Pigment

Typically, an anticorrosive coating system for long-term protection consists of a primer, one or several intermediate coats, and a topcoat. In such systems, zinc-rich primers are often used as they ensure good adhesion to the substrate and protect it from corrosion. Such coatings are very highly pigmented, which sometimes leads to losses in cohesive strength and deterioration of mechanical properties. Furthermore, Zn is known to be harmful to the environment. In this work we present Zn primers with reduced Zn content and better protective properties than traditional zinc-rich primers. The formulations of different Zn pigments in the epoxy matrix were developed with the concentration of zinc particles reduced to about 50% in the dry coating. To evaluate the distribution of pigments scanning electron microscopy has been employed. The anticorrosive properties were tested using the salt spray test and electrochemical impedance spectroscopy. The mechanical properties of the coatings were also tested.

With the aid of a microspectrophotometer the visual pigments and oil globules in the retina of the emu (Dromiceius novae-hollandiae), the brushland tinamou (Nothoprocta c. cinerascens) and the Chilean tinamou (Nothoprocta perdicaria sanborni) were characterized. All three of these palaeognathous birds contain in their rods a typical rhodopsin with "~max near 500 nm. Each of these birds has cones containing iodopsin-like visual pigments with ;~max in the 560-570 nm spectral region. No unequivocal evidence was obtained for the presence of cone pigments other than this iodopsin-like pigment, although one cell thought to be a cone, and containing a visual pigment with 2 .... near 498 nm, was observed in the retina of the brushland tinamou. The oil globule systems of the three palaeognathous species are identical to each other and are much simpler than is typical for neognathous birds in that only two different types of globule are present, one with 2T50 at 508 nm and another with 2r5o at 568 nm. Comparison of the data with observations made on neognathous species indicates (1) that palaeognathous birds probably have poorer color discrimination capabilities than neognathous birds and (2) that the tinamou is more closely related to the ratites than to the galliform species.

Crassiphycus corneus (J.Agardh) Gurgel, J.N.Norris et Fredericq (Gracilariales, Rhodophyta) is a species with high-quality and high yields of polysaccharides and is therefore an important agarophyte on the west coast of the Atlantic Ocean. On the northeastern coast of Brazil, the populations of this species are mostly composed of individuals of the wild red color strain and by some individuals of the green color strain, the latter being scarcely studied. This work characterizes and compares the physiological performance of the wild red strain and the green variant under different temperature and irradiance conditions in the laboratory. The results indicate that the green and red strains are similarly tolerant to low temperatures (18 ºC) but intolerant to high temperatures (35 ºC). Both strains exhibited the highest growth rate at 25 ºC and high irradiance (500 μmol photon·m–2·s–1). Under these conditions, photosynthetic rate and pigment content were similar in both color strains, bu...

At this work, the processing of waste after flotation of copper production slag to obtain iron oxide pigment is presented. Based on the results of the experiments, the influence of various factors and parameters on the processing of iron-containing waste (tailings) of the copper concentration plant-2 of the AMMC was studied; This approach is both uncomplicated and efficient for extracting Fe 2 O 3 , which is regarded as a primary ingredient in the manufacturing of iron pigment. It was found that when caustic soda is used for alkaline roasting, the iron oxides in the tailings react with nitrates and hydrates to form an insoluble solid phase. Additionally, it was discovered that firing temperatures above 350 °C result in the formation of a sodium aluminate compound. This compound and the iron compounds dissolve in solutions and negatively affect the quality of the resulting Fe 2 O 3 pigment.

Chlorophyll content in leaves of 11 Vitis vinifera L. indigenous varieties (Iasi vineyard, Romania) was determined by two independent methods: spectrophotometry (extraction) and with a Opti-Sciences CCM-200 plus chlorophyll content meter (non-destructive method) with the aim of comparing the results. Also, this study was conducted to establish the values of chlorophyll a/ chlorophyll b and chlorophyll/carotenoid ratio in middle leaves of vine stocks, in the phenophase of progressive growing of shoots. Area and perimeter of leaves in this phenophase were determined. Total chlorophyll concentration in leaf extract varied from 0.67±0.01 mg/g f.w. to 1.00±0.03 mg/ g f.w., being highly correlated with the chlorophyll content index values (CCI) recorded by CCM-200 (R 2 =0.9839; p<0.001). Similar situation was identi ied in the case of the chlorophyll b and CCI correlation (R 2 =0.9638; p<0.001). Chlorophyll a/b ratio in leaf extract varied signi icantly depending on variety, ranging from 1.06±0.01 to 2.43±0.01, with a chlorophyll/carotenoid ratio reaching up to 3.19±0.08. Compared to spectrophotometry, CCM-200 plus affords fast, reliable, economical, non-destructive chlorophyll content measurement, however, providing no details regarding chlorophyll components and ratios.

The Northwestern Iberian area is renowned for its abundant megalithic barrows, with some featuring painted megaliths. The motifs on those megalithic paintings are commonly interpreted as part of funeral practices and agency. However, archaeologists often lack information on both the composition of the colorants and the technical methods employed in their production, which also hold symbolic significance. This communication explores the processes involved in the production of prehistoric paintings and their significance. Through the project Funerary and ceremonial practices between the Neolithic and the Iron Age, approached by Archaeometry we began a programme of analyses on the megalithic paintings of north-central and northern Portugal, which are often poorly protected and preserved.

The fungal colorants produced by an Epiccocum nigrum selected strain showed a great potential as an economical source of natural pigments reason of their edible characters and easiness for pigment biosynthesis, coupled with the attractive luminosity, chromo and hue of the pigments. The fungus Epiccocum nigrum was isolated from air and the cultivation of moulds for pigment biosynthesis was performed in solid state fermentation system, in darkness conditions. The fungal colorants were characterized through UV-visible spectroscopy; HPLC and colour attribute analysis (Tristimulus Colorimetry). This complex of pigments is rich in carotenoids and flavonoids. The carotenoids content was of 948.48 mg/100g powder and the flavonoids content was of 52 mg/100g powder. As a result of the same process were also some compounds known as poliphenols (the anthocyanins type). The colour characteristics (CIE L * , a * , b * , C * ab , h ab) of the pigments in extract solution were L * = 93.745, a * =-20.541, b * = 91.991, C * ab = 94.256 and h ab = 102.59. The oil-in-water emulsions with fungal colorant were instrumentally evaluated during storage at room temperature through UV-visible spectroscopy, microscopically observation, conductometric and turbidity measurements. The emulsions with these colorants are milkiness. The experimental results of colour differences and its components in the case of coloured emulsions (at pH = 7) were: ∆L * = 26.67, ∆a * = 0.33, ∆b * =-8.04, ∆C * ab =-7.99, ∆h ab =-4.9, ∆H * ab =-0.87 and ∆E * ab = 27.86. From the results presented in this paper, it should be noted that the colour shade of emulsions containing fungal colorants was stable during storage under normal light for 35 days, the colour of emulsions remaining almost unchanged.

The phenolic composition of the skin of the Băbească neagră grapes grown in south-eastern Romania was studied by two extraction techniques, i. e., ultrasound-assisted extraction (UAE) and enzyme-assisted extraction (EAE). This study aimed to analyze the grape skin bioactive compounds and the antioxidant potential using ethanol of three different concentrations 50%, 70%, and 96% and acidified with acetic, citric acid, or hydrochloric acid. This research aimed to maximize the extraction of bioactive compounds from red grape skin by using commercially available oenological enzyme preparations, varying the enzyme dosage, pH, temperature and extraction time. The results indicated that the highest total anthocyanin content was obtained when using 70 % ethanol extract acidified with 0.1 N hydrochloric acid, characterized by 4.29±0.04 mg C3G/g DW for ultrasound extraction and 2.54±0.13 for enzyme-assisted extraction. The results of antioxidant potential of the extracts investigated showed t...

Anthocyanin is a water-soluble pigment existing in plants, and has various health benefits to humans. As far as that goes, the number and location of the hydroxyl groups of the parent nucleus have significant effects on the anthocyanin activities. This review summarizes anthocyanin content in fruits, the importance of anthocyanin in relation to human health, some aspects of anthocyanin biochemistry and their bioavailability, the distribution in some fruits, the biosynthetic pathway, different extraction, separation and purification methods, and also identification methods. Beneficial effects of anthocyanin pigments are reported in the scientific literature and these compounds are nowadays recognised as potentially therapeutic. The lack of antioxidant defense mechanisms in humans is associated with the cardiovascular and coronary artery diseases, cancer and diabetes, besides others.

Red wines of different ages (1-14 years) were analysed by Capillary zone electrophoresis (CZE). Pigments were separated using a fused silica capillary with an effective length of 56 cm and an internal diameter of 75 cm. Disodium tetraborate at 50 mM with a pH of 9.4 was used as buffer solution with methanol as modifier. Electrophoregrams were recorded at 280, 520 and 599 nm and spectra were measured from 200 to 599 nm using a diode array detector. Several differences in the CZE signals obtained for different aged wines were observed, as well as between red and white wines. The signals of a group of seven peaks increased in mature wines. A decrease in free anthocyanins was also identified in aged wine. The migration times of these compounds corresponded to charge/size ratios higher than those of free anthocyanins, and their spectra suggested combinations of anthocyanins with flavanols or tannins. The global CZE response of these pigmented polyphenolic polymers was linearly correlated with the spectrophotometric determination of polymeric pigments (96%) and age (92%).

Due to the fast mineralization and supply of NPK elements, insect frass has a very high potential for complete or partial replacement with mineral fertilizers. This research was conducted to investigate the effect of different levels of organic fertilizer of mealworm (yellow Tenebrio molitor larvae) as a growth substrate on the morphological indices and leaf greenness index of the ornamental plant Philodendron. To achieve the objectives of this research, an experiment was conducted in the form of a completely randomized design with three replications and 9 treatments (i.e., 27 pots in total). The treatments consisted of different proportions of mealworm fertilizer in combination with a conventional growing medium for philodendron plants in greenhouses. The results showed that the highest values of vegetative growth indices and leaf greenness index were obtained from the application of 40% perlite, 30% cocopeat, 10% mealworm, 10% vermiculite and 10% coal soil. However, an increase of more than 10% in mealworm fertilizer could not make a significant change in the investigated traits. In fact, it can be stated that when the replacement amount of mealworm fertilizer with cocopeat in the conventional substrate in greenhouse crops was 10 percent by volume, the highest values of vegetative growth and leaf greenness index were obtained, whereas a reduction in plant growth was observed at 15, 20 and 25 percent by volume and plants were found to be dead at volumes exceeding 30 percent. Due to the high salinity (10.3 dS m-1) and pH (8.55) of this frass, as well as the fact that changing the mealworm substrate might alter the type of produced frass, it is recommended to use substrates that reduce the salinity and pH of the final substrate.

Objective. e aim of this study was to evaluate the tear strength of MDX4-4210 and A-2186 silicones with different intrinsic pigments incorporated by mechanical and industrial methods, comparing nonaged and aged groups. Materials and Methods. Twenty-four groups were created according to the American Society for Testing and Materials D-624/type C, half nonaged and half aged (n � 10): bronze mechanical MDX4-4210, bronze industrial MDX4-4210, black mechanical MDX4-4210, black industrial MDX4-4210, pink mechanical MDX4-4210, pink industrial MDX4-4210, bronze mechanical A-2186, bronze industrial A-2186, black mechanical A-2186, black industrial A-2186, pink mechanical A-2186, and pink industrial A-2186. All specimens were submitted to tear strength analysis. Data were submitted to the ANOVA and Tukey test (p < 0.05). Results. An increase in the tear strength values was observed only for the bronze and black MDX4-4210, comparing nonaged and aged silicones (p < 0.05), regardless of the manufacturing method. ere was a difference in all comparisons between MDX4-4210 and A-2186 silicones with the same pigment type (p < 0.05), regardless of the manufacturing method. In all cases, there was no difference in the manufacturing method comparing the MDX4-4210 or A-2186 groups with the same pigment. Conclusion. Accelerated aging did not influence the tear strength in all aged A-2186 silicones and in aged pink industrial and mechanical MDX4-4210 silicones. e other MDX4-4210 groups had an increase in the results after aging. In all cases compared, the A-2186 groups had higher tear strength values than the MDX4-4210 groups. Mechanical and industrial methods can be used for silicone preparation, without changing the tear strength.

Objective. The aim of this study was to evaluate the tear strength of MDX4-4210 and A-2186 silicones with different intrinsic pigments incorporated by mechanical and industrial methods, comparing nonaged and aged groups. Materials and Methods. Twenty-four groups were created according to the American Society for Testing and Materials D-624/type C, half nonaged and half aged (n = 10): bronze mechanical MDX4-4210, bronze industrial MDX4-4210, black mechanical MDX4-4210, black industrial MDX4-4210, pink mechanical MDX4-4210, pink industrial MDX4-4210, bronze mechanical A-2186, bronze industrial A-2186, black mechanical A-2186, black industrial A-2186, pink mechanical A-2186, and pink industrial A-2186. All specimens were submitted to tear strength analysis. Data were submitted to the ANOVA and Tukey test (p&lt;0.05). Results. An increase in the tear strength values was observed only for the bronze and black MDX4-4210, comparing nonaged and aged silicones (p&lt;0.05), regardless of the ...

The purpose of this study was to evaluate the color stability of a maxillofacial elastomer with the addition of a nanoparticle pigment and/or an opacifier submitted to chemical disinfection and artificial aging. Specimens were divided into four groups (n = 30): group I: silicone without pigment or opacifier, group II: ceramic powder pigment, group III: Barium sulfate (BaSO 4) opacifier, and group IV: ceramic powder and BaSO 4 opacifier. Specimens of each group (n = 10) were disinfected with effervescent tablets, neutral soap, or 4% chlorhexidine gluconate. Disinfection was done three times a week during two months. Afterward, specimens were submitted to different periods of artificial aging. Color evaluation was initially done, after 60 days (disinfection period) and after 252, 504, and 1008 h of artificial aging with aid of a reflection spectrophotometer. Data were analyzed by three-way ANOVA and Tukey test (α = 0.05). The isolated factor disinfection did not statistically influence the values of color stability among groups. The association between pigment and BaSO 4 opacifier (GIV) was more stable in relationship to color change (E). All values of E obtained, independent of the disinfectant and the period of artificial aging, were considered acceptable in agreement with the norms presented in literature. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

The structural characterization of Mg 0.5 Cu 1.5 V x P 2−x O 7 (0.0 ≤ x ≤ 2.0) compositions was performed and the colour parameters of these materials measured. Solid solutions in the α-Cu 2 P 2 O 7 , β-Cu 2 P 2 O 7 and β-Cu 2 V 2 O 7 structures were obtained by incorporation of V(V) in the α-Cu 2 P 2 O 7 and β-Cu 2 P 2 O 7 structures and P(V) in the β-Cu 2 V 2 O 7 structure. Solid solutions with the α-Cu 2 P 2 O 7 structure are obtained at 500-600 °C when the vanadium:phosphorus ratio is lower than 2/3 (x ≤ 1.2). At 600 °C, these materials have a bright yellow colour. In these compositions, the transition to the β-Cu 2 P 2 O 7 structure occurs at 800 °C. This transition modifies the colour but it keeps the yellow colouration for compositions. At 1000 °C, the Cu 3 P 2 O 8 phase coexists with the β-Cu 2 P 2 O 7 phase and the yellow colouration is lost. Solid solutions with the β-Cu 2 V 2 O 7 structure are obtained at 600-800 °C when the amount of vanadium is high (x ≥ 1.5). The increase in the amount of vanadium in Mg 0.5 Cu 1.5 V x P 2−x O 7 (0.0 < x ≤ 2.0) compositions changes the colour of the materials from yellow to red at 600 °C (the Mg 0.5 Cu 1.5 P 2 O 7 composition, x = 0.0, is pale green). The colour of the materials darkens with increasing temperature and compositions with x > 1.5 melted at 1000 °C.

A pigment complex has been isolated from the biomass of bacteria Serratia marcescens ATCC 9986 and separated into single fractions by chromatography. An analysis of the fractions by spectrophotometry, thin layer chromatography, NMR spectroscopy and mass spectrometry enabled us to isolate the so called red frac tion, to confirm the identity of the product of the red fraction to the pigment prodigiosin, and to prove its purity. Some features of the toxic action of prodigiosin have been revealed. It has been found for the first time that the pigment is capable of inducing mutations in Salmonella typhimurium TA 100 cells (Ames test) and chromosomal damage in mammalian erythroblasts.

Colors of a collection set of postage stamps dated 1923 and corresponding to the hyperinflationary period of the German economy were identified with Raman and X-ray fluorescence (XRF) spectroscopies. Molecular systems associated to the blue, green and yellow colours were characterized. Blue colour is Prussian blue (Fe4[Fe(CN)6]3) and the green colour resulted to be a combination of Prussian blue and the yellow/orange pigment (PbCrO4) or a yellow β-naphthol like monoazopigment. The XRF data suggest that ZnO was used as filler.

Melanin is an almost ubiquitous pigment of brown to dark black color synthesized by living organisms. It has excellent potential for application in several fields, especially in pharmaceuticals. Yeasts are known for their ability to synthesize pigments, including melanin. These yeasts are considered black yeasts. However, there is little information on the synthesis of melanin by these yeasts. This work was designed to study the ability of black yeast to produce a diffusible dark pigment on agar. Two strains of black yeast, SN1 and SN2, were isolated from hydrocarbon-polluted soils. Based on morphological, physiological, and molecular analyses, the two strains SN1 and SN2 were identified as new species of the Exophiala phaeomuriformis strain. After pigment extraction, melanin was characterized using UV and Fourier transform infrared spectroscopy. We found that melanin synthesis is strongly affected by light and optimal parameters such as temperature 30°C, salinity between 10 and 30 ppt, and basic pH. Both melanin extracts also showed inhibitory activity against pathogenic germs, and activities were observed on E. coli (33.33 ± 2.88 mm), Pseudomonas aeruginosa (29.33 ± 4.61 mm), and Staphylococcus aureus (24.3 ± 7.65 mm). It was concluded that the melanin of the E. phaeomuriformis strain isolated from oil-polluted soils had high antibacterial activity. This high antibacterial activity could be a suitable source of new antibacterial natural products.

This study was conducted in the field and laboratories of the faculty of science and health-Koya university by exposing the seeds of cowpea plant (Vigna sinensis Savi) var. California black-eye to X-ray radiation in two different locations (In target or 30 cm out of target) inside the radiation chamber, for four different exposure times (0, 5, 10, or 20 min), to study the effect on some characteristics of seedling components. Results show that the exposure location to X-ray had non-significant effects on cowpea leaves content of photosynthetic pigments, whereas each of time of exposure with interaction between location and time of exposure had significant effects on chlorophyll a, total chlorophylls, and total carotenoids pigments. Regarding the X-ray effects on stomata characteristics, the results detect that there were non-significant differences between the location of exposure on stomata number on abaxial leaves surfaces and stomata length on adaxial leaves surfaces, whereas a s...

Dans le contexte pluviométrique déficitaire observé depuis plus de vingt ans en Afrique intertropicale, l'hydraulicité des fleuves de l'Afrique humide a nettement diminué depuis le début des années 80. Cette baisse se poursuit encore aujourd'hui alors qu'un retour à la normale du régime des pluies parait amorcé. L'évolution des écoulements annuels montre que le déficit annuel des ressources en eau est passé de 7% pour la décennie 70 à 16% pour la décennie 80 (365 km3 an-' dont 150 pour le fleuve Congo-Zaïre). Les chroniques montrent également dans la période actuelle d'exceptionnels débits d'étiage et des maximums annuels de crue plus faibles, la crue de printemps étant particulièrement amoindrie en régime équatorial. Le tarissement s'est considérablement accéléré traduisant un amenuisement des réserves souterraines. Ceci explique l'appauvrissement durable des ressources hydriques indépendant, pour un temps, d'une éventuelle amélioration des conditions climatiques et doit être pris en compte dans l'interprétation des expériences PEGI sur les flux de matières du bassin du Congo-Zaïre.

Biological control against microbial infections has a great potential as an alternative approach instead of fungicidal chemicals, which can cause environmental pollution. The pigment producerMetschnikowia andauensisbelongs to the antagonistic yeasts, but details of the mechanism by which it inhibits growth of other microbes are less known. Our results confirmed its antagonistic capacity on other yeast species isolated from fruits or flowers and demonstrated that the antagonistic capacity was well correlated with the size of the red pigmented zone. We have isolated and characterized its red pigment, which proved to be the iron chelating pulcherrimin. Its production was possible even in the presence of 0.05 mg/ml copper sulphate, which is widely used in organic vineyards because of its antimicrobial properties. Production and localisation of the pulcherrimin strongly depended on composition of the media and other culture factors. Glucose, galactose, disaccharides and the presence of p...

The researchers that were done regarded the evolution of phenolic compounds at superiors red wines from Burgund variety, obtained in Minis and Murfatlar vineyards during five years period of time. In the purpose to obtain extractive wines and intensely coloured, external enzymatic mixtures was experienced during the maceration and fermentative processes, and for some technological phases improvement for primary wine making process. During the hole period of study physical and chemical analyses were done to superior red wines obtained from Burgund variety, beginning with the end of alcoholic fermentation, malolactic fermentation, at 3 months, 6 months, 9 months, 12 months, 18 months and after that yearly, as for the wines obtained with external enzymatic mixtures used during the maceration-fermentation process, as for the one which weren't treated with enzymes. Through external enzymatic mixtures utilisation the antocians and total poliphenols to superior red wines obtained is the biggest contribution which contribute the their quality improvement, especially to colours and extractive character.

The Ultramarine Blue pigment (UB) is a sodium polysulfide aluminosilicate that reacts with the tricalcium aluminate (C3A) of the white Portland cement in presence of water, generating considerable amounts of early ettringite and a lesser proportion of tobermorite. This early ...

Disponible en: http://www.redalyc.org/src/inicio/ArtPdfRed.jsp?iCve=49620414005 ... Redalyc Sistema de Información Científica Red de Revistas Científicas de América Latina, el Caribe, España y Portugal ... GIRALDO, CAROLINA; MENDOZA, OSCAR; TOBÓN, JORGE IVÁN; ...

Tujuan dari penelitian ini adalah untuk mengetahui jenis-jenis pigmen yang ada pada cabai katokon dan melihat stabilitas pigmennya terhadap paparan suhu panas. Metode yang digunakan adalah ekstraksi pigmen dengan menggunakan aseton. Analisis pigmen dilakukan dengan spektofotometer UV-Vis dan KLT. Uji termostabilitas dilakukan dengan penambahan minyak kelapa atau VCO (Virgin Coconut Oil) dan dididihkan selama 5, 10, 15, dan 20 menit lalu di analisis dengan spektrofotometer UV-Vis. Terdapat 8 fraksi warna dari hasil KLT yaitu; biru, ungu, hijau, merah muda, merah, kuning, kuning tua, dan merah tua. Total karotenoid sebesar 0.93 mg/100 g mg/100 ml. Terjadi penurunan karotenoid pada pemanasan; 0,113164 mg/100ml (5 menit) 0,150986 mg/100 ml (10 menit), 0,099259 mg/100ml (15 menit), dan 0,024046 mg/100 ml (20 menit). 8 fraksi warna yang merupakan warna dari antosianin, klorofil, dan karotenoid menunjukan karakteristik senyawa yang ada di dalam pigmen berdasar berat molekulnya, dan sifat polaritasnya. Penurunan konsentrasi pigmen karotenoid disebabkan karena pemaparan panas menyebabkan pigmen kehilangan perlindungan dari membrannya, sehingga oksidasi dapat terjadi dengan mudah, terutama pada kondisi temperatur tinggi, yang mengakibatkan warna pigmen memudar.

Color is very important in the food industry. The need for food coloring requires manufacturers to use synthetic dyes that have the potential to cause poisoning and cancer. One source of natural dyes comes from bacteria that are symbiotic with coral reefs. The purpose of this study is to isolate and characterize the bacterial pigment that has symbiosis with Montipora sp. The research method consisted of bacterial isolation and identification, pigment identification with UV-Vis spectrofotometer (200 – 800 nm) and TLC. The results of isilation and identification showed that Rhodococcus sp is dominant bacterial which is produces of carotenoiids for self defense from UV rays. The pigment found in Rhodococcus sp has the potential as a natural pigment for food coloring. Keywords: carotenoids, Montipora, pigment, Rhodococcus sp. ABSTRAK Warna sangat penting dalam industri pangan. Kebutuhan pewarna makanan menuntut produsen memakai bahan pewarna sintetik yang berpotensi menyebabkan keracuna...

Considering the worldwide demand for colorants of natural origin, the utilization of ascomycete fungi as a prolific pigment producer unfolds a novel way to obtain these pigments for various applications, including food, cosmetic, and medical use. The presence of very few natural red pigment alternatives in the market also attracts research and industry priorities to unearth novel and sustainable red pigment producers. The present work is an attempt to identify a novel source of red color obtained from endophytic fungi isolated from terrestrial and marine habitats. Based upon the fungal capacity for pigment production, seven isolates of endophytic fungi were recognized as prospective pigment producers. Out of all, fungal isolate CPE04 was selected based upon its capacity to produce profuse extracellular red pigment. The isolate was identified as Talaromyces assiutensis, employing morphological features and phylogenetic characterization by internal transcribed spacer (ITS) sequences. ...

Background and Objective: Pigment production by microorganisms is important due to more rapid growth, higher efficiency, easier extraction, and antimicrobial effects compared to other methods. The aim of the present study is to isolate and identify antibiotic pigment-producing actinomycetes from the soil of the Persian Gulf and to evaluate the antibiotic activity of their pigments in the second half of 2014. Given that pathogenic bacteria increasingly become more resistant to common antibiotics, there is a need for new antibiotics. Methods: A total of 80 soil samples were collected from different areas and after preparing different dilutions (10-1-10-7), each sample was cultured on nutrient agar medium, specific Starch Casein Agar (SCA), and the International Streptomyces Project 2 (ISP2) media. Then, the actinomycete colonies were selected based on pigment production; pigments were extracted using sediment extraction with ethyl acetate; and the antibacterial property of their pigments were evaluated. The structure of colored extract compounds was identified by Thin layer chromatography (TLC). Molecular identification of the microorganisms was performed by 16S rRNA PCR. Result: The highest antibiotic effect of the pigments was observed in pathogenic bacterium S. aureus and Bacillus cereus, respectively. The lowest antimicrobial activity of the pigments was observed in Escherichia coli bacterium. All the studied fungi were resistant to the studied pigments. Conclusion: Since natural pigments at an appropriate dose are healthier than the chemical ones, using them is beneficial in various industries, such as antibiotics production. Also, by determining the structure of pigments and eliminating their toxic groups, they can be used in different industries.

The heterotrich ciliate Blepharisma japonicum produces red pigment blepharismins, which function as self-defense toxin against predators and as a photoreceptor for step-up photonegativity. The dibenzoperylenequinone moiety of blepharismins was shown to be biosynthesized via the polyketide pathway. In this paper, the starter units of the biosynthetic pathway of blepharismins were determined to be isovaleryl-CoA and butyryl-CoA by HPLC, LC/ESI-MS, and 1 H and 2 H NMR analyses of the pigments obtained from feeding experiment of L-leucine or sodium butyrate in excess and deuterium-labeled L-leucine.

Ultramarine blue are a family of mineral pigments that are commonly dispersed in construction materials (concrete, paints, and polymers) to obtain colored materials. Two different methods for encapsulating phase change materials (PCM) in pigments have been studied to obtain PCM/pigment composites with thermal storage capacity: capillary and vacuum impregnation methods. The aim is to obtain a pigment providing thermal storage capacity to construction materials (apart from color) by an easily scalable process. The optimized vacuum impregnation process provides an hexadecane/pigment composite having a latent heat of fusion of 44 J/g (around a 20%wt. hexadecane adsorbed in the pigment) while the optimized capillary impregnation process allows the fabrication of a pigment with a latent heat of fusion of 41 J/g (around a 18%wt. hexadecane). Durability of both materials has been tested by the rmodiffrac to metric measurements indicating in both cases, slow reductions of the area intensity of the XRD signals (up to 10% and 15% after 100 cycles). The long term degradation behavior at room temperature was tested by DSC showing a reduction of a 3% of the thermal storage capability after 1000h.Considering the degradation and scalability issues, capillary impregnation seems to be the most suitable process for the mass production of pigments having high thermal storage capacity.

A standard ultramarine pigment was used to produce phase change material composites. These type of pigments are conventionally used in construction sector once have been dispersed in different building components (paint, concrete, plastic). The main advantage of the use of n-hexadecane/pigment composite is that processes for building components manufacturing as the thermal storage capability is provided by the modified pigment. Vacuum impregnation method was employed optimizing the process variables to maximize the latent heat of the hexadecane/pigment composite. In addition to the process optimization, the stability of the composite having the maximum latent heat was investigated. The hexadecane/pigment composite providing the highest latent heat has a 20%wt. hexadecane adsorbed in the pigment. Durability of the material was tested by thermodiffractometic measurements showing a reduction of the area intensity up to 6.5% after the 100 cycles.

A six parent modified half diallel of blackcurrants was planted in a randomised complete block design at Irwell, Canterbury, New Zealand. Variance components, heritability and breeding values were estimated for nine antioxidant traits from processed whole blackcurrant fruit harvested in 2004. Additive genetic effects were the largest with relatively small dominance and experimental design effects. Phenotypic and genetic correlations were moderately high (r p > 0.53, r g > 0.46) between all traits apart from correlations with relative antioxidant activity and bioavailability ratios and the correlation between delphinidin rutinoside and cyanidin-glucoside. Narrow-sense heritability estimates were moderate to high (0.46-0.80) except for the relative antioxidant activity and bioavailability ratios (0.28), indicating that phenotypic selection of parents may be successful. Implications are discussed for breeding blackcurrants with increased antioxidant levels.

Our ability to see in bright light depends critically on the rapid rate at which cone photoreceptors detect and adapt to changes in illumination. This is achieved, in part, by their rapid response termination. In this study, we investigate the hypothesis that this rapid termination of the response in red cones is dependent on interactions between the 9-methyl group of retinal and red cone opsin, which are required for timely metarhodopsin (Meta) II decay. We used single-cell electrical recordings of fl ash responses to assess the kinetics of response termination and to calculate guanylyl cyclase (GC) rates in salamander red cones containing native visual pigment as well as visual pigment regenerated with 11-cis 9-demethyl retinal, an analogue of retinal in which the 9-methyl group is missing. After exposure to bright light that photoactivated more than ‫%2.0ف‬ of the pigment, red cones containing the analogue pigment had a slower recovery of both fl ash response amplitudes and GC rates (up to 10 times slower at high bleaches) than red cones containing 11-cis retinal. This fi nding is consistent with previously published biochemical data demonstrating that red cone opsin regenerated in vitro with 11-cis 9-demethyl retinal exhibited prolonged activation as a result of slowed Meta II decay. Our results suggest that two different mechanisms regulate the recovery of responsiveness in red cones after exposure to light. We propose a model in which the response recovery in red cones can be regulated (particularly at high light intensities) by the Meta II decay rate if that rate has been inhibited. In red cones, the interaction of the 9-methyl group of retinal with opsin promotes effi cient Meta II decay and, thus, the rapid rate of recovery.

Photoactivation of rhodopsin initiates both excitation and adaptation in vertebrate rod photoreceptors. Bleaching of rhodopsin to free opsin and all-trans-retinal in isolated rods produces a stable desensitization (bleaching adaptation) that is much larger than expected from pigment depletion alone. In our experiments, a 93% bleach produced a 500-fold increase in the light intensity required for saturation of the light response. This component of adaptation was 32-fold larger than the 16-fold increase expected from pigment depletion alone. 11-cis-Retinal, when delivered to isolated rods from liposomes, combines with free opsin to form a bleachable photopigment that fully restores sensitivity. 11-cis-Locked analogues of retinal combine with opsin to form unbleachable pigments in isolated bleached rods from the tiger salamander. They restore sensitivity to a substantial (16to 25-fold) but incomplete extent. The analogues apparently relieve a stable component of adaptation when they interact with opsin. Because these analogues do not detectably excite rods, the structural requirements of both retinal and opsin for the relief of adaptation are different from those of excitation. The biochemical basis of light adaptation resulting from pigment bleaching and the minimum structural requirements of retinal for its relief remain to be determined.

A remarkable feature of our visual system is the ability to resolve changes in light intensity that span more than 12 orders of magnitude. The upper end of this range is mediated by cone photoreceptors, which can report fast changes in ambient illumination and come in several types that are sensitive to different parts of the wavelength spectrum. A key requirement for cones to encode this wide range of light intensities is their ability to adapt sensitivity based both on the background light level (light adaptation) and on the extent of bleaching of their visual pigment (bleaching adaptation). Both light adaptation and bleaching adaptation allow the cones to reduce their sensitivity as the background light intensity increases, the goal of which is to prevent response saturation and extend the operating range of the cell (for review see Fain et al.

The RPE65 protein of the retinal pigment epithelium (RPE) enables the conversion of retinyl esters to the visual pigment chromophore 11-cis retinal. Fresh 11-cis retinal is generated from retinyl esters following photoisomerization of the visual pigment chromophore to all-trans during light detection. Large amounts of esters accumulate in Rpe65 −/− mice, indicating their continuous formation when 11-cis retinal generation is blocked. We hypothesized that absence of light, by limiting the conversion of esters to 11-cis retinal, would also result in the build-up of retinyl esters in the RPE of wild type mice. We used HPLC to quantify ester levels in organic extracts of the RPE from wild type and Rpe65 −/− mice. Retinyl ester levels in Sv/129 wild type mice that were dark adapted for various intervals over a 4-week period were similar to those in mice raised in cyclic light. In C57BL/6 mice however, which contain less Rpe65 protein, dark adaptation was accompanied by an increase in ester levels compared to cyclic light controls. Retinyl ester levels were much higher in Rpe65 −/− mice compared to wild type and kept increasing with age. The results suggest that the RPE65 role in retinyl ester homeostasis extends beyond enabling the formation of 11-cis retinal.

New visual pigments were formed with 4-hydroxy retinals in isolated vertebrate rod photoreceptors by exposing bleached rods from the tiger salamander, Ambystoma tigrinum, to lipid vesicles containing the analogues. Formation of physiologically active pigment was demonstrated by the restoration of sensitivity and by a shift of-50 nm in the peak of both the visual pigment absorptance spectrum and rod spectral sensitivity spectrum from-520 to-470 nm for 1 1-cis 4-hydroxy retinal. Membrane current recordings from the inner segments of isolated rods revealed excess fluctuations in membrane current after formation of the new pigment in bleached cells or after exposure of unbleached cells to flashes in the presence of the analogue. The excess current fluctuations are similar to the fluctuations elicited by steady light producing a few discrete responses per second, a rate-100 times greater than the normal rate of spontaneous events in darkness. These results suggest that analogues of retinal can produce alterations in the frequency of production of discrete responses in darkness in rod photoreceptors.

Biobased pigments are environmentally friendly alternatives to synthetic variants with an increased market demand. Production of pigments via fermentation is a promising process, yet optimization of the production yield and rate is crucial. Herein, we evaluated the potential of Penicillium purpurogenum to produce biobased pigments. Optimum sugar concentration was 30 g/L and optimum C:N ratio was 36:1 resulting in the production of 4.1–4.5 AU (namely Pigment Complex A). Supplementation with ammonium nitrate resulted in the production of 4.1–4.9 AU (namely Pigment Complex B). Pigments showed excellent pH stability. The major biopigments in Pigment Complex A were N-threonyl-rubropunctamin or the acid form of PP-R (red pigment), N-GABA-PP-V (violet pigment), PP-O (orange pigment) and monascorubrin. In Pigment Complex B, a novel biopigment annotated as N-GLA-PP-V was identified. Its basic structure contains a polyketide azaphilone with the same carboxyl-monascorubramine base structure as...

Betalains display color from yellow-orange to red-purple within few species of Chenopodiaceae family. The specific structures and consistencies upon pH are the most applicative features of betalains. Only several betalains are heavily understood and available as references due to their instabilities and rare appearances in only several edible crops. That requires robust techniques for large scale production and investigation of new betalainic sources. Countercurrent chromatography and centrifugal partition chromatography are preparative purification techniques based on continuous liquid-liquid extraction and have been applied on natural pigments such as anthocyanins and betalains. This work added to a few studies on betalains from some highly pigmented cultivars as Opuntia, Atriplex and Hylocereus; which results confirmed the feasibility of preparative isolation of pigments using CCC. The application of ion pair CCC on Opuntia pigments showed comparable distribution values between a...