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Křen V, Dvořáková J, Gambert U, Sedmera P, Havlíček V, Thiem J, Bezouška K. Corrigendum to “β-Glucosylation of chitooligomers by galactosyltransferase” [Carbohydr. Res. 305 (1998) 517–523]. Carbohydr Res 2015. [DOI: 10.1016/j.carres.2014.05.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Prikrylova V, Blumauerova M, Sedmera P, Vanek Z, Marsalek J, Kristan V, Прикрилова В, Блумаерова М, Седмера П, Ванек З, Марсалек И, Крищан В, Прикрилова В, Блумаерова М, Седмера П, Ванек З, Марсалек И, Крищан В. Strain Development in Streptomyces virginiae, a Producer of Virginiamycyn. ACTA ACUST UNITED AC 2014. [DOI: 10.1080/02052067.1987.10819271] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Volc J, Sedmera P, Halada P, Dwivedi P, Costa‐Ferreira M. Conversion of d‐Galactose to d‐threo‐Hexos‐2,3‐diulose by Fungal Pyranose Oxidase. J Carbohydr Chem 2011. [DOI: 10.1081/car-120021701] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Jind[rcheck]ich Volc
- a Institute of Microbiology , Academy of Sciences of the Czech Republic , Víde[ncheck]ská 1083, 142 20 , Prague 4 , Czech Republic
| | - Petr Sedmera
- a Institute of Microbiology , Academy of Sciences of the Czech Republic , Víde[ncheck]ská 1083, 142 20 , Prague 4 , Czech Republic
| | - Petr Halada
- a Institute of Microbiology , Academy of Sciences of the Czech Republic , Víde[ncheck]ská 1083, 142 20 , Prague 4 , Czech Republic
| | - Padmanabh Dwivedi
- a Institute of Microbiology , Academy of Sciences of the Czech Republic , Víde[ncheck]ská 1083, 142 20 , Prague 4 , Czech Republic
| | - Maria Costa‐Ferreira
- b Departamento de Biotecnologia , Instituto Nacional de Engenharia e Tecnologia Industrial (INETI) , Est. Paço do Lumiar 22, P‐1649‐038 , Lisboa Codex , Portugal
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Pospíšil S, Petříčková K, Sedmera P, Halada P, Olšovská J, Petříček M. Effect of starter unit availability on the spectrum of manumycin-type metabolites produced by Streptomyces nodosus ssp. asukaensis. J Appl Microbiol 2011; 111:1116-28. [PMID: 21854515 DOI: 10.1111/j.1365-2672.2011.05132.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS Production of minor asukamycin congeners and its new derivatives by combination of targeted genetic manipulations with specific precursor feeding in the producer of asukamycin, Streptomyces nodosus ssp. asukaensis. METHODS AND RESULTS Structural variations of manumycins lie only in the diverse initiation of the 'upper' polyketide chain. Inactivation of the gene involved in the biosynthesis of cyclohexanecarboxylic acid (CHC) turned off the production of asukamycin in the mutant strain and allowed an increased production of other manumycins with the branched end of the upper chain. The ratio of produced metabolites was further affected by specific precursor feeding. Precursor-directed biosynthesis of a new asukamycin analogue (asukamycin I, 28%) with linear initiation of the upper chain was achieved by feeding norleucine to the mutant strain. Another asukamycin analogue with the unbranched upper chain (asukamycin H, 14%) was formed by the CHC-deficient strain expressing a heterologous gene putatively involved in the formation of the n-butyryl-CoA starter unit of manumycin A. CONCLUSIONS Combination of the described techniques proved to be an efficient tool for the biosynthesis of minor or novel manumycins. SIGNIFICANCE AND IMPACT OF THE STUDY Production of two novel asukamycin derivatives, asukamycins H and I, was achieved. Variations appeared in the upper polyketide chain, the major determinant of enzyme-inhibitory features of manumycins, affecting their cancerostatic or anti-inflammatory features.
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Affiliation(s)
- S Pospíšil
- Institute of Microbiology AS CR, Prague, Czech Republic
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Slámová K, Gažák R, Bojarová P, Kulik N, Ettrich R, Pelantová H, Sedmera P, Křen V. 4-Deoxy-substrates for β-N-acetylhexosaminidases: How to make use of their loose specificity. Glycobiology 2010; 20:1002-9. [DOI: 10.1093/glycob/cwq058] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Gazák R, Purchartová K, Marhol P, Zivná L, Sedmera P, Valentová K, Kato N, Matsumura H, Kaihatsu K, Kren V. Antioxidant and antiviral activities of silybin fatty acid conjugates. Eur J Med Chem 2009; 45:1059-67. [PMID: 20036447 DOI: 10.1016/j.ejmech.2009.11.056] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Revised: 10/30/2009] [Accepted: 11/27/2009] [Indexed: 11/29/2022]
Abstract
Two selective acylation methods for silybin esterification with long-chain fatty acids were developed, yielding a series of silybin 7-O- and 23-O-acyl-derivatives of varying acyl chain lengths. These compounds were tested for their antioxidant (inhibition of lipid peroxidation and DPPH-scavenging) and anti-influenza virus activities. The acyl chain length is an important prerequisite for both biological activities, as they improved with increasing length of the acyl moiety.
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Affiliation(s)
- Radek Gazák
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, CZ-142 20 Prague, Czech Republic
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Affiliation(s)
- V. Křen
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, CZ-142 20, Prague 4, Czech Republic
| | - M. ščigelová
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, CZ-142 20, Prague 4, Czech Republic
| | - V. Přikrylová
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, CZ-142 20, Prague 4, Czech Republic
| | - V. Havliček
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, CZ-142 20, Prague 4, Czech Republic
| | - P. Sedmera
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, CZ-142 20, Prague 4, Czech Republic
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Abstract
Two new carbasugars (9 and 10) were isolated from Streptomyces lincolnensis DSM 40355 along with streptol (valienol, 8), gabosine I (valienone, 14), and glucosylglycerate. The reported (1)H and (13)C assignments are based on 1D ((1)H, (13)C, 1D-TOCSY, homodecoupling) and 2D (gCOSY, J-resolved, TOCSY, ROESY, gHSQC, gHMBC) NMR techniques and electrospray ionization FT mass spectrometry (ESI FTMS).
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Affiliation(s)
- Petr Sedmera
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20 Prague, Czech Republic.
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Gazák R, Sedmera P, Vrbacký M, Vostálová J, Drahota Z, Marhol P, Walterová D, Kren V. Molecular mechanisms of silybin and 2,3-dehydrosilybin antiradical activity--role of individual hydroxyl groups. Free Radic Biol Med 2009; 46:745-58. [PMID: 19138735 DOI: 10.1016/j.freeradbiomed.2008.11.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 11/19/2008] [Accepted: 11/20/2008] [Indexed: 10/21/2022]
Abstract
The flavonolignans silybin (1) and 2,3-dehydrosilybin (2) are important natural compounds with multiple biological activities operating at various cell levels. Many of these effects are connected with their radical-scavenging activities. The molecular mechanisms of the antioxidant activity of these compounds and even the functional groups responsible for this activity are not yet well known. Their mechanism can be inferred from the structures of the dimeric products obtained from radical-mediated reactions of selectively methylated derivatives of 1 and 2. The radical oxidation of 1 methylated at 7-OH and 2 methylated at both 3-OH and 7-OH yields C-C and C-O dimers that enable the molecular mechanism of their E-ring interaction with radicals to be elucidated and shows the importance of the 20-OH group in this respect. The pivotal role of the 3-OH group in the radical-scavenging activity of 2 was confirmed through the formation of another type of dimer from its selectively methylated derivative.
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Affiliation(s)
- Radek Gazák
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, CZ-142 20 Prague, Czech Republic
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Abstract
The structures of two new cyclosporins were elucidated by NMR and MS methods as cyclo[-MeBmt(1)-Abu(2)-Sar(3)-MeLeu(4)-Val(5)-MeLeu(6)-Ala(7)-d-Ala(8)-MeLeu(9)-MeNva(10)-MeVal(11)-] and cyclo[-MeBmt(1)-Abu(2)-Sar(3)-MeLeu(4)-Abu(5)-MeLeu(6)-Ala(7)-d-Ala(8)-MeLeu(9)-MeLeu(10)-MeVal(11)-].
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Affiliation(s)
- Marek Kuzma
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20 Prague, Czech Republic
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Affiliation(s)
- Jiří Kubisch
- a Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation , Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic E-mail:
- b University of Hamburg, Institute of Organic Chemistry , Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Lenka Weignerová
- a Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation , Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic E-mail:
- b University of Hamburg, Institute of Organic Chemistry , Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Sven Kötter
- a Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation , Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic E-mail:
- b University of Hamburg, Institute of Organic Chemistry , Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Thisbe K. Lindhorst
- a Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation , Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic E-mail:
- b University of Hamburg, Institute of Organic Chemistry , Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Petr Sedmera
- a Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation , Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic E-mail:
- b University of Hamburg, Institute of Organic Chemistry , Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Vladimír Křen
- a Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation , Vídeňská 1083, CZ-142 20 Prague 4, Czech Republic E-mail:
- b University of Hamburg, Institute of Organic Chemistry , Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
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Volc J, Leitner C, Sedmera P, Halada P, Haltrich D. Enzymatic Formation of Dicarbonyl Sugars: C-2 Oxidation of 1↠6 Disaccharides Gentiobiose, Isomaltose and Melibiose By Pyranose 2-Oxidase from Trametes Multicolor. J Carbohydr Chem 2008. [DOI: 10.1080/07328309908544049] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Jindřich Volc
- a Laboratory of Experimental Mycology, Institute of Microbiology, Academy of Sciences of the Czech Republic , Vídenská 1083, 142 20 Prague 4, Czech Republic
- b Division of Biochemical Engineering , Institute of Food Technology, University of Agricultural Sciences , Muthgasse 18, A-1190 Vienna, Austria
| | - Christian Leitner
- a Laboratory of Experimental Mycology, Institute of Microbiology, Academy of Sciences of the Czech Republic , Vídenská 1083, 142 20 Prague 4, Czech Republic
- b Division of Biochemical Engineering , Institute of Food Technology, University of Agricultural Sciences , Muthgasse 18, A-1190 Vienna, Austria
| | - Petr Sedmera
- a Laboratory of Experimental Mycology, Institute of Microbiology, Academy of Sciences of the Czech Republic , Vídenská 1083, 142 20 Prague 4, Czech Republic
- b Division of Biochemical Engineering , Institute of Food Technology, University of Agricultural Sciences , Muthgasse 18, A-1190 Vienna, Austria
| | - Petr Halada
- a Laboratory of Experimental Mycology, Institute of Microbiology, Academy of Sciences of the Czech Republic , Vídenská 1083, 142 20 Prague 4, Czech Republic
- b Division of Biochemical Engineering , Institute of Food Technology, University of Agricultural Sciences , Muthgasse 18, A-1190 Vienna, Austria
| | - Dietmar Haltrich
- a Laboratory of Experimental Mycology, Institute of Microbiology, Academy of Sciences of the Czech Republic , Vídenská 1083, 142 20 Prague 4, Czech Republic
- b Division of Biochemical Engineering , Institute of Food Technology, University of Agricultural Sciences , Muthgasse 18, A-1190 Vienna, Austria
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Trouillas P, Marsal P, Svobodová A, Vostálová J, Gazák R, Hrbác J, Sedmera P, Kren V, Lazzaroni R, Duroux JL, Walterová D. Mechanism of the antioxidant action of silybin and 2,3-dehydrosilybin flavonolignans: a joint experimental and theoretical study. J Phys Chem A 2008; 112:1054-63. [PMID: 18193843 DOI: 10.1021/jp075814h] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Flavonolignans from silymarin, the standardized plant extract obtained from thistle, exhibit various antioxidant activities, which correlate with the other biological and therapeutic properties of that extract. To highlight the mode of action of flavonolignans as free radical scavengers and antioxidants, 10 flavonolignans, selectively methylated at different positions, were tested in vitro for their capacity to scavenge radicals (DPPH and superoxide) and to inhibit the lipid peroxidation induced on microsome membranes. The results are rationalized on the basis of (i) the oxidation potentials experimentally obtained by cyclic voltammetry and (ii) the theoretical redox properties obtained by quantum-chemical calculations (using a polarizable continuum model (PCM)-density functional theory (DFT) approach) of the ionization potentials and the O-H bond dissociation enthalpies (BDEs) of each OH group of the 10 compounds. We clearly establish the importance of the 3-OH and 20-OH groups as H donors, in the presence of the 2,3 double bond and the catechol moiety in the E-ring, respectively. For silybin derivatives (i.e., in the absence of the 2,3 double bond), secondary mechanisms (i.e., electron transfer (ET) mechanism and adduct formation with radicals) could become more important (or predominant) as the active sites for H atom transfer (HAT) mechanism are much less effective (high BDEs).
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Affiliation(s)
- Patrick Trouillas
- Laboratoire de Biophysique, Université de Limoges, 2 rue du Docteur Marcland, 87025 Limoges, France.
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Abstract
A new ribose trisaccharide, alpha-Ribf-(1-->2)-alpha-Ribf-(1-->3)-alpha-Ribf (1), was isolated together with 5-O-(alpha-mannosyl)-myo-inositol (2), 2-O-(alpha-mannosyl)-myo-inositol (3), trehalose (4), and d-ribulose (5) from a submerged cultivation of Streptomyces coelicolor A3(2). The structures of these compounds were elucidated by spectroscopic and chemical methods. Concentrations of these compounds in the medium were in the range from 0.04 (1) to 0.5 (4) mg/mL.
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Affiliation(s)
- Stanislav Pospísil
- Institute of Microbiology, Academy of Sciences of the Czech Republic, VídenskA 1083, 142 20 Prague 4, Czech Republic.
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Kujawa M, Volc J, Halada P, Sedmera P, Divne C, Sygmund C, Leitner C, Peterbauer C, Haltrich D. Properties of pyranose dehydrogenase purified from the litter-degrading fungus Agaricus xanthoderma. FEBS J 2007; 274:879-94. [PMID: 17227387 DOI: 10.1111/j.1742-4658.2007.05634.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We purified an extracellular pyranose dehydrogenase (PDH) from the basidiomycete fungus Agaricus xanthoderma using ammonium sulfate fractionation and ion-exchange and hydrophobic interaction chromatography. The native enzyme is a monomeric glycoprotein (5% carbohydrate) containing a covalently bound FAD as its prosthetic group. The PDH polypeptide consists of 575 amino acids and has a molecular mass of 65 400 Da as determined by MALDI MS. On the basis of the primary structure of the mature protein, PDH is a member of the glucose-methanol-choline oxidoreductase family. We constructed a homology model of PDH using the 3D structure of glucose oxidase from Aspergillus niger as a template. This model suggests a novel type of bi-covalent flavinylation in PDH, 9-S-cysteinyl, 8-alpha-N3-histidyl FAD. The enzyme exhibits a broad sugar substrate tolerance, oxidizing structurally different aldopyranoses including monosaccharides and oligosaccharides as well as glycosides. Its preferred electron donor substrates are D-glucose, D-galactose, L-arabinose, and D-xylose. As shown by in situ NMR analysis, D-glucose and D-galactose are both oxidized at positions C2 and C3, yielding the corresponding didehydroaldoses (diketoaldoses) as the final reaction products. PDH shows no detectable activity with oxygen, and its reactivity towards electron acceptors is rather limited, reducing various substituted benzoquinones and complexed metal ions. The azino-bis-(3-ethylbenzthiazolin-6-sulfonic acid) cation radical and the ferricenium ion are the best electron acceptors, as judged by the catalytic efficiencies (k(cat)/K(m)). The enzyme may play a role in lignocellulose degradation.
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Affiliation(s)
- Magdalena Kujawa
- Division of Food Biotechnology, Department of Food Sciences and Technology, BOKU - University of Natural Resources and Applied Life Sciences, Vienna, Austria
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Affiliation(s)
- Michaela Scigelova
- a Institute of Microbiology, Academy of Sciences of the Czech Republic , Videnska, 1083 , CZ-142 20, Prague , Czech Republic
| | - Petr Sedmera
- a Institute of Microbiology, Academy of Sciences of the Czech Republic , Videnska, 1083 , CZ-142 20, Prague , Czech Republic
| | - Vladimir Havlicek
- a Institute of Microbiology, Academy of Sciences of the Czech Republic , Videnska, 1083 , CZ-142 20, Prague , Czech Republic
| | - Vera Prikrylova
- a Institute of Microbiology, Academy of Sciences of the Czech Republic , Videnska, 1083 , CZ-142 20, Prague , Czech Republic
| | - Vladimir Kren
- a Institute of Microbiology, Academy of Sciences of the Czech Republic , Videnska, 1083 , CZ-142 20, Prague , Czech Republic
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Hrnčíř Š, Kopoldové J, Vereš K, Dědkové V, Hanuš V, Sedmera P. Degradation of 14C-L-histidine during chromatography and electrophoresis. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580150108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Jegorov A, Buchta M, Sedmera P, Kuzma M, Havlicek V. Accurate product ion mass spectra of galanthamine derivatives. J Mass Spectrom 2006; 41:544-8. [PMID: 16541391 DOI: 10.1002/jms.1015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
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Buchta M, Jegorov A, Hušák M, Cejka J, Kratochvíl B, Kuzma B, Sedmera P. Crystal structure of taxuspinanane A acetonitrile solvate, C47H59NO14 · CH3CN. Z KRIST-NEW CRYST ST 2006. [DOI: 10.1524/ncrs.2006.221.14.97] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Buchta M, Jegorov A, Hušák M, Čejka J, Kratochvíl B, Kuzma M, Sedmera P. Crystal structure of taxuspinanane A acetonitrile solvate, C47H59NO14 · CH3CN. Z KRIST-NEW CRYST ST 2006. [DOI: 10.1524/ncrs.2006.221.1.97] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract C49H62N2O14, orthorhombic, P212121 (no. 19), a = 9.46370(3)Å, b = 12.29468(3) Å, c = 40.46176(4) Å, V = 4707.9 Å3, Z = 4, Rgt(F) = 0.102, wRref(F) = 0.099, T = 150 K.
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Affiliation(s)
- M. Buchta
- 1IVAX Pharmaceuticals, Research and Development, Ostravská 29, 747 70 Opava, Czech Republic
| | - A. Jegorov
- 2IVAX Pharmaceuticals, Research and Development, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - M. Hušák
- 3Prague Institute of Chemical Technology, Department of Solid State Chemistry, Technická 5, 166 28 Prague 6, Czech Republic
| | - J. Čejka
- 3Prague Institute of Chemical Technology, Department of Solid State Chemistry, Technická 5, 166 28 Prague 6, Czech Republic
| | - B. Kratochvíl
- 3Prague Institute of Chemical Technology, Department of Solid State Chemistry, Technická 5, 166 28 Prague 6, Czech Republic
| | - M. Kuzma
- 4Academy of Sciences of the Czech Republic, Institute of Microbiology, Vídeňská 1083, 142 20 Prague 4, Czech Republic
| | - P. Sedmera
- 4Academy of Sciences of the Czech Republic, Institute of Microbiology, Vídeňská 1083, 142 20 Prague 4, Czech Republic
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Dzubák P, Hajdúch M, Gazák R, Svobodová A, Psotová J, Walterová D, Sedmera P, Kren V. New derivatives of silybin and 2,3-dehydrosilybin and their cytotoxic and P-glycoprotein modulatory activity. Bioorg Med Chem 2006; 14:3793-810. [PMID: 16466920 DOI: 10.1016/j.bmc.2006.01.035] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Revised: 01/11/2006] [Accepted: 01/17/2006] [Indexed: 10/25/2022]
Abstract
Large series of O-alkyl derivatives (methyl and benzyl) of silybin and 2,3-dehydrosilybin was prepared. Selective alkylation of the silybin molecule was systematically investigated. For the first time we present here, for example, preparation of 19-nor-2,3-dehydrosilybin. All prepared silybin/2,3-dehydrosilybin derivatives were tested for cytotoxicity on a panel of drugs sensitive against multidrug resistant cell lines and the ability to inhibit P-glycoprotein mediated efflux activity. We have identified effective and relatively non-cytotoxic inhibitors of P-gp derived from 2,3-dehydrosilybin. Some of them were more effective inhibitors at concentrations lower than a standard P-gp efflux inhibitor cyclosporin A. Another group of 2,3-dehydrosilybin derivatives also had better inhibitory effects on P-gp efflux but a cytotoxicity comparable with that of parent 2,3-dehydrosilybin. Structural requirements for improving inhibitory activity and reducing toxicity of 2,3-dehydrosilybin were established. Effect of E-ring substitution as well as an influence of the substituent size at the C-7-OH position of A-ring on P-gp-inhibitory activity was evaluated for the first time in this study.
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Affiliation(s)
- Petr Dzubák
- Department of Paediatrics, Faculty of Medicine, Palacký University and University Hospital in Olomouc, Puskinova 6, CZ-775 20, Czech Republic
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Fialová P, Carmona AT, Robina I, Ettrich R, Sedmera P, Přikrylová V, Petrásková-Hušáková L, Křen V. Glycosyl azide—a novel substrate for enzymatic transglycosylations. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.10.040] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Plísková M, Vondrácek J, Kren V, Gazák R, Sedmera P, Walterová D, Psotová J, Simánek V, Machala M. Effects of silymarin flavonolignans and synthetic silybin derivatives on estrogen and aryl hydrocarbon receptor activation. Toxicology 2005; 215:80-9. [PMID: 16076518 DOI: 10.1016/j.tox.2005.06.020] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 06/13/2005] [Accepted: 06/23/2005] [Indexed: 10/25/2022]
Abstract
Silymarin, a standardized mixture of flavonolignans, or its major constituents could be effective for prevention and treatment of hepatic damage or skin cancer. However, their potential side effects, such as modulation of endocrine functions via the disruption of estrogen receptor (ER) and/or aryl hydrocarbon receptor (AhR) activation, are largely unknown. In the present study, we investigated impact of silymarin, its constituents and a series of their synthetic derivatives on ER- and AhR-mediated activities using in vitro reporter gene assays. We found that none of the compounds under study affected the AhR-mediated activity in rat hepatoma cells. Contrary to that, several compounds behaved as either partial or full ER agonists. Silymarin elicited partial ER activation, with silybin B being probably responsible for a majority of the weak ER-mediated activity of silymarin; silybin A and other flavonolignans were found to be inactive and potent ER agonist taxifolin is only a minor constituent of silymarin. To our knowledge, this is probably the first time, when receptor-specific in vitro effects of separated diastereomers have been demonstrated. In contrast to silymarin constituents, the synthetic silybin derivatives, potentially useful as chemoprotective agents, did not modulate the ER-mediated activity, with exception of 23-O-pivaloylsilybin. Interestingly, 7-O-benzylsilybin potentiated ER-mediated activity of 17beta-estradiol despite possessing no estrogenic activity. In conclusion, our data suggest that estrogenicity of some silymarin constituents should be taken in account as their potential side effect when considered as chemopreventive compounds. These results also stress the need to study biological activities of purified or synthesized diastereomers of silybin derivatives.
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Gazák R, Svobodová A, Psotová J, Sedmera P, Prikrylová V, Walterová D, Kren V. Oxidised derivatives of silybin and their antiradical and antioxidant activity. Bioorg Med Chem 2005; 12:5677-87. [PMID: 15465345 DOI: 10.1016/j.bmc.2004.07.064] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2004] [Accepted: 07/27/2004] [Indexed: 11/21/2022]
Abstract
Carboxylic acids derived from silybin (1) and 2,3-dehydrosilybin (2) with improved water solubility were prepared by selective oxidation of parent compounds and a new inexpensive method for preparation of 2,3-dehydrosilybin from silybin was developed and optimised. The antioxidative properties of the above-mentioned compounds and of side product 3a from oxidation of compound 1 were determined by cyclic voltammetry, free radical scavenging (DPPH, superoxide) assays, and by inhibition of in vitro generated liver microsomal lipid peroxidation. Dehydrogenation at C((2))-C((3)) in flavonolignans (silybin vs 2,3-dehydrosilybin; silybinic acid vs 2,3-dehydrosilybinic acid) strongly improved antioxidative properties (analogously as in flavonoids taxifolin vs quercetin). Thus, in antioxidative properties, dehydrosilybin was superior to silybin by one order, but its water solubility is too low for application in aqueous milieu. On the other hand, 2,3-dehydrosilybinic acid is a fairly soluble derivative with antilipoperoxidation and antiradical activities better than that of silybin.
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Affiliation(s)
- Radek Gazák
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation, Vídenská 1083, CZ-142 20 Prague, Czech Republic
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Cvak L, Jegorov A, Sedmera P, Císarová I, Cejka J, Kratochvíl B, Pakhomova S. Norleucine, a natural occurrence in a novel ergot alkaloid γ-ergokryptinine. Amino Acids 2005; 29:145-50. [PMID: 15723237 DOI: 10.1007/s00726-005-0180-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Accepted: 11/11/2004] [Indexed: 11/26/2022]
Abstract
A novel natural peptide ergot alkaloid gamma-ergokryptinine containing norleucine has been isolated from ergot sclerotia of the field-growing parasitic fungus Claviceps purpurea CCM 8059. Its structure was deduced from the NMR and mass spectral data. The final structural proof was provided by the crystal structure determination, which is the first X-ray structure of a natural Nle-containing secondary metabolite. The conformations of three ergopeptinines: gamma-ergokryptinine, ergoladinine, and alpha-ergokryptinine were compared.
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Affiliation(s)
- L Cvak
- IVAX Pharmaceuticals, R&D, Opava-Komárov, Czech Republic
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28
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Sedmera P, Halada P, Peterbauer C, Volc J. A new enzyme catalysis: 3,4-dioxidation of some aryl β-d-glycopyranosides by fungal pyranose dehydrogenase. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.09.149] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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29
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Volc J, Sedmera P, Kujawa M, Halada P, Kubátová E, Haltrich D. Conversion of lactose to β-d-galactopyranosyl-(1 → 4)-d-arabino-hexos-2-ulose-(2-dehydrolactose) and lactobiono-1,5-lactone by fungal pyranose dehydrogenase. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcatb.2004.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Simerská P, Pišvejcová A, Kuzma M, Sedmera P, Křen V, Nicotra S, Riva S. Regioselective enzymatic acylation of N-acetylhexosamines. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcatb.2003.10.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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31
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Halada P, Leitner C, Sedmera P, Haltrich D, Volc J. Identification of the covalent flavin adenine dinucleotide-binding region in pyranose 2-oxidase from Trametes multicolor. Anal Biochem 2003; 314:235-42. [PMID: 12654310 DOI: 10.1016/s0003-2697(02)00661-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We present the first report on characterization of the covalent flavinylation site in flavoprotein pyranose 2-oxidase. Pyranose 2-oxidase from the basidiomycete fungus Trametes multicolor, catalyzing C-2/C-3 oxidation of several monosaccharides, shows typical absorption maxima of flavoproteins at 456, 345, and 275 nm. No release of flavin was observed after protein denaturation, indicating covalent attachment of the cofactor. The flavopeptide fragment resulting from tryptic/chymotryptic digestion of the purified enzyme was isolated by anion-exchange and reversed-phase high-performance liquid chromatography. The flavin type, attachment site, and mode of its linkage were determined by mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy of the intact flavopeptide, without its prior enzymatic degradation to the central aminoacyl moiety. Mass spectrometry identified the attached flavin as flavin adenine dinucleotide (FAD). Post-source decay analysis revealed that the flavin is covalently bound to histidine residue in the peptide STHW, consistent with the results of N-terminal amino acid sequencing by Edman degradation. The type of the aminoacyl flavin covalent link was determined by NMR spectroscopy, resulting in the structure 8alpha-(N(3)-histidyl)-FAD.
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Affiliation(s)
- Petr Halada
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, CZ-142 20 Prague 4, Czech Republic.
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32
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Klásek A, Koristek K, Sedmera P, Halada P. A New Synthesis of 4-Alkyl/Aryl-5,6-dihydro-2H-pyrano[3,2-c]quinoline-2,5-diones and Molecular Rearrangement of Their 3-Bromo Derivatives to 2-Alkyl/Aryl-4-oxo-4,5-dihydrofuro[3,2-c]quinoline-3-carboxylic Acids. HETEROCYCLES 2003. [DOI: 10.3987/com-02-9681] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Pospísil S, Sedmera P, Halada P, Spizek J. Oxidation of lincomycin by hydrogen peroxide restricts its potential biotransformation with haloperoxidases. Folia Microbiol (Praha) 2002; 46:376-8. [PMID: 11899467 DOI: 10.1007/bf02814424] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Lincomycin biotransformation was conducted by using Streptomyces venezuelae and Streptomyces phaeochromogenes cell-free extracts. Reaction products were isolated and identified by MS and NMR spectroscopy as lincomycin sulfoxide and lincomycin sulfone. Both compounds arise also by chemical oxidation with hydrogen peroxide; this reaction represents a new efficient way for the preparation of lincomycin sulfoxide and lincomycin sulfone and simultaneously excludes the biotransformation of lincomycin using haloperoxidases.
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Affiliation(s)
- S Pospísil
- Institute of Microbiology, Academy of Sciences of the Czech Republic, 124 20 Prague, Czechia.
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34
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Smrcina M, Lorenc M, Hanus V, Sedmera P, Kocovsky P. Synthesis of enantiomerically pure 2,2'-dihydroxy-1,1'-binaphthyl, 2,2'-diamino-1,1'-binaphthyl, and 2-amino-2'-hydroxy-1,1'-binaphthyl. Comparison of processes operating as diastereoselective crystallization and as second order asymmetric transformation. J Org Chem 2002. [DOI: 10.1021/jo00032a055] [Citation(s) in RCA: 208] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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Varga V, Mach K, Hiller J, Thewalt U, Sedmera P, Polasek M. (C5H5-nMen)2TiCl2/Mg/Me3SnC.tplbond.CSnMe3 (n = 0, 2-5) Systems. Formation and Crystal Structures of (C5Me5)2Ti(.eta.2-Me3SnC.tplbond.CSnMe3) and [(C5H5-nMen)2Ti(.mu.-.eta.2:.eta.1-C.tplbond.CSnMe3)]2 (n = 0, 2) Complexes. Organometallics 2002. [DOI: 10.1021/om00003a047] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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36
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Volc J, Sedmera P, Halada P, Daniel G, Přikrylová V, Haltrich D. C-3 oxidation of non-reducing sugars by a fungal pyranose dehydrogenase: spectral characterization. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1381-1177(02)00014-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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37
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Kuzma M, Jegorov A, Hesso A, Tornaeus J, Sedmera P, Havlícek V. Role of amino acid N-methylation in cyclosporins on ring opening and fragmentation mechanisms during collisionally induced dissociation in an ion trap. J Mass Spectrom 2002; 37:292-298. [PMID: 11921370 DOI: 10.1002/jms.283] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The product ion mass spectra (collisionally induced dissociation mass spectra) of 12 different cyclosporins modified at every N-methylated amino acid residue with respect to cyclosporin A were compared and the effect of N-demethylation on ring opening mechanisms was evaluated. The four preferential protonation sites were identified in [MeBmt(1)]-cyclosporins. Three sites represented the N-methylated nitrogens of Sar(3), MeLeu(6) and MeLeu(9), while the remaining one represented the lactone group formed by the intramolecular N,O-acyl shift. Selective N-demethylation resulted either in the deletion of the entire fragment ion series or its substantial attenuation. The structures of three new natural cyclosporins in the study were supported by NMR data.
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Affiliation(s)
- Marek Kuzma
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, CZ-142 20 Prague 4, Czech Republic
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38
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Kren V, Fiserová A, Weignerová L, Stibor I, Halada P, Prikrylová V, Sedmera P, Pospísil M. Clustered ergot alkaloids modulate cell-mediated cytotoxicity. Bioorg Med Chem 2002; 10:415-24. [PMID: 11741789 DOI: 10.1016/s0968-0896(01)00291-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Dimers of agroclavine (1) and terguride (2), as well as a series of terguride oligomers, for example trimers (5, 6), tetramer (7), hexamer (8) and functionalized tergurides for further complex clustering were synthesized. Terguride oligomers were screened for their direct cellular toxicity on lymphoma cell lines in vitro and for their immunomodulating activities, represented by the natural killer (NK) cell-mediated cytotoxicity, as the most sensitive screening marker during immune responses. Dimers linked via aromatic spacer showed a high toxicity (1 microM) to lymphoma cells, which was not detected in other derivatives. In vitro and ex vivo experiments performed on mouse spleen lymphocytes in the presence of terguride oligomers demonstrated an immunosuppressive effect of dimers with aromatic spacer (4c-d) and NK cell stimulatory effect of terguride hexamer (8) and trimer with aliphatic spacer (5c). There is a considerable evidence that indolic part of molecule contributes to immunosuppressive action of terguride, which is potentiated in dimers carrying aromatic linker. This effect can be reversed by higher oligomerization of the respective alkaloids.
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Affiliation(s)
- Vladimír Kren
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, CZ 142 20 4, Prague, Czech Republic.
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39
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Volc J, Kubátová E, Daniel G, Sedmera P, Haltrich D. Screening of basidiomycete fungi for the quinone-dependent sugar C-2/C-3 oxidoreductase, pyranose dehydrogenase, and properties of the enzyme from Macrolepiota rhacodes. Arch Microbiol 2001; 176:178-86. [PMID: 11511865 DOI: 10.1007/s002030100308] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2001] [Accepted: 05/11/2001] [Indexed: 10/27/2022]
Abstract
Mycelial cultures of 76 strains of lignocellulose-degrading basidiomycete fungi were screened for the activity of pyranose dehydrogenase, a novel sugar oxidoreductase recently detected in Agaricus bisporus. Of these fungi, 37 strains belonging to seven phylogenetically related genera of mostly litter-decomposing Agaricales were positive for the dehydrogenase, based on activity assays towards D-glucose with 1,4-benzoquinone or ferricenium ion as electron acceptors, and on TLC/HPLC analyses of the reaction products. Lack of activity with O(2) as the oxidant, specificity for C-3 of D-glucose, and active extracellular secretion of the enzyme were used as criteria to differentiate pyranose dehydrogenase from pyranose 2-oxidase (EC 1.1.3.10), known to be produced by numerous wood-rotting fungi. Extracellular pyranose dehydrogenase from Macrolepiota rhacodes was heavily glycosylated. The enzyme was characterized as a 78-kDa flavoprotein under denaturing conditions and a 76-kDa native protein using gel filtration. This enzyme had a maximum extracellular activity of 4.1 U ml(-1) in 39-day liquid cultures. It exhibited broad selectivity for sugar substrates and oxidized D-glucose (K(m)=1.82) exclusively at C-3 to 3-dehydro-D-glucose (D-ribo-hexos-3-ulose), in contrast to pyranose dehydrogenases from Agaricus species, which acted at both C-3 and C-2 of D-glucose. The N-terminal sequence, AVVYRHPDEL, showed significant similarity with that reported for A. bisporus.
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Affiliation(s)
- J Volc
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídenská 1083, 142 20 Prague 4, Czech Republic.
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Abstract
NMR studies showed that 11-demethylcyclosporin A (cyclosporin E) and 11-demethylcyclosporin B exist as single species both in polar and nonpolar solvents. They adopt the same conformation that was found in the solid state.
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Affiliation(s)
- P Sedmera
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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42
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Kroulík J, Čejka J, Šebek P, Sedmera P, Halada P, Havlíček V, Nešpůrek S, Kratochvíl B, Kuthan J. Photoisomerization of 2,4,4,6-tetraaryl-4H-selenopyrans: a new heterocyclic ring contraction. Mendeleev Communications 2001. [DOI: 10.1070/mc2001v011n03abeh001430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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43
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Simánek V, Kubisch J, Sedmera P, Halada P, Gazák R, Skottová N, Kren V. Chemoenzymatic Preparation of Oligoglycosides of Silybin, the Flavonolignan from Silybum marianum. HETEROCYCLES 2001. [DOI: 10.3987/com-00-s(i)89] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Kren V, Ulrichová J, Kosina P, Stevenson D, Sedmera P, Prikrylová V, Halada P, Simánek V. Chemoenzymatic preparation of silybin beta-glucuronides and their biological evaluation. Drug Metab Dispos 2000; 28:1513-7. [PMID: 11095591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
Chemoenzymatic glucuronidation of the optically pure silybin A (1) using ovine liver glucuronyl transferase afforded three beta-glucuronides of silybin, substituted at phenolic OH groups at the positions C-20 (2), C-7 (3), and C-5 (4) formed in the yields 27, 62.5, and 2.5%, respectively. Using these standards, it was shown that the main silybin conjugate in humans is its 20-beta-D-glucuronate (2), while the C-7 regioisomer (3) was formed in lower proportion. The rate of conjugation of (natural) silybin diastereomers 10S, 11S and 10R, 11R, and therefore also their metabolism in humans is rather different. The radical scavenging activity of 2 is considerably lower than that of its aglycone (1); however, the activity of 3 is higher than in the silybin. These findings corroborate the hypothesis that, at physiological pH, the exclusive target for one-electron oxidation of the silybin molecule is the o-methoxy-phenolic structure at C-19, C-20. This is first pharmacological study using optically pure silybin.
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Affiliation(s)
- V Kren
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Biotransformation, Prague, Czech Republic.
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45
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Volc J, Sedmera P, Halada P, Prikrylová V, Haltrich D. Double oxidation of D-xylose to D-glycero -pentos-2,3-diulose (2,3-diketo-D-xylose) by pyranose dehydrogenase from the mushroom Agaricus bisporus. Carbohydr Res 2000; 329:219-25. [PMID: 11086703 DOI: 10.1016/s0008-6215(00)00167-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Pyranose dehydrogenase purified to homogeneity from the mycelia of the basidiomycete fungus Agaricus bisporus catalyzed the oxidation of D-xylose at C-2 to D-threo-pentos-2-ulose (2-keto-D-xylose) and successively at C-3 to D-glycero-pentos-2,3-diulose (2,3-diketo-D-xylose) using 1,4-benzoquinone as an electron acceptor. The sites of oxidation were deduced from the spectroscopic analysis (MS, NMR) of the N,N-diphenylhydrazone derivatives of the reaction products.
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Affiliation(s)
- J Volc
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague.
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46
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Rep M, Kaagman JWF, Elsevier CJ, Sedmera P, Hiller J, Thewalt U, Horáček M, Mach K. Reactions of methyl-substituted titanocene–bis(trimethylsilyl)acetylene complexes with acetone azine: crystal structures of (η5:η1-C5HMe3CH2CMe2NH)2Ti and (C5Me5)2Ti(NCMe2). J Organomet Chem 2000. [DOI: 10.1016/s0022-328x(99)00671-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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47
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Cvak L, Stuchlík J, Schreiberová M, Sedmera P, Havlíček V, Flieger M, Čejka J, Kratochvíl B, Jegorov A. Selective Reduction of Peptidic Ergot Alkaloids. ACTA ACUST UNITED AC 2000. [DOI: 10.1135/cccc20001762] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Five 6'-deoxoergopeptines were prepared in 51-68% yield by selective reduction of parent alkaloids with lithium aluminium hydride in tetrahydrofuran at low temperature. New compounds were characterized by mass spectrometry and NMR spectroscopy. The conformation of the peptide part in starting compounds and reduced derivatives is discussed on the basis of crystal structure determination of 6'-deoxo-9,10-dihydroergotamine dihydrate butan-2-one solvate as a representative member of the series.
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Abstract
Enzymatic synthesis of lysergol β-D-glucuronide (2) using ovine microsomal uridine 5'-diphosphoglucuronyl transferase and uridine 5'-diphosphoglucuronic acid (Na3-salt) is demonstrated.
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49
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Jegorov A, Cvak L, Husek A, Šimek P, Heydová A, Ondráček J, Pakhomova S, Hušák M, Kratochvíl B, Sedmera P, Havlíček V. Synthesis and Crystal Structure Determination of Cyclosporin H. ACTA ACUST UNITED AC 2000. [DOI: 10.1135/cccc20001317] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Acid-catalyzed degradation of cyclosporin A was studied in various solvents and products of reaction were monitored by HPLC. Identification of amino acids and their chirality were determined after hydrolysis and derivatization by GC-MS. Cyclosporin H was isolated as the principal product and its structure was determined by X-ray diffraction: Cyclosporin H- diethyl ether-water (1 : 0.5 : 1) crystallizes in the monoclinic space group I2 with a = 12.338(2) Å, b = 18.963(2) Å, c = 34.074(3) Å, β = 96.47(2)°, Z = 4, and V = 7 921.4(17) Å3.
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50
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Weignerová L, Sedmera P, Huňková Z, Halada P, Křen V, Casali M, Riva S. Enzymatic synthesis of iso-globotriose from partially protected lactose. Tetrahedron Lett 1999. [DOI: 10.1016/s0040-4039(99)01950-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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