Composition, and Antioxidant and Antimicrobial Activity.

Marine microalgae and cyanobacteria are sources of diverse bioactive compounds with potential biotechnological applications in food, feed, nutraceutical, pharmaceutical, cosmetic and biofuel industries. In this study, five microalgae, Nitzschia sp. S5, Nanofrustulum shiloi D1, Picochlorum sp. D3, Tetraselmis sp. Z3 and Tetraselmis sp. C6, and the cyanobacterium Euhalothece sp. C1 were isolated from the Adriatic Sea and characterized regarding their growth kinetics, biomass composition and specific products content (fatty acids, pigments, antioxidants, neutral and polar lipids). The strain Picochlorum sp. D3, showing the highest specific growth rate (0.009 h-1), had biomass productivity of 33.98 ± 0.02 mg L-1 day-1. Proteins were the most abundant macromolecule in the biomass (32.83-57.94%, g g-1). Nanofrustulum shiloi D1 contained significant amounts of neutral lipids (68.36%), while the biomass of Picochlorum sp. D3, Tetraselmis sp. Z3, Tetraselmis sp. C6 and Euhalothece sp. C1 was rich in glycolipids and phospholipids (75%). The lipids of all studied microalgae predominantly contained unsaturated fatty acids. Carotenoids were the most abundant pigments with the highest content of lutein and neoxanthin in representatives of Chlorophyta and fucoxanthin in strains belonging to the Bacillariophyta. All microalgal extracts showed antioxidant activity and antimicrobial activity against Gram-negative E. coli and S. typhimurium and Gram-positive S. aureus.

Pigment Composition of Nine Brown Algae from the Iberian Northwestern Coastline: Influence of the Extraction Solvent.

Brown algae are ubiquitously distributed in the NW coastline of the Iberian Peninsula, where they stand as an underexploited resource. In this study, five solvents were applied to the extraction of pigments from nine brown algae, followed by their determination and quantification by HPLC-DAD. A total of 13 compounds were detected: Six were identified as chlorophylls, six were classified as xanthophylls, and one compound was reported as a carotene. Fucoxanthin was reported in all extracts, which is the most prominent pigment of these algae. Among them, L. saccharina and U. pinnatifida present the highest concentration of fucoxanthin (4.5-4.7 mg∙g-1 dry weight). Ethanol and acetone were revealed as the most efficient solvents for the extraction of pigments, showing a maximal value of 11.9 mg of total pigments per gram of dry alga obtained from the ethanolic extracts of H. elongata, followed by the acetonic extracts of L. ochroleuca. Indeed, ethanol was also revealed as the most efficient solvent according to its high extraction yield along all species evaluated. Our results supply insights into the pigment composition of brown algae, opening new perspectives on their commercial exploitation by food, pharmaceutical, and cosmeceutical industries.

Structurally diverse Monascus pigments with hypolipidemic and hepatoprotective activities from highland barley Monascus.

Highland barley Monascus has historically been used in solid state fermentation and traditional fermented foods in Tibet. It is possessed of the characteristics of medicine and food. Three new 8,13-unsaturated benzocyclodiketone-conjugated Monascus pigments (1-3), three new benzofuran Monascus pigments (4-6), three new butylated malonyl Monascus pigments (7-9), and eleven known Monascus pigment derivatives (10-20) were isolated from highland barley Monascus for the first time. Their structures were determined by analyzing NMR, MS, UV, and IR spectral data and compared with relevant references. Among them, compounds 2, 4, 6 showed important inhibition of pancreatic lipase activity, and decreased significantly FFA-induced lipid accumulation in HepG2 liver cells. Additionally, compounds 1, 10, 14, 16, 18 exhibited certain hepatoprotective activities against the damage in acetaminophen-induced HepG2 cells. The plausible biogenetic pathway and preliminary structure activity relationship of the selected compounds were scientifically summarized and discussed in this work.

Optimized separation of anhydrosafflor yellow B from safflower by high-speed counter-current chromatography and evaluation of its cardio-protective effect.

Anhydrosafflor yellow B (AHSYB) is a major active water-soluble pigment in Safflower, but it has not received enough attention yet. In this study, high-speed counter-current chromatography (HSCCC) was used to prepare AHSYB from safflower. The parameters of the separation process were optimized by response surface methodology for the first time. The entropy weight method (EWM) was applied to calculate the information entropy and the weight of five indexes, and then figure out a comprehensive index of the HSCCC separation effect. Under the optimized separation conditions, a HSCCC apparatus speed of 850 rpm, a flow rate of 2 mL min-1 for the mobile phase and a separation temperature of 40 °C for AHSYB were achieved with a purity of 98%. Furthermore, AHSYB was found to have cardio-protective effects by inhibiting apoptosis via the mitochondrial-mediated pathway in oxygen-glucose deprivation/reoxygenation-induced H9c2 cells. This research provides good method guides for the rapid and efficient separation of active compounds from food-grade Chinese herb medicines.

Azaphilones and Meroterpenoids from the Soft Coral-Derived Fungus Penicillium glabrum glmu003.

Two new azaphilone compounds, daldinins G (1) and H (2), together with nine known compounds daldinin D (3), sargassopenilline B (4), austalide V (5), austalide K (6), austalide P (7), austalide P acid (8), austalide H (9), 13-O-deacetyaustalide I (10), and 17-O-demethylaustalide B (11), were isolated from the soft coral-derived fungus Penicillium glabrum glmu003. The new structures of 1 and 2 were elucidated on the basis of 1D and 2D NMR, mass spectra, and electronic circular dichroism (ECD) data analysis. Compound 5 showed weak inhibitory activity against pancreatic lipase (PL) with IC50 value of 23.9 µg/mL.

Extraction and optimization of Penicillium sclerotiorum strain AK-1 pigment for fabric dyeing.

Recently, the demand for fungal pigments has increased due to their several benefits over synthetic dyes. Many species of fungi are known to produce pigments and a large number of fungal strains for pigment production are yet to be extensively investigated. The natural pigment from sustainable natural sources has good economic and industrial value. Many synthetic colorants used in textile and various industries have many harmful effects on the human population and environment. Pigments and coloring agents may be extracted from a wide range of fungal species. These compounds are among the natural compounds having the most significant promise for medicinal, culinary, cosmetics, and textile applications. This study attempts to isolate and optimize the fermentation conditions of Penicillium sclerotiorum strain AK-1 for pigment production. A dark yellow-colored pigment was isolated from the strain with significant extractive value and antioxidant capacity. This study also identifies that the pigment does not have any cytotoxic effect and is multicomponent. The pigment production was optimized for the parameters such as pH, temperature, carbon and nitrogen source. Fabric dyeing experiments showed significant dyeing capacity of the pigment on cotton fabrics. Accordingly, the natural dye isolated from P. sclerotiorum strain AK-1 has a high potential for industrial-scale dyeing of cotton materials.

Identification of the pigment and its role in UV resistance in Paecilomyces variotii, a Chernobyl isolate, using genetic manipulation strategies.

Fungi produce secondary metabolites that are not directly involved in their growth, but often contribute to their adaptation to extreme environmental stimuli and enable their survival. Conidial pigment or melanin is one of the secondary metabolites produced naturally by a polyketide synthesis (PKS) gene cluster in several filamentous fungi and is known to protect these fungi from extreme radiation conditions. Several pigmented or melanized fungi have been shown to grow under extreme radiation conditions at the Chernobyl nuclear accident site. Some of these fungi, including Paecilomyces variotii, were observed to grow towards the source of radiation. Therefore, in this study, we wanted to identify if the pigment produced by P. variotii, contributes to providing protection against radiation condition. We first identified the PKS gene responsible for synthesis of pigment in P. variotii and confirmed its role in providing protection against UV irradiation through CRISPR-Cas9 mediated gene deletion. This is the first report that describes the use of CRISPR methodology to create gene deletions in P. variotii. Further, we showed that the pigment produced by this fungus, was not inhibited by DHN-melanin pathway inhibitors, indicating that the fungus does not produce melanin. We then identified the pigment synthesized by the PKS gene of P. variotii, as a naptho-pyrone Ywa1, by heterologously expressing the gene in Aspergillus nidulans. The results obtained will further aid in understanding the mechanistic basis of radiation resistance.

Electrochromic Properties and Electrochemical Behavior of Marennine, a Bioactive Blue-Green Pigment Produced by the Marine Diatom Haslea ostrearia.

Marennine has long been known as the unique peculiar pigment responsible for the natural greening of oysters. It is specifically produced by the marine diatom Haslea ostrearia and it is a natural blue molecule indeed promising for food industry because of the rarity of such non-toxic, blue-colored pigments. In the search for its still not defined molecular structure, investigation of the color changes with the redox state has been carried out combining different approaches. Reducing and oxidizing chemicals have been added to purified marennine solutions and a stable blue-green color has been confirmed for the oxidized state, while a yellow color corresponded to the reduced unstable state. Raman spectroscopy has been used to monitor changes in the Raman spectra corresponding to the different colored states, and cyclic voltammetry has allowed the detection of a redox system in which protons and electrons are exchanged. These findings show that marennine is a suitable stable blue pigment for use in food applications and help in the elucidation of the chromophore structure.