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Seung Bum Park - One of the best experts on this subject based on the ideXlab platform.
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rational perturbation of the Fluorescence quantum yield in emission tunable and predictable Fluorophores seoul Fluors by a facile synthetic method involving c h activation
Angewandte Chemie, 2014Co-Authors: Eun Joung Choi, Eunha Kim, Youngjun Lee, Seung Bum ParkAbstract:Fluorescence imaging enables the uniquely sensitive observation of functional‐ and molecular‐recognition events in living cells. However, only a limited range of biological processes have been subjected to imaging because of the lack of a design strategy and difficulties in the synthesis of biosensors. Herein, we report a facile synthesis of emission‐tunable and predictable Seoul‐Fluors, 9‐aryl‐1,2‐dihydrolopyrrolo[3,4‐b]indolizin‐3‐ones, with various R1 and R2 substituents by coinage‐metal‐catalyzed intramolecular 1,3‐dipolar cycloaddition and subsequent palladium‐mediated C—H activation. We also showed that the quantum yields of Seoul‐Fluors are controlled by the electronic nature of the substituents, which influences the extent of photoinduced electron transfer. On the basis of this understanding, we demonstrated our design strategy by the development of a Seoul‐Fluor‐based chemosensor 20 for reactive oxygen species that was not accessible by a previous synthetic route.
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9 aryl 1 2 dihydropyrrolo 3 4 b indolizin 3 one seoul Fluor as a smart platform for colorful ratiometric Fluorescent ph sensors
Chemical Communications, 2011Co-Authors: Eunha Kim, Sanghee Lee, Seung Bum ParkAbstract:In this communication, we report that 9-aryl-1,2-dihydropyrrolo[3,4-b]indolizin-3-one (Seoul-Fluor) can serve as a potential platform for colorful ratiometric Fluorescent pH sensors by simple incorporation of pH responsive elements on Seoul-Fluor. Seoul-Fluor-based Fluorescent pH sensors allow the emission- and pH-tuning ability upon protonation by varying their pKa values and electronic characteristics of substituents by a rational design.
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emission wavelength prediction of a full color tunable Fluorescent core skeleton 9 aryl 1 2 dihydropyrrolo 3 4 b indolizin 3 one
Journal of the American Chemical Society, 2011Co-Authors: Eunha Kim, Minseob Koh, Byung Joon Lim, Seung Bum ParkAbstract:In this paper we report on a novel Fluorescent core skeleton, 9-aryl-1,2-dihydropyrrolo[3,4-b]indolizin-3-one, which we named Seoul-Fluor, having tunable and predictable photophysical properties. Using a concise and practical one-pot synthetic procedure, a 68-member library of new Fluorescent compounds was synthesized with diverse substituents. In Seoul-Fluor, the electronic characteristics of the substituents, as well as their positional changes, have a close correlation with their photophysical properties. The systematic perturbation of electronic densities on the specific positions of Seoul-Fluor, guided with the Hammett constant, allows emission wavelength tunability covering the full color range. On the basis of these observations and a computational analysis, we extracted a simple first-order correlation of photophysical properties with the theoretical calculation and accurately predicted the emission wavelength of Seoul-Fluors through the rational design. In this study, we clearly demonstrate that Seoul-Fluor can provide a powerful gateway for the generation of desired Fluorescent probes without the need for a tiresome synthesis and trial-and-error process.
Eunha Kim - One of the best experts on this subject based on the ideXlab platform.
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rational perturbation of the Fluorescence quantum yield in emission tunable and predictable Fluorophores seoul Fluors by a facile synthetic method involving c h activation
Angewandte Chemie, 2014Co-Authors: Eun Joung Choi, Eunha Kim, Youngjun Lee, Seung Bum ParkAbstract:Fluorescence imaging enables the uniquely sensitive observation of functional‐ and molecular‐recognition events in living cells. However, only a limited range of biological processes have been subjected to imaging because of the lack of a design strategy and difficulties in the synthesis of biosensors. Herein, we report a facile synthesis of emission‐tunable and predictable Seoul‐Fluors, 9‐aryl‐1,2‐dihydrolopyrrolo[3,4‐b]indolizin‐3‐ones, with various R1 and R2 substituents by coinage‐metal‐catalyzed intramolecular 1,3‐dipolar cycloaddition and subsequent palladium‐mediated C—H activation. We also showed that the quantum yields of Seoul‐Fluors are controlled by the electronic nature of the substituents, which influences the extent of photoinduced electron transfer. On the basis of this understanding, we demonstrated our design strategy by the development of a Seoul‐Fluor‐based chemosensor 20 for reactive oxygen species that was not accessible by a previous synthetic route.
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9 aryl 1 2 dihydropyrrolo 3 4 b indolizin 3 one seoul Fluor as a smart platform for colorful ratiometric Fluorescent ph sensors
Chemical Communications, 2011Co-Authors: Eunha Kim, Sanghee Lee, Seung Bum ParkAbstract:In this communication, we report that 9-aryl-1,2-dihydropyrrolo[3,4-b]indolizin-3-one (Seoul-Fluor) can serve as a potential platform for colorful ratiometric Fluorescent pH sensors by simple incorporation of pH responsive elements on Seoul-Fluor. Seoul-Fluor-based Fluorescent pH sensors allow the emission- and pH-tuning ability upon protonation by varying their pKa values and electronic characteristics of substituents by a rational design.
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emission wavelength prediction of a full color tunable Fluorescent core skeleton 9 aryl 1 2 dihydropyrrolo 3 4 b indolizin 3 one
Journal of the American Chemical Society, 2011Co-Authors: Eunha Kim, Minseob Koh, Byung Joon Lim, Seung Bum ParkAbstract:In this paper we report on a novel Fluorescent core skeleton, 9-aryl-1,2-dihydropyrrolo[3,4-b]indolizin-3-one, which we named Seoul-Fluor, having tunable and predictable photophysical properties. Using a concise and practical one-pot synthetic procedure, a 68-member library of new Fluorescent compounds was synthesized with diverse substituents. In Seoul-Fluor, the electronic characteristics of the substituents, as well as their positional changes, have a close correlation with their photophysical properties. The systematic perturbation of electronic densities on the specific positions of Seoul-Fluor, guided with the Hammett constant, allows emission wavelength tunability covering the full color range. On the basis of these observations and a computational analysis, we extracted a simple first-order correlation of photophysical properties with the theoretical calculation and accurately predicted the emission wavelength of Seoul-Fluors through the rational design. In this study, we clearly demonstrate that Seoul-Fluor can provide a powerful gateway for the generation of desired Fluorescent probes without the need for a tiresome synthesis and trial-and-error process.
Ofer Bar-yosef - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE Experimental Barley Flour Production in 12,500-Year-Old Rock-Cut Mortars in Southwestern Asia
2016Co-Authors: David Eitam, Mordechai E. Kislev, Adiel Karty, Ofer Bar-yosefAbstract:Experimental archaeology at a Natufian site in the Southern Levant documents for the first time the use of 12,500-year-old rock-cut mortars for producing wild barley flour, some 2,000 to 3,000 years before cereal cultivation. Our reconstruction involved processing wild barley on the prehistoric threshing floor, followed by use of the conical mortars (a common feature in Natufian sites), thereby demonstrating the efficient peeling and milling of hulled grains. This discovery complements nearly 80 years of investigations suggesting that the Natufians regularly harvested almost-ripe wild cereals using sickles hafted with flint blades. Sickles had been replicated in the past and tested in the field for harvesting cereals, thusly obtaining the characteristic sheen along the edge of the hafted flint blades as found in Natufian rem-nants. Here we report that Natufian wide and narrow conical mortars enabled the process-ing of wild barley for making the groats and fine flour that provided considerable quantities of nourishment. Dishes in the Early Natufian (15,000–13,500 CalBP) were groat meals and porridge and subsequently, in the Late Natufian (13,500–11,700 CalBP), we suggest that unleavened bread made from fine flour was added. These food preparing techniques wid-ened the dietary breadth of the sedentary Natufian hunter-gatherers, paving the way to the emergence of farming communities, the hallmark of the Neolithic Revolution
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Experimental Barley Flour Production in 12,500-Year-Old Rock-Cut Mortars in Southwestern Asia.
PloS one, 2015Co-Authors: David Eitam, Mordechai E. Kislev, Adiel Karty, Ofer Bar-yosefAbstract:Experimental archaeology at a Natufian site in the Southern Levant documents for the first time the use of 12,500-year-old rock-cut mortars for producing wild barley flour, some 2,000 to 3,000 years before cereal cultivation. Our reconstruction involved processing wild barley on the prehistoric threshing floor, followed by use of the conical mortars (a common feature in Natufian sites), thereby demonstrating the efficient peeling and milling of hulled grains. This discovery complements nearly 80 years of investigations suggesting that the Natufians regularly harvested almost-ripe wild cereals using sickles hafted with flint blades. Sickles had been replicated in the past and tested in the field for harvesting cereals, thusly obtaining the characteristic sheen along the edge of the hafted flint blades as found in Natufian remnants. Here we report that Natufian wide and narrow conical mortars enabled the processing of wild barley for making the groats and fine flour that provided considerable quantities of nourishment. Dishes in the Early Natufian (15,000–13,500 CalBP) were groat meals and porridge and subsequently, in the Late Natufian (13,500–11,700 CalBP), we suggest that unleavened bread made from fine flour was added. These food preparing techniques widened the dietary breadth of the sedentary Natufian hunter-gatherers, paving the way to the emergence of farming communities, the hallmark of the Neolithic Revolution.
Sanghee Lee - One of the best experts on this subject based on the ideXlab platform.
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9 aryl 1 2 dihydropyrrolo 3 4 b indolizin 3 one seoul Fluor as a smart platform for colorful ratiometric Fluorescent ph sensors
Chemical Communications, 2011Co-Authors: Eunha Kim, Sanghee Lee, Seung Bum ParkAbstract:In this communication, we report that 9-aryl-1,2-dihydropyrrolo[3,4-b]indolizin-3-one (Seoul-Fluor) can serve as a potential platform for colorful ratiometric Fluorescent pH sensors by simple incorporation of pH responsive elements on Seoul-Fluor. Seoul-Fluor-based Fluorescent pH sensors allow the emission- and pH-tuning ability upon protonation by varying their pKa values and electronic characteristics of substituents by a rational design.
Minseob Koh - One of the best experts on this subject based on the ideXlab platform.
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emission wavelength prediction of a full color tunable Fluorescent core skeleton 9 aryl 1 2 dihydropyrrolo 3 4 b indolizin 3 one
Journal of the American Chemical Society, 2011Co-Authors: Eunha Kim, Minseob Koh, Byung Joon Lim, Seung Bum ParkAbstract:In this paper we report on a novel Fluorescent core skeleton, 9-aryl-1,2-dihydropyrrolo[3,4-b]indolizin-3-one, which we named Seoul-Fluor, having tunable and predictable photophysical properties. Using a concise and practical one-pot synthetic procedure, a 68-member library of new Fluorescent compounds was synthesized with diverse substituents. In Seoul-Fluor, the electronic characteristics of the substituents, as well as their positional changes, have a close correlation with their photophysical properties. The systematic perturbation of electronic densities on the specific positions of Seoul-Fluor, guided with the Hammett constant, allows emission wavelength tunability covering the full color range. On the basis of these observations and a computational analysis, we extracted a simple first-order correlation of photophysical properties with the theoretical calculation and accurately predicted the emission wavelength of Seoul-Fluors through the rational design. In this study, we clearly demonstrate that Seoul-Fluor can provide a powerful gateway for the generation of desired Fluorescent probes without the need for a tiresome synthesis and trial-and-error process.
