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Fujiwara M, Kono N, Hirayama A, Malay AD, Nakamura H, Ohtoshi R, Numata K, Tomita M, Arakawa K. Xanthurenic Acid Is the Main Pigment of Trichonephila clavata Gold Dragline Silk. Biomolecules 2021; 11:563. [PMID: 33921320 PMCID: PMC8070366 DOI: 10.3390/biom11040563] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 11/16/2022] Open
Abstract
Spider silk is a natural fiber with remarkable strength, toughness, and elasticity that is attracting attention as a biomaterial of the future. Golden orb-weaving spiders (Trichonephila clavata) construct large, strong webs using golden threads. To characterize the pigment of golden T. clavata dragline silk, we used liquid chromatography and mass spectrometric analysis. We found that the major pigment in the golden dragline silk of T. clavata was xanthurenic acid. To investigate the possible function of the pigment, we tested the effect of xanthurenic acid on bacterial growth using gram-negative Escherichia coli and gram-positive Bacillus subtilis. We found that xanthurenic acid had a slight antibacterial effect. Furthermore, to investigate the UV tolerance of the T. clavata threads bleached of their golden color, we conducted tensile deformation tests and scanning electron microscope observations. However, in these experiments, no significant effect was observed. We therefore speculate that golden orb-weaving spiders use the pigment for other purposes, such as to attract their prey in the sunlight.
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Affiliation(s)
- Masayuki Fujiwara
- Institute for Advanced Biosciences, Keio University, Nihonkoku 403-1, Daihoji, Tsuruoka, Yamagata 997-0013, Japan; (M.F.); (N.K.); (A.H.); (M.T.)
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan
| | - Nobuaki Kono
- Institute for Advanced Biosciences, Keio University, Nihonkoku 403-1, Daihoji, Tsuruoka, Yamagata 997-0013, Japan; (M.F.); (N.K.); (A.H.); (M.T.)
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan
| | - Akiyoshi Hirayama
- Institute for Advanced Biosciences, Keio University, Nihonkoku 403-1, Daihoji, Tsuruoka, Yamagata 997-0013, Japan; (M.F.); (N.K.); (A.H.); (M.T.)
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan
| | - Ali D. Malay
- Biomacromolecules Research Team: RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; (A.D.M.); (K.N.)
| | - Hiroyuki Nakamura
- Spiber Inc.: Mizukami 234-1, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan; (H.N.); (R.O.)
| | - Rintaro Ohtoshi
- Spiber Inc.: Mizukami 234-1, Kakuganji, Tsuruoka, Yamagata 997-0052, Japan; (H.N.); (R.O.)
| | - Keiji Numata
- Biomacromolecules Research Team: RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan; (A.D.M.); (K.N.)
| | - Masaru Tomita
- Institute for Advanced Biosciences, Keio University, Nihonkoku 403-1, Daihoji, Tsuruoka, Yamagata 997-0013, Japan; (M.F.); (N.K.); (A.H.); (M.T.)
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan
- Faculty of Environment and Information Studies, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan
| | - Kazuharu Arakawa
- Institute for Advanced Biosciences, Keio University, Nihonkoku 403-1, Daihoji, Tsuruoka, Yamagata 997-0013, Japan; (M.F.); (N.K.); (A.H.); (M.T.)
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan
- Faculty of Environment and Information Studies, Keio University, Endo 5322, Fujisawa, Kanagawa 252-0882, Japan
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Torres S, González-Ramírez M, Gavilán J, Paz C, Palfner G, Arnold N, Fuentealba J, Becerra J, Pérez C, Cabrera-Pardo JR. Exposure to UV-B Radiation Leads to Increased Deposition of Cell Wall-Associated Xerocomic Acid in Cultures of Serpula himantioides. Appl Environ Microbiol 2019; 85:e00870-19. [PMID: 31285193 PMCID: PMC6715839 DOI: 10.1128/aem.00870-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 06/27/2019] [Indexed: 11/20/2022] Open
Abstract
Many fungi are thought to have developed morphological and physiological adaptations to cope with exposure to UV-B radiation, but in most species, such responses and their protective effects have not been explored. Here, we study the adaptive response to UV-B radiation in the widespread, saprotrophic fungus Serpula himantioides, frequently found colonizing coniferous wood in nature. We report the morphological and chemical responses of S. himantioides to controlled intensities of UV-B radiation, under in vitro culture conditions. Ultraviolet radiation induced a decrease in the growth rate of S. himantioides but did not cause gross morphological changes. Instead, we observed accumulation of pigments near the cell wall with increasing intensities of UV-B radiation. Nuclear magnetic resonance (NMR) and high-performance liquid chromatography-mass spectrometry (HPLC-MS) analyses revealed that xerocomic acid was the main pigment present, both before and after UV-B exposure, increasing from 7 mg/liter to 15 mg/liter after exposure. We show that xerocomic acid is a photoprotective metabolite with strong antioxidant abilities, as evidenced by DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt], and oxygen radical absorbance capacity (ORAC) assays. Finally, we assessed the capacity of xerocomic acid as a photoprotective agent on HEK293 cells and observed better photoprotective properties than those of β-carotene. Xerocomic acid is therefore a promising natural product for development as a UV-protective ingredient in cosmetic and pharmaceutical products.IMPORTANCE Our study shows the morphological and chemical responses of S. himantioides to controlled doses of UV-B radiation under in vitro culture conditions. We found that increased biosynthesis of xerocomic acid was the main strategy adopted by S. himantioides against UV-B radiation. Xerocomic acid showed strong antioxidant and photoprotective abilities, which has not previously been reported. Our results indicate that upon UV-B exposure, S. himantioides decreases its hyphal growth rate and uses this energy instead to increase the biosynthesis of xerocomic acid, which is allocated near the cell wall. This metabolic switch likely allows xerocomic acid to efficiently defend S. himantioides from UV radiation through its antioxidant and photoprotective properties. The findings further suggest that xerocomic acid is a promising candidate for development as a cosmetic ingredient to protect against UV radiation and should therefore be investigated in depth in the near future both in vitro and in vivo.
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Affiliation(s)
- Solange Torres
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Mariela González-Ramírez
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Javiera Gavilán
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Cristian Paz
- Departamento de Ciencias Básicas, Universidad de La Frontera, Temuco, Chile
| | - Goetz Palfner
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Norbert Arnold
- Department of Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Halle, Germany
| | - Jorge Fuentealba
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - José Becerra
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Claudia Pérez
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Jaime R Cabrera-Pardo
- Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
- Departamento de Química, Facultad de Ciencias, Universidad del Bio-Bio, Concepción, Chile
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Abstract
The influence of six different light regimes throughout the photosynthetically active radiation range (from 400 to 700 nm, including blue, green, yellow, red-orange, red, and white) at two intensities (100 and 300 µmol photons m-2 s-1) on pigmentation was assessed for the centric marine diatom Coscinodiscus granii for the first time. Chlorophyll (Chl) a and fucoxanthin were the dominating pigments in all treatments. The cellular concentrations of light harvesting pigment (Chl a, Chl c1 + c2, and fucoxanthin) were higher at 100 than at 300 µmol photons m-2 s-1 at all wavelengths, with the largest increases at red and blue light. The normalized concentrations of photoprotective pigments (violaxanthin, zeaxanthin, diadinoxanthin, and diatoxanthin) were higher at high light intensity than in cells grown at low light intensity. An increase in β-carotene in low light conditions is expected as the increased Chl a was related to increased photosynthetic subunits which require β-carotene (bound to photosystem core). At 300 µmol photons m-2 s-1, yellow light resulted in significantly lower concentration of most of the detected pigments than the other wavelengths. At 100 µmol photons m-2 s-1, W and B light led to statistically lower and higher concentration of most of the detected pigments than the other wavelengths, respectively.
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Affiliation(s)
- Yanyan Su
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark.
- Carlsberg Research Laboratory, Bjerregaardsvej 5, 2500, Valby, Denmark.
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García-Portela M, Riobó P, Reguera B, Garrido JL, Blanco J, Rodríguez F. Comparative ecophysiology of Dinophysis acuminata and D. acuta (DINOPHYCEAE, DINOPHYSIALES): effect of light intensity and quality on growth, cellular toxin content, and photosynthesis. J Phycol 2018; 54:899-917. [PMID: 30298602 DOI: 10.1111/jpy.12794] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/24/2018] [Indexed: 06/08/2023]
Abstract
Dinoflagellates of the genus Dinophysis are the most persistent producers of lipophilic shellfish toxins in Western Europe. Their mixotrophic nutrition requires a food chain of cryptophytes and plastid-bearing ciliates for sustained growth and photosynthesis. In this study, cultures of D. acuminata and D. acuta, their ciliate prey Mesodinium rubrum and the cryptophyte, Teleaulax amphioxeia, were subject to three experimental settings to study their physiological response to different combinations of light intensity and quality. Growth rates, pigment analyses (HPLC), photosynthetic parameters (PAM-fluorometry), and cellular toxin content (LC-MS) were determined. Specific differences in photosynthetic parameters were observed in Dinophysis exposed to different photon fluxes (10-650 μmol photons · m-2 · s-1 ), light quality (white, blue and green), and shifts in light regime. Dinophysis acuta was more susceptible to photodamage under high light intensities (370-650 μmol photons · m-2 · s-1 ) than D. acuminata but survived better with low light (10 μmol photons · m-2 · s-1 ) and to a prolonged period (28 d) of darkness. Mesodinium rubrum and T. amphioxeia showed their maximal growth rate and yield under white and high light whereas Dinophysis seemed better adapted to grow under green and blue light. Toxin analyses in Dinophysis showed maximal toxin per cell under high light after prey depletion at the late exponential-plateau phase. Changes observed in photosynthetic light curves of D. acuminata cultures after shifting light conditions from low intensity-blue light to high intensity-white light seemed compatible with photoacclimation in this species. Results obtained here are discussed in relation to different spatiotemporal distributions observed in field populations of D. acuminata and D. acuta in northwestern Iberia.
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Affiliation(s)
- María García-Portela
- Spanish Institute of Oceanography (IEO), Oceanographic Centre of Vigo, 36390 Vigo, Pontevedra, Spain
| | - Pilar Riobó
- Marine Research Institute (IIM-CSIC), 36208 Vigo, Pontevedra, Spain
| | - Beatriz Reguera
- Spanish Institute of Oceanography (IEO), Oceanographic Centre of Vigo, 36390 Vigo, Pontevedra, Spain
| | | | - Juan Blanco
- Marine Research Centre (CIMA), 36620 Vilanova de Arousa, Pontevedra, Spain
| | - Francisco Rodríguez
- Spanish Institute of Oceanography (IEO), Oceanographic Centre of Vigo, 36390 Vigo, Pontevedra, Spain
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Waterman MJ, Bramley-Alves J, Miller RE, Keller PA, Robinson SA. Photoprotection enhanced by red cell wall pigments in three East Antarctic mosses. Biol Res 2018; 51:49. [PMID: 30463628 PMCID: PMC6247747 DOI: 10.1186/s40659-018-0196-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 11/03/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Antarctic bryophytes (mosses and liverworts) are resilient to physiologically extreme environmental conditions including elevated levels of ultraviolet (UV) radiation due to depletion of stratospheric ozone. Many Antarctic bryophytes synthesise UV-B-absorbing compounds (UVAC) that are localised in their cells and cell walls, a location that is rarely investigated for UVAC in plants. This study compares the concentrations and localisation of intracellular and cell wall UVAC in Antarctic Ceratodon purpureus, Bryum pseudotriquetrum and Schistidium antarctici from the Windmill Islands, East Antarctica. RESULTS Multiple stresses, including desiccation and naturally high UV and visible light, seemed to enhance the incorporation of total UVAC including red pigments in the cell walls of all three Antarctic species analysed. The red growth form of C. purpureus had significantly higher levels of cell wall bound and lower intracellular UVAC concentrations than its nearby green form. Microscopic and spectroscopic analyses showed that the red colouration in this species was associated with the cell wall and that these red cell walls contained less pectin and phenolic esters than the green form. All three moss species showed a natural increase in cell wall UVAC content during the growing season and a decline in these compounds in new tissue grown under less stressful conditions in the laboratory. CONCLUSIONS UVAC and red pigments are tightly bound to the cell wall and likely have a long-term protective role in Antarctic bryophytes. Although the identity of these red pigments remains unknown, our study demonstrates the importance of investigating cell wall UVAC in plants and contributes to our current understanding of UV-protective strategies employed by particular Antarctic bryophytes. Studies such as these provide clues to how these plants survive in such extreme habitats and are helpful in predicting future survival of the species studied.
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Affiliation(s)
- Melinda J. Waterman
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 Australia
- Department of Chemistry and Biology, University of Santiago, Alameda, 3363 Santiago, Chile
| | - Jessica Bramley-Alves
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 Australia
| | - Rebecca E. Miller
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 Australia
- School of Ecosystem and Forest Sciences, University of Melbourne, Richmond, VIC 3121 Australia
| | - Paul A. Keller
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Sharon A. Robinson
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522 Australia
- Department of Chemistry and Biology, University of Santiago, Alameda, 3363 Santiago, Chile
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Arjmandi M, Otón M, Artés F, Artés-Hernández F, Gómez PA, Aguayo E. Microwave flow and conventional heating effects on the physicochemical properties, bioactive compounds and enzymatic activity of tomato puree. J Sci Food Agric 2017; 97:984-990. [PMID: 27246969 DOI: 10.1002/jsfa.7824] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 05/16/2016] [Accepted: 05/25/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND Thermal processing causes a number of undesirable changes in physicochemical and bioactive properties of tomato products. Microwave (MW) technology is an emergent thermal industrial process that offers a rapid and uniform heating, high energy efficiency and high overall quality of the final product. The main quality changes of tomato puree after pasteurization at 96 ± 2 °C for 35 s, provided by a semi-industrial continuous microwave oven (MWP) under different doses (low power/long time to high power/short time) or by conventional method (CP) were studied. RESULTS All heat treatments reduced colour quality, total antioxidant capacity and vitamin C, with a greater reduction in CP than in MWP. On the other hand, use of an MWP, in particular high power/short time (1900 W/180 s, 2700 W/160 s and 3150 W/150 s) enhanced the viscosity and lycopene extraction and decreased the enzyme residual activity better than with CP samples. For tomato puree, polygalacturonase was the more thermo-resistant enzyme, and could be used as an indicator of pasteurization efficiency. CONCLUSION MWP was an excellent pasteurization technique that provided tomato puree with improved nutritional quality, reducing process times compared to the standard pasteurization process. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Mitra Arjmandi
- College of Agriculture and Natural Resources, University of Tehran, Iran
- Postharvest and Refrigeration Group, Universidad Politécnica de Cartagena (UPCT), 30203 Cartagena, Murcia, Spain
- Institute of Plant Biotechnology, UPCT, 30202 Cartagena, Murcia, Spain
| | - Mariano Otón
- Institute of Plant Biotechnology, UPCT, 30202 Cartagena, Murcia, Spain
| | - Francisco Artés
- Postharvest and Refrigeration Group, Universidad Politécnica de Cartagena (UPCT), 30203 Cartagena, Murcia, Spain
- Institute of Plant Biotechnology, UPCT, 30202 Cartagena, Murcia, Spain
| | - Francisco Artés-Hernández
- Postharvest and Refrigeration Group, Universidad Politécnica de Cartagena (UPCT), 30203 Cartagena, Murcia, Spain
- Institute of Plant Biotechnology, UPCT, 30202 Cartagena, Murcia, Spain
| | - Perla A Gómez
- Institute of Plant Biotechnology, UPCT, 30202 Cartagena, Murcia, Spain
| | - Encarna Aguayo
- Postharvest and Refrigeration Group, Universidad Politécnica de Cartagena (UPCT), 30203 Cartagena, Murcia, Spain
- Institute of Plant Biotechnology, UPCT, 30202 Cartagena, Murcia, Spain
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Thang K, Au K, Rakovski C, Prakash A. Effect of phytosanitary irradiation and methyl bromide fumigation on the physical, sensory, and microbiological quality of blueberries and sweet cherries. J Sci Food Agric 2016; 96:4382-4389. [PMID: 26805024 DOI: 10.1002/jsfa.7648] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 01/19/2016] [Accepted: 01/20/2016] [Indexed: 06/05/2023]
Abstract
BACKGROUND The objective of this study was to determine whether irradiation could serve as a suitable phytosanitary treatment alternative to methyl bromide (MB) fumigation for blueberries and sweet cherry and also to determine the effect of phytosanitary irradiation treatment on survival of Salmonella spp. and Listeria monocytogenes on these fruit. 'Bluecrop' blueberries (Vaccinium corymbosum) and 'Sweetheart' cherries (Prunus avium) were irradiated at 0.4 kGy or fumigated with methyl bromide and evaluated for quality attributes during storage. RESULTS Irradiation caused an immediate decrease in firmness of both fruit without further significant change during storage. Fumigated fruit, in contrast, softened by 11-14% during storage. Irradiation did not adversely affect blueberry and cherry shelf-life. MB fumigation did not impact blueberry and cherry quality attributes initially; however, fumigated fruit exhibited greater damage and mold growth than the control and irradiated samples during storage. Irradiation at 400 Gy resulted in a ∼1 log CFU g(-1) reduction in Salmonella spp. and Listeria monocytogenes counts, indicating that this treatment cannot significantly enhance safety. CONCLUSION This study indicates that irradiation at a target dose of 0.4 kGy for phytosanitary treatment does not negatively impact blueberry and cherry quality and can serve as an alternative to methyl bromide fumigation. © 2016 Society of Chemical Industry.
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Affiliation(s)
- Karen Thang
- Food Science Program, Chapman University, One University Drive, Orange, CA 92866, USA
| | - Kimberlee Au
- Food Science Program, Chapman University, One University Drive, Orange, CA 92866, USA
| | - Cyril Rakovski
- Faculty of Mathematics, Chapman University, One University Drive, Orange, CA 92866, USA
| | - Anuradha Prakash
- Food Science Program, Chapman University, One University Drive, Orange, CA 92866, USA
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Vargas MA, Geish MA, Maciel FE, Cruz BP, Filgueira DDMVB, Ferreira GDJ, Nery LEM, Allodi S. Influence of the dark/light rhythm on the effects of UV radiation in the eyestalk of the crab Neohelice granulata. Comp Biochem Physiol C Toxicol Pharmacol 2010; 151:343-50. [PMID: 20060494 DOI: 10.1016/j.cbpc.2009.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 12/20/2009] [Accepted: 12/22/2009] [Indexed: 01/06/2023]
Abstract
Crustaceans are interesting models to study the effects of ultraviolet (UV) radiation, and many species may be used as biomarkers for aquatic contamination of UV radiation reaching the surface of the Earth. Here, we investigated cell damage in the visual system of crabs Neohelice granulata that were acclimated to either 12L:12D, constant light, or constant dark, and were exposed to UVA or UVB at 12:00h (noon). The production of reactive oxygen species (ROS), antioxidant capacity against peroxyl radicals (ACAP), lipid peroxidation (LPO) damage, catalase activity, and pigment dispersion in the eye were evaluated. No significant differences from the three groups of controls (animals acclimated to 12L:12D, or in constant light, or not exposed to UV radiation) were observed in animals acclimated to 12L:12D, however, crabs acclimated to constant light and exposed to UV radiation for 30min showed a significant increase in ROS concentration, catalase activity, and LPO damage, but a decrease in ACAP compared with the controls. Crabs acclimated to constant darkness and exposed to UV for 30min showed a significantly increased ROS concentration and LPO damage, but the ACAP and catalase activity did not differ from the controls (animals kept in the dark while the experimental group was being exposed to UV radiation). Pigment dispersion in the pigment cells of eyes of animals acclimated to constant light was also observed. The results indicate that UVA and UVB alter specific oxidative parameters; however, the cell damage is more evident in animals deviated from the normal dark/light rhythm.
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Affiliation(s)
- Marcelo Alves Vargas
- Programa de Pós-Graduação em Ciências Morfológicas, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro-UFRJ, 21941-590, Rio de Janeiro, RJ, Brazil
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Mapari SAS, Meyer AS, Thrane U. Photostability of natural orange-red and yellow fungal pigments in liquid food model systems. J Agric Food Chem 2009; 57:6253-61. [PMID: 19534525 DOI: 10.1021/jf900113q] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The variation in the photostability among the currently authorized natural pigments limits their application span to a certain type of food system, and more robust alternatives are being sought after to overcome this problem. In the present study, the photostability of an orange-red and a yellow fungal pigment extract produced by ascomycetous fungi belonging to the genera Penicillium and Epicoccum , respectively, were studied in a soft drink model medium and in citrate buffer at low and neutral pH. The quantitative and qualitative color change pattern of the fungal pigment extracts indicated an enhanced photostability of fungal pigment extracts compared to the commercially available natural colorants Monascus Red and turmeric used as controls. Yellow components of the orange-red fungal pigment extract were more photostable than the red components. Chemistry of the photodegradation of the orange-red pigment extract was studied by high-performance liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS), and a light-induced formation of a structural analogue of sequoiamonascin C, a Monascus -like polyketide pigment discovered in the extract of Penicillium aculeatum IBT 14263 on yeast extract sucrose (YES) medium, was confirmed in the soft drink medium at pH 7.
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Affiliation(s)
- Sameer A S Mapari
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, DK-2800 Kgs Lyngby, Denmark
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Leutenegger A, D'Angelo C, Matz MV, Denzel A, Oswald F, Salih A, Nienhaus GU, Wiedenmann J. It's cheap to be colorful. Anthozoans show a slow turnover of GFP-like proteins. FEBS J 2007; 274:2496-505. [PMID: 17419724 DOI: 10.1111/j.1742-4658.2007.05785.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Pigments homologous to the green fluorescent protein (GFP) contribute up to approximately 14% of the soluble protein content of many anthozoans. Maintenance of such high tissue levels poses a severe energetic penalty to the animals if protein turnover is fast. To address this as yet unexplored issue, we established that the irreversible green-to-red conversion of the GFP-like pigments from the reef corals Montastrea cavernosa (mcavRFP) and Lobophyllia hemprichii (EosFP) is driven by violet-blue radiation in vivo and in situ. In the absence of photoconverting light, we subsequently tracked degradation of the red-converted forms of the two proteins in coral tissue using in vivo spectroscopy and immunochemical detection of the post-translational peptide backbone modification. The pigments displayed surprisingly slow decay rates, characterized by half-lives of approximately 20 days. The slow turnover of GFP-like proteins implies that the associated energetic costs for being colorful are comparatively low. Moreover, high in vivo stability makes GFP-like proteins suitable for functions requiring high pigment concentrations, such as photoprotection.
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Kaffarnik F, Seidlitz HK, Obermaier J, Sandermann H, Heller W. Environmental and developmental effects on the biosynthesis of UV-B screening pigments in Scots pine (Pinus sylvestris L.) needles. Plant Cell Environ 2006; 29:1484-91. [PMID: 16898012 DOI: 10.1111/j.1365-3040.2006.01518.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The major UV-B screening pigments of the epidermal layer of Scots pine (Pinus sylvestris) needles are flavonol 3-o-glycosides (F3Gs) esterified with hydroxycinnamic acids at positions 3" and 6". Acylation is the last step in biosynthesis and is catalysed by position-specific hydroxycinnamoyl transferases (3" and 6"HCT). The UV-B dependence of these enzyme activities was studied in primary needles of Scots pine seedlings grown under different UV-B conditions in environmentally controlled sun simulators. 6"HCT activity was induced upon UV-B irradiation while 3"HCT activity was not induced but showed high constitutive values. To investigate the biosynthesis of diacylated F3Gs during needle development under natural conditions, the HCT activities and metabolite contents were analysed in needles of field-grown mature pine trees. Accumulation of diacylated compounds as well as of 6"HCT activity occurred transiently in the first year of needle development only. In contrast, 3"HCT activity exhibited broad maxima in two consecutive years during needle growth. The data suggest that acylated F3Gs are first formed as soluble compounds which are then translocated into the cell wall to be bound by their hydroxycinnamoyl residues.
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Affiliation(s)
- Florian Kaffarnik
- Institute of Biochemical Plant Pathology, GSF-Research Center for Environment and Health, Neuherberg, Germany
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Abstract
A simple approach for spectral reconstruction of spectral reflection by whole apple fruit is described. It is shown that an approximation to the reflection spectrum can be obtained by making a simple assumption on the shape of the featureless scattering and using known spectral properties of the following pigment pools: (i) thylakoid-bound chlorophylls and carotenoids, (ii) cuticular/vacuolar phenolics, (iii) extrathylakoid chloroplasts/chromoplasts carotenoids, and (iv) vacuolar anthocyanins. The in vivo spectra of individual pigment pools estimated in bleaching experiments or as a difference between fruit with high and low pigment content are presented. In most cases simulations based on a linear combination of spectra proved to be effective, but fruit with high chlorophyll content necessitated the use of a non-linear model. The models succeeded in simulating reflection spectra of fruit widely differing in pigment content and composition with relative error lower than +/-4% over the visible range. The estimated relative contributions by the pigment pools into total reflection were found to be sensitive indicators of apple fruit ripening and could be useful in evaluating the light screening efficacy by flavonoids and carotenoids under stress conditions.
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Affiliation(s)
- Mark N Merzlyak
- Department of Physiology of Microorganisms, Faculty of Biology, Moscow State University, 119992, GSP-2 Moscow, Russia.
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Bhandari R, Sharma PK. High-light–induced Changes on Photosynthesis, Pigments, Sugars, Lipids and Antioxidant Enzymes in Freshwater (Nostoc spongiaeforme) and Marine (Phormidium corium) Cyanobacteria. Photochem Photobiol 2006; 82:702-10. [PMID: 16464127 DOI: 10.1562/2005-09-20-ra-690] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We studied the effects of high-light exposure (500 micromol m(-2) s(-1) of photosynthetic active radiation) on the cyanobacteria Nostoc spongiaeforme Agardh, a fresh-water alga, and Phormidium corium Agardh (Gomont), a marine alga, with respect to photosynthesis, pigments, sugar content, lipid peroxidation, fatty acids composition, antioxidant enzymes activity and DNA. It was seen that the ratio of variable fluorescence (Fv) to maximum fluorescence (Fm), which is indicative of photosynthetic efficiency, decreased because of the light treatment. The damage to photosynthesis occurred in the antenna system and the photosynthetic II reaction center. Photobleaching of photosynthetic pigments was also observed. High-light treatment also resulted in decreased sugar content, which was probably due to the effect on photosynthesis. Peroxidation of membrane lipids, indicating oxidative damage to lipids and a high level of unsaturation in the cell membrane, was also observed. The activity of antioxidant enzyme superoxide dismutase and ascorbate peroxidase was increased, probably as a result of oxidative damage observed in the form of lipid peroxidation. Quantitative decreases in phospholipid and glycolipid levels were also observed. The level of unsaturated fatty acids in total lipids and glycolipids remained unchanged in both species; however, the level of saturated fatty acids decreased, which slightly changed the ratio in favor of unsaturated fatty acids. Degradation of DNA was also observed in both species. There was a transient plateau 2-4 h after exposure to high-light treatment in the Fv/Fm ratio and in levels of phycobilisome pigments, sugars and antioxidant enzymes after an initial decrease 1 h after the treatment. These findings may indicate a period of partial adaptation to high light that is due to the efficiency of protective processes operational in the two species, which subsequently failed after a longer exposure duration of 4-6 h.
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Abstract
The way flowers appear to insects is crucial for pollination. Here we describe an internal light-filtering effect in the flowers of Mirabilis jalapa, in which the visible fluorescence emitted by one pigment, a yellow betaxanthin, is absorbed by another, a violet betacyanin, to create a contrasting fluorescent pattern on the flower's petals. This finding opens up new possibilities for pollinator perception as fluorescence has not previously been considered as a potential signal in flowers.
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Affiliation(s)
- Fernando Gandía-Herrero
- Departamento de Bioquímica y Biología Molecular A, Unidad Docente de Biología, Facultad de Veterinaria, Universidad de Murcia, 30100 Espinardo, Murcia, Spain
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17
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Zadok U, Klare JP, Engelhard M, Sheves M. The hydroxylamine reaction of sensory rhodopsin II: light-induced conformational alterations with C13=C14 nonisomerizable pigment. Biophys J 2005; 89:2610-7. [PMID: 16085771 PMCID: PMC1366761 DOI: 10.1529/biophysj.105.065631] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sensory rhodopsin II, a repellent phototaxis receptor from Natronomonas (Natronobacterium) pharaonis (NpSRII), forms a complex with its cognate transducer (NpHtrII). In micelles the two proteins form a 1:1 heterodimer, whereas in membranes they assemble to a 2:2 complex. Similarly to other retinal proteins, sensory rhodopsin II undergoes a bleaching reaction with hydroxylamine in the dark which is markedly catalyzed by light. The reaction involves cleavage of the protonated Schiff base bond which covalently connects the retinal chromophore to the protein. The light acceleration reflects protein conformation alterations, at least in the retinal binding site, and thus allows for detection of these changes in various conditions. In this work we have followed the hydroxylamine reaction at different temperatures with and without the cognate transducer. We have found that light irradiation reduces the activation energy of the hydroxylamine reaction as well as the frequency factor. A similar effect was found previously for bacteriorhodopsin. The interaction with the transducer altered the light effect both in detergent and membranes. The transducer interaction decreased the apparent light effect on the energy of activation and the frequency factor in detergent but increased it in membranes. In addition, we have employed an artificial pigment derived from a retinal analog in which the critical C13=C14 double bond is locked by a rigid ring structure preventing its isomerization. We have observed light enhancement of the reaction rate and reduction of the energy of activation as well as the frequency factor, despite the fact that this pigment does not experience C13=C14 double bond isomerization. It is suggested that retinal excited state polarization caused by light absorption of the "locked" pigment polarizes the protein and triggers relatively long-lived protein conformational alterations.
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Affiliation(s)
- U Zadok
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot, Israel
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Kiat-amnuay S, Johnston DA, Powers JM, Jacob RF. Color Stability of Dry Earth Pigmented Maxillofacial Silicone A-2186 Subjected to Microwave Energy Exposure. J Prosthodont 2005; 14:91-6. [PMID: 16011619 DOI: 10.1111/j.1532-849x.2005.00017.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE The purpose of this study was to measure spectrophotometrically the color stability of pigmented A-2186 silicone maxillofacial elastomer with 10% by volume of titanium white dry earth opacifier before and after exposure to microwave energy over a simulated 1.5-year period of microwave sterilization. MATERIALS AND METHODS A-2186 silicone elastomer opacified with titanium white dry earth pigment, pigmented with 5 cosmetic dry earth pigment colors [no pigment (control) group (Pc), red (Pr), yellow ochre (Py), burnt sienna (Po), and a mixture of Pr + Py + Po color group (P3)], was used in this study. Each of the 5 experimental groups consisted of 5 specimens. All specimens were placed in a 250 ml glass beaker filled with 150 ml of water (replenished for each microwave exposure). An exposure of 6 minutes was used 18 times (simulating 1.5 years of microwave sterilization with one 6 minute exposure monthly). Reflectance values were measured by spectrophotometer. Three- and two-way analyses of variance with repeated measures were performed for the color difference (DeltaE*) with the factors of group/color/months, and group/months, respectively. Means were compared by Tukey Honest Significant Difference (HSD) multiple range test calculated at the 0.05 level of significance using SPSS. RESULTS The trained human eye can detect color changes (DeltaE*) greater than 1.0. Most DeltaE* values of the red pigment group at all intervals and the mixed pigment group at 15- and 18- month intervals increased significantly greater than 1.0 (p < 0.001) compared with the control group. Yellow and burnt sienna groups remained the most color stable over time with DeltaE* values below 0.35. CONCLUSIONS Lack of color stability of red dry earth pigmented A-2186 silicone maxillofacial elastomers was clinically significant after 12-month exposure to microwave energy as compared with yellow, burnt sienna, and opacified A-2186 dry earth pigments.
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Affiliation(s)
- Sudarat Kiat-amnuay
- Department of Restorative Dentistry and Biomaterials, The University of Texas Dental Branch at Houston, Houston, TX 77030, USA.
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Gajdek P, Bober B, Mej E, Bialczyk J. Sensitised decomposition of microcystin-LR using UV radiation. J Photochem Photobiol B 2004; 76:103-6. [PMID: 15488721 DOI: 10.1016/j.jphotobiol.2004.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/09/2004] [Revised: 06/08/2004] [Accepted: 06/10/2004] [Indexed: 05/01/2023]
Abstract
UV radiation was applied to degrade cyanobacterial hepatotoxin, microcystin-LR in the presence of phycocyanin as a model natural sensitiser. The concentrations of both the toxin and the pigment used in the experiments were higher by several orders of magnitude than found in the environment. The photoreaction parameters were optimised. The process was found to be of limited use for water treatment due to its low efficacy. Additionally, pronounced UV-induced bleaching of the pigment significantly reducing the photoreaction rates of the toxin was observed for the highest UV radiation intensities applied.
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Affiliation(s)
- Piotr Gajdek
- Department of Plant Physiology and Development, Faculty of Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
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Gouveia GR, Marques DS, Cruz BP, Geracitano LA, Nery LEM, Trindade GS. Antioxidant defenses and DNA damage induced by UV-A and UV-B radiation in the crab Chasmagnathus granulata (Decapoda, Brachyura). Photochem Photobiol 2004; 81:398-403. [PMID: 15493956 DOI: 10.1562/2004-05-26-ra-179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The photoprotector role of pigment dispersion in the melanophores of the crab, Chasmagnathus granulata, against DNA and oxidative damages caused by UV-A and UV-B was investigated. Intact and eyestalkless crabs were used. In eyestalkless crabs, the dorsal epidermis of the cephalothorax (dispersed melanophores) and the epidermis of pereiopods (aggregated melanophores) were analyzed. Intact crabs showed only dispersed melanophores in the two epidermis. Antioxidant enzymes activity and lipoperoxidation content were analyzed after UV-A (2.5 J/cm2) or UV-B (8.6 J/cm2) irradiation. DNA damage was analyzed by single cell electrophoresis (comet) assay, after exposure to UV-B (8.6 J/cm2). UV-A radiation increased the glutatione-S-transferase activity in the pereiopods epidermis of eyestalkless crabs (P<0.05). UV-B radiation induced DNA damage in the dorsal epidermis of eyestalkless crabs (P<0.05). In pereiopod epidermis of eyestalkless crabs, there was no significant difference between control and UV-B-exposed crabs. In the pereiopods epidermis of eyestalkless, the control group showed higher scores of DNA damage and approximately 50% of cellular viability. Because in eyestalkless and irradiated crabs the cellular viability was approximately 5%, it was not possible to observe nuclei for determination of DNA damage. The findings show that melanophores can play a role in the defense against harmful effects of a momentary exposure to UV radiation.
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Affiliation(s)
- Glauce R Gouveia
- Fundação Universidade Federal do Rio Grande-FURG, Departamento de Ciências Fisiológicas, Programa de Pós-graduação em Ciências Fisiológicas-Fisiologia Animal Comparada, Rio Grande, Rio Grande do Sul, Brazil
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21
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Tran NH, Scarbecz M, Gary JJ. In vitro evaluation of color change in maxillofacial elastomer through the use of an ultraviolet light absorber and a hindered amine light stabilizer. J Prosthet Dent 2004; 91:483-90. [PMID: 15153857 DOI: 10.1016/s002239130400112x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
STATEMENT OF PROBLEM External prostheses composed of silicone elastomers exhibit an unwanted color change over time. PURPOSE This study evaluated color stability when an ultraviolet light absorber and hindered amine light stabilizer were mixed in the maxillofacial elastomer containing either organic or inorganic pigments. MATERIAL AND METHODS The materials used were an RTV silicone elastomer, 1 natural inorganic dry-earth pigment (burnt sienna) and 2 synthesized organic pigments (hansa yellow and alizarin red), ultraviolet light absorber (UVA) and hindered amine light stabilizer (HALS). Specimens (n=160) were fabricated in a custom mold and randomly assigned and exposed to weathering sites in Miami and Phoenix for approximately 3 months. Eight test groups (2 of each 4 material types with or without additives) of 10 specimens each were assigned to each site. L*, a*, b* readings were obtained before and after weathering from a spectrocolorimeter. Nonpigmented elastomers served as the control. Three-factor ANOVA was conducted to examine interaction effects between weathering sites, specimen type, and the presence of additive (alpha=.05). Overall color change (Delta E) and change in color coordinates (Delta L*, Delta a*, Delta b*) of specimen groups with and without additive were analyzed with independent sample t tests. RESULTS In specimen groups with the additives (UVA and HALS), color change decreased significantly (P<.05) in burnt sienna and hansa yellow in Phoenix and in the control and hansa yellow in Miami. Additives did not affect color change in the alizarin red group. CONCLUSION UVA and HALS were shown to be effective in retarding color change in some circumstances.
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Affiliation(s)
- Ngoc H Tran
- Department of Restorative Dentistry, Division of Proshodontics, College of Dentistry, University of Tennessee, Memphis, 38163, USA
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22
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Krasnovskiĭ AA. [Photodynamic activity and singlet oxygen]. Biofizika 2004; 49:305-21. [PMID: 15129630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The primary mechanisms for the photodynamic action of pigments and dyes, the principles of their division into mechanisms of type I and type II, and the role of these processes in biological systems are reviewed. Singlet oxygen is considered to be an indicator of the mechanisms of photodynamic reactions. The methods of its detection are described, which are based on the use of chemical traps, measurements of infrared phosphorescance at 1270 nm, and the registration singlet oxygen-sensitized delayed fluorescence caused by the summation of the energy of two singlet oxygen molecules by one dye molecule.
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Affiliation(s)
- A A Krasnovskiĭ
- Bakh Institute of Biochemistry, Russian Academy of Sciences, Lomonosov Moscow State University, Moscow, Russia
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Nakajima N, Sugimoto M, Yokoi H, Tsuji H, Ishihara K. Comparison of acylated plant pigments: light-resistance and radical-scavenging ability. Biosci Biotechnol Biochem 2003; 67:1828-31. [PMID: 12951524 DOI: 10.1271/bbb.67.1828] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The acylated plant pigments synthesized by lipase-catalyzed transesterification with aromatic acids were compared in respect of their light-resistance and radical-scavenging ability. With both the flavonols and anthocyanins, their acylated derivatives were more stable against illumination with fluorescent light than their non-acylated glucosides. Their radical-scavenging ability partially decreased or was retained by acylation to the glucoside molecules.
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Affiliation(s)
- Nobuyoshi Nakajima
- Department of Nutritional Science, Okayama Prefectural University, Soja, Okayama 719-1197, Japan.
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Curtin C, Zhang W, Franco C. Manipulating anthocyanin composition in Vitis vinifera suspension cultures by elicitation with jasmonic acid and light irradiation. Biotechnol Lett 2003; 25:1131-5. [PMID: 12966999 DOI: 10.1023/a:1024556825544] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Jasmonic acid altered the accumulation of major anthocyanins in Vitis vinifera cell culture. Peonidin 3-glucoside content at day three was increased from 0.3 to 1.7 mg g(-1) dry cell wt while other major anthocyanins were increased by smaller increments. By day 14, the content of methylated and acylated anthocyanins (peonidin 3-p-coumaroylglucoside and malvidin 3-p-coumaroylglucoside) was 6.3 mg g(-1) DCW, in response to treatment with jasmonic acid, and comprising approximately 45% (w/w) of total anthocyanins. In comparison, the untreated control culture contained 1.2 mg g(-1) DCW which made up approximately 32% (w/w) of total anthocyanins. Light further enhanced anthocyanin accumulation induced by jasmonic acid elicitation. The content of peonidin 3-glucoside at day 3 was 6.6 mg g(-1) DCW, 22-fold higher than control cultures while the content in response to light irradiation alone was 0.6 mg g(-1) DCW. When a highly pigmented cell line was elicited with jasmonic acid total anthocyanins increased from 9.2 to 20.7 mg g(-1) DCW, but there was no change in the anthocyanin composition.
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Affiliation(s)
- Chris Curtin
- Cooperative Research Centre for Bioproducts and Department of Medical Biotechnology, School of Medicine, Flinders University, Bedford Park, SA 5042, Adelaide, Australia
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Han T, Sinha RP, Häder DP. Effects of intense PAR and UV radiation on photosynthesis, growth and pigmentation in the rice-field cyanobacterium Anabaena sp. Photochem Photobiol Sci 2003; 2:649-54. [PMID: 12859148 DOI: 10.1039/b212652d] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The relative importance of photosynthetically active radiation and UV on photoinhibition has been studied in the cyanobacterium Anabaena sp. by measuring the effective quantum yield, growth, pigmentation and fluorescence emission.
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Affiliation(s)
- Taejun Han
- Institut für Botanik und Pharmazeutische Biologie, Friedrich-Alexander-Universität, Erlangen, Germany
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26
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Voeste D, Levine LH, Levine HG, Blum V. Pigment composition and concentrations within the plant (Ceratophyllum demersum L.) component of the STS-89 C.E.B.A.S. Mini-Module spaceflight experiment. Adv Space Res 2003; 31:211-214. [PMID: 12580173 DOI: 10.1016/s0273-1177(02)00740-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Closed Equilibrated Biological Aquatic System (C.E.B.A.S.) Mini-Module, a Space Shuttle middeck locker payload which supports a variety of aquatic inhabitants (fish, snails, plants and bacteria) in an enclosed 8.6 L chamber, was tested for its biological stability in microgravity. The aquatic plant, Ceratophyllum demersum L., was critical for the vitality and functioning of this artificial mini-ecosystem. Its photosynthetic pigment concentrations were of interest due to their light harvesting and protective functions. "Post-flight" chlorophyll and carotenoid concentrations within Ceratophyllum apical segments were directly related to the quantities of light received in the experiments, with microgravity exposure (STS-89) failing to account for any significant deviation from ground control studies.
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Affiliation(s)
- D Voeste
- Faculty of Biology, C.E.B.A.S. Center of Excellence, Ruhr-University Bochum, Bochum, FRG
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Ho DDM, London R, Zimmerman GB, Young DA. Laser-tattoo removal--a study of the mechanism and the optimal treatment strategy via computer simulations. Lasers Surg Med 2002; 30:389-97. [PMID: 12116333 DOI: 10.1002/lsm.10065] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND AND OBJECTIVE The physical mechanisms for laser-tattoo interactions and the tattoo particle breakup process are not well understood. This study investigates whether the mechanism of the breakup process can be identified via computer simulations and proposes a treatment strategy that can potentially minimize the collateral damage to the surrounding tissues. Note that the "removal" of tattoo particles is defined here as breakup of particles into smaller ones with sizes approaching or smaller than the visible wavelength of light so that they become less visible. STUDY DESIGN/MATERIALS AND METHODS The radiation-hydrodynamics code LATIS is used for the modeling. We first identify the magnitude of the tensile stress generated inside graphite tattoo particles as functions of laser pulse length and particle size. We then calculate the relationship between the surface laser fluence (defined as the time integrated energy flux) and the tensile strength of the tattoo particle at a given depth. RESULTS If the laser pulse length is sufficiently short, strong acoustic waves with tensile strengths exceeding the fracture thresholds for graphite are generated. The strength of the wave decreases with particle size and increases as the laser pulse length decreases. Simulation results are in general agreement with clinical studies. Although temperatures of the tattoo particles never reach the melting point, a cavitation bubble around the particle can be formed. The steam generated can get into the cracked particles and induce steam-carbon reactions. Laser energy density decreases rapidly with the skin depth. Therefore, the minimum surface laser fluence, for a given pulse length, required for breaking up tattoo particles at a given skin depth, increases with particle depth. CONCLUSIONS Computer simulations confirm that the breakup of tattoo particles is photoacoustic. For the same amount of laser energy, a shorter pulse is more efficient. The optimal pulse length is approximately 10-100 picosecond to minimize the laser fluence and the collateral damage. It is more difficult to break up the smallest tattoo particles that have diameters smaller than 10 nm; however, smaller particles are less important because they are less visible. Tissue surrounding the tattoo particles can be damaged by cavitation bubbles. These bubbles could be the cause of the empty vacuoles in the ash-white lesions throughout the dermis seen after treatment. Steam-carbon reactions can be induced. Particles then become grossly transparent because of this reaction. Different laser intensity should be used for pigments at different depths in order to minimize the collateral damage to the dermis.
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Affiliation(s)
- Darwin D-M Ho
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
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Beevers H. Re: Feild TS, et al. Why leaves turn red in autumn. The role of anthocyanins in senescing leaves of red-osier dogwood. [2001] Plant Physiol 127:566-574. Plant Physiol 2002; 128:783. [PMID: 11915842 PMCID: PMC526252 DOI: 10.1104/pp.900027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Abstract
OBJECTIVE To emphasize the wisdom of small test areas when treating cosmetic tattoos and the need for multiple laser systems. METHODS A 48-year-old woman requested removal of permanent makeup (cosmetic tattoos) of her eyebrows and around her lips. Physical examination revealed a brown tattoo of both eyebrows and dark red lip liner around both lips. A test area was performed on the red tattoo of the lips. A frequency-doubled Nd:YAG laser (532 nm, 2.0 J/cm2, 2 mm spot size) was used for the lip area, while the same laser at 1064 nm, 3.9 J cm2, 2 mm spot size was utilized for the eyebrows. The lip area immediately turned black. The patient returned for follow-up 1 month later; the black ink on the lip was treated with the same laser at 1064 nm, 3 mm spot size, 4.2 J/cm2, with satisfactory resolution in two monthly treatments. Both brown eyebrow turned bright orange and were treated with 532 nm, 3 mm, 3.0 J/cm2. One month later the eyebrows were a mixture of yellow ink and dark green. The yellow area was treated with 532 nm, 3 mm, 2.3 J/cm2, while the dark green was treated with the 1064 nm, 3 mm spot size, 4.2 J/cm2. One month later little improvement was noted, so Q-switched ruby laser at 694 nm, 6 mm spot size, 16 J/cm2 was utilized. An additional four monthly treatments were given utilizing a combination of both ruby and 532 nm ND:YAG lasers for green and yellow pigment, respectively. RESULTS Significant but incomplete resolution of the tattoo ink was achieved. CONCLUSION Multiple laser systems are needed to remove cosmetic tattoos. Test areas must be done before treatment.
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Affiliation(s)
- Gloria Jimenez
- Department of Dermatology and Cutaneous Surgery, University of Miami School of Medicine, Miami, Florida 33136, USA
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Ortwerth BJ, Chemoganskiy V, Olesen PR. Studies on singlet oxygen formation and UVA light-mediated photobleaching of the yellow chromophores in human lenses. Exp Eye Res 2002; 74:217-29. [PMID: 11950232 DOI: 10.1006/exer.2001.1114] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The protein-bound chromophores, which increase with aging in the human lens, act as UVA sensitizers, producing almost exclusively singlet oxygen in vitro. Direct irradiation of whole, aged human lenses with high intensity UVA light (200 mW cm(-2) for 24 hr), however, failed to produce singlet oxygen damage, as evidenced by the lack of either His or Trp photodestruction. Total homogenates of human lenses prepared in a cuvette under air did show destruction of His and Trp residues by UVA light, but no destruction was seen when equivalent homogenates were prepared under argon. These data are consistent with the idea that the low oxygen levels in the lens prevent singlet oxygen damage in vivo.UVA irradiation of aged human lenses in culture caused an extensive photobleaching of the yellow chromophores. A time course indicated that the photobleaching increased with time, with significant color loss apparent after 6 hr. Homogenization of the irradiated and dark control lenses in 6 M guanidine-HCl, followed by determination of the difference spectrum, showed approximately 50% bleaching of compounds with a lambda(max) at 355 nm. Similarly, fluorophores with a lambda(max) for excitation of 355 nm and for emission of 420 nm were 50% destroyed by the UVA light. Similar results were obtained in vitro by the anaerobic irradiation of a sonication-solubilized WI fraction from type II brunescent cataracts and from aged human lenses. In this system, there was an initial bleaching of 15% after 30 min of irradiation, followed by a slow increase over the next 6 hr to a final bleaching of 30%. The addition of 1.0 m M ascorbic acid, but not 1.0 m M glutathione (GSH), increased the photobleaching to 60% under argon, and the loss of ascorbate could be detected under these anaerobic conditions. In the presence of air, UVA light produced no photobleaching, but rather caused a three-fold increase in absorbance at 345 nm, which was prevented by the inclusion of 1.0 m M ascorbic acid and almost 50% inhibited by 1.0 m M GSH. The data are consistent with the conversion of the triplet state of the sensitizers to anion and cation radicals in the absence of oxygen. Photobleaching may occur either by dismutation of the anion radical or by reduction of the anion radical by ascorbate via type I chemistry. UVA irradiation of an enriched fraction of sensitizers from a proteolytic digest from type II cataract lenses produced a 63% bleaching at 330 nm in the absence of oxygen, and the almost complete loss of the A(330) absorbing and 350/450 nm fluorescent peaks upon HPLC separation. This loss correlated with the loss of the ability of the irradiated fraction to produce singlet oxygen in vitro upon subsequent UVA irradiation.
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Affiliation(s)
- Beryl J Ortwerth
- Mason Eye Institute, University of Missouri, Columbia, MO 65212, U.S.A
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Abstract
STATEMENT OF PROBLEM Maxillofacial prostheses require frequent replacement because the elastomer and its color additives undergo changes. PURPOSE This study attempted to determine whether predictable color changes occur when 3 pigments are individually incorporated into a specific silicone elastomer. MATERIAL AND METHODS The materials included an RTV elastomer; 1 natural inorganic pigment, burnt sienna; and 2 synthetic organic pigments, Hansa yellow and alizarin red. Eight test groups of 10 polymerized specimens were established. Groups 1 and 2, acting as the control, involved only the elastomer. Groups 3 and 4 were composed of elastomer and burnt sienna. Groups 5 and 6 consisted of elastomer and Hansa yellow. Groups 7 and 8 comprised elastomer and alizarin red. Odd-numbered groups were assigned to a test site in Miami, Fla., whereas the even numbered groups went to Phoenix, Ariz. Specimens weathered in Miami and Phoenix received sunlight exposures of 1305.7 MJ/m2 and 1310.2 MJ/m2, respectively, over time. Before and after weathering, the L* a* b* color parameter (DeltaE*) of each specimen was determined spectrophotometrically. RESULTS Mean color changes that occurred in Arizona were larger than those produced in Florida. Specifically, these differences ranged from 0.4 (alizarin red groups) to 2.36 units for the 2 unpigmented control groups. Other differences showed significance for the unpigmented (P=.001), burnt sienna (P=.006), and Hansa yellow groups (P=.001). CONCLUSION Outdoor weathering tests in which documented ASTM methods were used provided a valid baseline for future research on color changes in maxillofacial prostheses.
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Affiliation(s)
- J J Gary
- College of Dentistry, University of Tennessee, Memphis, Tenn 38163, USA.
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Poutaraud A, Di Gregorio F, Tin VC, Girardin P. Effect of light on hypericins contents in fresh flowering top parts and in an extract of St. John's Wort (Hypericum perforatum). Planta Med 2001; 67:254-259. [PMID: 11345698 DOI: 10.1055/s-2001-12003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
St. John's Wort is a medicinal plant increasingly used for its antidepressive activity. Hypericins are considered as one of the compounds contributing to the activity of the extract. These naphthodianthrones exist in various forms in Hyperici herba. Protopseudohypericin and protohypericin (protopigments) are converted into pseudohypericin and hypericin (pigments) under the action of light. The aim of this work is to study the influence of light on the phototransformation of protopigments into pigments. Two experiments were carried out. The studies were performed on one hand, on plant material in order to know the proportion of these substances in various plant parts and the possibility of transforming the protopigments into pigments under the action of sunlight; on the other hand, in the extract to determine the optimal wavelength allowing this transformation. Three parts of the fresh plant (buds, flowers, leaves) were treated with sunlight on three levels of exposure. Liquid extracts were exposed to various types of light with wavelengths ranging between 480 and 660 nm by means of diodes. The flowering tops of St. John's Wort contain a share of approximately 30% hypericins in the form of protopseudohypericin and protohypericin: buds (48%), flowers (30%), leaves (17%). After an exposure of fresh buds to sunlight for 16 hours the share of protopigments was then 32%. In the extract, the transformation of the protopigments is total and requires less energy than in the plant material. The optimal wavelength for the transformation of the protopigments in the extract is around 515 nm (green), close to the optimum absorption level of protopigments.
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Affiliation(s)
- A Poutaraud
- National Institute of Agronomic Research, Colmar, France.
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Cseh Z, Rajagopal S, Tsonev T, Busheva M, Papp E, Garab G. Thermooptic effect in chloroplast thylakoid membranes. Thermal and light stability of pigment arrays with different levels of structural complexity. Biochemistry 2000; 39:15250-7. [PMID: 11106505 DOI: 10.1021/bi001600d] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In chloroplast thylakoid membranes, chiral macrodomains, i.e., large arrays of pigment molecules with long-range chiral order, have earlier been shown to undergo light-induced reversible and irreversible structural changes; such reorganizations did not affect the short-range, excitonic pigment-pigment interactions. These structural changes and similar changes in lamellar aggregates of the main chlorophyll a/b light-harvesting complexes exhibited a linear dependence on the intensity of light that was not utilized in photosynthesis. It has been hypothesized that the light-induced rearrangements are driven by a thermooptic effect, i.e., thermal fluctuations due to the dissipation of excess excitation energies [Barzda, V., et al. (1996) Biochemistry 35, 8981-8985]. To test this hypothesis, we have utilized circular dichroism (CD) spectroscopy to investigate the structural stability of the chiral macrodomains and the constituent bulk pigment-protein complexes of granal thylakoid membranes against heat and prolonged, intense illumination. (i) In intact thylakoid membranes, the chiral macrodomains displayed high stability below 40 degrees C, but they were gradually disassembled between 50 and 60 degrees C; the thermal stability of the chiral macrodomains could be decreased substantially by suspending the membranes in reaction media that were hypotonic or had low ionic strength. (ii) The chiral macrodomains were also susceptible to high light: prolonged illumination with intense white light (25 min, 2500 microE m(-)(2) s(-)(1), 25 degrees C) induced similar, irreversible disassembly to that observed at high temperatures; in different preparations, lower thermal stability was coupled to lower light stability. (iii) The light stability depended significantly on the temperature: between about 5 and 15 degrees C, the macrodomains in the intact thylakoids were virtually not susceptible to high light; in contrast, the same preillumination at 35-40 degrees C almost completely destroyed the chiral macrodomains. (iv) As testified by the excitonic CD bands, the molecular organization of the pigment-protein complexes in all samples exhibited very high thermal stability between about 15 and 65 degrees C, and virtually total immunity against intense illumination. These data are fully consistent with the hypothesis of a thermooptic effect, and are interpreted within the frame of a simple model.
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Affiliation(s)
- Z Cseh
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, H-6701 Szeged, Hungary
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Abstract
Photophysical properties of curcumin, 1,7-bis-(4-hydroxy-3-methoxy phenyl)-1,6-heptadiene-2,5-dione, a pigment found in the rhizomes of Curcuma longa (turmeric) have been studied in different kinds of organic solvent and also in Triton X-100 aqueous micellar media using time-resolved fluorescence and transient absorption techniques having pico and nanosecond time resolution, in addition to steady-state absorption and fluorescence spectroscopic techniques. Steady-state absorption and fluorescence characteristics of curcumin have been found to be sensitive to the solvent characteristics. Large change (delta mu = 6.1 Debye) in dipole moments due to photoexcitation to the excited singlet state (S1) indicates strong intramolecular charge transfer character of the latter. Curcumin is a weakly fluorescent molecule and the fluorescence decay properties in most of the solvents could be fitted well to a double-exponential decay function. The shorter component having lifetime in the range 50-350 ps and percent contribution of amplitude more than 90% in different solvents may be assigned to the enol form, whereas the longer component, having lifetime in the range 500-1180 ps with less than 10% contribution may be assigned to the di-keto form of curcumin. Our nuclear magnetic resonance study in CDCl3 and dimethyl sulfoxide-D6 also supports the fact that the enol form is present in the solution by more than about 95% in these solvents. Excited singlet (S1) and triplet (T1) absorption spectrum and decay kinetics have been characterized by pico and nanosecond laser flash photolysis. Quantum yield of the triplet is low (phi T < or = 0.12). Both the fluorescence and triplet quantum yields being low (phi f + phi T < 0.18), the photophysics of curcumin is dominated by the energy relaxation mechanism via the internal conversion process.
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Affiliation(s)
- S M Khopde
- Radiation Chemistry & Chemical Dynamics Division, Bhabha Atomic Research Center, Trombay, Mumbai, India
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35
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Abstract
Photophysical properties of curcumin, 1,7-bis-(4-hydroxy-3-methoxy phenyl)-1,6-heptadiene-2,5-dione, a pigment found in the rhizomes of Curcuma longa (turmeric) have been studied in different kinds of organic solvent and also in Triton X-100 aqueous micellar media using time-resolved fluorescence and transient absorption techniques having pico and nanosecond time resolution, in addition to steady-state absorption and fluorescence spectroscopic techniques. Steady-state absorption and fluorescence characteristics of curcumin have been found to be sensitive to the solvent characteristics. Large change (delta mu = 6.1 Debye) in dipole moments due to photoexcitation to the excited singlet state (S1) indicates strong intramolecular charge transfer character of the latter. Curcumin is a weakly fluorescent molecule and the fluorescence decay properties in most of the solvents could be fitted well to a double-exponential decay function. The shorter component having lifetime in the range 50-350 ps and percent contribution of amplitude more than 90% in different solvents may be assigned to the enol form, whereas the longer component, having lifetime in the range 500-1180 ps with less than 10% contribution may be assigned to the di-keto form of curcumin. Our nuclear magnetic resonance study in CDCl3 and dimethyl sulfoxide-D6 also supports the fact that the enol form is present in the solution by more than about 95% in these solvents. Excited singlet (S1) and triplet (T1) absorption spectrum and decay kinetics have been characterized by pico and nanosecond laser flash photolysis. Quantum yield of the triplet is low (phi T < or = 0.12). Both the fluorescence and triplet quantum yields being low (phi f + phi T < 0.18), the photophysics of curcumin is dominated by the energy relaxation mechanism via the internal conversion process.
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Affiliation(s)
- S M Khopde
- Radiation Chemistry & Chemical Dynamics Division, Bhabha Atomic Research Center, Trombay, Mumbai, India
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Eraso AJ, Albesa I. Elevation of alanine amino transferase and aspartate amino transferase produced by pyoverdin, a photolabile pigment of Pseudomonas fluorescens. Nat Toxins 2000; 6:61-5. [PMID: 9888631 DOI: 10.1002/(sici)1522-7189(199804)6:2<61::aid-nt5>3.0.co;2-#] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The effect of three forms pyoverdin on mouse liver was studied. Significant increases of alanine amino transferase (ALT) and aspartate amino transferase (AST) were obtained in mice after ingestion of water with forms A and C. The effect on liver was more evident with A than with C. Pyoverdin was purified by means of salt saturation, solvent extractions and ion-exchange chromatography. Fluorescent peaks obtained in the presence of light were different from those eluted under dark conditions. The relative amounts of pyoverdin A, B and C varied when dark purification procedure was employed. Form A decreased while C increased in the absence of light. Optimum conditions for C were in the dark without iron. When C was exposed to light, it changed to form A. Fast Atom Bombardment (FAB) mass spectrometry of pyoverdin form C gave a form at M+ = 1324 m.u., which is 9 m.u. less than pyoverdin purified in the presence of light. The results suggest that light can influence pyoverdin stability and toxicity.
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Affiliation(s)
- A J Eraso
- Departmento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Argentina
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Abstract
The effect of irradiation with electron beams on the microbiological quality and color properties of red paprika was examined. The irradiation doses ranged from 0 to 12.5 kGy. The counts performed were total mesophilic aerobic microorganisms, Enterobacteriaceae, coliforms, sulfite-reducing clostridia, molds, and yeasts. It was concluded that molds, yeasts, and sulfite-reducing clostridia were the most resistant species, although a 10-kGy dose of irradiation leads to optimum sanitation. Extractable color and apparent color were analyzed to appraise the incidence of the irradiation treatments in the color properties of red paprika. Extractable color was determined according to the American Spice Trade Association method, and apparent color was analyzed by reflectance using the CIELab color space. Data showed no significant differences between the color properties of irradiated and nonirradiated samples. Irradiation was a suitable procedure to minimize the bioburden of red paprika with small modifications of its color properties.
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Affiliation(s)
- J M Nieto-Sandoval
- Agricultural Chemistry Department, Faculty of Chemistry, University of Murcia, Spain
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38
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Abstract
Ultrafast dynamics of excitation transfer in the Photosystem I (PSI) core antenna from the cyanobacterium Synechocystis sp. PCC 6803 were detected at 77 K by using femtosecond transient absorption spectroscopy with selective excitation at 700, 695, and 710 nm. At low temperature, the efficiency of uphill energy transfer in the core antenna significantly decreases. As a result, the spectral profile of the PSI equilibrated antenna shifts to lower energies because of a change of chlorophyll (Chl) excited-state distribution. Observed on a 2-ns time scale, P700 photooxidation spectra are largely excitation wavelength independent. In the early time spectra, excitation of P700 induces transient photobleaching at 698 nm accompanied by a resonant photobleaching band at 683 nm decaying within 250-300 fs. Chemical oxidation of P700 does not affect the transient band at 683 nm. This band is also present in 200-fs spectra induced by selective excitation of Chls at 710 nm (red pigments C708), which suggests that this high-energy transition may reflect an excitonic interaction between pigments of the reaction center and closely located red pigments. Possible candidates for the interacting molecules in the 4-angstroms crystal structure of cyanobacterial PSI are discussed.
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Affiliation(s)
- A N Melkozernov
- Department of Chemistry and Biochemistry, Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe 85287-1604, USA
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van Thor JJ, Pierik AJ, Nugteren-Roodzant I, Xie A, Hellingwerf KJ. Characterization of the photoconversion of green fluorescent protein with FTIR spectroscopy. Biochemistry 1998; 37:16915-21. [PMID: 9836584 DOI: 10.1021/bi981170f] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Green Fluorescent Protein (GFP) is a bioluminescence protein from the jelly fish Aequorea victoria. It can exist in at least two spectroscopically distinct states: GFP395 and GFP480, with peak absorption at 395 and 480 nm, respectively, presumably resulting from a change in the protonation state of the phenolic ring of its chromophore. When GFP is formed upon heterologous expression in Escherichia coli, its chromophore is mainly present as the neutral species. UV and visible light convert (the chromophore of) GFP quantitatively from this neutral- into the anionic form. On the basis of X-ray diffraction, it was recently proposed (Brejc, K. et al. (1997) Proc. Natl. Acad. Sci. USA 94, 2306-2311; Palm, G. J. et al. (1997) Nat. Struct. Biol. 4, 361-365) that the carboxylic group of Glu222 functions as the proton acceptor of the chromophore of GFP, during the transition from the neutral form (i.e., GFP395) to the ionized form (GFP480). However, X-ray crystallography cannot detect protons directly. The results of FTIR difference spectroscopy, in contrast, are highly sensitive to changes in the protonation state between two conformations of a protein. Here we report the first characterization of GFP, and its photoconversion, with FTIR spectroscopy. Our results clearly show the change in protonation state of the chromophore upon photoconversion. However, they do not provide indications for a change of the protonation state of a glutamate side chain between the states GFP395 and GFP480, nor for an isomerization of the double bond that forms part of the link between the two rings of the chromophore.
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Affiliation(s)
- J J van Thor
- Laboratories for Microbiology and for Biochemistry, E.C. Slater Institute, University of Amsterdam, Amsterdam, The Netherlands
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Klevanik AV. The structural organization of the antenna chromophore protein complexes in membranes of the photosynthetic bacterium Rhodopseudomonas viridis. Membr Cell Biol 1998; 12:9-26. [PMID: 9829255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
A possible structural and functional organization of the antenna chromophore protein complexes (CPC) in the Rhodopseudomonas viridis membranes was considered in terms of structural models proposed by Zuber and Brunisholz (in Chlorophylls, ed. H. Scheer (Boca Raton: CRC Press, 1991):626-703). Analysis of the absorption spectra led to the conclusion that the number of the antenna bacteriochlorophyll molecules per reaction center (RC) is 30 +/- 3 both for chromophores and quantasomes of Rps. viridis. It implies a multicentral organization of the CPCs around RCs, when the CPC of cyclic structure is formed by (alpha beta gamma)4 polypeptides. A multicentral model predicts an almost linear dependence of the antenna fluorescence yield on the oxidized primary donor concentration if the antenna fluorescence lifetimes are assumed to be 60-70 and 110-120 ps for the open and closed RCs, respectively, which is in agreement with the experimental observations. We conclude that the Rps. viridis membrane domain consists of 4-6 RCs surrounded by 6-22 CPCs, and both of these protein subsystems are packed into a hexagonal array.
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Affiliation(s)
- A V Klevanik
- Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
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41
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Abstract
PURPOSE This literature review provides information about pigments used for facial and somatoprostheses. MATERIAL This information includes common pigment and index names and numbers, lightfastness categories, chemical type and class, and the chemical formulas of the common pigments used in maxillofacial prosthetics. CONCLUSION It can be deduced from this review that the pigments used with silicone elastomers do exhibit a color change, and that a color change is to be expected.
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Affiliation(s)
- J J Gary
- Department of Prosthodontics, University of Tennessee at Memphis, Tenn., USA
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Pant B, Kato Y, Kumagai T, Matsuoka T, Sugiyama M. Blepharismin produced by a protozoan Blepharisma functions as an antibiotic effective against methicillin-resistant Staphylococcus aureus. FEMS Microbiol Lett 1997; 155:67-71. [PMID: 9345766 DOI: 10.1111/j.1574-6968.1997.tb12687.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A ciliated protozoan, Blepharisma japonicum, produces a photosensitive red pigment, blepharismin (BLR). This study showed that the pigment inhibits the growth of Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA) resistant to arbekacin (ABK), which is the most effective aminoglycoside antibiotic against MRSA and used world wide. Although the minimum inhibitory concentration (MIC) of BLR to the ABK-resistant MRSA strain was 6.25 micrograms/ml in dark, it was decreased to 1.25 micrograms/ml by irradiation with white light of 65 W/m2 for 30 min, suggesting that the antibacterial activity of BLR is photoactivated. Our findings suggested that the antibacterial activity of BLR in dark is due to inhibition of protein synthesis. In addition, we found that BLR is bactericidal and enhances synergistically the antibacterial activity of ABK.
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Affiliation(s)
- B Pant
- Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, Japan
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Ferguson JE, Andrew SM, Jones CJ, August PJ. The Q-switched neodymium:YAG laser and tattoos: a microscopic analysis of laser-tattoo interactions. Br J Dermatol 1997; 137:405-10. [PMID: 9349338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Nd:YAG laser effectively removes or lightens amateur and professional tattoos. The biomechanics of the removal of tattoo particles at the cellular level are incompletely understood. We examined biopsies obtained from 35 amateur and professional tattoos (including coloured tattoos), treated on three or more occasions with the Nd:YAG laser. Biopsies taken immediately after laser treatment showed vacuolation with complete clearance of tattoo particles in the most superficial layers of the dermis, as assessed by light and electron microscopy. We propose that the 'disappearance' of the tattoo particle arises from the formation of atomic species and gaseous products, which are rapidly dissolved in the extracellular fluid. Residual fragmented particles that are commonly found in the mid- and lower dermis are rephagocytosed. The interaction between the Nd:YAG laser and black tattoo particles at 1064 nm, and red tattoo particles at 532 nm, appears to be specific, as there was little evidence of thermal damage to adjacent cells or stromal collagen.
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Abstract
Human skin, especially the epidermis, contains several major solar ultraviolet-radiation- (UVR-) absorbing endogenous chromophores including DNA, urocanic acid, amino acids, melanins and their precursors and metabolites. The lack of solubility of melanins prevents their absorption spectra being defined by routine techniques. Indirect spectroscopic methods show that their spectral properties depend on the stimulus for melanogenesis. The photochemical consequences of UVR absorption by some epidermal chromophores are relatively well understood whereas we lack a detailed understanding of the consequent photobiological and clinical responses. Skin action spectroscopy is not a reliable way of relating a photobiological outcome to a specific chromophore but is important for UVR hazard assessment. Exogenous chromophores may be administered to the skin in combination with UVR exposure for therapeutic benefit, or as sunscreens for the prevention of sunburn and possibly skin cancer.
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Affiliation(s)
- A R Young
- Department of Photobiology, St John's Institute of Dermatology, St Thomas' Hospital, London UK.
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45
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Abstract
BACKGROUND Available information of the effect of sun exposure on the biologic activity and morphologic characteristics of nevi is based on a few cross-sectional studies. According to these, nevi excised in summer show a higher mitotic count, a greater extent of the junctional component, and more frequent regression and inflammation. OBJECTIVE Our goals were to obtain data on the seasonal prevalence of digital epiluminescence microscopy (D-ELM) patterns in acquired melanocytic nevi (AMN) and to test the reliability of D-ELM as a substitute for histology in prospective studies of the morphologic response of AMN to sun exposure. METHODS Two independent series of AMN located on intermittently sun-exposed body sites and undergoing D-ELM in winter (n=121) and in summer (n=116) were compared for the prevalence of major ELM patterns. RESULTS Cases in the summer series showed a greater frequency of a broad and prominent pigment network; black dots with varied size, irregular distribution, and peripheral location; and peripheral depigmentation. CONCLUSION On the basis of known histologic correlates of D-ELM features, our findings were consistent with studies of seasonal histologic changes in AMN. D-ELM may be a useful tool in the prospective evaluation of effects of sun exposure on AMN morphology.
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Affiliation(s)
- I Stanganelli
- Department of Dermatology and the Center for Cancer Prevention, Santa Maria delle Croci Hospital, Ravenna, Italy
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46
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Abstract
Five dry pigments and one maxillofacial elastomer were evaluated for color changes (delta E) resulting from prolonged exposure to two types of ultraviolet light. The elastomer, pigments, and pigmented elastomers were subjected to each ultraviolet light source for 400, 600, and 1800 hours, and delta E color shifts were determined. The unpigmented elastomer underwent minimally perceptible color change after 600 hours of exposure to both types of ultraviolet light. Two pigments underwent substantial color change after 400 hours, whereas the remaining three pigments remained color stable after 1800 hours. It was concluded that for the materials tested, early color changes in a prosthesis may be the result of degradation of certain ultraviolet light-susceptible pigments, whereas longer term color shifts may be caused by color changes within the elastomer.
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Affiliation(s)
- M W Beatty
- Department of Adult Restorative Dentisitry, University of Nebraska Medical Center, College of Dentistry, Lincoln, USA
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Abstract
BACKGROUND AND OBJECTIVE The development of the Alexandrite laser for the removal of blue-black tattoos is described. STUDY DESIGN/MATERIALS AND METHODS The responses of an animal study, using professionally tattooed skin and a human study involving 22 (professional and nonprofessional) blue-black tattoos, to the Alexandrite laser are reported. RESULTS Histopathologic evaluation of tattooed pig skin biopsies demonstrated the method of removal of dermal tattoo pigment. An average 11.6 treatments were required to remove completely the ten human blue-black professional tattoos compared to an average of 10.3 treatments to reach the same endpoint in six subjects with nonprofessional tattoos. CONCLUSION Of significance was the fact that unlike the Q-switched Ruby and Nd:YAG lasers where punctate bleeding and tissue splattering have been reported to occur during laser tattoo removal, epidermal integrity was maintained during exposure of tattooed skin to the Q-switched Alexandrite laser at therapeutic fluences used.
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Affiliation(s)
- T J Stafford
- Tufts University, Boston, Massachusetts 02116, USA
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Zelickson BD, Mehregan DA, Zarrin AA, Coles C, Hartwig P, Olson S, Leaf-Davis J. Clinical, histologic, and ultrastructural evaluation of tattoos treated with three laser systems. Lasers Surg Med 1994; 15:364-72. [PMID: 7885170 DOI: 10.1002/lsm.1900150406] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We examined the response of tattoo pigments treated with three commercially available lasers: Q-switched ruby, Q-Switched neodynium:yttrium,aluminum,garnet (Nd:YAG), and the alexandrite. Tattoos applied to hairless guinea pigs and treated with the aforementioned lasers were evaluated clinically, histologically, and ultrastructurally. Clinical evaluation showed red brown, dark brown, and orange pigment responded best to the Nd:YAG laser (1064 nm). The alexandrite laser was most effective for removing blue and green pigment, the Q-switched ruby laser was most effective for removing purple and violet pigment, and the Nd:YAG laser (532 nm) removed red pigment the best. Black pigment was lightened equally with the Nd:YAG laser (1064 nm) and (532 nm) and the alexandrite laser (755 nm). No clinical scarring was observed; however, some colors turned black after treatment. Histologic and ultrastructural examination showed epidermal and dermal damage to be most evident after treatment with the Nd:YAG laser. Our study shows that certain tattoo pigments respond better to different laser systems.
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Affiliation(s)
- B D Zelickson
- Department of Dermatology, University of Minnesota Medical School, Minneapolis 55455
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Abstract
BACKGROUND All previous treatment modalities for the removal of tattoos, with the possible exception of the Q-switched ruby and YAG lasers, result in scarring. OBJECTIVE The purpose of this study was to investigate the use of a new laser that may remove tattoo pigment without leaving a scar. METHODS A Yucatan micropig was tattooed by a professional tattoo artist with black, blue, green, and red pigments. These tattoos were then treated with single overlapping pulses with the alexandrite laser (wavelength 755 nm, pulse 100 nsec) and evaluated clinically and histologically. Comparison treatment with an argon laser (wavelength 488 nm, 514 nm, continuous-wave) and flashlamp-pumped dye laser (wavelength 585 nm, pulse 450 microseconds) was performed as well for removal of red tattoo pigment. RESULTS The alexandrite laser was found to be very effective in removal of professional and amateur black tattoo pigment, moderately effective in removal of blue and green pigment, and minimally effective in removal of red pigment. No scarring was seen clinically or histologically. CONCLUSION The alexandrite laser shows promise as a treatment modality for tattoo removal without scarring.
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Affiliation(s)
- R E Fitzpatrick
- Dermatology Associates of San Diego County, Inc, Encinitas, CA 92024
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Paranich AV, Chaĭkina LA. [The effect of alimentary vitamin E on the seasonal fluctuations in the level of fluorescent lipopigments in the tissues of irradiated rats]. Radiobiologiia 1993; 33:49-54. [PMID: 8469747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In seasonal experiments (spring and autumn) with Wistar female rats, a study was made of the level of lipopigments (LP) and alpha-tocopherol (TPh) fluorescence in the liver and brain. Seasonal peculiarities of the parameters under study and their dependence on Vitamin E ingestion have been revealed. After irradiation of animals, an intimate morphofunctional relationship between LP and TP and its sensitivity to alimentary factors have been found. One hour following irradiation, part of LP is disintegrated thus releasing the TPh reserve. This may be the part of the complex of adaptation changes on the postirradiation metabolic effects.
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