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Natural Pigment (natural + pigment)
Selected AbstractsThe Effect of Preparation Procedures on the Morphology of Melanin from the Ink Sac of Sepia officinalisPIGMENT CELL & MELANOMA RESEARCH, Issue 1 2003Yan Liu The structure of melanin extracted from the ink sac of the cuttlefish Sepia officinalis was examined for different methods of isolation and purification of the pigment. Scanning electron microscopy (SEM) images of Sepia eumelanin prepared by different procedures establish that multi-,m-sized aggregates reported by previous workers are generated by their sample preparation, and that the dominant constituents of Sepia melanin are ,150 nm spherical granules. Brunauer-Emmett-Teller (BET) measurements reveal that Sepia eumelanin from Sigma (prepared by spray drying the pigment) has a surface area of 14.3 m2/g. Pigment extracted directly from the fresh ink sac and then freeze-dried has a surface area of 21.5 m2/g, while CO2 -supercritically dried has a surface area of 37.5 m2/g. This is consistent with SEM images showing that the process of freeze-drying produces aggregates, but to a lesser extent than spray drying. Supercritical drying of the sample produces suspensions of the individual ,150 nm granule, which is more reflective of the natural pigment. Brunauer-Emmett-Teller surface area analysis and Barrett-Joyner-Halenda (BJH) pore volume analysis indicate that the surface of the granules is not smooth and the interior of the granules is not porous, but rather the aggregates of granules are porous. Ultra-high resolution SEM and atomic force microscopy (AFM) images show the granules are easily deformed and are comprised of smaller constituents. De-aggregation of the granules by sonication and ultra-filtration reveal a range of structures depending on the pore size of the membrane used. The implications of these results on quantifying photochemical properties and kinetic reaction rate constants of melanin are discussed. [source] Characteristics of paint systems prepared from dammar with the addition of natural pigmentPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3 2009N. M. Omar Abstract Adhesion and electrochemical properties of paint system prepared from dammar binder or binder from Dipterocarpus grandifolius with the addition of natural pigment have been investigated. In this work, carotenoid pigment obtained from Capsicum annum (dried chili pepper) was added into the mixture of dammar resin and acrylic polyol resin to form the organic paint system. Five different paint systems were formulated on the basis of various concentrations of dammar resin, and their viscosities were measured by using Brookefield Viscometer. The paint systems were proofed on Aluminum steel Q-panels as a substrate. The cured paint systems were then evaluated by using the crosshatch adhesion method to test their adhesion properties according to ASTM D3359 standards. The corrosion potential property of paint was characterized by using electrochemical impedance spectroscopy (EIS) while the coated substrate was exposed to 3% NaCl for 30 days. Comparative results have been presented in terms of number of damage grids for the crosshatch test in each sample at different viscosity conditions and also regarding the ability of the coated sample to resist the corrosion potential. The result shows that the paint system with a composition of 35% dammar (CD35%) possessed the best adhesion performance compared to other CD paint compositions. Furthermore, CD35% also had higher corrosion resistance after 30 days of exposure in the 3% NaCl solution. The decrease in coating resistance values is associated with the electrolyte penetration into the coating system. The results showed that the developed organic paint system prepared from dammar improved the adhesion and electrochemical properties of a paint system. Addition of natural pigment to the formulation may enhance the attractiveness and vibrancy of the color. Copyright © 2009 John Wiley & Sons, Ltd. [source] ISOLIQUIRITIGENIN INHIBITS THE PROLIFERATION AND INDUCES THE APOPTOSIS OF HUMAN NON-SMALL CELL LUNG CANCER A549 CELLSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2004Ya-Ling Hsu SUMMARY 1.,Isoliquiritigenin (ISL) is a natural pigment with the simple chalcone structure 4,2,,4,-trihydroxychalcone. In the present study, we report, for the first time, ISL-induced inhibition of the proliferation of the human non-small cell lung cancer A549 cell line. 2.,The results showed that ISL not only inhibited A549 cell proliferation, but also induced apoptosis and blocked cell cycle progression in the G1 phase. An ELISA assay demonstrated that ISL significantly increased the expression of p53 and p21/WAF1 protein, which caused cell cycle arrest. 3.,An enhancement in Fas and its two ligands, namely membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), may be responsible for the apoptotic effect induced by ISL. 4.,Taken together, the results indicate that the p53 and Fas/FasL apoptotic system may participate in the antiproliferative activity of ISL in A549 cells. [source] Antiadult T-cell leukemia effects of brown algae fucoxanthin and its deacetylated product, fucoxanthinolINTERNATIONAL JOURNAL OF CANCER, Issue 11 2008Chie Ishikawa Abstract Adult T-cell leukemia (ATL) is a fatal malignancy of T lymphocytes caused by human T-cell leukemia virus type 1 (HTLV-1) infection and remains incurable. Carotenoids are a family of natural pigments and have several biological functions. Among carotenoids, fucoxanthin is known to have antitumorigenic activity, but the precise mechanism of action is not elucidated. We evaluated the anti-ATL effects of fucoxanthin and its metabolite, fucoxanthinol. Both carotenoids inhibited cell viability of HTLV-1-infected T-cell lines and ATL cells, and fucoxanthinol was approximately twice more potent than fucoxanthin. In contrast, other carotenoids, ,-carotene and astaxanthin, had mild inhibitory effects on HTLV-1-infected T-cell lines. Importantly, uninfected cell lines and normal peripheral blood mononuclear cells were resistant to fucoxanthin and fucoxanthinol. Both carotenoids induced cell cycle arrest during G1 phase by reducing the expression of cyclin D1, cyclin D2, CDK4 and CDK6, and inducing the expression of GADD45,, and induced apoptosis by reducing the expression of Bcl-2, XIAP, cIAP2 and survivin. The induced apoptosis was associated with activation of caspase-3, -8 and -9. Fucoxanthin and fucoxanthinol also suppressed I,B, phosphorylation and JunD expression, resulting in inactivation of nuclear factor-,B and activator protein-1. Mice with severe combined immunodeficiency harboring tumors induced by inoculation of HTLV-1-infected T cells responded to treatment with fucoxanthinol with suppression of tumor growth, showed extensive tissue distribution of fucoxanthinol, and the presence of therapeutically effective serum concentrations of fucoxanthinol. Our preclinical data suggest that fucoxanthin and fucoxanthinol could be potentially useful therapeutic agents for patients with ATL. © 2008 Wiley-Liss, Inc. [source] Instrumental measurement of orange juice colour: a reviewJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 6 2005Antonio Jesús Meléndez-Martínez Abstract Colour of orange juice is provided by carotenoids, which belong to one of the main classes of natural pigments, although the colour of particular orange varieties, blood oranges, is mainly due to anthocyanins. Colour of food influences consumers' preferences. For orange juices, some studies have revealed that the colour of citrus beverages in general is related to the consumer's perception of the quality of these products. The USA attaches great importance to the objective evaluation of orange juice colour, to the point that this attribute is evaluated for the commercial classification of the product on the basis of its quality. Apart from the importance of orange juice colour in relation to the quality of the product, it is important to accurately measure this parameter since it has been demonstrated that colour measurements can be used to estimate the carotenoid content rapidly for quality control purposes. Owing to this factors, several techniques and instruments have been developed over the years. This review assesses these methods and the results gained from them. Copyright © 2005 Society of Chemical Industry [source] Colour and colour vision of creatures great and smallCOLORATION TECHNOLOGY, Issue 2 2006Tim L Dawson Today the mechanisms of human colour vision are well understood because of the detailed communication feedback possible in experimental studies. The situation with other species in the animal kingdom is less easy to investigate and understand. In the present review, examples of the colour and colour vision of various animal species are described, selected mainly because they are particularly interesting and indeed colourful. The chemical structures and the relationships of the natural pigments involved also receive attention. Despite many decades of vision research, many aspects of colour vision remain unclear. Nevertheless increasing knowledge in all these fields may someday help to elucidate the neurological pathways underlying other animals' colour vision to the same extent as is at present known for human vision. [source] | |||||||||||||