The Experts below are selected from a list of 78 Experts worldwide ranked by ideXlab platform
Bo Gil Choi - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of C _6-epimer Derivatives of diacetoxy Acetal Derivative of santonin and their inducing effects on HL-60 leukemia cell differentiation
Archives of Pharmacal Research, 2011Co-Authors: Sin Ho Kweon, Joon Hee Hong, Bo Gil ChoiAbstract:Induction of differentiation is a new and promising approach to leukemia therapy, well illustrated by the treatment of acute promyelocytic leukemia with 1,25-dihydroxyvitamin D_3 [1,25-(OH)_2D_3] or all- trans retinoic acid (ATRA). Using combination of either 1,25-(OH)_2D_3 or ATRA and chemotherapy, adverse effects 1,25-(OH)_2D_3 or ATRA such as hypercalcemic effects have decreased, and long-term survival has improved. In a previous study, we demonstrated that santonin could be chemically modified into a diacetoxy Acetal Derivative of santonin with strong differentiation-inducing activity. In this study, we further synthesized C_6-epimer Derivatives of diacetoxy Acetal Derivative of santonin and tested their effects on HL-60 cell differentiation. Some of the C_6-epimer Derivatives themselves induced increases in cell differentiation. Especially, (11 S )-3,3-(ethylenedioxy) eudesmano-13-ol-6β-acetate ( 7 ) was demonstrated to induce differentiation with larger than 80% of the cells attaining a differentiated phenotype. Importantly, 7 strongly enhanced differentiation of HL-60 cells in a dose-dependent manner when combined with either low doses of 1,25-(OH)_2D_3 or ATRA. The ability to enhance the differentiation potential of 1,25-(OH)_2D_3 or ATRA by 7 may improve outcomes in the therapy of acute promyelocytic leukemia.
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Synthesis of DAAS Derivatives and their enhancement of HL-60 leukemia cell differentiation
Archives of Pharmacal Research, 2008Co-Authors: Sun Young Chung, Bo Gil ChoiAbstract:DAAS is the diacetoxy Acetal Derivative of a-santonin and induces HL-60 cell differentiation into granulocytes. In this report, we investigated the structure-activity relationship (SAR) of DAAS Derivatives in the differentiation of human HL-60 leukemia cells. Although its Derivatives themselves had less effect on HL-60 cell differentiation than DAAS, the monoacetyl Derivative, 2 , mainly induced HL-60 cell differentiation. Moreover, compound 2 synergistically enhanced all- trans retinoic acid (ATRA)-induced HL-60 cell differentiation when combined with 50 nM ATRA, a well-known differentiation inducer. This enhancing effect is similar to that of DAAS in ATRA-induced differentiation.
Sun Young Chung - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of DAAS Derivatives and their enhancement of HL-60 leukemia cell differentiation
Archives of Pharmacal Research, 2008Co-Authors: Sun Young Chung, Bo Gil ChoiAbstract:DAAS is the diacetoxy Acetal Derivative of a-santonin and induces HL-60 cell differentiation into granulocytes. In this report, we investigated the structure-activity relationship (SAR) of DAAS Derivatives in the differentiation of human HL-60 leukemia cells. Although its Derivatives themselves had less effect on HL-60 cell differentiation than DAAS, the monoacetyl Derivative, 2 , mainly induced HL-60 cell differentiation. Moreover, compound 2 synergistically enhanced all- trans retinoic acid (ATRA)-induced HL-60 cell differentiation when combined with 50 nM ATRA, a well-known differentiation inducer. This enhancing effect is similar to that of DAAS in ATRA-induced differentiation.
Sin Ho Kweon - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of C _6-epimer Derivatives of diacetoxy Acetal Derivative of santonin and their inducing effects on HL-60 leukemia cell differentiation
Archives of Pharmacal Research, 2011Co-Authors: Sin Ho Kweon, Joon Hee Hong, Bo Gil ChoiAbstract:Induction of differentiation is a new and promising approach to leukemia therapy, well illustrated by the treatment of acute promyelocytic leukemia with 1,25-dihydroxyvitamin D_3 [1,25-(OH)_2D_3] or all- trans retinoic acid (ATRA). Using combination of either 1,25-(OH)_2D_3 or ATRA and chemotherapy, adverse effects 1,25-(OH)_2D_3 or ATRA such as hypercalcemic effects have decreased, and long-term survival has improved. In a previous study, we demonstrated that santonin could be chemically modified into a diacetoxy Acetal Derivative of santonin with strong differentiation-inducing activity. In this study, we further synthesized C_6-epimer Derivatives of diacetoxy Acetal Derivative of santonin and tested their effects on HL-60 cell differentiation. Some of the C_6-epimer Derivatives themselves induced increases in cell differentiation. Especially, (11 S )-3,3-(ethylenedioxy) eudesmano-13-ol-6β-acetate ( 7 ) was demonstrated to induce differentiation with larger than 80% of the cells attaining a differentiated phenotype. Importantly, 7 strongly enhanced differentiation of HL-60 cells in a dose-dependent manner when combined with either low doses of 1,25-(OH)_2D_3 or ATRA. The ability to enhance the differentiation potential of 1,25-(OH)_2D_3 or ATRA by 7 may improve outcomes in the therapy of acute promyelocytic leukemia.
Joon Hee Hong - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of C _6-epimer Derivatives of diacetoxy Acetal Derivative of santonin and their inducing effects on HL-60 leukemia cell differentiation
Archives of Pharmacal Research, 2011Co-Authors: Sin Ho Kweon, Joon Hee Hong, Bo Gil ChoiAbstract:Induction of differentiation is a new and promising approach to leukemia therapy, well illustrated by the treatment of acute promyelocytic leukemia with 1,25-dihydroxyvitamin D_3 [1,25-(OH)_2D_3] or all- trans retinoic acid (ATRA). Using combination of either 1,25-(OH)_2D_3 or ATRA and chemotherapy, adverse effects 1,25-(OH)_2D_3 or ATRA such as hypercalcemic effects have decreased, and long-term survival has improved. In a previous study, we demonstrated that santonin could be chemically modified into a diacetoxy Acetal Derivative of santonin with strong differentiation-inducing activity. In this study, we further synthesized C_6-epimer Derivatives of diacetoxy Acetal Derivative of santonin and tested their effects on HL-60 cell differentiation. Some of the C_6-epimer Derivatives themselves induced increases in cell differentiation. Especially, (11 S )-3,3-(ethylenedioxy) eudesmano-13-ol-6β-acetate ( 7 ) was demonstrated to induce differentiation with larger than 80% of the cells attaining a differentiated phenotype. Importantly, 7 strongly enhanced differentiation of HL-60 cells in a dose-dependent manner when combined with either low doses of 1,25-(OH)_2D_3 or ATRA. The ability to enhance the differentiation potential of 1,25-(OH)_2D_3 or ATRA by 7 may improve outcomes in the therapy of acute promyelocytic leukemia.
Jonathan Clayden - One of the best experts on this subject based on the ideXlab platform.
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connective synthesis of 5 5 disubstituted hydantoins by tandem α amination and α arylation of silyl ketene Acetals
Chemical Science, 2019Co-Authors: Rakesh K Saunthwal, Matthew T Cornall, Roman Abrams, John W Ward, Jonathan ClaydenAbstract:5,5-Disubstituted hydantoins, formally the cyclisation products of quaternary amino acids, were formed connectively from simple ester-derived starting materials by a one-pot tandem method. Amination of the silyl ketene Acetal Derivative of a methyl ester takes place by silver-catalysed addition to the NN bond of an azocarboxamide, generating a N-amino-N′-aryl urea Derivative of a substituted aminoester. Treatment with a base forms an ester enolate which undergoes arylation by intramolecular migration of an aryl ring to the α-position of the ester. The product undergoes ring closure to a hydantoin, which may itself be deprotected and functionalised. Aryl migration is successful with rings of various electronic character and with esters bearing functionalised and unfunctionalised chains, and the products have features in common with several bioactive compounds.
