Natural Pigments Research Articles

Metabolic engineering of Mucor circinelloides to improve astaxanthin production.

Astaxanthin is a bioactive natural pigment with antioxidant properties. It has extensive applications within the industrial sector as well as in human and animal health. Mucor circinelloides is a zygomycete fungus that accumulates β-carotene as the main carotenoid compound. M. circinelloides is a well-known model organism among Mucorales for studying carotenogenesis in fungi, which makes it a promising candidate for the biotechnological production of carotenoids. In this study, β-carotene hydroxylase (crtR-B) and ketolase (bkt) genes (codon-optimized) were coexpressed from Haematococcus pluvialis in M. circinelloides using two potent promoters gpd1 and zrt1 respectively to generate an astaxanthin-producing biofactory. Following 72h of cultivation, the recombinant M. circinelloides Mc-57 obtained in this study produced 135 ± 8µg/g of astaxanthin. This is the highest reported amount in M. circinelloides to date. The mRNA levels of crtR-B and bkt in Mc-57 were assayed using RT-qPCR. These levels showed a 5.7-fold increase at 72h and a 5.5-fold increase at 24h, respectively, compared to the control strain. This demonstrated the successful overexpression of both genes, which correlated with the production of astaxanthin in the Mc-57. Moreover, the addition of glutamate (2g/L) and mevalonate (15 mM) resulted in an increase in astaxanthin production in the recombinant strain. The results showed that the combined addition of these metabolic precursors resulted in 281 ± 20µg/g of astaxanthin, which is 2.08-fold higher than the control medium (135 ± 8µg/g). The addition of metabolic precursors also positively impacted the biomass growth of Mc-57, reaching 11.2 ± 0.57g/L compared to 9.1 ± 0.23g/L (control medium). The study successfully addressed the challenge of balancing the accumulation of astaxanthin with biomass growth, which has been regarded as common bottleneck in the metabolic engineering of microbial cells. The development of a recombinant fungal strain of M. circinelloides not only increased astaxanthin content. Additionally, it provided a foundation for further improvement of the biotechnological production of astaxanthin in M. circinelloides.

Ecofriendly hybrid natural fiber reinforced polypropylene composites from biowastes

The used ground coffee waste (GCW) and tea leaf waste (TLW), the large wastes from the beverage process, were selected as natural reinforcement and natural pigment in the polypropylene (PP) matrix. In this work, the maleic anhydride polypropylene (MAPP) was added to the composites to develop the compatibility between fillers, fibers, and polymer matrix. The TLW/PP composites, GCW/PP composites, and GCW/TLW/PP hybrid composites were prepared in the ratio of TLW and GCW ranging from 0 to 30 wt% with the addition of MAPP at 5 wt% of fillers. The presence of GCW and TLW in the PP matrix decreased tensile properties and impact resistance but increased flexural modulus and hardness of PP at high concentrations of GCW and TLW. The increase in GCW and TLW concentration slightly reduced melting temperature but it enhanced the tensile and flexural modulus. Furthermore, it enhanced the hardness, thermal and rheological properties of the composites. The TLW/PP composites had better mechanical properties, and rheological properties than GCW/PP composites but thermal properties were quite similar. The mechanical properties of GCW/TLW/PP hybrid composites were better than those of GCW/PP composites but lower than those of TLW/PP composites. The rheological and thermal behaviour of hybrid composites were like that of TLW/PP composites. Incorporating MAPP improves the mechanical and rheological behavior of PP composites by enhancing the interaction among PP, GCW, and TLW. However, this addition does not significantly enhance the composites’ thermal properties. The optimum composite was hybrid composites of GCW/TLW/PP consisting of GCW of 10 wt%, TLW of 20 wt%, and MAPP of 1.5 wt% which presented good mechanical, thermal, and rheological properties. The mechanical properties of this hybrid composites were as follows: a tensile strength of 26.35 MPa, elongation at break of 10.91%, tensile modulus of 636.69 MPa, flexural strength of 45.57 MPa, flexural modulus of 3632.86 MPa, impact resistance of 12.72 kJ/m2, and a Shore D hardness of 76.15. The overall results showed that GCW and TLW can be used as reinforcement material and natural pigment in the polymer matrix.

Quantifying pigment features of Thangka Five Buddhas using hyperspectral imaging

Thangka, a masterpiece of Tibetan painting, is renowned for its adept use of natural mineral pigments such as gold, turquoise, and cinnabar, which imbue it with profound artistic and historical significance. Presently, chemical analysis methods relying on microscopic perspectives are prevalent in researching the pigment components of cultural artifacts. However, these methods suffer from quantization gaps and carry the risk of damaging the relics. Hence, in this study, we focus on Thangka Five Buddha as our experimental sample and propose a novel approach utilizing Linear Spectral Mixed Analysis (LSMA) based on Hyperspectral Imaging (HSI) technology to perform quantitative analysis of pigment components at a sub-pixel level. The results indicate the following. 1) A database of spectral curves for 25 representative Thangka pigments was established, covering 196 bands from 393 to 800 nm VIR-NIR range. 2) The LSMA model successfully separated the 13 pigment components of the Thangka at the sub-pixel level, achieving a Root Mean Square Error (RMSE) of 0.0186, which indicates high classification accuracy. 3) The quantitative analysis reveals that 33.07 % of the area is painted using a single pigment, while 56.01 % is painted using a combination of two pigments. Verdigris (18.56 %), malachite (17.52 %), and cinnabar (10.91 %) are the pigment types with the highest proportions among them. Out of the 521 pigment combinations, verdigris and turquoise (4.55 %), malachite and calcite (4.02 %), minium and cinnabar (2.87 %), and turquoise and malachite (2.82 %) are more commonly used. 4) The application of quantitative analysis methods demonstrates significant potential in painting techniques, authentication processes, and establishing historical dating, among other areas of study.

Analysis of Eleonore Koch's artwork and powdered pigments from MAC-USP and Pinacoteca of São Paulo collections

Eleonore Koch is a German artist known for her paintings featuring arrangements of colors and ordinary objects. She spent a significant part of her life in Brazil, where she had the opportunity to interact with and learn from Alfredo Volpi, a colorist artist who introduced her to the tempera technique and the use of natural and mineral pigments, replacing oil-based industrial ones. A collection of powdered pigments she used during her lifetime was studied by spectroscopic analysis, forming an initial basis of knowledgement about Koch's pigments. In this paper, one painting from the Museum of Contemporary Art of the University of Sao Paulo (MAC-USP) collection was analyzed by spectroscopic (ED-XRF, Raman and FTIR) and imaging techniques. The painting palette was compared with some powdered pigments from the artist's collection. The pigments identified in the artwork are Chrome Oxide Green, Titanium White, Phthalocyanine Blue, Ivory or Bone Black and a yellowish/brown pigment rich in hematite. The findings indicate that most of the pigments found in Koch's artwork were also part of her personal collection.

Radish red protects against early diabetic kidney disease through inhibiting inflammation, pyroptosis and insulin resistance via IRAK1 signaling suppression

Diabetic kidney disease (DKD) is a major diabetic complication and a leading cause of end-stage renal disease (ESRD), but the therapeutic strategies for DKD are still limited. Red radishes (Raphanus sativus L.) are a rich source of natural anthocyanins that have antioxidant, anti-apoptotic and anti-inflammatory activities. In this study, we attempted to explore the effects of natural pigment anthocyanin called radish red (RR) extracted from red radishes on DKD progression and the underlying molecular mechanisms. RR dose-dependently reduced the tubular cell injury, indicated by the decreased expression of kidney injury molecule 1 (KIM1). Furthermore, releases of pro-inflammatory cytokines including interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) stimulated by HF were strongly relieved by RR. Inflammatory response and pyroptosis were also identified to be induced by HF stimulation but were mitigated by RR in HK2 cells through repressing nuclear factor-κB (NF-κB) activation and NLR family, pyrin domain-containing 3 (NLRP3) inflammasome. IR and lipogenesis due to HF exposure were also significantly ameliorated by RR in HK2 cells. Mechanistically, RNA-Seq analysis showed that RR strongly depressed interleukin-1 receptor-associated kinase-1 (IRAK1)-mediated NLRP3 inflammasome, pyroptosis, IR and lipid deposition. Importantly, IRAK1 overexpression almost diminished the beneficial effects of RR, while being rescued upon NLRP3 knockdown in HF-treated HK2 cells, revealing that RR performed its nephroprotective functions in diabetic kidney via inactivating the IRAK1-NLRP3 signaling pathway. Similarly, animal studies confirmed that RR supplementation efficiently ameliorated HFF-caused metabolic disturbance, IR, renal dysfunctions in mice and improved structural kidney damage. Consistently, RR consumption dramatically reduced lipid accumulation, inflammatory response and pyroptosis in kidney tissues of HFF-challenged mice mainly through repressing IRAK1-NLRP3 axis. Our results demonstrated that dietary supplementation with RR may serve as an IRAK1-NLRP3 inhibitor for preventing and treating diabetic nephropathy.

Fusarium verticillioides pigment: production, response surface optimization, gamma irradiation and encapsulation studies

BackgroundNatural pigments are becoming more significant because of the rising cost of raw materials, pollution, and the complexity of synthetic pigments. Compared to synthetic pigments, natural pigments exhibit antimicrobial properties and is less allergic. Pigments from microbial sources could easily be obtained in an inexpensive culture media, produced in high yields, and microbes are capable of producing different colored pigments. Searching for new sources for natural pigments to replace synthetic ones in food applications has become an urgent necessity, but the instability of these compounds is sometimes considered one of the obstacles that reduce their application. Encapsulation provides an ideal solution for natural dye protection through a controlled release strategy. Thus, this study aims at isolation of several soil fungi and subsequent screening their pigment production ability. The chosen pigment-producing fungal strain underwent full identification. The produced pigment was extracted with ethyl acetate and estimated spectrophotometrically. As there is a necessity to obtain a high pigment yield for efficient industrial application, the best production medium was tested, optimum conditions for maximum dye production were also investigated through the response surface methodology, and gamma irradiation was also employed to enhance the fungal productivity. Encapsulation of the produced pigment into chitosan microsphere was tested. The pigment release under different pH conditions was also investigated.ResultsA new strain, Fusarium verticillioides AUMC 15934 was chosen and identified for a violet pigment production process. Out of four different media studied, the tested strain grew well on potato dextrose broth medium. Optimum conditions are initial medium pH 8, 25 °C-incubation temperature, and for 15-day incubation period under shaking state. Moreover, a 400 Gy irradiation dose enhanced the pigment production. Chitosan microsphere loaded by the pigment was successfully prepared and characterized by infrared spectroscopy and scanning electron microscopy.ConclusionThis irradiated Fusarium strain provides a more economically favorable source for production of a natural violet dye with an optimum productivity, enhanced yield, and improved properties (such as, enhanced stability, controlled release, and bioaccessibility) by encapsulation with chitosan for efficient application in food industry.

Microbial Pigment Isolation, Culturing, and Extraction to Use as Textile Dyes

The textile industry is one of the largest worldwide polluters of clean water due to the heavy use of synthetic dyes. These chemicals negatively affect the environment, especially aquatic life due to their toxic and mutagenic properties. Synthetic dyes cause harm to human health such as skin allergies and respiratory sensitization. Several advantages such as ease of extraction, availability, high yields and no seasonal variation make microbial pigments the most ideal source of natural pigments. This study was done to isolate colour pigment producing bacteria and fungi from soil collected from organic farms from various locations in Sri Lanka. Out of 7 soil samples, 3 yielded pigment producing bacteria and fungi. In total, 9 pigment producing bacteria and 3 pigment producing fungi were isolated. Gause’s synthetic agar yielded the most pigmented isolates. Isolates were inoculated in broths and pigment production was observed. Extracellular pigments produced by 5 of the bacterial isolates were extracted by a water-based method. The antibacterial activity of the pigments in their crude and concentrated forms was tested using the well diffusion method against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P. Inhibition zone against S. aureus was observed for both crude (12.33±0.58mm) and concentrated pigments (9.67±0.58mm) extracted from purple pigment producing bacterial isolate (BPU). This pigment has the potential to be used in antibacterial textile preparation. Extracted pigments were used to dye scoured cotton fabric with the use of 3% alum as mordant. Pigment from BPU isolate resulted in better coloured fabric.

Designing LiDAR‐Detectable Dark‐Tone Materials with High Near‐Infrared Reflectivity for Autonomous Driving: A Comprehensive Review

AbstractAutonomous driving relies on the precise recognition of objects using light detection and ranging (LiDAR) technology, that operates at a specific wavelength of 905 nm. Black objects, such as carbon black used in vehicle coating, tend to absorb this specific wavelength significantly, which limits the performance of LiDAR sensors. To address this issue, researchers have explored creating dark‐toned materials that can be detected by LiDAR with high NIR reflectivity while maintaining a true blackness (L* < 20 based on the CIE color coordinates). These materials fall into two categories: organic and inorganic pigments. Organic pigments can be synthetically adjusted to achieve true blackness by manipulating their functional groups, but achieving high NIR reflectivity remains challenging, often requiring a bilayer structure with NIR‐reflective white base and an upper layer of organic black pigments. Additionally, the need for hydrophobic additives and resistance to degradation from sunlight further restricts their use. In the case of inorganic pigments, the desired LiDAR‐detectable properties can be obtained through careful control of their composition, structure, and morphology, allowing for single‐layer coatings with appropriate design. This review highlights recent advancements in developing organic and inorganic LiDAR‐detectable black pigments and outlines future material design strategies for autonomous vehicle systems.

Understanding the Molecular Interactions Between Pandan Pigment and Food Components for Enhanced Thermal Stability

Pandan pigment (Pandanus amaryllifolius) is widely used as a natural food coloring and flavoring agent. However, its application in food is limited because of its susceptibility to thermal degradation during food processing, which affects both pigment stability and color. Despite its growing use, there is limited research on how common food ingredients can mitigate this degradation. This study addresses this gap by exploring the effects of sucrose, lactose, rice starch, whey protein, and soy protein isolate on the thermal and color stability of pandan pigment under various heating conditions (65 °C, 95 °C, 115 °C, and 121 °C for 15 min). Spectroscopic techniques (UV–visible, infrared, and fluorescence) and laser confocal microscopy were used to elucidate the molecular interactions. The results revealed that rice starch provided the strongest protection, followed by whey protein, soy protein isolate, lactose, and sucrose, although the protective effects decreased at higher temperatures. These findings offer new insights into the use of sugars and proteins to increase the thermal stability of natural pigments in food applications.

Measurements of Phagocytosis in Trabecular Meshwork Cells.

The restriction in the movement of aqueous humor through the trabecular meshwork is known to play an important role in the pathogenesis of glaucomas. Among the functions of the trabecular meshwork that help to prevent this restriction and maintain the movement of aqueous humor is phagocytosis. Cells in the trabecular meshwork actively phagocytose pigment, cellular debris, and other materials in order to help keep the drainage pathway clear. A decrease in phagocytosis has thus been implicated in the development of glaucomas. In this chapter, we outline two methods using fluorescent markers that can be used to measure the phagocytic properties of trabecular meshwork cells in culture.

Microencapsulated carotenoids from orange sweet potato: Degradation kinetics and physicochemical properties

AbstractThe use of natural pigments in the food industry has increased due to their health benefits. Carotenoids are natural pigments that carry the disadvantage of sensitivity to temperature, light and the presence of enzymes and oxygen. Microencapsulation technology is widely used to protect these compounds against degradation, preserving their physicochemical characteristics. The research objective was to obtain the kinetics of carotenoid degradation of a microencapsulated extract of orange‐fleshed sweet potato (Ipomoea batatas L.) and to establish its physicochemical properties. The sweet potato extract was obtained using ultrasound and then microencapsulated by spray drying using maltodextrin as the wall material. The microencapsulate obtained was subjected to degradation kinetics at 30, 40 and 50°C. Carotenoid quantification analysis, colour, rehydration properties, antioxidant capacity, Fourier‐transform infrared (FTIR) and RAMAN spectroscopy and microstructural characterisation were performed on the microencapsulated carotenoids. From the kinetic analysis, the activation energy of the sweet potato extract was 16.31 kJ/mol while that of the microencapsulated sweet potato extract was 10.27 kJ/mol. Thus, it can be concluded that the microencapsulation process improved the stability of carotenoids subjected to thermal conditions. FTIR and RAMAN spectra confirmed the microencapsulation of the carotenoids. The microencapsulated powder showed a hygroscopicity of 0.22 g/100 g, wettability of 49 s and high solubility. The results obtained in the kinetics are a useful tool to predict losses during the process of heating the carotenoids from sweet potato, thus allowing improvement and selection of the products to which this powder can be applied, in either thermal or cold processes.

Examining Carotenoid Metabolism Regulation and Its Role in Flower Color Variation in Brassica rapa L.

Carotenoids are vital organic pigments that determine the color of flowers, roots, and fruits in plants, imparting them yellow, orange, and red hues. This study comprehensively analyzes carotenoid accumulation in different tissues of the Brassica rapa mutant "YB1", which exhibits altered flower and root colors. Integrating physiological and biochemical assessments, transcriptome profiling, and quantitative metabolomics, we examined carotenoid accumulation in the flowers, roots, stems, and seeds of YB1 throughout its growth and development. The results indicated that carotenoids continued to accumulate in the roots and stems of YBI, especially in its cortex, throughout plant growth and development; however, the carotenoid levels in the petals decreased with progression of the flowering stage. In total, 54 carotenoid compounds were identified across tissues, with 30 being unique metabolites. Their levels correlated with the expression pattern of 22 differentially expressed genes related to carotenoid biosynthesis and degradation. Tissue-specific genes, including CCD8 and NCED in flowers and ZEP in the roots and stems, were identified as key regulators of color variations in different plant parts. Additionally, we identified genes in the seeds that regulated the conversion of carotenoids to abscisic acid. In conclusion, this study offers valuable insights into the regulation of carotenoid metabolism in B. rapa, which can guide the selection and breeding of carotenoid-rich varieties.

Nutritional Benefits of Lycopene and Beta‐Carotene: A Comprehensive Overview

ABSTRACTCertain carotene components, such as lycopene and beta‐carotene, are found in tomatoes, carrots, sweet potatoes, etc. and are good for human health. It gives plants their distinctive red color. A class of lipid‐soluble natural pigments known as carotenoids is the precursor of vitamin A and is vital for antioxidant defense against peroxides in cells and tissues. This review provides an overview of the current state of knowledge and research on the sources, structures, physiochemical properties, absorption and metabolism, functional advantages, and prevention of many diseases associated with lycopene and beta‐carotene. These antioxidants have been linked to a lower risk of cardiovascular disease and cancer, and they also help draw pollinators to flowers. Carrots and sweet potatoes are also rich sources of beta‐carotene, which strengthens the immune system and improves eye health. The vivid color of many plants reproductive organs, including flowers and fruits, is caused by carotenoid, a secondary metabolite that is produced in plastids. The distinctive red color and many other health advantages are attributed to lycopene. When ingested through food or supplements, lycopene and beta‐carotene help manage and prevent a number of diseases, including cancer, metabolic, inflammatory, cardiovascular, hepatic, ophthalmic, skeletal, and infertility disorders. The main point is that toxicity is uncommon, and these carotenoids are generally accepted to be safe at different doses. Including these nutrients in your diet can improve your general health and provide illness prevention.

The Green Extraction of Blueberry By-Products: An Evaluation of the Bioactive Potential of the Anthocyanin/Polyphenol Fraction.

In the context of a circular economy, this study explores the valorization of blueberry pomace (BP) as a source of bioactive compounds using sustainable extraction methods. Microwave-assisted extraction (MAE) and microwave-assisted subcritical water extraction (MASWE) were employed to obtain two distinct fractions: MAE 1° and MASWE 2°. The first extract, MAE 1°, obtained at 80 °C, had a high total anthocyanin content (21.96 mgCya-3-glu/gextract), making it suitable as a natural pigment. Additionally, MAE 1° exhibited significant enzyme inhibition, particularly against α-amylase and β-glucosidase, suggesting potential anti-diabetic and anti-viral applications. The second extract, MASWE 2°, obtained at 150 °C, contained a higher total phenolic content (211.73 mgGAE/gextract) and demonstrated stronger antioxidant activity. MASWE 2° showed greater inhibition of acetylcholinesterase and tyrosinase, indicating its potential for use in Alzheimer's treatment, skincare, or as a food preservative. MASWE 2° exhibited cytotoxicity against HeLa cells and effectively mitigated H2O2-induced oxidative stress in HaCat cells, with MAE 1° showing similar but less pronounced effects. A tested formulation combining MAE 1° and MASWE 2° extracts in a 3:2 ratio effectively enhanced anthocyanin stability, demonstrating its potential as a heat-stable pigment. The extract characteristics were compared with a conventional method (MeOH-HCl in reflux condition), and the protocol's sustainability was assessed using several green metric tools, which provided insights into its environmental impact and efficiency.

Intelligent Packaging Systems with Anthocyanin: Influence of Different Polymers and Storage Conditions

With the aim of meeting the growing demand for safe food, intelligent packaging has emerged, which monitors the conditions of the food and informs the consumer about its quality directly at the time of purchase. Among intelligent packaging options, colorimetric indicator films, which change color in response to changes in the food, such as the release of volatile compounds, have been widely studied. Among them, pH indicator films composed of dyes sensitive to small variations in the pH value of the food surface have received greater attention in recent years. Anthocyanins, which are natural pigments, have stood out as one of the most commonly used sources of dyes in the production of these indicator films. In this context, the present review aims to present an updated overview of research employing anthocyanins in indicator films, including their stability under different storage conditions, the influence of different polymers used in their production, and alternative techniques for maintaining stability.

Polymerizable fatty acid surfactant: Encapsulation of organic pigments for excellent colloidal stability in aqueous solution and water-repellent property

Organic pigments are indispensable in various applications due to their vibrant colors and durability, yet their low polarity often hinders their dispersion in an aqueous solution, leading to large aggregation and sedimentation. To address these limitations, dispersants and encapsulation techniques have been explored. In this study, nanoscale encapsulated pigments were synthesized using a novel polymerizable surfactant, sodium 11-methacrylamidoundecanoic acid (NaMAAUA), along with hydrophobic monomer of styrene or butyl methacrylate. NaMAAUA contains a pendant group of amphiphilic fatty acid, and acts as a dispersant and emulsifier, forming a copolymer shell around the pigments. The apolar tail in NaMAAUA provides hydrophobic interaction with pigments, and the polar carboxyl headgroup exposes in the water phase and enables the formation of strong hydrogen bonds with cellulose. Therefore, the resulting encapsulated pigment exhibits excellent dispersion stability, water-repellent property, washing fastness and UV resistance when applied to paper and cotton fabric, expanding the practical utility of organic pigments in an environmentally conscious manner. Characterization via various analytical techniques validates the efficacy of this approach, paving the way for enhanced pigment applications.

Bioactive compounds and in vitro biological properties of Arthrospira platensis and Athrospira maxima: a comparative study

Cyanobacteria, especially Arthrospira, are valuable resources of nutrients and natural pigments with many beneficial health-related properties. This study optimized the extraction conditions of Arthrospira to achieve high phenolic contents and antioxidant activities. Under optimized extraction conditions, the bioactive compounds (phenolics and pigment components), antioxidant activities, and inhibitions of the key enzymes relevant to some non-communicable diseases were compared between Arthrospira platensis and Arthrospira maxima. Optimized extraction conditions were determined as 2 h shaking time, 50 °C extraction temperature, and 1% (w/v) solid-to-liquid ratio, giving effective phenolic and phycocyanin contents using aqueous extraction, while 80% (v/v) aqueous ethanolic extraction provided high total chlorophyll content. Most antioxidant activities were higher using 80% (v/v) aqueous ethanolic extracts. Both Arthrospira species inhibited the key enzymes involved in controlling non-communicable diseases including hyperlipidemia (lipase), diabetes (α-amylase, α-glucosidase, and dipeptidyl peptidase-IV), Alzheimer’s disease (acetylcholinesterase, butyrylcholinesterase and β-secretase), and hypertension (angiotensin-converting enzyme). High inhibitory activities were detected against β-secretase (BACE-1), the enzyme responsible for β-amyloid plaque formation in the brain that acts as a significant hallmark of Alzheimer’s disease. Arthrospira extract and donepezil (Alzheimer’s disease drug) synergistically inhibited BACE-1, suggesting the potential of Arthrospira extracts as effective BACE-1 inhibitors. Interestingly, A. maxima exhibited higher bioactive compound contents, antioxidant activities, and key enzyme inhibitions than A. platensis, indicating high potential for future food and medicinal applications.

Laser-induced fluorescence spectroscopic investigation of Echium amoenum decoction

Herbs containing medicinal ingredients with nutritional value have recently gained attention as an alternative to synthetic drugs. Aside from their pharmaceutical worthiness, a variety of naturally occurring chromophores with specific optical properties have made them valuable sources of natural pigments for many biophotonic applications. Echium Amoenum (EA) is one of the colorful flowers that has been used in traditional medicine for a long time. To our knowledge, although several studies have been carried out on the characterization of EA ingredients and their chemical activities, information on EA fluorescence is still lacking. Here, laser induced fluorescence (LIF) features of the decoction of EA petals were evaluated and found to be highly dependent on the excitation wavelength, EA concentration, and detection geometry. The abundance of pigments, the boundaries of their absorption/emission spectral regions, and the corresponding energy transfer ascertain the contribution of certain chromophores to the cumulative fluorescence activity. Upon deconvolution of the LIF spectra, it was revealed that the different emission bands of rosmarinic acid (corresponding to its dissociated forms) and the luminescent activity of luteolin and β-carotene mainly determine the quantum distribution of the fluorescence of EA. Angular measurement of LIF in a symmetric cylindrical arrangement revealed the presence of the inner filters mainly due to the reabsorption of LIF photons by anthocyanins (flavone, pelargonidin, delphinidin and cyanidin) and carotenoids. We hope that the obtained results will be useful in various fields of photochemistry and biophotonics.

Research Progress on Bioactive Substances of Beets and Their Functions

As a globally cultivated and economic crop, beets are particularly important in the cane sugar and feed industries. Beet pigments are among the most important natural pigments, while various chemical components in beets display beneficial biological functions. Phenolic substances and betalains, as the main bioactive compounds, determine the functional characteristics of beets. This review categorizes the basic types of beets by the chemical composition of bioactive substances in their leaves, stems, and roots and emphatically summarizes the research progress made on the functions of two major substances in different types of beets: phenolic compounds and betalain pigments. This study provides useful insights for the comprehensive and effective application of beets in the health food and pharmaceutical industries.

Fabrication of dye-sensitized solar cells with natural dye pigments derived from mustard green (Brassica juncea L) and turmeric (Curcuma longa L)

Abstract Natural dye molecules are good alternatives for the ruthenium-based sensitizer for use in dye-sensitized solar cell (DSSC) application. In this research, we have reported the potential application of natural pigment extracts as a dye-sensitizer in DSSC. Natural dyes were extracted using simple maceration technique from natural sources such as mustard green (Brassica juncea L) and turmeric (Curcuma longa L). UV-Vis and FT-IR characterization were employed to examined the optical characteristics and identify their functional groups of the dyes, respectively. The UV-Vis characterization of mustard green dye and turmeric dye show a wide absorption in visible region. The FT-IR spectrum of mustard green dye and turmeric dye show the presence the anchoring groups. The DSSC’s performance was studied using current-voltage (I-V) measurements and electrochemical impedance spectroscopy (EIS). It was observed that the DSSC with turmeric dye shows better photovoltaic performance than DSSC with mustard green dye correlated to its longer charge carrier lifetime.