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Regioselectivity-driven evolution of CYP102D1 for improved synthesis of 3'-ortho-dihydroxyisoflavone
Choi, K.Y.,Yang, Y.H.,Kim, B.g. IPC Science and Technology Press ; Elsevier Scienc 2015 Enzyme and microbial technology Vol.71 No.-
<P>Daidzein is a major component of isoflavones, and its hydroxylated forms are valuable phytochemicals with anti-cancer and anti-oxidant activity. Due to the limitations of chemical synthesis of these hydroxylated structures, alternative enzymatic synthesis has been attempted. Previously, several protein-engineering approaches using CYP102D1 were investigated; these produced mutants with daidzein hydroxylation activity and regioselectivity through rational design (F96V/M246I) and saturation mutagenesis (A273H/G274E/T277G). However, the generated mutants have low regioselectivity (F96V/M246I) or low hydroxylation activity (A273H/G274E/T277G). Here, we characterized mutants capable of catalyzing C3'-specific daidzein hydroxylation with enhanced hydroxylation activity and regioselectivity. In order to obtain regioselectivity toward the daidzein C3'-position, site-saturation mutagenesis on the substrate-binding region of CYP102D1 F96V/M246I was investigated. A high-throughput screening assay was then performed, based on O-dealkylation activity against the daidzein analog substrate 4'-O-methyl-daidzein. This resulted in a mutant with more than 23-fold improved hydroxylation activity (55.6 +/- 17.9 mu M-1 min(-1), or 48.4 mg/L titer) and regioselectivity over the 3'/6-position that was increased by three-fold (from 0.9 to 2.6) compared with the F96V/M246I template enzyme. Furthermore, we carried out docking simulation studies that could partially explain the effects of these mutations on C3'-specific hydroxylation activity. (C) 2015 Elsevier Inc. All rights reserved.</P>
Copper-catalyzed Regioselective Hydroaminations of Allylic Sulfones With Aromatic Amines
Kundo Kim,조수홍,박수빈,이윤미 대한화학회 2021 Bulletin of the Korean Chemical Society Vol.42 No.4
The highly regioselective copper-catalyzed hydroaminations of terminal or γ-substituted allylic sulfones with aromatic amines is described. The combination of an N-heterocyclic carbene-copper complex and KOt-Bu plays an important role in promoting selective amination under mild reaction conditions. This catalytic reaction tolerates a wide range of functional groups and enables the efficient syntheses of new and versatile functionalized β-amino sulfones in high yields (up to 98%) with >98% regioselectivity.
Plant Flavonoid O-Methyltransferases: Substrate Specificity and Application and Application
Kim, Bong-Gyu,Sung, Su-Hyun,Chong, You-Hoon,Lim, Yoon-Gho,Ahn, Joong-Hoon 한국식물학회 2010 Journal of Plant Biology Vol.53 No.5
Flavonoids consist of a large family of compounds, which has been estimated to be more than 10,000 compounds. The structural diversity of these compounds comes from different modification reactions. The O-methylation reaction is one of the most important modification reactions of flavonoids and the resulting O-methylated flavonoids have been shown to display new biological activities. The regioselective and substrate specific O-methylation is mediated by O-methyltranferases (OMTs). To date, 30 flavonoid OMTs (FOMTs) have been biochemically characterized from various plants. FOMTs utilize common reaction mechanisms to transfer a methyl group to the hydroxyl group of the flavonoid. Phylogenetic tree analysis along with biochemical characterization of FOMTs provides clues about their substrate specificity and regioselectivity. FOMTs can be used for the production of O-methylated flavonoids that have a particular biological activity.
Plant Flavonoid O-Methyltransferases: Substrate Specificity and Application
김봉규,Su Hyun Sung,Youhoon Chong,Yoongho Lim,Joong-Hoon Ahn 한국식물학회 2010 Journal of Plant Biology Vol.54 No.5
Flavonoids consist of a large family of compounds,which has been estimated to bemore than 10,000 compounds. The structural diversity of these compounds comes from different modification reactions. The O-methylation reaction is one of the most important modification reactions of flavonoids and the resulting O-methylated flavonoids have been shown to display new biological activities. The regioselective and substrate specific O-methylation is mediated by O-methyltranferases (OMTs). To date, 30 flavonoid OMTs (FOMTs) have been biochemically characterized from various plants. FOMTs utilize common reaction mechanisms to transfer a methyl group to the hydroxyl group of the flavonoid. Phylogenetic tree analysis along with biochemical characterization of FOMTs provides clues about their substrate specificity and regioselectivity. FOMTs can be used for the production of O-methylated flavonoids that have a particular biological activity.
Jiyeon Park,채정현 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.8
A selective synthetic method of the 2,5-biaryltriazolones has been developed via copper-catalyzed N-arylation reaction. Aryltriazolones, which were readily prepared from commercially available compounds, were N-arylated to 2,5-biaryltriazolones with high regioselectivity. This approach allows for access to a variety of 2,5-biaryl-1,2,4-trizol-3-ones in a simple and practical manner.
Park, Ji-Yeon,Chae, Jung-Hyun Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.8
A selective synthetic method of the 2,5-biaryltriazolones has been developed via copper-catalyzed N-arylation reaction. Aryltriazolones, which were readily prepared from commercially available compounds, were N-arylated to 2,5-biaryltriazolones with high regioselectivity. This approach allows for access to a variety of 2,5-biaryl-1,2,4-trizol-3-ones in a simple and practical manner.
Regio- and Stereoselective Reactions of (S)-(1-Methylpyrrolidin-2-yl)methyl Allyl Sulfide
Park, Ho-Koon,Baik, Nam-Hoon,Lee, Jae-Yeol,Kim, Soo-Ja,Ham, Won-Hoon The Pharmaceutical Society of Korea 1991 Archives of Pharmacal Research Vol.14 No.4
The synthesis and regioselective reactions of a chiral allyl sulfide. (S)-(+)-(1-methylpyrrolidin-2-yl)methyl allyl sulfide (MAS, 1) are described. Remarkable ${\alpha}-regioselectivity$ was observed in the alkylation of the carbanion of MAS while 1:3 mixtures of ${\alpha}-and\;{\gamma}-adducts$ were produced in the addition of the MAS anion to aldehydes. However, a dramatic change of the regioselectivity was witnessed when Lewis acids such as $Et_3Al$, $Et_3B$, and $Ti(O^iPr)_4$ were used as additives in the addition reaction. In these cases, ${\alpha}-adducts$ were formed exclusively. A rationale for the change of regioselectivity is provided. And the stereochemical aspect of the addition reaction is also described.
Chan Woo Lee,Joo Yuen Park,김현욱,Ki-Whan Chi 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.5
Regioselective perfluorinated [3+2] cycloadducts and 1,2-adducts have been prepared by 1,3-dipolar cycloaddition between benzaldoxime NH-nitrone and perfluorinated alkene, perfluoro-2-methyl-2-pentene. Although the cycloaddition reaction is carried out at room temperature, the corresponding perfluorinated compounds are effectively produced in a high yield. In particular, the methoxy-substituted adducts (4 and 7a) show the self-assembled structure by intermolecular interactions. These derivatives were characterized by IR, 1H and 19F NMR, and the absolute structure of perfluorinated adducts was confirmed by X-ray crystallography.
김재현,이규연,이필호 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.7
An efficient method for the bismuth-catalyzed regioselective synthesis of pyranocoumarins and furocoumarins has been developed from the reaction of 4-hydroxycoumarins with propargyl alcohols. The reaction proceeds through sequential propargylation and intramolecular cyclization reactions catalyzed by bismuth(III) triflate.
Regioselective Addition Reactions of the Organoindium Reagents onto α, β-Unsaturated Ketones
이필호,Hyun Kim,이구연,Dong Seomoon,Sundae Kim,Heechul Kim,Hyunseok Kim,Miae Lee,Eunkyong Shim,Seokju Lee,Misook Kim,Mijeong Han,Kwanghyun Noh,Madabhushi Sridhar 대한화학회 2004 Bulletin of the Korean Chemical Society Vol.25 No.11
Regioselectivity on the reactions of α,β-enones with organoindium such as in situ generated allylindium and allenylindium was systematically studied in the presence of TMSCl as an additive. Treatment of 2-cyclohexen- 1-one, carvone, 2-cyclohepten-1-one, and chalcone with allylindium reagent produced 1,4-addition products in good yields, while 2-cyclopenten-1-one, 2-methyl-2-cyclopenten-1-one, 4,4-dimethylcyclohexen-1-one, 3- nonen-2-one, 4-hexen-3-one, and 4-phenyl-3-buten-2-one afforded 1,2-addition products. Indium reagent derived from indium and propargyl bromide in Grignard type gave addition products in good yields, under which the successive addition of α,β-enone and TMSCl were necessary. Although organoindium reagent derived from propargyl bromide produced propargylated compound in Grignard type except 2-cyclohepten-1- one, indium reagent obtained from 1-bromo-2-butyne having γ-methyl group gave allenylated product in Barbier type.