241 results on '"Bong Rae Cho"'
Search Results
2. Organelle-specific blue-emitting two-photon probes for calcium ions: Combination with green-emitting two-photon probe for simultaneous detection of proton ions
- Author
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Seung Taek Hong, Mun Seok Kim, Bo Ra Kim, Eun Jeong Lee, Yeo Uk Yoon, Kyu Cheol Paik, Man So Han, Eun Sun Kim, and Bong Rae Cho
- Subjects
Ions ,Photons ,Calcium ,Protons ,Lysosomes ,Fluorescent Dyes ,Analytical Chemistry - Abstract
In this study, we developed organelle-specific blue-emitting two-photon (TP) probes for Ca
- Published
- 2022
3. Hollow porous silica nanospheres for enfuvirtide delivery carrier
- Author
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Bong Rae Cho
- Subjects
chemistry.chemical_compound ,Materials science ,Enfuvirtide ,chemistry ,Chemical engineering ,medicine ,General Chemistry ,Porosity ,medicine.drug ,Tetraethyl orthosilicate - Published
- 2019
4. Reactions of 2,4‐Dinitrophenyl 5‐substituted‐2‐thiophenecarboxylates with R 2 NH/R 2 NH 2 + in 20 Mol % DMSO(aq). Effects of 5‐Thienyl Substituent and Leaving Group on the Reaction Mechanism
- Author
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Kyu Cheol Paik, Sang Yong Pyun, Man So Han, and Bong Rae Cho
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chemistry.chemical_compound ,Reaction mechanism ,Aminolysis ,chemistry ,Hammett equation ,Mole ,Leaving group ,Substituent ,Dinitrophenyl ,General Chemistry ,Medicinal chemistry - Published
- 2019
5. Two-Photon Probes for Golgi Apparatus: Detection of Golgi Apparatus in Live Tissue by Two-Photon Microscopy
- Author
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Man So Han, Kyu Cheol Paik, Mun Seok Kim, Bong Rae Cho, Seung Taek Hong, and Ji-Woo Choi
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Benzoxazoles ,Photons ,Pyrazine ,Chemistry ,010401 analytical chemistry ,Golgi Apparatus ,Apoptosis ,Golgi apparatus ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Analytical Chemistry ,Rats, Sprague-Dawley ,symbols.namesake ,chemistry.chemical_compound ,Drug Stability ,Microscopy, Fluorescence ,Two-photon excitation microscopy ,Biophysics ,symbols ,Animals ,Humans ,Oligopeptides ,Fluorescent Dyes ,HeLa Cells - Abstract
We have developed blue- and yellow-emitting two-photon probes (BGolgi-blue and PGolgi-yellow) from 6-(benzo[ d]oxazol-2-yl)-2-naphthalylamine and 2,5-bis(benzo[ d]oxazol-2-yl)pyrazine derivatives as the fluorophores and trans-Golgi-network peptide (SDYQRL) as the Golgi-apparatus-targeting moiety. HeLa cells labeled with BGolgi-blue and PGolgi-yellow emitted two-photon-excited fluorescence at 462 and 560 nm, respectively, with effective two-photon-action cross-section values of 1860 and 1600 × 10
- Published
- 2019
6. PyrPeg, a Blood-Brain-Barrier-Penetrating Two-Photon Imaging Probe, Selectively Detects Neuritic Plaques, Not Tau Aggregates
- Author
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Jong Hyun Park, Bong Rae Cho, Yeon Ha Ju, Ae Nim Pae, Ji Woo Choi, Seungyeop Baek, Yunsook Choi, Changdev G. Gadhe, Mun Seok Kim, Ki Duk Park, Hoon Ryu, Young-Soo Kim, C. Justin Lee, and Seung Jae Hyeon
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Pathology ,medicine.medical_specialty ,Physiology ,Cognitive Neuroscience ,Tau protein ,Plaque, Amyloid ,tau Proteins ,Protein aggregation ,Blood–brain barrier ,Biochemistry ,Two-photon excitation microscopy ,In vivo ,Alzheimer Disease ,Microscopy ,medicine ,Humans ,Senile plaques ,Amyloid beta-Peptides ,biology ,Chemistry ,Brain ,Cell Biology ,General Medicine ,Olfactory bulb ,medicine.anatomical_structure ,Blood-Brain Barrier ,biology.protein - Abstract
Amyloid-β (Aβ) tracers have made a significant contribution to the treatment of Alzheimer's disease (AD) by allowing a definitive diagnosis in living patients. Unfortunately, they also detect tau and other protein aggregates that compromise test accuracy. In AD research, there has been a growing need for in vivo Aβ imaging by two-photon microscopy, which enables deep-brain-fluorescence imaging. There is no suitable neuritic Aβ probe for two-photon microscopy. Here we report PyrPeg, a novel two-photon fluorescent probe that can selectively target insoluble Aβ rather than tau and α-synuclein aggregates in the AD model brain and postmortem brain. When injected intravenously, PyrPeg detects the neuritic plaques in the brain and olfactory bulb of the AD model. PyrPeg may serve as a useful blood-brain-barrier-penetrating diagnostic tool for optical and functional monitoring of insoluble forms of Aβ aggregates in the living AD brain.
- Published
- 2020
7. Two-photon probes for the endoplasmic reticulum: its detection in a live tissue by two-photon microscopy
- Author
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Man So Han, Mun Seok Kim, Yeo Uk Yoon, Seung Hye Choi, Ji Woo Choi, Seong Shick Ryu, Taebo Sim, Kyu Cheol Paik, Seung Taek Hong, and Bong Rae Cho
- Subjects
KDEL ,Peptide ,Fluorene ,Naphthalenes ,Endoplasmic Reticulum ,Catalysis ,chemistry.chemical_compound ,Two-photon excitation microscopy ,Microscopy ,Materials Chemistry ,Moiety ,Humans ,Fluorescent Dyes ,chemistry.chemical_classification ,Fluorenes ,Photons ,Molecular Structure ,Endoplasmic reticulum ,Optical Imaging ,Metals and Alloys ,General Chemistry ,Fluorescence ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Microscopy, Fluorescence, Multiphoton ,chemistry ,Ceramics and Composites ,Biophysics ,Peptides ,HeLa Cells - Abstract
We report blue- and green-emitting two-photon probes derived from naphthalene and fluorene derivatives (as fluorophores) and an endoplasmic reticulum (ER) retrieval peptide (KDEL; as an ER-targeting moiety) that can detect the ER in a live cell by both one-photon and two-photon microscopy (TPM) and in a live tissue by TPM.
- Published
- 2020
8. Two-Photon Probe for TNF-α. Assessment of the Transmembrane TNF-α Level in Human Colon Tissue by Two-Photon Microscopy
- Author
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Hoon Jai Chun, Man So Han, Kyu Cheol Paik, Mun Seok Kim, Jung Nyoung Heo, Ji Woo Choi, Min Cheol Pyo, Eun Jeong Lee, Bong Rae Cho, Eun Sun Kim, Seung Taek Hong, Byumseok Koh, Eunyoung Yoon, and Seong Ji Choi
- Subjects
Photolysis ,Chemistry ,Cell Survival ,Colon ,Tumor Necrosis Factor-alpha ,Analytical chemistry ,Carbazoles ,Hydrogen-Ion Concentration ,Transmembrane protein ,Infliximab ,Analytical Chemistry ,Mice ,Microscopy, Fluorescence, Multiphoton ,RAW 264.7 Cells ,Two-photon excitation microscopy ,Aqueous buffer ,Animals ,Humans ,Absorption (electromagnetic radiation) ,Human colon ,Fluorescent Dyes - Abstract
We developed Pyr1-infliximab: a two-photon probe for TNF-α. Pyr1-infliximab showed absorption maxima at 280 and 438 nm and an emission maximum at 610 nm in an aqueous buffer and effective two-photon action cross-section values of (520-2830) × 10
- Published
- 2019
9. Difference in Elimination Effect of Volatile Compounds by Two Different Nanostructures of Chromium Ion-doped TiO2
- Author
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Bong Rae Cho
- Subjects
Nanostructure ,Materials science ,Inorganic chemistry ,Doping ,Trimethylamine ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Chromium atom ,0104 chemical sciences ,Ammonia ,chemistry.chemical_compound ,chemistry ,0210 nano-technology - Published
- 2018
10. Elimination Reactions of Aryl Furylacetates Promoted by R2 NH in MeCN: Effects of Base Solvent and β-Aryl Group on the Ketene-forming Transition State
- Author
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Sang Yong Pyun, Bong Rae Cho, Byung Tae Kim, Man So Han, and Kyu Cheol Paik
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chemistry.chemical_classification ,Base (chemistry) ,Double bond ,010405 organic chemistry ,Stereochemistry ,Aryl ,Kinetics ,Ketene ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,0104 chemical sciences ,Solvent ,Elimination reaction ,chemistry.chemical_compound ,chemistry ,Group (periodic table) - Abstract
Ketene-forming elimination from C4H3(O)CH2C(O)OC6H3-2-X-4-NO2 (1) promoted by R2NH in MeCN has been studied. The reactions produced elimination products and exhibited second-order kinetics with Bronsted β = 0.51, and |βlg| = 0.47–0.53, indicating that the reaction proceeds by the E2 mechanism via an E2-central transition state. Comparison of β, |βlg|, ΔH≠, and ΔS≠ values for R2NH-promoted eliminations from ArCH2C(O)OC6H3-2-X-4-NO2 reveals that the transition-state structures for Ar = furyl and thienyl are similar and more symmetrical than that for Ar = Ph. This outcome has been attributed to the greater double bond stabilizing ability of the former than that of the latter.
- Published
- 2017
11. Two-Photon Probes for pH: Detection of Human Colon Cancer using Two-Photon Microscopy
- Author
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Hoon Jai Chun, Man So Han, Seung Taek Hong, Bong Rae Cho, Kyu Cheol Paik, Seong Jun Park, Sung An Kwon, Tae Hyeong Kim, Ji Woo Choi, Jung Nyoung Heo, and Eun Sun Kim
- Subjects
Absorption (pharmacology) ,Tris ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Cell Line ,Analytical Chemistry ,chemistry.chemical_compound ,Two-photon excitation microscopy ,Humans ,Fluorescent Dyes ,Photons ,Molecular Structure ,Chemistry ,Vesicle ,Hep G2 Cells ,Hydrogen-Ion Concentration ,HCT116 Cells ,021001 nanoscience & nanotechnology ,Molecular biology ,0104 chemical sciences ,Human colon cancer ,Microscopy, Fluorescence, Multiphoton ,Biochemistry ,Cell culture ,Colonic Neoplasms ,Hepatic stellate cell ,0210 nano-technology ,Citric acid - Abstract
We have developed two-photon (TP) pH-sensitive probes (BH-2 and BHEt-1) that exhibit absorption and emission maxima at 370 and 466 nm, and TP absorption cross-section values of 51 and 61 GM (1 GM = 10–50cm4s/photon), respectively, at 750 nm and pH 3.0 in a universal buffer (0.1 M citric acid, 0.1 M KH2PO4, 0.1 M Na2B4O7, 0.1 M Tris, 0.1 M KCl)/1,4-dioxane (7/3) solution. The TPM images of CCD-18co (a normal colon cell line) and HCT116 cells (a colon cancer cell line) labeled with BH-2 were too dim to be distinguished. When the same cells were labeled with BHEt-1, however, the TPM image of the HCT116 cells was much brighter than that of CCD-18co cells, and the relative proportion of the acidic vesicles (Pacid) of the former was 5-fold larger than that of latter. BHEt-1 could also differentiate HepG2 cells (a human liver cancer cell line) from LX-2 cells (a human hepatic stellate cell line) with a 6-fold larger Pacid value. Human colon cancer tissues labeled with BHEt-1 showed similar results, demonstrating...
- Published
- 2017
12. Two-Photon Tracer for Human Epidermal Growth Factor Receptor-2: Detection of Breast Cancer in a Live Tissue
- Author
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Chang Su Lim, Dong Eun Kang, Man So Han, Kyu Cheol Paik, Seung Taek Hong, Ji-Woo Choi, and Bong Rae Cho
- Subjects
0301 basic medicine ,Absorption (pharmacology) ,Light ,Receptor, ErbB-2 ,Recombinant Fusion Proteins ,Breast Neoplasms ,Nanotechnology ,Analytical Chemistry ,HeLa ,03 medical and health sciences ,Breast cancer ,Two-photon excitation microscopy ,Cell Line, Tumor ,TRACER ,Microscopy ,medicine ,Animals ,Humans ,Fluorescent tracer ,Human Epidermal Growth Factor Receptor 2 ,Benzofurans ,Fluorescent Dyes ,Mice, Inbred BALB C ,biology ,Chemistry ,biology.organism_classification ,medicine.disease ,030104 developmental biology ,Pyrazines ,Biophysics - Abstract
We have developed a two-photon fluorescent tracer (Pyr-affibody) that shows high selectivity for human epidermal growth factor receptor-2 (HER-2). Pyr-affibody showed absorption and emission maxima at 439 and 574 nm, respectively, with a two-photon absorption cross-section value of 40 × 10–50 cm4s/photon (GM) at 750 nm in aqueous buffer solution. The effective two-photon action cross-section value measured in HeLa cells was 600 GM at 730 nm, a value sufficient to obtain bright two-photon microscopy (TPM) images. Using Pyr-affibody, it was possible to detect HER-2 overexpressing cells and breast cancers at a depth of 90–130 μm in live mouse tissue by TPM.
- Published
- 2016
13. Readily Accessible and Predictable Naphthalene-Based Two-Photon Fluorophore with Full Visible-Color Coverage
- Author
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Ja Young Koo, Hwan Myung Kim, Young-Hee Shin, Dahahm Kim, Chang Su Lim, Cheol Ho Heo, Seung Bum Park, and Bong Rae Cho
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Fluorophore ,010405 organic chemistry ,business.industry ,Organic Chemistry ,Nanotechnology ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Fluorescence ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Wavelength ,chemistry ,Two-photon excitation microscopy ,Optoelectronics ,business ,Biosensor ,Excitation ,Visible spectrum ,Naphthalene - Abstract
Herein we report 22 acedan-derived, two-photon fluorophores with synthetic feasibility and full coverage of visible wavelength emission. The emission wavelengths were predicted by computational analysis, which enabled us to visualize multicolor images by two-photon excitation with single wavelength, and to design a turn-on, two-photon fluorescence sensor for endogenous H2 O2 in Raw 264.7 macrophage and rat brain hippocampus ex vivo.
- Published
- 2016
14. Elimination Reactions of (E)-2,4,6-TrinitrobenzaldehydeO-Benzoyloximes Promoted by R2NH/R2NH2+in 70 mol% MeCN (aq). Effects of the β-Aryl Group and Leaving Group on Nitrile-Forming Transition States
- Author
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Sang Yong Pyun, Man So Han, Kyu Cheol Paik, and Bong Rae Cho
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Reaction mechanism ,Nitrile ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Aryl ,Kinetics ,Leaving group ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Medicinal chemistry ,Transition state ,0104 chemical sciences ,chemistry.chemical_compound ,Elimination reaction ,E1cB-elimination reaction - Abstract
Elimination reactions of (E)-2,4,6-(NO2 ) 3C6H2CHNOC(O)C6H4X (3) promoted by R2NH/R2NH2 + in 70 mol% MeCN (aq) have been studied. The reactions produced elimination products and exhibited second-order kinetics. The β and |βlg| values remained nearly the same for all leaving groups and bases. The results can be described by the negligible pxy interaction coefficient, pxy = ∂β/∂pK lg = ∂βlg/∂pK BH ≈ 0, which provides a strong support for the (E1cb)irr mechanism. For eliminations from (E)-ArCHNOC(O)C6H4X (1, 3) and (E)-2,4,6-(NO2)3C6H2CHNOAr′ (2, 3), the change of the β-aryl group (Ar) from 2,4-dinitrophenyl (1) to 2,4,6-trinitrophenyl (3) increased the rate by 270-fold without appreciable change in the transition state structure. On the other hand, the leaving group (OAr′) variation from benzoate (3) to 4-nitrophenoxy (2) induced a change in reaction mechanism from (E1cb)irr to E2. These results have been attributed to the cyclic transition state for the nitrile-forming eliminations involving the benzoate leaving group.
- Published
- 2016
15. Reactions of Aryl 5-substituted-2-Thiophenecarboxylates Promoted by 4-Z-C6H4O−/4-Z-C6H4OH in 20 mol % DMSO(aq). Effect of Nucleophile on Acyl-Transfer Reaction
- Author
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Kyu Cheol Paik, Man So Han, Sang Yong Pyun, and Bong Rae Cho
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chemistry.chemical_compound ,chemistry ,Nucleophile ,Stereochemistry ,Dimethyl sulfoxide ,Aryl ,Mole ,Kinetics ,Nucleophilic substitution ,General Chemistry ,Medicinal chemistry - Abstract
Nucleophilic substitution reactions of 5-XC4H2 (S)C(O)OC6H3 -2-Y-4-NO2 (1) promoted by 4-Z-C6H4O −/4-Z-C6H4OH in 20 mol % dimethyl sulfoxide (DMSO)(aq) have been studied kinetically. The reactions exhibited second-order kinetics with βacyl = −2.52 to −2.83, ρ(x) = 2.81–3.16, βnuc = 0.88–0.04 and βlg = −0.94, respectively. The results have been interpreted with an addition–elimination mechanism in which the nucleophilic attack occurs in the rate-determining step. Comparison with existing data reveals that the rate-determining step changes from the second to the first step by the change in the nucleophile from R2NH/R2NH2 + to 4-Z-C6H4O −/4-Z-C6H4OH.
- Published
- 2015
16. Two-photon probes for biomedical imaging
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Chang Su Lim and Bong Rae Cho
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Two-photon excitation microscopy ,Chemistry ,Organic Chemistry ,Drug Discovery ,Medical imaging ,Nanotechnology ,Biochemistry - Published
- 2015
17. Extermination of influenza virus H1N1 by a new visible-light-induced photocatalyst under fluorescent light
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Bong Rae Cho and Sei-Young Choi
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Cancer Research ,Light ,Ultraviolet Rays ,viruses ,chemistry.chemical_element ,02 engineering and technology ,Manganese ,Biology ,engineering.material ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Virus ,Catalysis ,Fluorescence ,law.invention ,Influenza A Virus, H1N1 Subtype ,Coating ,Transition metal ,law ,Virology ,Fluorescent lamp ,Titanium ,Magnesium ,021001 nanoscience & nanotechnology ,Photochemical Processes ,0104 chemical sciences ,Infectious Diseases ,chemistry ,Photocatalysis ,engineering ,Virus Activation ,0210 nano-technology ,Visible spectrum - Abstract
A new visible-light-induced photocatalyst based on several transition metals (iron, magnesium and manganese)-loaded TiO2 was evaluated for its anti-viral activity with influenza virus H1N1. Under a fluorescent lamp of 1000 lx, λ > 410 nm, the virus was eradicated to more than 99% within 30 min. Since this photocatalyst can be used for coating plastics, wall papers and walls, it would be desirable to use this photocatalyst to reduce viral transmission via droplets and aerosols as well as surface contact for disinfection.
- Published
- 2017
18. A Two-Photon Probe for Near-Membrane Zinc Ions
- Author
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Young Ho Lee, Chang Su Lim, Hee Jung Park, Bong Rae Cho, and Kailash Rathore
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Chemistry ,Zinc ion ,Organic Chemistry ,Analytical chemistry ,food and beverages ,chemistry.chemical_element ,Zinc ,Laser ,law.invention ,Membrane ,Two-photon excitation microscopy ,law ,Excited state ,Femtosecond ,Microscopy - Abstract
A two-photon probe for near-membrane zinc ions that can be excited by 800 nm femtosecond laser pulses and emit at 500 nm is reported. The probe can be easily loaded into cells and tissue slices to visualize near-membrane zinc ions in live cells and tissues for a long period of time through the use of two-photon microscopy.
- Published
- 2014
19. Elimination Reactions of Aryl Furylacetates Promoted by R2NH-R2NH2+in 70 mol% MeCN(aq). Effects of β-Aryl on the Ketene-Forming Transition-State
- Author
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Bong Rae Cho, Ju Chang Kim, and Sang Yong Pyun
- Subjects
chemistry.chemical_compound ,Elimination reaction ,Transition (genetics) ,Stereochemistry ,Chemistry ,Aryl ,Mole ,Ketene ,General Chemistry ,Medicinal chemistry ,E1cB-elimination reaction - Abstract
the effect of the β-aryl group on the ketene-formingelimination was assessed.Key Words : Elimination, E2 and E1cb Mechanism, β–Aryl Group effectIntroductionExtensive studies of the structure-reactivity relationshipsin the ketene-forming elimination reactions have led to thequalitative understanding of the relationship between thereactant structure and the mechanism.
- Published
- 2014
20. Two-Photon Probe for Cu2+ with an Internal Reference: Quantitative Estimation of Cu2+ in Human Tissues by Two-Photon Microscopy
- Author
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Hoon Jai Chun, Chang Su Lim, Eun Sun Kim, Dong Eun Kang, Bong Rae Cho, and Ji-Yeon Kim
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inorganic chemicals ,biology ,Colorectal cancer ,Chemistry ,Metal ions in aqueous solution ,Analytical chemistry ,chemistry.chemical_element ,medicine.disease ,Copper ,Cofactor ,Analytical Chemistry ,Ion ,Two-photon excitation microscopy ,Microscopy ,medicine ,biology.protein ,Biophysics ,Cytotoxicity - Abstract
Copper ions play a crucial role in living systems as cofactors of numerous metalloenzymes. To quantitatively estimate the Cu2+ concentration in human tissue, we have developed a two-photon (TP) probe with an internal reference (ACCu2) that shows significant TP action cross-section and high selectivity for Cu2+ and can quantitatively estimate the Cu2+ concentration in human colon tissues by dual-color two-photon microscopy (TPM) imaging with minimum interference from other competing metal ions or pH and minimum cytotoxicity and photostability problems. The Cu2+ concentrations in human normal colon, polyp, and colon cancer tissues were found to be 8.3 ± 0.3, 13 ± 2, and 22 ± 3 μM, respectively. This result suggests that ACCu2 may be useful for the diagnosis of human colon cancer.
- Published
- 2014
21. Preparation of hollow porous silica nanospheres and their potential for glucagon-like peptide-1 delivery
- Author
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Bong Rae Cho
- Subjects
Biomaterials ,Polymers and Plastics ,Chemical engineering ,Chemistry ,Metals and Alloys ,Porosity ,Glucagon-like peptide-1 ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Published
- 2019
22. Two-Photon Fluorescent Probes for Metal Ions in Live Tissues
- Author
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Dong Eun Kang, Bong Rae Cho, Avik Ranjan Sarkar, and Hwan Myung Kim
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Diagnostic Imaging ,Photons ,Chemistry ,Metal ions in aqueous solution ,Nanotechnology ,Fluorescence ,Inorganic Chemistry ,Imaging Tool ,Two-photon excitation microscopy ,Metals ,Microscopy ,Animals ,Humans ,Physical and Theoretical Chemistry ,Biological imaging ,Fluorescent Dyes - Abstract
Two-photon microscopy (TPM) is a new imaging tool that can detect biological targets deep inside a live tissue. To faciltate the use of TPM in biomedical research, a variety of two-photon (TP) probes for specific applications are needed. In this Forum Article, we describe the design strategy, photophysical properties, and biological imaging applications of a selection of our recent studies in the development of TP probes for metal ions. Small-molecule TP turn-on probes, organelle-targeted probes, and multicolor emissive probes for dual-color imaging are briefly reviewed.
- Published
- 2013
23. Effects of Sesame Meal on Growth Performances and Fatty acid Composition, Free Amino Acid Contents, and Panel Tests of Loin of Hanwoo Steers
- Author
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Bong Rae Cho, Chang Bon Choi, and Sung Il Kim
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Meal ,Ecology ,Veterinary (miscellaneous) ,Marbled meat ,Loin ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Palmitic acid ,chemistry.chemical_compound ,Oleic acid ,chemistry ,Hanwoo ,Animal Science and Zoology ,Palatability ,Food science ,Unsaturated fatty acid ,Food Science - Abstract
The feed value of sesame meal, a main agricultural by-product from the northern area of Gyeongsangbuk-do province, was assessed in Hanwoo steers. A total of twelve Hanwoo steers (average BW = 412.08 kg) were allocated into a Control (fed no sesame meal) or Treatment (fed sesame meal from 14.6 months of age) group, considering BW and ages, and the animals were fed for a total of 480 days. The final BW, total gain and ADG for the Control and Treatment groups were 741.17 kg and 762.67 kg, 331.84 kg and 347.84 kg, and 0.69 kg and 0.72 kg, respectively, showing better performances in sesame meal-fed animals. Feed requirements during the whole experimental period improved by feeding sesame meal (15.31 and 14.87 for Control and Treatment group, respectively). Hanwoo steers fed sesame meal also showed a 22.83 kg heavier cold carcass weight (424.17 kg and 447.00 kg in the Control and Treatment group, respectively), and 2.41% improved dressing percentages (58.60% and 57.22% for the Control and Treatment group, respectively). The area of the M. longissimus dorsi was 91.83 cm 2 and 88.33 cm 2 in the Control and Treatment group, respectively. The final yield of A and B grade meat were 50 : 50% and 33.3 : 66.7% from the Control and Treatment group, respectively. The average marbling score was 4.83 and 5.50, and the numeric values for quality grade was 2.17 and 2.67 for the Control and Treatment group, respectively, showing better beef quality in sesame meal-fed Hanwoo steers. In fact, there were two animals with beef quality 1 ++ in the sesame meal-fed group. The melting point of lipid extracted from the M. longissimus dorsi of Hanwoo steers was significantly (p
- Published
- 2013
24. Effect of Terminal Labeling of Fluorescent Dyes on Ribozyme Activity
- Author
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Bong Rae Cho
- Subjects
Terminal (electronics) ,biology ,Biochemistry ,Chemistry (miscellaneous) ,Chemistry ,Ribozyme ,biology.protein ,Chemical Engineering (miscellaneous) ,Fluorescence ,Molecular biology - Published
- 2015
25. Quantitative Estimation of the Total Sulfide Concentration in Live Tissues by Two-Photon Microscopy
- Author
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Eun Sun Kim, Hoon Jai Chun, Chang Su Lim, Sun Young Yang, Sajal Kumar Das, and Bong Rae Cho
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chemistry.chemical_classification ,HEPES ,Molecular Structure ,Sulfide ,Cell Survival ,Colon ,Chemistry ,Hydrogen sulfide ,High selectivity ,Analytical chemistry ,Sulfides ,equipment and supplies ,Rats ,Analytical Chemistry ,Kinetics ,chemistry.chemical_compound ,Microscopy, Fluorescence, Multiphoton ,Reaction rate constant ,Two-photon excitation microscopy ,Excited state ,Microscopy ,Animals ,Humans ,Cells, Cultured ,HeLa Cells - Abstract
Hydrogen sulfide (H2S) is a newly recognized transmitter, which protects various organs from oxidative stress. In this article, we report a ratiometric two-photon probe, TFCA, which can be excited by 750 nm femtosecond pulses, shows a 110-fold increase in the intensity ratio upon reaction with HS(-) and high selectivity for HS(-) and can visualize the total sulfide ([H2S] + [HS(-)]) distribution in live tissue by two-photon microscopy (TPM). We also developed a kinetic method to quantitatively estimate the total sulfide concentration ([H2S] + [HS(-)]) in live tissues. The kinetic method allowed us to measure the observed rate constants (kobs) for the sulfide-induced deazidation reaction of TFCA in live cells and tissues using TPM. The total sulfide concentration was calculated by using kobs = k2[HS(-)], with the k2 value determined in HEPES/EtOH (1/1, pH = 7.2), and [H2S]/[HS(-)] = [H(+)]/Ka. The total sulfide concentration was found to be nearly zero in HeLa cells and 4-7 μM in rat colon tissues.
- Published
- 2013
26. Reactions of 4-Nitrophenyl 2-Thiophenecarboxylates with R2NH/R2NH2+in 20 mol % DMSO (aq). Effects of 5-Thienyl Substituent and Base Strength
- Author
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Sang Yong Pyun and Bong Rae Cho
- Subjects
chemistry.chemical_classification ,Base (chemistry) ,Stereochemistry ,Substituent ,General Chemistry ,Resonance (chemistry) ,Medicinal chemistry ,chemistry.chemical_compound ,Aminolysis ,chemistry ,Nucleophile ,Hammett equation ,Mole ,Reactivity (chemistry) - Abstract
value increased with a stronger electron-withdrawing 5-thienyl substituent, the Hammett plots arelinear except for X = MeO, and Yukawa-Tsuno plots are linear with ρ = 0.79-1.32 and r = 0.28-0.93,respectively. The ρ value increased and r value decreased with a stronger nucleophile, indicating an increase inthe electron density at the C=O bond and a decrease in the resonance demand. These results have beeninterpreted with enhanced N-C bond formation in the transition state with the reactivity increase. Key Words : Aminolysis, Bronsted-type plot, Hammett plot, Yukawa-Tsuno plot IntroductionExtensive studies of the structure-reactivity relationshipsin the acyl transfer reactions from XC
- Published
- 2013
27. A Ratiometric Two-Photon Fluorescent Probe Reveals Reduction in Mitochondrial H2S Production in Parkinson’s Disease Gene Knockout Astrocytes
- Author
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Dong-Joo Choi, Bong Rae Cho, Hwan Myung Kim, Sung Keun Bae, Cheol Ho Heo, Debabrata Sen, and Eun Hye Joe
- Subjects
Protein Deglycase DJ-1 ,medicine.disease_cause ,Biochemistry ,Neuroprotection ,Catalysis ,Colloid and Surface Chemistry ,Two-photon excitation microscopy ,medicine ,Humans ,Hydrogen Sulfide ,Cytotoxicity ,Gene knockout ,Fluorescent Dyes ,Oncogene Proteins ,Molecular Structure ,biology ,Chemistry ,Intracellular Signaling Peptides and Proteins ,Parkinson Disease ,General Chemistry ,equipment and supplies ,Cystathionine beta synthase ,Fluorescence ,Mitochondria ,Astrocytes ,Biophysics ,biology.protein ,Protons ,Oxidation-Reduction ,Oxidative stress - Abstract
Hydrogen sulfide (H2S) is a multifunctional signaling molecule that exerts neuroprotective effects in oxidative stress. In this article, we report a mitochondria-localized two-photon probe, SHS-M2, that can be excited by 750 nm femtosecond pulses and employed for ratiometric detection of H2S in live astrocytes and living brain slices using two-photon microscopy (TPM). SHS-M2 shows bright two-photon-excited fluorescence and a marked change in emission color from blue to yellow in response to H2S, low cytotoxicity, easy loading, and minimum interference from other biologically relevant species including reactive sulfur, oxygen, and nitrogen species, thereby allowing quantitative analysis of H2S levels. Molecular TPM imaging with SHS-M2 in astrocytes revealed that there is a correlation between the ratiometric analysis and expression levels of cystathionine β-synthase (CBS), the major enzyme that catalyzes H2S production. In studies involving DJ-1, a Parkinson's disease (PD) gene, attenuated H2S production in comparison with wild-type controls was observed in DJ-1-knockout astrocytes and brain slices, where CBS expression was decreased. These findings demonstrate that reduced H2S levels in astrocytes may contribute to the development of PD and that SHS-M2 may be useful as a marker to detect a risk of neurodegenerative diseases, including PD.
- Published
- 2013
28. Two-photon probes for biomedical applications
- Author
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Chang Su Lim and Bong Rae Cho
- Subjects
Lipid Bilayers ,Clinical science ,Nanotechnology ,Review Article ,Two-photon probes ,Biochemistry ,Lower energy ,Mini review ,lcsh:Biochemistry ,Two-photon excitation microscopy ,Long period ,Autophagy ,Esophagitis ,Humans ,lcsh:QD415-436 ,lcsh:QH301-705.5 ,Molecular Biology ,Lipid rafts ,Fluorescent Dyes ,Physics ,Photons ,Microscopy, Confocal ,General Medicine ,Mitochondria ,Cell biology ,lcsh:Biology (General) ,Molecular Probes ,Lysosomes - Abstract
Two-photon microscopy (TPM), which uses two photons of lower energy as the excitation source, is a vital tool in biology and clinical science, due to its capacity to image deep inside intact tissues for a long period of time. To make TPM a more versatile tool in biomedical research, we have developed a variety of two-photon probes for specific applications. In this mini review, we will briefly discuss two-photon probes for lipid rafts, lysosomes, mitochondria, and pH, and their biomedical applications. [BMB Reports 2013; 46(4): 188-194]
- Published
- 2013
29. Eliminations from (E)-2,4-Dinitrobenzaldehyde O-Aryloximes Promoted by R3N/R3NH+in 70 mol% MeCN(aq). Effects of Leaving Group and Base-Solvent on the Nitrile-Forming Transition-State
- Author
-
Sang Yong Pyun and Bong Rae Cho
- Subjects
chemistry.chemical_classification ,Reaction mechanism ,Nitrile ,Base (chemistry) ,Leaving group ,General Chemistry ,Photochemistry ,Medicinal chemistry ,Catalysis ,Solvent ,chemistry.chemical_compound ,Elimination reaction ,chemistry ,E1cB-elimination reaction - Abstract
Elimination reactions of (E)-2,4-(NO2)2C6H2CH=NOC6H3-2-X-4-NO2 (1a-e) promoted by R3N/R3NH + in 70 mol % MeCN(aq) have been studied kinetically. The reactions are second-order and exhibit Bronsted β = 0.800.84 and |βlg| = 0.39-0.42, respectively. For all leaving groups and bases employed in this study, the β and |βlg| values remained almost the same. The results can be described by a negligible pxy interaction coefficient, pxy = ∂β/pKlg = ∂βlg/pKBH ≈ 0, which describes the interaction between the base catalyst and the leaving group. The negligible pxy interaction coefficient is consistent with the (E1cb)irr mechanism. Change of the base-solvent system from R3N/MeCN to R3N/R3NH + -70 mol % MeCN(aq) changed the reaction mechanism from E2 to (E1cb)irr. Noteworthy was the relative insensitivity of the transition state structure to the reaction mechanism change.
- Published
- 2013
30. Mitochondrial-Targeted Two-Photon Fluorescent Probes for Zinc Ions,H2O2, and Thiols in Living Tissues
- Author
-
Bong Rae Cho and Hwan Myung Kim
- Subjects
chemistry.chemical_classification ,Aging ,Reactive oxygen species ,Cell ,chemistry.chemical_element ,Cell Biology ,General Medicine ,Glutathione ,Mitochondrion ,Biochemistry ,Fluorescence ,Redox ,Oxygen ,chemistry.chemical_compound ,medicine.anatomical_structure ,chemistry ,Two-photon excitation microscopy ,medicine - Abstract
Mitochondria provide the energy of the cells and are the primary site of oxygen consumption and the major source of reactive oxygen species. In mitochondria, metal ions and glutathione play vital roles in maintaining their structure and the redox environment. To understand their roles in mitochondria, it is crucial to monitor each of these chemical species in the mitochondria at the cell, tissue, and organism levels. An ideal tool for such purpose is the use of two-photon microscopy (TPM). Until recently, however, there has been no report on the two-photon (TP) probes suitable for such applications. In this paper, we summarize the mitochondria-targeted TP probes for Zn2+, H2O2, and thiols, as well as their bioimaging applications.
- Published
- 2013
31. Simultaneous Imaging of Mitochondria and Lysosomes by Using Two-Photon Fluorescent Probes
- Author
-
Min Kyu Park, Ji Hee Han, Sun Keun Park, Bong Rae Cho, Hwan Myung Kim, Chang Su Lim, and Hyung Joong Kim
- Subjects
Diagnostic Imaging ,Photons ,Photon ,Molecular Structure ,Chemistry ,Organic Chemistry ,General Chemistry ,Mitochondrion ,Fluorescence ,Catalysis ,Mitochondria ,Mice ,Autofluorescence ,Two-photon excitation microscopy ,Biophysics ,Animals ,Lysosomes ,Fluorescent Dyes - Published
- 2012
32. Eliminations from (E)-2,4-Dinitrobenzaldehyde O-Aryloximes Promoted by R3N in MeCN. Effects of β-Aryl Group and Base-Solvent on the Nitrile-Forming Transition-State
- Author
-
Eun Mi Ryu, Sang Yong Pyun, and Bong Rae Cho
- Subjects
Solvent ,chemistry.chemical_compound ,Nitrile ,Chemistry ,Stereochemistry ,Group (periodic table) ,Picrate ,Aryl ,Leaving group ,Substituent ,General Chemistry ,Medicinal chemistry ,Reaction coordinate - Abstract
The transition state was shifted toward theE1cb corner by an electron-withdrawing β-aryl substituentand toward the E1 intermediate and the product by astronger base in the reaction coordinate diagram. On theother hand, when the leaving group was changed from 2,4-dinitrophenoxide to picrate, the ρ value decreased but the βvalue increased. The results are in conflict with the predic-tion of the reaction coordinate diagram because both ρ and βvalues should be decreased with a better leaving group. Theunusual changes in the transition-state structure noted withthe leaving group variation have been interpreted as result-ing from a large difference in the anion-stabilizing ability ofthe leaving groups. However, the validity of this interpreta-tion remains to be verified. To determine whether a change in mechanism could berealized by introducing an even more electron-withdrawingβ-aryl substituent, we have now studied the reactions of ( E)-2,4-dinitrobenzaldehyde O-aryloxime with R
- Published
- 2012
33. Dual-Color Imaging of Magnesium/Calcium Ion Activities with Two-Photon Fluorescent Probes
- Author
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Ji Hee Han, Xiaohu Dong, Bong Rae Cho, Hwan Myung Kim, Cheol Ho Heo, and Zhihong Liu
- Subjects
Ions ,Photons ,Molecular Structure ,Chemistry ,Radiochemistry ,Analytical chemistry ,Hep G2 Cells ,Fluorescence ,Analytical Chemistry ,Ion ,Microscopy, Fluorescence, Multiphoton ,BCAM ,Two-photon excitation microscopy ,Microscopy ,Humans ,Molecule ,Calcium ,Magnesium ,Dual color ,Intracellular ,Fluorescent Dyes - Abstract
We report two-photon probes (FMg1 and FMg2) that can selectively detect intracellular free Mg(2+) ([Mg(2+)](i)) in live cells and tissues by two-photon microscopy. Combined with BCaM, a two-photon probe for near-membrane Ca(2+) ([Ca(2+)](m)), FMg2 allows dual-color imaging of Mg(2+)/Ca(2+) activities in live cells and [Mg(2+)](i) /[Ca(2+)](m) distributions in live tissues at a depth of 100-200 μm.
- Published
- 2012
34. A Small-Molecule Two-Photon Probe for Nitric Oxide in Living Tissues
- Author
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Hwan Myung Kim, Eun Won Seo, Cheol Ho Heo, Ji Hee Han, Bong Rae Cho, and Jae Ho Shin
- Subjects
Diagnostic Imaging ,Photons ,Molecular Structure ,Organic Chemistry ,Analytical chemistry ,General Chemistry ,Nitric Oxide ,Small molecule ,Fluorescence ,Catalysis ,Nitric oxide ,Mice ,chemistry.chemical_compound ,Microscopy, Fluorescence, Multiphoton ,chemistry ,Two-photon excitation microscopy ,Microscopy ,Biophysics ,Animals ,Molecular imaging ,Nitrogen oxides ,Fluorescent Dyes - Abstract
Two-photon microscopy (TPM) has become an indispensable tool in the study of biology and medicine due to the capability of this method for molecular imaging deep inside intact tissues. For the maximum utilization of TPM, a variety of two-photon (TP) probes for specific applications are needed. In this article, we report a small-molecule TP probe (ANO1) for nitric oxide (NO) that shows a rapid and specific NO response, a 68-fold fluorescence enhancement in response to NO, and a maximum TP-action cross-section of 170 GM (GM: 10(-50) cm(4) photon(-1)) upon reaction with excess NO. This probe can be easily loaded into cells and tissues and can real-time monitor NO in living tissues at 100-180 μm depth for longer than 1200 s through the use of TPM, with minimum interference from other biologically relevant species.
- Published
- 2012
35. Measurement of pH Values in Human Tissues by Two-Photon Microscopy
- Author
-
Eun Sun Kim, Hoon Jai Chun, Bong Rae Cho, Hee Jung Park, Tae Hee Lee, Chang Su Lim, and Ji Hee Han
- Subjects
Microscopy, Confocal ,Pyridines ,Chemistry ,Analytical chemistry ,General Medicine ,General Chemistry ,Hydrogen-Ion Concentration ,Naphthalenes ,Esophageal Diseases ,medicine.disease ,Gastroesophageal Junction ,Catalysis ,Two-photon excitation microscopy ,Live cell imaging ,Toxicity ,Microscopy ,medicine ,Biophysics ,Esophageal sphincter ,Humans ,Esophagogastric Junction ,Oxazoles ,Esophagitis ,Fluorescent Dyes ,HeLa Cells - Abstract
pH values go live! A ratiometric two-photon (TP) probe (NP1, see scheme) that has a significant TP action cross-section, high photostability, negligible toxicity, and can estimate pH values in live cells and human tissues by two-photon microscopy is described. NP1 can detect the difference in pH between live cells from the gastroesophageal junction (GEJ) and the lower esophageal sphincter of patients with and without esophagitis.
- Published
- 2012
36. pH-responsive water soluble smart vesicles containing a bis(styryl)benzene derivative for two-photonmicroscopy imaging
- Author
-
Ji Hee Han, Boram Kim, Bong Rae Cho, Okhil K. Nag, Chang Su Lim, Han Young Woo, Jihye Jang, and Bao Lam Nguyen
- Subjects
Materials science ,Two-photon excitation microscopy ,Transmission electron microscopy ,Bilayer ,Vesicle ,Microscopy ,Materials Chemistry ,Analytical chemistry ,Quantum yield ,General Chemistry ,Nanocarriers ,Photochemistry ,Fluorescence - Abstract
We report self-assembled polymeric nanovesicles composed of 1,4-bis{4′-[N,N-bis(6′′-trimethylammoniumhexyl)amino]styryl}benzene tetrabromide (C1), poly[(ethylene oxide)-block-(sodium 2-acrylamido-2-methyl-1-propane sulfonate)] (Em-An), and hexadecyltrimethylammonium bromide (C16). Transmission electron microscopy (TEM) micrographs confirm the vesicular bilayer structures and atomic force microscopy (AFM) images show that the C1/Em-An/C16 complexes form spherical nanostructures with a particle size ranging from 40 to 80 nm. The encapsulation of C1 inside the nanovesicles enhances ∼2-fold the fluorescence quantum yield (η) and two-photon action cross-section (ηδ, where δ is the two-photon absorption cross-section), and allows internalization into the cells, as revealed by the bright two-photon microscopy (TPM) images of human cervical epithelioid carcinoma (HeLa) cells labeled with the nanovesicles. Moreover, nanovesicles containing a chemotherapeutic drug and a neutral molecule can also be prepared. Furthermore, the C1/vesicular complex is disassembled under acidic conditions, highlighting its potential as a pH-responsive smart nanocarrier for the intracellular drug delivery. These results suggest a new possibility of using nanovesicles as efficient two-photon probes for TPM imaging and possibly as nanocarriers for intracellular drug delivery.
- Published
- 2012
37. Detection of Cu(I) and Zn(II) ions in colon tissues by multi-photon microscopy: novel marker of antioxidant status of colon neoplasm
- Author
-
Hoon Jai Chun, Chang Su Lim, Ho Sang Ryu, Eun Sun Kim, Hong Sik Lee, Chang Duck Kim, Bong Rae Cho, Yong Sik Kim, Yoon Tae Jeen, Yeon Seok Seo, Soon Ho Um, and Bora Keum
- Subjects
Adult ,Pathology ,medicine.medical_specialty ,Antioxidant ,Adenoma ,medicine.medical_treatment ,Normal colon ,Pilot Projects ,Multi photon microscopy ,Antioxidants ,Pathology and Forensic Medicine ,Superoxide dismutase ,Cell Line, Tumor ,medicine ,Biomarkers, Tumor ,cancer ,Humans ,Aged ,Ions ,biology ,Chemistry ,Carcinoma ,General Medicine ,Middle Aged ,medicine.disease ,Fluorescence ,Molecular biology ,Trace Elements ,Zinc ,Microscopy, Fluorescence, Multiphoton ,Molecular Probes ,Colonic Neoplasms ,Colon neoplasm ,biology.protein ,Adenocarcinoma ,Original Article ,GI neoplasms ,Copper - Abstract
Aims Establishing probe-based analysis is important for developing multi-photon microscopy (MPM) to make an early diagnosis of colon neoplasm and assess its antioxidant status. Cu(I) and Zn(II) ions are trace elements which roll as cofactors of antioxidant, superoxide dismutase. However, there have been no reports on the features of MPM image using probe of Cu(I) and Zn(II) ions. Our main objective in this study was application of newly developed multi-photon probe (MP) probe on Cu(I) and Zn(II) ions as a tool to assess antioxidative status of colon neoplasm. Methods This study was a pilot study. Colon cancer cell lines (ACT116 and HT-29), NIH3T3 cells and tissues of normal colon mucosa and colon neoplasm obtained during colonoscopic biopsy from 17 patients were stained with MP probes for Cu(I) and Zn(II) (ACu1 and AZn1). Cu(I)/Zn(II) levels in the cells and tissues were determined by detecting MP-excited fluorescence by MPM. Results MPM images of cells stained with MP probes revealed that Cu(I) was more abundant in ACT116 and HT-29 cells than in NIH3T3 cells, while Zn(II) was more abundant in NIH3T3 cells than in ACT116 and HT-29 cells. Normal tissues had a defined texture, whereas adenoma/adenocarcinoma tissues were amorphous. The level of Cu(I) increased and that of Zn(II) decreased with the transition from normal to adenoma to adenocarcinoma tissue. Conclusion MPM can be used to determine the relative Cu(I)/Zn(II) levels in cells and colon tissues by using ACu1 and AZn1 as MPM probes. These finding are new research tools for gastroenterologists to assess antioxidant status of colon neoplasm.
- Published
- 2012
38. Measurement of the Nucleus Area and Nucleus/Cytoplasm and Mitochondria/Nucleus Ratios in Human Colon Tissues by Dual-Colour Two-Photon Microscopy Imaging
- Author
-
Dong Eun Kang, Hoon Jai Chun, Bong Rae Cho, Chang Su Lim, Seung Taek Hong, Eun Sun Kim, and Ji-Yeon Kim
- Subjects
Diagnostic Imaging ,Cytoplasm ,Pathology ,medicine.medical_specialty ,Colon ,Colon Adenoma ,Biology ,Mitochondrion ,Sensitivity and Specificity ,Article ,Two-photon excitation microscopy ,Organelle ,medicine ,Humans ,Fluorescent Dyes ,Cell Nucleus ,Multidisciplinary ,Molecular Structure ,Reproducibility of Results ,DNA ,Fluorescence ,Mitochondria ,Cell nucleus ,Microscopy, Fluorescence, Multiphoton ,Spectrometry, Fluorescence ,medicine.anatomical_structure ,Colonic Neoplasms ,Biophysics ,Nucleus ,HeLa Cells - Abstract
We developed two-photon (TP) probes for DNA (ABI-Nu), cytoplasm (Pyr-CT) and mitochondria (BF-MT). We found that ABI-Nu binds to AT in the minor groove, while ABI-Nu and BF-MT are effective for tracking in the cytoplasm and mitochondria, respectively. These probes showed very large effective two-photon action cross section values of 2230, 1555 and 790 Göppert-Mayer units (1 GM = 10−50 cm4 s photon−1molecule−1) at 740 nm with emission maxima at 473, 561 and 560 nm, respectively, in each organelle. Using these probes, we quantitatively estimated the mean nuclear area and the ratios of nuclei to cytoplasm and mitochondria to nuclei in human colon tissues by dual-colour two-photon microscopy imaging within 2 h after biopsy. The mean nuclear area and the nuclei to cytoplasm and mitochondria to cytoplasm ratios increased in the following order: normal colon mucosa
- Published
- 2015
39. ChemInform Abstract: Two-Photon Probes for Biomedical Imaging
- Author
-
Chang Su Lim and Bong Rae Cho
- Subjects
Optics ,Two-photon excitation microscopy ,business.industry ,Chemistry ,Medical imaging ,General Medicine ,business - Published
- 2015
40. Fluorescent turn-on Zn2+ sensing in aqueous and cellular media
- Author
-
Sankarprasad Bhuniya, Chang Su Lim, Bong Rae Cho, Tuhin Pradhan, Sungtae Kim, Jae Hong Lee, Jong Seung Kim, and Sumin Lee
- Subjects
inorganic chemicals ,Aqueous solution ,Confocal ,Metals and Alloys ,Condensed Matter Physics ,Fluorescence ,Combinatorial chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,biological sciences ,health occupations ,Materials Chemistry ,Fluorescence microscope ,bacteria ,Moiety ,Organic chemistry ,Chelation ,Carboxylate ,Electrical and Electronic Engineering ,Instrumentation ,Intracellular - Abstract
A naphthalimide-based water soluble Zn2+ sensor bearing polyamino carboxylate as a metal chelating moiety was synthesized and its application for the selective detection of Zn2+ ion in 100% aqueous solution is demonstrated. The newly developed fluorescent sensor exhibits selective binding affinity towards Zn2+ and pH insensitivity in biologically relevant range. Confocal fluorescent microscopy images indicate that this probe works effectively for intracellular Zn2+ imaging with high cell permeability.
- Published
- 2011
41. Two-Photon Lysotrackers for in Vivo Imaging
- Author
-
Chang Su Lim, Isravel Antony Danish, Ji Hee Han, Ji Hoon Son, Hwan Myung Kim, and Bong Rae Cho
- Subjects
Photons ,business.industry ,Chemistry ,Organic Chemistry ,Colocalization ,Nanotechnology ,Laser ,Hippocampus ,Molecular Imaging ,Rats ,law.invention ,Two-photon excitation microscopy ,law ,Excited state ,Long period ,Microscopy ,Femtosecond ,Animals ,Optoelectronics ,Amines ,business ,Preclinical imaging ,Fluorescent Dyes - Abstract
We report two-photon Lysotrackers (CLT-blue and CLT-yellow) that can be excited by 750-840 nm femtosecond laser pulses and emit at 470 and 550 nm, respectively. They can be easily loaded into cells and tissue slices for visualization of lysosomes in live cells and tissues for a long period of time through two-photon microscopy. When combined with appropriate two-photon probes for other biological targets, these novel probes would greatly facilitate the two-photon microscopy colocalization experiments.
- Published
- 2011
42. Ratiometric Detection of Mitochondrial Thiols with a Two-Photon Fluorescent Probe
- Author
-
Hyung Joong Kim, Ji Hee Han, Bong Rae Cho, Goutam Masanta, Chang Su Lim, and Hwan Myung Kim
- Subjects
chemistry.chemical_classification ,Photons ,General Chemistry ,Biochemistry ,Fluorescence ,Catalysis ,Mitochondria ,Microscopy, Fluorescence, Multiphoton ,Colloid and Surface Chemistry ,chemistry ,Two-photon excitation microscopy ,Microscopy ,Thiol ,Ph range ,Biophysics ,Humans ,Sulfhydryl Compounds ,Selectivity ,Cytotoxicity ,Fluorescent Dyes ,HeLa Cells - Abstract
We report a ratiometric two-photon probe (SSH-Mito) for mitochondrial thiols. This probe shows a marked blue-to-yellow emission color change in response to RSH, a significant two-photon cross section, good mitochondrial thiol selectivity, low cytotoxicity, and insensitivity to pH over the biologically relevant pH range, allowing the direct visualization of RSH levels in live cells as well as in living tissues at 90-190 μm depth without interference from other biologically relevant species through the use of two-photon microscopy.
- Published
- 2011
43. Elimination Reactions of (E)-2,4,6-Trinitrobenzaldehyde O-Aryloximes Promoted by R3N/R3NH+in 70 mol% MeCN(aq). Effect of β-Aryl Group the Nitrile-Forming Transition-State
- Author
-
Bong Rae Cho, Sang Yong Pyun, and Woong Sub Byun
- Subjects
Nitrile ,Stereochemistry ,Aryl ,Kinetics ,Leaving group ,chemistry.chemical_element ,General Chemistry ,Medicinal chemistry ,chemistry.chemical_compound ,Elimination reaction ,chemistry ,Mole ,Carbon ,Bond cleavage - Abstract
Nitrile-forming eliminations from (1) promoted by in 70 mol % MeCN(aq) have been studied kinetically. When X = , the reactions exhibited second-order kinetics as well as Brnsted = 0.63 and = 0.34-0.46, and an E2 mechanism is evident. As the leaving group was made poorer (X = H, Cl, and ), Brnsted value increased from 0.63 to 0.85-0.89 without much change in the value E2, indicating that structure of the transition state changed to an E1cb-like with extensive bond cleavage, significant negative charge development at the -carbon, and limited -OAr bond cleavage.
- Published
- 2011
44. In Vivo Imaging of Near-Membrane Calcium Ions with Two-Photon Probes
- Author
-
Chang Su Lim, Ji Hee Han, Isravel Antony Danish, Min Young Kang, and Bong Rae Cho
- Subjects
Cations, Divalent ,Chemistry ,Metal ions in aqueous solution ,Cell Membrane ,Organic Chemistry ,Analytical chemistry ,chemistry.chemical_element ,General Chemistry ,Calcium ,Hippocampus ,Biochemistry ,Fluorescence ,Cell Line ,Ion ,Dissociation constant ,Mice ,Microscopy, Fluorescence, Multiphoton ,Membrane ,Two-photon excitation microscopy ,Animals ,Preclinical imaging ,Fluorescent Dyes - Abstract
We report a two-photon (TP) probe (ACaLN) for near-membrane Ca(2+) that shows a 13-fold TP excited fluorescence (TPEF) enhancement in response to Ca(2+), dissociation constants (K(d)(TP)) of (1.9±0.2) μM, pH-insensitivity at the biologically relevant pH, and can detect near-membrane Ca(2+) in live cells for more than 1500 s and in living tissues at 120 μm depth without interference from other metal ions. Comparison with existing probes provides a useful strategy for the design of efficient TP probes for the near-membrane metal ions.
- Published
- 2011
45. Two‐Photon Probes for Zn 2+ Ions with Various Dissociation Constants. Detection of Zn 2+ Ions in Live Cells and Tissues by Two‐Photon Microscopy
- Author
-
Bong Rae Cho, Isravel Antony Danish, Chang Su Lim, Yu Shun Tian, Min Young Kang, and Ji Hee Han
- Subjects
Analytical chemistry ,chemistry.chemical_element ,Zinc ,Hippocampus ,Biochemistry ,Ion ,HeLa ,Two-photon excitation microscopy ,Animals ,Humans ,Fluorescent Dyes ,Ions ,Photons ,Aqueous solution ,biology ,Organic Chemistry ,General Chemistry ,Hydrogen-Ion Concentration ,biology.organism_classification ,Photobleaching ,Fluorescence ,Rats ,Dissociation constant ,Microscopy, Fluorescence, Multiphoton ,chemistry ,HeLa Cells - Abstract
A series of Zn(2+)-selective two-photon fluorescent probes (AZnM1-AZnN) that had a wide range of dissociation constants (K(d) (TP) =8 nm-12 μM) were synthesized. These probes showed appreciable water solubility (>3 μM), cell permeability, high photostability, pH insensitivity at pH>7, significant two-photon action cross-sections (86-110 GM) upon complexation with Zn(2+), and can detect the Zn(2+) ions in HeLa cells and in living tissue slices of rat hippocampal at a depth of >80 μm without mistargeting and photobleaching problems. These probes can potentially find application in the detection of various amounts of Zn(2+) ions in live cells and intact tissues.
- Published
- 2011
46. A Two-Photon Turn-On Probe for Lipid Rafts with Minimum Internalization
- Author
-
Jun Han Lee, Chang Su Lim, Hwan Myung Kim, Chul Hoon Kim, Hyung Joong Kim, Taiha Joo, Bong Rae Cho, and Yu Shun Tian
- Subjects
Alkanesulfonates ,Biochemistry ,Cell Line ,chemistry.chemical_compound ,Membrane Microdomains ,Two-photon excitation microscopy ,2-Naphthylamine ,Fluorescence microscope ,Humans ,Molecular Biology ,Lipid raft ,Fluorescent Dyes ,Photons ,Vesicle ,Organic Chemistry ,Sarcosine ,Raft ,Fluorescence ,Sphingomyelins ,Cell biology ,Cholesterol ,Microscopy, Fluorescence ,chemistry ,Phosphatidylcholines ,Biophysics ,Molecular Medicine ,Sphingomyelin ,Laurdan - Abstract
The lo domains, also called lipid rafts, are believed to serve as a platform to support various cellular processes such as signal transduction, membrane trafficking, pathogen invasion, cholesterol homeostasis, neurodegenerative diseases, and angiogenesis. The existence of lipid rafts has been demonstrated in mammalian cells and in model membranes by using various techniques such as atomic force microscopy, fluorescence microscopy, and coherent anti-Stokes Raman scattering microscopy. To understand their roles in cell biology, it is crucial to visualize such domains in the live cells and tissues. An ideal tool for this purpose is two-photon microscopy (TPM) that utilizes two near-infrared photons for excitation. The advantages of TPM include the capability of visualizing the real-time activities of the biological targets in live cells and intact tissues at >100 mm depth with minimum interference due to the tissue preparation artifacts that can extend ~70 mm from the tissue surface. For maximum utilization of TPM, many TP probes for specific applications are needed. However, TP probes for such applications are rare. Earlier, we reported a membrane TP polarity probe, CL, which showed several advantages over laurdan including greater sensitivity to the solvent polarity, brighter TPM image, and more precise reflection of the cell environment. We also developed a TP turn-on probe, CL2, which showed larger TP action cross-section and higher sensitivity to the polarity of the environment than CL. This allowed selective detection of the lipid rafts in live cells and tissues by TPM. Unfortunately, CL2 had one shortcoming; it internalized into the cytoplasm upon prolonged incubation with cells, causing a blurred TPM image. To overcome this problem, we have designed a new TP turn-on (off-on) probe (SL2) that has sodium sulfonate in the head group and exclusively stains the plasma membrane. Herein, we report that SL2 can detect the lipid rafts in the live cells and intact tissues without internalization problems by simply collecting the TP excited fluorescence (TPEF) by using TPM. The preparation of SL2 is given in the Supporting Information. The solubility of SL2 in water was 7 mm, which is sufficient to stain the cells (Figure S1 in the Supporting Information). The change of the head group from a carboxylic acid (CL2, 4 mm) to a sulfonate increased the water solubility by ~ twofold. The absorption and emission spectra of SL2 showed gradual bathochromic shifts with increasing solvent polarity (Figure 1A and Table S1) indicating the charge-transfer character of the emitting state. The shifts were larger for the emission than for the absorption spectra (21 vs. 126 nm). Moreover, the fluorescence quantum yield (F) increased by 22-fold as the solvent was changed from EtOH/H2O (F=0.04) to THF (F=0.88). CL2 showed similar behavior except that fluorescence enhancement factor (FEF) was lower [FEF(CL2)=16 versus FEF(SL2)= 22] (Table S1). Hence, the fluorescence of SL2 is more sensitive to the polarity of the environment than that of CL2. The fluorescence intensity of SL2 showed similar decrease with the hydrophilicity of the large unilamellar vesicles (LUVs) in the order, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cholesterol (DPPC/CHL (40 mol%), lo)>DOPC/sphingomyelin/CHL (1:1:1, raft mixture)>1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC, ld ; Figure S2). The relative fluorescence intensities of SL2 in DPPC/CHL/raft mixture/DOPC in the 420–520 nm range are 7.0/4.8/1.0, respectively; SL2 emits sevenfold stronger fluorescence in the lo than in the ld domain. The slightly weaker fluorescence in the raft mixture than in DPPC/CHL can be explained if SL2 exists in 63/37 ratio in the lo/ld domains of the raft mixture with 7/1 intensity ratio (vide supra). A similar result was reported for CL2 (lo/ld=86:14). [12] This indicates high preference of these probes to reside in the lo domain, which can be attributed to the more favorable hydrophobic interactions with sphingomyelin when compared to DOPC. The sensitivity of the laurdan derivatives on the polarity of the environment originates from the intramolecular charge [a] C. S. Lim, J. H. Lee, Dr. Y. S. Tian, Prof. B. R. Cho Department of Chemistry, Korea University 1-Anamdong, Seoul, 136-701 (Korea) Fax: (+82)2-3290-3544 E-mail : chobr@korea.ac.kr [b] H. J. Kim, Prof. H. M. Kim Division of Energy Systems Research, Ajou University Suwon, 443-749 (Korea) E-mail : kimhm@ajou.ac.kr [c] Dr. C. H. Kim, Prof. T. Joo Department of Chemistry, Pohang University of Science and Technology Pohang, 790-784 (Korea) E-mail : thjoo@postech.ac.kr Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cbic.201000609.
- Published
- 2010
47. A two-photon excited luminescence of water-soluble rhodamine–platinum(II) complex: Fluorescent probe specific for Hg2+ detection in live cell
- Author
-
Jong Seung Kim, Jun Feng Zhang, Bong Rae Cho, and Chang Su Lim
- Subjects
Ultraviolet Rays ,Metal ions in aqueous solution ,Analytical chemistry ,chemistry.chemical_element ,Photochemistry ,Analytical Chemistry ,Rhodamine ,chemistry.chemical_compound ,Two-photon excitation microscopy ,Microscopy ,Humans ,Fluorescent Dyes ,Platinum ,Ions ,Rhodamines ,Water ,Mercury ,Fluorescence ,Mercury (element) ,Microscopy, Fluorescence ,Models, Chemical ,Solubility ,chemistry ,Metals ,Spectrophotometry, Ultraviolet ,Luminescence ,HeLa Cells - Abstract
The first example of cyclometalated platinum(II)-containing rhodamine probe (1) with two-photon induced luminescent properties was synthesized and investigated for mercury detection. A highly selective color change of 1, from light yellow to pink, is observed only in the presence of Hg2+ due to the formation of 1,3,4-oxadiazole ring in 2. This selectivity of Hg2+ with color changes can be observed easily by the naked-eye. Meanwhile, a remarkable turn-on and selective 20-fold fluorescent enhancement of 1 upon binding with Hg2+ over the other tested metal ions was observed. The water-soluble probe 1 was successfully applied in the visualizing of the site of Hg2+ accumulation as well as estimating of trace amounts of mercury ions in live HeLa cells by two-photon microscopy.
- Published
- 2010
48. Two-Photon Absorption Properties of Cationic 1,4-Bis(styryl)benzene Derivative and Its Inclusion Complexes with Cyclodextrins
- Author
-
Okhil K. Nag, In Hong Kim, Rati Ranjan Nayak, Chang Su Lim, Han Young Woo, Bong Rae Cho, and Kwangseuk Kyhm
- Subjects
Cyclodextrins ,Photons ,Cationic polymerization ,Photochemistry ,Two-photon absorption ,Medicinal chemistry ,Absorption ,Surfaces, Coatings and Films ,Quaternary Ammonium Compounds ,chemistry.chemical_compound ,Spectrometry, Fluorescence ,chemistry ,Stilbenes ,Benzene derivatives ,Materials Chemistry ,Humans ,Quantum Theory ,Physical and Theoretical Chemistry ,Absorption (chemistry) ,Ferricyanides ,Benzene ,HeLa Cells - Abstract
Two-photon absorption properties of 1,4-bis{4'-[N,N-bis(6''-trimethylammoniumhexyl)amino]styryl}benzene tetrabromide (C1) and its inclusion complexes (ICs) with cyclodextrins (CDs) have been studied. Upon complexation with CDs, the absorption spectra of C1 showed a slight red shift, whereas the emission spectra showed a blue shift with concomitant increase in the fluorescence quantum efficiency. A Stern-Volmer study using K(3)Fe(CN)(6) as a quencher revealed significant reduction in the photoinduced charge transfer quenching, in accord with the IC formation. Comparison of the spectroscopic results reveals that C1 forms increasingly more stable ICs in the order C1/beta-CDC1/gamma-CDC1/(3gamma:beta)-CD (gamma-CD/beta-CD 3:1, mole ratio). Moreover, the two-photon action cross section of C1 increased from 200 GM for C1 to 400 GM for C1/beta-CD, 460 GM for C1/gamma-CD, and 650 GM for C1/(3gamma:beta)-CD, respectively. Furthermore, the two-photon microscopy images of HeLa cells stained with C1 emitted strong two-photon excited fluorescence in the plasma membrane. These results provide a useful guideline for the development of efficient two-photon materials for bioimaging applications.
- Published
- 2010
49. Base-promoted elimination reactions of (E)- and (Z)-arylaldehyde O-benzoyloximes. Effects of stereochemistry, β-aryl group and base-solvent on the nitrile-forming transition states
- Author
-
Bong Rae Cho and Sang Yong Pyun
- Subjects
chemistry.chemical_classification ,Nitrile ,Base (chemistry) ,Aryl ,Organic Chemistry ,Photochemistry ,Medicinal chemistry ,Transition state ,Solvent ,lcsh:QD241-441 ,chemistry.chemical_compound ,Elimination reaction ,chemistry ,lcsh:Organic chemistry ,Group (periodic table) ,E1cB-elimination reaction - Published
- 2010
50. Mitochondrial oxidative phosphorylation system is recruited to detergent-resistant lipid rafts during myogenesis
- Author
-
Joo Hyung Lee, Hyo-Jung Choo, Young Mi Ham, Young Gyu Ko, Seok Won Hyung, Hwan Myung Kim, Jae Sung Yi, Sung Gil Chi, Jin Hong, Sang Won Lee, Bong Rae Cho, Joong Won Lee, Soonyoung Jung, Chang Seok Lee, Do Sik Min, Gyesoon Yoon, Bong Woo Kim, and Min Ju Kang
- Subjects
Proteomics ,Detergents ,Oxidative phosphorylation ,Biology ,Mitochondrion ,Muscle Development ,Biochemistry ,Cell Line ,Mice ,Membrane Microdomains ,medicine ,Extracellular ,Animals ,Phosphorylation ,Molecular Biology ,Lipid raft ,Sarcolemma ,Myogenesis ,Skeletal muscle ,Mitochondria ,Cell biology ,Oxygen ,medicine.anatomical_structure ,lipids (amino acids, peptides, and proteins) ,Signal transduction - Abstract
Since detergent-resistant lipid rafts play important roles in the signal transduction for myogenesis, their comprehensive proteomic analysis could provide new insights to understand their function in myotubes. Here, the detergent-resistant lipid rafts were isolated from C2C12 myotubes and analyzed by capillary RPLC/MS/MS. Among the 327 proteins (or protein groups) identified, 28% were categorized to the plasma membrane or raft proteins, 29% to mitochondria, 20% to microsomal proteins, 10% to other proteins, and 13% to unknown proteins. The localization of oxidative phosphorylation (OXPHOS) complexes in the sarcolemma lipid rafts was further confirmed from C2C12 myotubes by cellular fractionation, surface-biotin labeling, immunofluorescence, and lipid raft fractionation. After adding exogenous cytochrome c, the sarcolemma isolated from myotubes had an ability to consume oxygen in the presence of NADH or succinate. The generation of NADH-dependent extracellular superoxide was increased by inhibiting or downregulating OXPHOS I, III, and IV in myotubes, indicating that OXPHOS proteins are major sources for extracellular ROS in skeletal muscle. With all these data, we can conclude that OXPHOS proteins are associated with the sarcolemma lipid rafts during C2C12 myogenesis to generate extracellular ROS.
- Published
- 2010
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