The Experts below are selected from a list of 846 Experts worldwide ranked by ideXlab platform
Hikoya Hayatsu - One of the best experts on this subject based on the ideXlab platform.
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porphyrins as possible preventers of heterocyclic amine carcinogenesis
Cancer Letters, 1999Co-Authors: Hikoya Hayatsu, Chitose Sugiyama, Sakae Arimotokobayashi, Tomeo NegishiAbstract:Our studies have shown that hemin and Chlorophyllin can directly interact with heterocyclic amines (HAs) and prevent their mutagenic actions. Hemin and Chlorophyllin can trap HAs efficiently, probably by forming face-to-face complexes with them. The trapping was most clearly demonstrated by use of solid-supported porphyrins, hemin-agarose and Chlorophyllin-chitosan. Furthermore, spectroscopic measurements have suggested that there are interactions in solution between the porphyrins and the HAs. A number of in vivo data have been accumulated by efforts from many laboratories for the anticarcinogenic and antigenotoxic properties of porphyrins, particularly Chlorophyllin, against HAs.
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iron Chlorophyllin mediated conversion of 3 hydroxyamino 1 methyl 5h pyrido 4 3 b indole trp p 2 nhoh into its nitroso derivative
Mutation Research, 1998Co-Authors: Sakae Arimotokobayashi, Naomi Inada, Hiromi Nakano, Haruki Rai, Hikoya HayatsuAbstract:Abstract Early work from our laboratory has shown that the mutagenicity of heterocyclic amines in Salmonella can be inhibited by hemin and Chlorophyllins. We have speculated that the inhibition is a result of complex formation between heterocyclic amines and the pigments, and the speculation has been given a line of experimental evidence. We have now found that ferric-Chlorophyllin (Fe-Chlorophyllin) can modify the mutagenicity of 3-hydroxyamino-1-methyl-5 H -pyrido[4,3- b ]indole (Trp-P-2(NHOH)), a metabolically activated form of 3-amino-1-methyl-5 H -pyrido[4,3- b ]indole (Trp-P-2). The mutagenicity of Trp-P-2(NHOH)) in Salmonella typhimurium TA 98 (without S9) was strongly inhibited by an addition of an equimolar Fe-Chlorophyllin in the pre-incubation mixture. Fe-Chlorophyllin also inhibited the mutagenicity of 2-hydroxyamino-6-methyldipyrido[1,2- a :3′,2′- d ] imidazole (Glu-P-1(NHOH)). A rapid change in the UV spectrum of a mixture of Trp-P-2(NHOH) and Fe-Chlorophyllin was observed. Analysis by high performance liquid chromatography showed that Trp-P-2(NHOH) was converted into 3-nitroso-1-methyl-5 H -pyrido[4,3- b ]indole (Trp-P-2(NO)), the mutagenic potency of which is a quarter of that of Trp-P-2(NHOH). Furthermore, the mutagenicity of Trp-P-2(NO), in turn, was inhibited by Fe-Chlorophyllin. We conclude that the suppression of the mutagenicity of Trp-P-2(NHOH) is ascribable to the oxidative function of Fe-Chlorophyllin, coupled with its ability to form complex formation with the planar surface of the heterocyclic amine molecules.
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binding of polycyclic planar mutagens to Chlorophyllin resulting in inhibition of the mutagenic activity
Mutation Research, 1993Co-Authors: Sakae Arimoto, Hiromi Nakano, Haruki Rai, Sumie Fukuoka, Chiho Itome, Hikoya HayatsuAbstract:Chlorophyllin is known to inhibit the mutagenicity of a variety of compounds. Using highly purified samples of Chlorophyllin and its family compounds, we studied the mechanism of the inhibition. Since mutagens with polycyclic planar structures are particularly strongly inhibited, it seemed likely that the inhibition arises by trapping of the mutagens by Chlorophyllin through complex formation at the planar surfaces of these molecules. To explore this possibility, we prepared a Sepharose bearing covalently linked Chlorophyllin as ligand, and the adsorption of mutagens to this Sepharose was measured. Three different Chlorophyllin derivatives were used, i.e., copper-chlorin, iron-chlorin and chlorin, to investigate the role of metal in the center of the Chlorophyllin chromophore. Adsorption of 37 different compounds, mostly mutagens, in 0.02 M Tris-HCl buffer at pH 8.0 to these Chlorophyllin-Sepharose preparations was studied in a quantitative manner. The results showed that most of the compounds having three or more fused rings were strongly adsorbed with apparent dissociation constants of 10(-5)-10(-6) M, whereas those having two fused rings or one ring were only poorly adsorbed. Since the three Sepharose adsorbents gave similar adsorption profiles, it appeared that the central metal in the Chlorophyllin molecule does not play a crucial role in the adsorption. We also measured the inhibitory effect of copper-chlorin against the mutagenicity of some of these compounds using the Salmonella assay. The results showed that those mutagens that were strongly adsorbable to copper-chlorin-Sepharose were subject to efficient inhibition by copper-chlorin, whereas many of those only poorly adsorbed were inhibited only weakly. We concluded that trapping by complex formation plays a role in the antimutagenic actions of Chlorophyllin against many mutagens, particularly notable being the actions against ICR-170, quinacrine, aflatoxin B1, Trp-P-1 and Trp-P-2. An unusual behavior of Trp-P-2 in the adsorption process, i.e., a very tight complex formation at an extremely low Trp-P-2 concentration, was found; the implication of this phenomenon in relation to the real environmental setting is discussed.
Zivile Luksiene - One of the best experts on this subject based on the ideXlab platform.
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towards better microbial safety of fresh produce Chlorophyllin based photosensitization for microbial control of foodborne pathogens on cherry tomatoes
Journal of Photochemistry and Photobiology B-biology, 2018Co-Authors: Egle Paskeviciute, Bernadeta Zudyte, Zivile LuksieneAbstract:Abstract The aim of this study is to evaluate the antimicrobial efficiency of Chlorophyllin-based photosensitization for microbial control of cherry tomatoes. Chlorophyllin-based photosensitization (1.5 × 10−4 M, 3 J/cm2) significantly (2.4 log) reduced the population of naturally distributed surface attached various mesophilic bacteria (microbiota) on tomatoes. Moreover, the population of thermoresistant strains of food pathogens Bacillus cereus and Listeria monocytogenes inoculated on tomatoes was reduced by 1.5 log and 1.6 log respectively after this treatment. Conventional washing with water reduced the population of Listeria on tomato by 0.6 log and Bacillus by 0.8 log. In comparison, hypochlorite treatment reduced Listeria on tomatoes by 1.4 log and Bacillus by 1.6 log. The regrowth of mesophilic bacteria and thermoresistant Listeria on the surface of tomatoes after photosensitization was delayed for 28 days and 14 days respectively. Moreover, photosensitization did not induce harmful effects on main parameter of nutritional quality of tomatoes, i.e. antioxidant activity of tomatoes remained unchanged (27.5 mM Fe2+/kg). Eventually, this treatment did not induce visible thermal effects in fruit matrix and prolonged the shelf-life of tomatoes by 4 days. In our opinion, Chlorophyllin-based photosensitization has a huge potential as alternative to not-chemical food preservation technology, saving water and energy. In addition, fast development of light emitting diodes (LED's) and light sources based on LED technologies make this treatment low cost, environmentally friendly and easy to maintain.
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effective photosensitization based inactivation of gram food pathogens and molds using the Chlorophyllin chitosan complex towards photoactive edible coatings to preserve strawberries
Photochemical and Photobiological Sciences, 2016Co-Authors: Irina Buchovec, Viktorija Lukseviciute, Arunas Marsalka, I Reklaitis, Zivile LuksieneAbstract:This study is focused on the novel approaches to enhance the inactivation of the Gram (−) food pathogen Salmonella enterica and harmful molds in vitro and on the surface of strawberries using the Chlorophyllin–chitosan complex. Salmonella enterica (∼1 × 107 CFU mL−1) was incubated with Chlorophyllin 1.5 × 10−5 M (Chl, food additive), chitosan 0.1% (CHS, food supplement) or the Chlorophyllin–chitosan complex (1.5 × 10−5 M Chl–0.1% CHS) and illuminated with visible light (λ = 405 nm, light dose 38 J cm−2) in vitro. Chlorophyllin (Chl)-based photosensitization inactivated Salmonella just by 1.8 log. Chitosan (CHS) alone incubated for 2 h with Salmonella reduced viability 2.15 log, whereas photoactivated Chl–CHS diminished bacterial viability by 7 log. SEM images indicate that the Chl–CHS complex under these experimental conditions covered the entire bacterial surface. Significant cell membrane disintegration was the main lethal injury induced in Gram (−) bacteria by this treatment. Analysis of strawberry decontamination from surface-inoculated Salmonella indicated that photoactivated Chl–CHS (1.5 × 10−5 M Chl–0.1% CHS, 30 min incubation, light dose 38 J cm−2) coatings diminished the pathogen population on the surface of strawberries by 2.2 log. Decontamination of strawberries from naturally distributed yeasts/molds revealed that chitosan alone reduced the population of yeasts/molds just by 0.4 log, Chl-based photosensitization just by 0.9 log, whereas photoactivated Chl–CHS coatings reduced yeasts/molds on the surface of strawberries by 1.4 log. Electron paramagnetic resonance spectroscopy confirmed that no additional photosensitization-induced free radicals have been found in the strawberry matrix. Visual quality (color, texture) of the treated strawberries was not affected either. In conclusion, photoactive Chl–CHS exhibited strong antimicrobial action against more resistant to photosensitization Gram (−) Salmonella enterica in comparison with Gram (+) bacteria in vitro. It reduced significantly the viability of strawberry surface-attached yeasts/molds and inoculated Salmonella without any negative impact on the visual quality of berries. Experimental data support the idea that photoactivated Chl–CHS can be a useful tool for the future development of edible photoactive antimicrobial coatings which can preserve strawberries and prolong their shelf-life according to requirements of “clean green technology”.
Asger Geppel - One of the best experts on this subject based on the ideXlab platform.
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hplc ms analysis of the green food colorant sodium copper Chlorophyllin
Innovative Food Science and Emerging Technologies, 2007Co-Authors: Alan Mortensen, Asger GeppelAbstract:Abstract Five commercial samples of sodium copper Chlorophyllin, a green food colorant, were analysed by high-performance liquid chromatography (HPLC) using diode-array detection (DAD) and mass spectrometry (MS). Some of the constituents were identified using authentic standards, whereas others were identified tentatively based on their absorption spectra and mass data. The composition of three of the samples was very similar, whereas the other two were quite different. In the three former samples, the three largest peaks could be assigned to Cu chlorin e 6 , Cu chlorin p 6 , and Cu isochlorin e 4 . In one of the two other samples, these three compounds were also among the largest peaks, whereas Cu chlorin e 6 was a small peak in the last sample and Cu chlorin p 6 was absent altogether. Porphyrins were also present in the samples, while except in one of the samples chlorins derived from chlorophyll b were largely absent. Industrial relevance Sodium copper Chlorophyllin is a green food colorant made from chlorophyll. Sodium copper Chlorophyllin is made by saponifying chlorophyll and coppering the resulting product. This processing leads to a complex mixture of compounds. An analytical method was developed that can be used to identify many of these compounds and show the extent of coppering and degradation of sodium copper Chlorophyllin, which may be used industrially to optimize the production of sodium copper Chlorophyllin.
Ursula Maria Lanfermarquez - One of the best experts on this subject based on the ideXlab platform.
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copper Chlorophyllin a food colorant with bioactive properties
Food Research International, 2012Co-Authors: Tathyana Tumolo, Ursula Maria LanfermarquezAbstract:Abstract Copper Chlorophyllin (Cu-Chl) is a chlorophyll-derived food colorant, commercially available as a complex mixture of different chlorin molecules. Several studies have reported great variability in the composition of the mixture as well as the presence of porphyrins and uncoppered chlorin derivatives. The intake of Chlorophyllin and its relationship with possible health benefits have been also the subject of several studies and the results have drawn attention to the possibility that this compound may serve not just as a food colorant, but also as a potential bioactive product with antimutagenic, anticarcinogenic and antioxidant activities; however, its mechanisms of action are not yet well understood. Attaining knowledge of its mechanisms of absorption, bioavailability and consequent bioactivity is essential for the exploration of its potential health-related applications. The purpose of this paper is to present an overview of bioactivities concerning Cu-Chl and provide a discussion on the latest scientific research findings on its human health benefits.
Sakae Arimotokobayashi - One of the best experts on this subject based on the ideXlab platform.
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porphyrins as possible preventers of heterocyclic amine carcinogenesis
Cancer Letters, 1999Co-Authors: Hikoya Hayatsu, Chitose Sugiyama, Sakae Arimotokobayashi, Tomeo NegishiAbstract:Our studies have shown that hemin and Chlorophyllin can directly interact with heterocyclic amines (HAs) and prevent their mutagenic actions. Hemin and Chlorophyllin can trap HAs efficiently, probably by forming face-to-face complexes with them. The trapping was most clearly demonstrated by use of solid-supported porphyrins, hemin-agarose and Chlorophyllin-chitosan. Furthermore, spectroscopic measurements have suggested that there are interactions in solution between the porphyrins and the HAs. A number of in vivo data have been accumulated by efforts from many laboratories for the anticarcinogenic and antigenotoxic properties of porphyrins, particularly Chlorophyllin, against HAs.
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iron Chlorophyllin mediated conversion of 3 hydroxyamino 1 methyl 5h pyrido 4 3 b indole trp p 2 nhoh into its nitroso derivative
Mutation Research, 1998Co-Authors: Sakae Arimotokobayashi, Naomi Inada, Hiromi Nakano, Haruki Rai, Hikoya HayatsuAbstract:Abstract Early work from our laboratory has shown that the mutagenicity of heterocyclic amines in Salmonella can be inhibited by hemin and Chlorophyllins. We have speculated that the inhibition is a result of complex formation between heterocyclic amines and the pigments, and the speculation has been given a line of experimental evidence. We have now found that ferric-Chlorophyllin (Fe-Chlorophyllin) can modify the mutagenicity of 3-hydroxyamino-1-methyl-5 H -pyrido[4,3- b ]indole (Trp-P-2(NHOH)), a metabolically activated form of 3-amino-1-methyl-5 H -pyrido[4,3- b ]indole (Trp-P-2). The mutagenicity of Trp-P-2(NHOH)) in Salmonella typhimurium TA 98 (without S9) was strongly inhibited by an addition of an equimolar Fe-Chlorophyllin in the pre-incubation mixture. Fe-Chlorophyllin also inhibited the mutagenicity of 2-hydroxyamino-6-methyldipyrido[1,2- a :3′,2′- d ] imidazole (Glu-P-1(NHOH)). A rapid change in the UV spectrum of a mixture of Trp-P-2(NHOH) and Fe-Chlorophyllin was observed. Analysis by high performance liquid chromatography showed that Trp-P-2(NHOH) was converted into 3-nitroso-1-methyl-5 H -pyrido[4,3- b ]indole (Trp-P-2(NO)), the mutagenic potency of which is a quarter of that of Trp-P-2(NHOH). Furthermore, the mutagenicity of Trp-P-2(NO), in turn, was inhibited by Fe-Chlorophyllin. We conclude that the suppression of the mutagenicity of Trp-P-2(NHOH) is ascribable to the oxidative function of Fe-Chlorophyllin, coupled with its ability to form complex formation with the planar surface of the heterocyclic amine molecules.