Search Results (289)

In the context of critical challenges in curcumin-modified polyurethane synthesis—including limited curcumin bioavailability and suboptimal biodegradability/biocompatibility—a novel polyurethane material (Cur-PU) with good mechanical, shape memory, pH-responsive, and biocompatibility was synthesized via a one-pot, two-step synthetic protocol in which HO-PCL-OH served as the soft segment and curcumin was employed as the chain extender. The experimental results demonstrate that with the increase in Cur units, the crystallinity of the Cur-PU material decreases from 32.6% to 5.3% and that the intensities of the diffraction peaks at 2θ = 21.36°, 21.97°, and 23.72° in the XRD pattern gradually diminish. Concomitantly, tensile strength decreased from 35.5 MPa to 19.3 MPa, and Shore A hardness declined from 88 HA to 65 HA. These observations indicate that the sterically hindered benzene ring structure of Cur imposes restrictions on HO-PCL-OH crystallization, leading to lower crystallinity and retarded crystallization kinetics in Cur-PU. As a consequence, the material’s tensile strength and hardness are diminished. Except for the Cur-PU-3 sample, all other variants exhibited exceptional shape-memory functionality, with R_f and R_r exceeding 95%, as determined by three-point bending method. Analogous to pure curcumin solutions, Cur-PU solutions demonstrated pH-responsive chromatic transitions: upon addition of hydroxide ion (OH⁻) solutions at increasing concentrations, the solutions shifted from yellow-green to dark green and finally to orange-yellow, enabling sensitive pH detection across alkaline gradients. Hydrolytic degradation studies conducted over 15 weeks in air, UPW, and pH 6.0/8.0 phosphate buffer solutions revealed mass loss <2% for Cur-PU films. Surface morphological analysis showed progressive etching with the formation of micro-to-nano-scale pores, indicative of a surface-erosion degradation mechanism consistent with pure PCL. Biocompatibility assessments via L929 mouse fibroblast co-culture experiments demonstrated ≥90% cell viability after 72 h, while relative red blood cell hemolysis rates remained below 5%. Collectively, these findings establish Cur-PU as a biocompatible material with tunable mechanical properties, and pH responsiveness, underscoring its translational potential for biomedical applications such as drug delivery systems and tissue engineering scaffolds. Full article

Monascus purpureus is a filamentous fungus renowned for producing bioactive secondary metabolites, including lovastatin and azaphilone pigments. Lovastatin is valued for its cholesterol-lowering properties and cardiovascular benefits, while Monascus pigments exhibit anti-cancer, anti-inflammatory, and antimicrobial activities, underscoring their pharmaceutical and biotechnological relevance. This study evaluated the impact of carbohydrate-derived elicitors—mannan oligosaccharides, oligoguluronate, and oligomannuronate—on the enhancement of pigment and lovastatin production in M. purpureus C322 under submerged fermentation. Elicitors were added at 48 h in shake flasks and 24 h in 2.5 L stirred-tank fermenters. All treatments increased the production of yellow, orange, and red pigments and lovastatin compared to the control, with higher titres upon scale-up. OG led to the highest orange pigment yield (1.2 AU/g CDW in flasks; 1.67 AU/g CDW in fermenters), representing 2.3- and 3.0-fold increases. OM yielded the highest yellow and red pigments (1.24 and 1.35 AU/g CDW in flasks; 1.58 and 1.80 AU/g CDW in fermenters) and the highest lovastatin levels (10.46 and 12.6 mg/g CDW), corresponding to 2.03–3.03-fold improvements. These results highlight the potential of carbohydrate elicitors to stimulate metabolite biosynthesis and facilitate scalable optimisation of fungal fermentation. Full article

The color of flowers in Osmanthus fragrans is regulated by carotenoid metabolism. The orange-red variety, Dangui, is believed to have evolved from the yellow variety, Jingui, through a natural bud mutation. This study uses the Jingui cultivar ‘Jinqiu Gui’ (JQG) and its bud mutation cultivar ‘Huolian Jindan’ (HLJD) as materials, combining genome resequencing, ultrastructural observation, targeted metabolomics, and transcriptomic analysis to elucidate the molecular and cellular mechanisms underlying flower color variation. Phylogenetic analysis confirms that HLJD is a natural bud mutation of JQG. Ultrastructural observations reveal that during petal development, chromoplasts are transformed from proplastids. In HLJD petals, starch granules degrade more slowly and exhibit abnormal morphology, resulting in chromoplasts displaying crystalline, tubular, and fibrous composite structures, in contrast to the typical spherical plastoglobuli found in JQG. Targeted metabolomics identified 34 carotenoids, showing significant increases in the levels of ε-carotene, γ-carotene, α-carotene, and β-carotene in HLJD petals compared to JQG, with these levels continuing to accumulate throughout the flowering process, while the levels of the cleavage products α-ionone and β-ionone decrease. Transcriptomic analysis indicates that carotenoid metabolic pathway genes do not correlate directly with the phenotype; however, 49 candidate genes significantly associated with pigment accumulation were identified. Among these, the expression of genes such as glycoside hydrolases (LYG036752, etc.), sucrose synthase (LYG010191), and glucose-1-phosphate adenylyltransferase (LYG003610) are downregulated in HLJD. This study proposes for the first time the pathway of “starch degradation delay → chromoplast structural abnormalities → carotenoid cleavage inhibition” for deepening flower color, providing a new theoretical model for the metabolic regulation of carotenoids in non-photosynthetic tissues of plants. This research not only identifies key target genes (such as glycoside hydrolases) for the color breeding of O. fragrans but also establishes a theoretical foundation for the color enhancement of other ornamental plants. Full article

The colour evolution of malvidin-3-O-glucoside (Mv-3-O-glc) elicited by caffeic acid (CAF), (+)-catechin (CA), or syringic acid (SI) was spectrophotometrically monitored in model wine solution, modulating the malvidin-to-polyphenol molar ratio (1:1 to 1:20) and the pH (2.8–3.8). The spectral features provided the thermodynamic parameters Gibbs free energy (ΔG⁰) and equilibrium constant (K_eq), showing that the copigmentation extent is maximized at pH 3.6 and a higher molar ratio (1:20), and that copigments have different efficiency. In a long-term evolution (12 months), transient complexes evolved into different colour characteristics. Spectrophotometry and colorimetry (chroma C*, hue H*, and lightness L*) revealed the formation of stable pigments with peculiar orange-reddish colour when CAF was present; however, in the case of CA, an accentuated yellow tone was observed. SI showed minimum impact in the long-term evolution of Mv-3-O-glc. This study expands knowledge on oenological copigmentation, further exploring its potential implication in the colour of aged red wines. Full article

This study evaluated the phenolic, carotenoid, and elemental compositions of three hawthorn species—Crataegus: C. tanacetifolia (yellow), C. orientalis (orange), and C. microphylla (red)—collected from Şebinkarahisar, Türkiye. Liquid chromatography tandem mass spectrometry (LC-MS-MS) analysis revealed that C. microphylla had the highest phenolic content, notably epicatechin, gallic acid, and quercetin. It also showed the highest levels of β-carotene and lutein, highlighting its nutraceutical potential. C. orientalis was rich in rutin and taxifolin. Inductively coupled plasma mass spectrometry (ICP-MS) results showed significant mineral content, including Fe, Mn, Ca, and Se. About 60 g of dried hawthorn could meet 7–8% of daily selenium needs. In C. tanacetifolia, toxicological tests showed no substantial health hazards, with target hazard quotient (THQ) values below 1 and carcinogenic risk (CR) values within tolerable levels (e.g., Ni-CR: 4.68 × 10⁻⁵). Lead (Pb) and arsenic (As) levels were below detection thresholds in all samples, indicating that hawthorn fruits from this location are safe. The study also shows how species-specific and geographical factors affect hawthorn fruit nutrition and safety. Full article

During fruit ripening in Capsicum species, substantial amounts of carotenoids accumulate in the pericarp. While the carotenoid biosynthesis pathway in Capsicum species has been extensively investigated from various angles, the transcriptional regulation of genes encoding carotenoid biosynthetic enzymes remains less understood in this non-climacteric horticultural crop compared to tomato, a climacteric fruit. In the present study, we investigated the function of the NAM, ATAF1/2 or CUC2 81 (CaNAC81) transcription factor gene. This gene was selected through RNA-Seq co-expression analysis based on the correlation between expressed transcription factor gene profiles and those of carotenoid structural genes. To determine its role in regulating the expression of biosynthetic-related carotenogenic genes, we performed Virus-Induced Gene Silencing (VIGS) assays in the Serrano-type C. annuum ‘Tampiqueño 74’. Fruits from plants infected with a pTRV2:CaNAC81 construct (silenced fruits) exhibited altered carotenoid pigmentation accumulation, manifested as yellow-orange spots, in contrast to fruits from non-agroinfected controls (NTC) and fruits from plants infected with the empty TRV2 construct (red fruits). Quantitative real-time PCR (qPCR) assays confirmed decreased transcript levels of CaNAC81 in fruits displaying altered pigmentation, along with reduced transcription of the PSY gene, which encodes the carotenoid biosynthetic enzyme phytoene synthase (PSY). High-performance liquid chromatography (HPLC) analysis revealed a distinct carotenoid pigment accumulation pattern in fruits from plants showing silencing symptoms, characterized by low concentrations of capsanthin and zeaxanthin and trace amounts of capsorubin, compared to control plants (NTC). These findings suggest the involvement of CaNAC81 in the regulatory network of the carotenoid biosynthetic pathway in chili pepper fruits. Full article

Betalains are nitrogen-containing, water-soluble, and non-toxic natural pigments found in various plant species. Among these, Celosia argentea (Amaranthaceae) has garnered attention as a significant source, accumulating substantial quantities of both red–purple betacyanins and yellow–orange betaxanthins. Impressively, betalain concentrations in C. argentea inflorescences can reach up to 14.91 mg/g dry weight (DW), a level comparable to that reported in red beetroot. Beyond harvesting from inflorescences, betalains can also be produced using cell culture systems, which can yield even higher amounts, up to 42.08 mg/g DW. Beyond their role as vibrant natural colorants, betalains exhibit impressive health-promoting properties, most notably potent antioxidant activities. For instance, C. argentea inflorescence extracts demonstrate approximately 84.07% 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 88.70% 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging. Extracts derived from cell cultures show even higher scavenging capacities, reaching up to 99.28% for ABTS and 99.63% for DPPH, rivaling the antioxidant standard (ascorbic acid). Further research indicates additional potential benefits, including anti-inflammatory, antimicrobial, anticancer, antidiabetic, and hepatoprotective properties. This diverse bioactivity underpins their value across various industries. Betalains serve as natural colorants and functional ingredients in food and beverages, offer sustainable alternatives for textile dyeing, and hold therapeutic promise in cosmetics and pharmaceuticals. This review critically examines existing research on betalain production in C. argentea. Recognizing that research specific to C. argentea is less extensive compared with that on species such as Beta vulgaris and Hylocereus polyrhizus, this review analyzes its biosynthetic pathways, diverse biological properties, and wide-ranging applications. This is achieved by integrating available C. argentea-specific data with relevant insights drawn from these more broadly studied betalain sources. Furthermore, the review discusses perspectives on future research directions aimed at optimizing yield and exploring the full potential of betalains, specifically within C. argentea. Full article

Rapeseed (Brassica napus L.) has been cultivated as an ornamental plant in recent years. However, the metabolic and regulatory processes involved in pigment accumulation in. B. napus flowers are poorly understood. To address this knowledge gap, we conducted a multi-omics analysis of the orange-red-flowered ‘OrP’ and the yellow-flowered ‘ZS11’ rapeseed cultivars. The total anthocyanin content of ‘OrP’ petals was 5.420-fold and 3.345-fold higher than ‘ZS11’ petals at the S2 and S4 developmental stages, respectively. The red coloration of ‘OrP’ flowers resulted primarily from the presence of anthocyanin pigment derivatives. The up-regulated differentially expressed genes (DEGs) of four stages in ‘OrP’ were found to be significantly enriched in phenylpropanoid, flavonoid, and anthocyanin metabolism-associated GO and KEGG terms. Weighted Gene Co-expression Network Analysis (WGCNA) revealed that 51 DEGs were linked to anthocyanin metabolism, including several structural genes such as BnaCHS, BnaF3H, BnaF3′H, BnaCHS, BnaDFR, BnaANS, BnaUGTs, and the transcription factor (TF) genes BnaHY5, BnaBBX22, BnaPIL1, BnaPAP2, BnaTT8, BnaTTG2, and BnaMYBL2. Furthermore, we found that three main factors affecting the relative content of anthocyanins in petals were likely responsible for the fading of ‘OrP’ petals, namely the significantly down-regulated expression of genes (BnaDFR, BnaANS, BnaPAP2, BnaTT8, and BnaTTG2) related to anthocyanin biosynthesis, the significantly up-regulated expression of genes (Bna.BGLUs, Bna.PRXs, and BnaMYBL2) related to anthocyanin degradation or the negative regulation of anthocyanin biosynthesis, and the rapidly increasing petals area. Full article

Background: This study investigates the cytotoxicity of microbial polyketides biosynthesized by Monascus species through both in silico and in vitro approaches. Methods: Six main know Monascus-derived polyketides were analysed in silico an an vitro. Results: In silico tests reveal that the main derived compounds exhibit lipophilic properties, indicating their potential suitability as active ingredients in dermato-cosmetic formulations. In silico tests revealed significant flexibility and high degrees of unsaturation for some Monascus-derived polyketides, suggesting a broad interaction potential and a propensity for chemical instability. In silico permeability tests indicated low epidermal penetration. Cytotoxicity assays conducted in vitro on a HaCaT cell line revealed varying levels of cytotoxicity among the three classes of fungal polyketides. Yellow polyketides derived from Monascus purpureus and Monascus ruber exhibited moderate cytotoxicity, while orange polyketides derived from the same strains showed low cytotoxicity. Red, orange, and yellow polyketides derived from a high-productive Monascus sp. genus showed low or negligible cytotoxicity. After 48 h of exposure, the cytotoxic profiles of all Monascus polyketides remained relatively stable. The IC₅₀ values obtained through linear or nonlinear models supplied by EXCEL MS Office or for the Systat programme indicated moderate-to-low cytotoxicity for polyketides derived from Monascus ruber and Monascus purpureus. The bioproducts derived from high-productive Monascus sp. exhibited weak or negligible cytotoxicity. Conclusions: The results obtained suggest that the Monascus-derived polyketides possess promising properties for therapeutic and cosmetic applications, but their chemical stability must be considered in the case of dermatological formulations. Full article

Multicolour graphene quantum dots (GQDs), from blue to orange emitting, were successfully synthesized via a one-step hydrothermal method using potassium hydrogen phthalate and o-phenylenediamine as the raw materials. After purification by silica gel column chromatography, four kinds of GQDs with maximum emission wavelengths of 420 nm (blue), 500 nm (green), 540 nm (yellow), and 555 nm (orange) were obtained, and all had a high quantum yield (9.7%, 8.8%, 9.3%, and 10.3%, respectively). The structural characterization revealed that the synthesized GQDs had a regular morphology, with a size of 2–3 nm and a thickness of 1–2 nm. The D-band-to-G-band ratio was less than 0.3, indicating that the GQDs had a high degree of graphitization. In addition, the emission peaks of the GQDs were red-shifted as the particle size increased, confirming that their luminescence was dominated by the quantum confinement effect. By analyzing the surface states and the functional groups of the multicolour GQDs, it was found that the GQDs had a similar elemental composition, which further proved that the emission wavelengths did not depend on the surface element composition, but conformed to the luminescence mechanism regulated by the quantum-limited effect. Furthermore, the four types of GQDs exhibited low cytotoxicity and good stability, suggesting their potential applications in biomarkers and for the synchronous detection of a variety of analytes. Full article

Betalains are hydrophilic natural pigments commonly found in plants of the Caryophyllales order, as well as in specific species and genera of fungi, such as Hygrocybe, Hygrophorus, and Amanita muscaria. Betalains are sorted into two groups: betacyanins, which form red-violet pigments, and betaxanthins, which form yellow-orange pigments. These compounds can be employed as colorimetric sensors and biosensors. This paper provides a review of the isolation methods of betalains and the various applications of betalains as colorimetric sensors and biosensors. The review was conducted by collecting publications over the last decade. The results show that betalains can be used as a colorimetric sensor to identify metal compounds in water and nonmetal compounds that indicate the quality of food. In addition, betaxanthin has been used for developing cell-based biosensors from yeast and bacteria. Furthermore, betalain as a colorimetric sensor and biosensor is developed by using an innovative digital detector, such as a smartphone. Nevertheless, the fragile stability of betalains presents a significant barrier during the extraction. As a result, future studies could focus on adding innovative technologies for optimizing extraction and also developing betalain as novel bio-indicators for specific analytes. Full article

Destructive methods, though traditionally used to evaluate fruit safety, frequently do not deliver complete and detailed information. Non-destructive methods, especially spectroscopy, provide an effective solution for fast, efficient, and non-invasive assessments of quality and safety. This study utilized visible and near-infrared (Vis-NIR) spectroscopy to quantify the nitrate content in three cultivars of bell pepper—orange, yellow, and red—across a spectral range spanning 350 to 1150 nanometers. The nitrate content was assessed destructively, and spectral data were examined through partial least squares regression (PLSR). Model efficacy was measured using the root mean square error (RMSE) and coefficient of determination (R²). The R² values, indicative of the model’s predictive efficacy, were determined to be 0.77, 0.85, and 0.81 for the yellow, red, and orange types, respectively. To optimize wavelength selection and improve model performance, a hybrid approach was utilized, integrating a support vector machine (SVM) with four meta-heuristic algorithms: particle swarm optimization (PSO), genetic algorithm (GA), imperialistic competitive algorithm (ICA), and ant colony optimization (ACO). The SVM-PSO approach proved to be the most efficient in pinpointing 15 key wavelengths. Following this, three modeling techniques—PLSR, multiple linear regression (MLR), and artificial neural network (ANN)—were utilized with the identified wavelengths. Among these, ANN represented the best performance, achieving validation R² values of 0.99, 0.97, and 0.92 for the yellow, red, and orange varieties, respectively. Compared to traditional PLSR and MLR models, which reached validation R² values up to 0.93, the ANN model demonstrated a significant improvement in prediction accuracy. This quantitative improvement highlights the advantage of combining hybrid meta-heuristic wavelength selection with ANN modeling. The results underscore the promise of visible/near-infrared (Vis/NIR) spectroscopy, integrated with sophisticated modeling approaches, as an effective non-invasive method for estimating nitrate concentrations in bell peppers. This technique represents a significant advancement in supporting food safety measures and quality assurance processes. Full article

Biological studies on symmetry can be expanded to consider red (longer wavelengths) and blue (shorter wavelengths) shifts as antisymmetries (opposite-pattern symmetries), which may arise from similar underlying causes (invariant process symmetries). In this context, classic shift asymmetries of redder plumage in response to higher dietary carotenoids appear conceptually incomplete, as potential blue-shifted counterparts were not considered. A latent symmetric response is highlighted by recent evidence showing that the maximum absorbance bands of various colorful plumage pigments are red-shifted in birds with ultraviolet-sensitive (UVS) color vision but blue-shifted in those with violet-sensitive (VS) color vision. Blue-shifted responses to increased dietary carotenoid contents may also be underestimated, as relevant studies have focused on species-rich but uniformly UVS Passerida passerines. This study explored the relationship between pattern–process symmetries and diets of VS Piciformes–Coraciiformes by gauging the responses of their plumage reflectance to a modified diet index (Diet_c), where the overall rank carotenoid contents of food items were weight-averaged by three levels of importance in a species’ diet. In the case of both sexes, the main long-wavelength reflectance band for the three carotenoid-based pigment classes defined the same graded series of blue shifts in response to higher Diet_c. Yellow showed a strong absolute (negative slope) blue shift, orange showed a weaker absolute blue shift, and red exhibited only a blue shift (flat, non-significant slope) relative to absolute red shifts (positive slope). The secondary shorter-wavelength reflectance band was also unresponsive to Diet_c in the VS Piciformes–Coraciiformes (relative blue shift) compared with earlier evidence for it decreasing (absolute red shift) at higher Diet_c in UVS species. Results for the intervening minimum reflectance (maximum absorbance) band were intermediate between those for the other reflectance bands. No pigment class monopolized lower or higher Diet_c, but red was less variable overall. Phylogenetic independence, sexually similar responses, and specimen preservation reinforced characterizations. A review of avian perceptual studies suggested that VS models discriminate yellows and oranges extremely well, consistent with the importance of the corresponding carotenoids as Diet_c indicators. Both UVS and VS species appear to produce putatively more costly and possibly beneficial carotenoid metabolites and/or concentrations in response to higher Diet_c, supporting underlying invariant processes in relation to carotenoid limitations and honest signaling despite opposite plumage shifts and their different chemical bases. In symmetry parlance, pigment classes (red) or wavebands (short) that lack responses to Diet_c suggest broken pattern and process symmetry. The biology of VS Piciformes–Coraciiformes may favor such exceptions owing to selection for visual resemblance and tuning specializations, although universal constraints on physical and chemical properties of (particularly red) carotenoids may favor certain functional tendencies. Thus, symmetry principles organize carotenoid diversity into a simplified and predictive framework linked to color vision. Full article

Dy³⁺ single-doped and Dy³⁺/Eu³⁺ co-doped ZnO:B₂O₃:WO₃:Nb₂O₅ glass was successfully synthesized using the melt quenching method. The amorphous character of the prepared samples was confirmed by X-ray diffraction (XRD). The glass transition and crystallization temperatures were examined by differential scanning calorimetry (DSC). Raman spectroscopy was applied to investigate the glass microstructure. Physical properties like the density, molar volume, oxygen molar volume and oxygen packing density of the glass were also determined. The photoluminescence excitation (PLE) and emission (PL) spectra of the resultant glass types were measured. The obtained Dy³⁺ single-doped glass was characterized by strong luminescence at 482 and 574 nm, corresponding to the ⁴F_9/2 → ⁶H_15/2 (blue) and ⁴F_9/2 → ⁶H_13/2 (yellow) transitions, respectively, and weak luminescence at 663 nm and 753 nm due to the ⁴F_9/2 → ⁶H_11/2 (red) and ⁴F_9/2 → ⁶H_9/2 + ⁶F_11/2 (red) transitions. The luminescence results indicate that energy transfer from the Dy³⁺ to Eu³⁺ ions occurs in the proposed glass system. The emitted light from the Dy³⁺ single-doped glass was found to be yellow-orange. The Dy³⁺/Eu³⁺ co-doped samples emitted darker orange light. The obtained results show that the investigated types of glass have the potential to be used as orange light-emitting materials. Full article

This study investigates the catalytic potential of silver nanoparticles (AgNPs) synthesized using aqueous Cymbopogon citratus (lemongrass) extract for the degradation of toxic textile dyes, offering an eco-friendly solution to industrial wastewater treatment. The green-synthesized AgNPs demonstrated remarkable degradation efficiency (>94%) for multiple dyes, such as rhodamine B, methyl red, methyl orange, methylene blue, eosin yellow, and Eriochrome black T, in the presence of sodium borohydride. Optimization studies employing a one-factor-at-a-time approach revealed the critical influence of AgNPs and reductant concentration, temperature, and pH. Kinetic analysis confirmed pseudo-first-order degradation behavior. Reactive species scavenging experiments established that hydroxyl radicals and holes played dominant roles in the degradation mechanism. Notably, the AgNPs retained catalytic activity across eight reuse cycles with negligible performance loss, demonstrating strong potential for repeated application. Comparative analysis with data from the literature highlights the superior performance of C. citratus-derived AgNPs in terms of reaction rate and efficiency. This work underscores the value of plant-extract-mediated AgNPs synthesis not only for its environmental compatibility but also for its catalytic effectiveness. The study advances the practical applicability of green nanotechnology in wastewater remediation and supports its integration into sustainable industrial practices. Full article