Igor Mikhailopulo | The National Academy of Sciences of Belarus (original) (raw)

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Papers by Igor Mikhailopulo

Research paper thumbnail of 5'-Phosphorylation of natural nucleosides and their modified analogs by intact Erwinia herbicola cells: specificity with respect to donors and acceptors of phosphate group

Biopolymers & Cell, May 20, 1989

Conformation of plasma fibronectin was determined by circular dichroism and thermal perturbation ... more Conformation of plasma fibronectin was determined by circular dichroism and thermal perturbation differential spectroscopy with different ionic strength of the solution. It was found that conformational transition in fibronectin molecule, induced by an increase of the ionic solution strength was followed by no changes in secondary and tertiary structure of protein but was a result of changes in relative arrangement and domain-domain interaction in space.

Research paper thumbnail of Synthesis And Spectral Properties of Uric Acid Ribosides

Nucleosides, Nucleotides & Nucleic Acids, Feb 1, 1986

Abstract Ribosylation of trimethylsilyl uric acid by tetra O-acetyl-β-D-ribofuranose in the prese... more Abstract Ribosylation of trimethylsilyl uric acid by tetra O-acetyl-β-D-ribofuranose in the presence of trimethylsilyl trifluoromethanesulfonate as the condensing agent was studied at various ratio of the reactants. As a result uric acid N7-monoriboside and N7, N7, N7-diriboside were obtained and their spectral properties examined.

Research paper thumbnail of Synthesis of uracil nucleosides of D-xyluronic acid derivatives

Carbohydrate Research, Aug 1, 1975

Research paper thumbnail of Synthesis of 2,6-Dihalogenated Purine Nucleosides by Thermostable Nucleoside Phosphorylases

Advanced Synthesis & Catalysis, Mar 25, 2015

The enzymatic transglycosylation of 2,6‐dichloropurine (26DCP) and 6‐chloro‐2‐fluoropurine (6C2FP... more The enzymatic transglycosylation of 2,6‐dichloropurine (26DCP) and 6‐chloro‐2‐fluoropurine (6C2FP) with uridine, thymidine and 1‐(β‐D‐arabinofuranosyl)‐uracil as the pentofuranose donors and recombinant thermostable nucleoside phosphorylases from G. thermoglucosidasius or T. thermophilus as biocatalysts was studied. Selection of 26DCP and 6C2FP as substrates is determined by their higher solubility in aqueous buffer solutions compared to most natural and modified purines and, furthermore, synthesized nucleosides are valuable precursors for the preparation of a large number of biologically important nucleosides. The substrate activity of 26DCP and 6C2FP in the synthesis of their ribo‐ and 2′‐deoxyribo‐nucleosides was closely similar to that of related 2‐amino‐ (DAP), 2‐chloro‐ and 2‐fluoroadenines; the efficiency of the synthesis of β‐D‐arabinofuranosides of 26DCP and 6C2FP was lower vs. that of DAP under similar reaction conditions. For a convenient and easier recovery of the biocatalysts, the thermostable enzymes were immobilized on MagReSyn® epoxide beads and the biocatalyst showed high catalytic efficiency in a number of reactions. As an example, 6‐chloro‐2‐fluoro‐(β‐D‐ribofuranosyl)‐purine (9), a precursor of various antiviral and antitumour drugs, was synthesized by the immobilized enzymes at 60 °C under high substrate concentrations (uridine:purine ratio of 2:1, mol). The synthesis was successfully scaled‐up [uridine (2.5 mmol), base (1.25 mmol); reaction mixture 50 mL] to afford 9 in 60% yield. The reaction reveals the great practical potential of this enzymatic method for the efficient production of modified purine nucleosides of pharmaceutical interest.magnified image

Research paper thumbnail of Synthesis of oligoriboadenylates and their thiophosphate analogues using salicylchlorophosphite

Collection of Czechoslovak Chemical Communications, 1990

Research paper thumbnail of ChemInform Abstract: UNUSUAL REACTION OF 3-CARBOMETHOXY-Δ2-PYRAZOLINE IN THE PRESENCE OF LEAD TETRAACETATE

Chemischer Informationsdienst, 1977

ChemInform Abstract Der Pyrazolincarbonsäuremethylester (I) reagiert mit Bleitetraacetat in Benzo... more ChemInform Abstract Der Pyrazolincarbonsäuremethylester (I) reagiert mit Bleitetraacetat in Benzol zu einem Gemisch der Verbindungen (II) und (III).

Research paper thumbnail of ChemInform Abstract: EINE NEUE RK. VON ACETYLSALICYLSAEURECHLORID MIT 1,2‐, 1,3‐ UND 1,4‐DIOLEN UND ALKOHOLEN

Chemischer Informationsdienst, 1973

Acetylsalicylsäurechlorid (I) reagiert mit den Diolen (II) in Pentan, Benzol, Acetonitril oder Di... more Acetylsalicylsäurechlorid (I) reagiert mit den Diolen (II) in Pentan, Benzol, Acetonitril oder Dioxan in 60‐90%iger Ausbeute zu den Chlor‐acetaten (III) und Salicylsäure (IV).

Research paper thumbnail of Nucleoside 5'-triphosphates modified in the sugar moiety as substrates for DNA polymerases

Collection of Czechoslovak Chemical Communications, 1996

Research paper thumbnail of ChemInform Abstract: MODIFIED NUCLEOSIDES. V. SYNTHESIS OF PYRAZOLE NUCLEOSIDES

Chemischer Informationsdienst, 1976

Durch Anlagerung des Diazoessigesters (II) an das Acetat des Propargylalkohols (I) entsteht bevor... more Durch Anlagerung des Diazoessigesters (II) an das Acetat des Propargylalkohols (I) entsteht bevorzugt das Pyrazol (III) neben der isomeren Verbindung (IV).

Research paper thumbnail of Methyl 1-deoxy-1-( N 1 -thyminyl)-�- D -psicofuranoside

Acta Crystallogr E Struct Rep, 2007

Research paper thumbnail of ChemInform Abstract: DEOXY ANALOGS OF CARBOXYAMINOIMIDAZOLE RIBOTIDE

Chemischer Informationsdienst, 1980

Bei Einwirkung des Säurechlorids (II) auf das Ribonucleosid (I) entsteht ein Gemisch der isomeren... more Bei Einwirkung des Säurechlorids (II) auf das Ribonucleosid (I) entsteht ein Gemisch der isomeren Chlorderivate (III) und (IV).

Research paper thumbnail of (2'-5') Oligoadenylate Analogues Useful as Inhibitors of HOST-V5.-GRAFT Response

Research paper thumbnail of ChemInform Abstract: GLYCOSYLATION OF N4-BENZOYLCYTOSINE BY ACETYLATED GLYCALS

Chemischer Informationsdienst, 1980

Research paper thumbnail of Recognition of Artificial Nucleobases by E. coli Purine Nucleoside Phosphorylase versus its Ser90Ala Mutant in the Synthesis of Base-Modified Nucleosides

Chemistry (Weinheim an der Bergstrasse, Germany), Jan 31, 2015

A wide range of natural purine analogues was used as probe to assess the mechanism of recognition... more A wide range of natural purine analogues was used as probe to assess the mechanism of recognition by the wild-type (WT) E. coli purine nucleoside phosphorylase (PNP) versus its Ser90Ala mutant. The results were analyzed from viewpoint of the role of the Ser90 residue and the structural features of the bases. It was found that the Ser90 residue of the PNP 1) plays an important role in the binding and activation of 8-aza-7-deazapurines in the synthesis of their nucleosides, 2) participates in the binding of α-D-pentofuranose-1-phosphates at the catalytic site of the PNP, and 3) catalyzes the dephosphorylation of intermediary formed 2-deoxy-α-D-ribofuranose-1-phosphate in the trans-2-deoxyribosylation reaction. 5-Aza-7-deazaguanine manifested excellent substrate activity for both enzymes, 8-amino-7-thiaguanine and 2-aminobenzothiazole showed no substrate activity for both enzymes. On the contrary, the 2-amino derivatives of benzimidazole and benzoxazole are substrates and are converted...

Research paper thumbnail of Synthesis of 2,6‐Dihalogenated Purine Nucleosides by Thermostable Nucleoside Phosphorylases

Advanced Synthesis & Catalysis, 2015

The enzymatic transglycosylation of 2,6‐dichloropurine (26DCP) and 6‐chloro‐2‐fluoropurine (6C2FP... more The enzymatic transglycosylation of 2,6‐dichloropurine (26DCP) and 6‐chloro‐2‐fluoropurine (6C2FP) with uridine, thymidine and 1‐(β‐D‐arabinofuranosyl)‐uracil as the pentofuranose donors and recombinant thermostable nucleoside phosphorylases from G. thermoglucosidasius or T. thermophilus as biocatalysts was studied. Selection of 26DCP and 6C2FP as substrates is determined by their higher solubility in aqueous buffer solutions compared to most natural and modified purines and, furthermore, synthesized nucleosides are valuable precursors for the preparation of a large number of biologically important nucleosides. The substrate activity of 26DCP and 6C2FP in the synthesis of their ribo‐ and 2′‐deoxyribo‐nucleosides was closely similar to that of related 2‐amino‐ (DAP), 2‐chloro‐ and 2‐fluoroadenines; the efficiency of the synthesis of β‐D‐arabinofuranosides of 26DCP and 6C2FP was lower vs. that of DAP under similar reaction conditions. For a convenient and easier recovery of the biocat...

Research paper thumbnail of ChemInform Abstract: Phosphonate Isostere of Nucleoside 3′- and 2′-Phosphates as Precursors of the Related Oligonucleotides

Research paper thumbnail of ChemInform Abstract: Nucleotides. Part. 58. Synthesis and Biological Activity of (2′→5′) Oligoadenylate Trimers Containing a 5′‐Terminal 5′‐Amino‐5′‐deoxy‐ or 5′‐Amino‐3′,5′‐dideoxyadenosine Derivative

ChemInform, 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of ChemInform Abstract: Synthesis of 9-(2,3-Dideoxy-2,3-difluoro-β-D-arabinofuranosyl)adenine

Research paper thumbnail of Reactions of (Diethylamino)Sulfur Trifluoride (DAST) with Methyl-5-O-Benzyl-β-D-arabino- and -xylo-furanosides

Synlett, 1996

Reaction of (diethylamino)sulfur trifluoride (DAST) with methyl-5-O-benzyl-β-D-arabinofuranoside ... more Reaction of (diethylamino)sulfur trifluoride (DAST) with methyl-5-O-benzyl-β-D-arabinofuranoside (1) in CH2Cl2 at room temperature for 3-5 h, followed by silica gel column chromatography afforded ribo2 and lyxo3 fluorides in 41 and 21% yield, respectively. Under similar conditions with xylo-isomer 4 as starting material, epoxide 5 and ribo fluoride 6 were isolated in 33 and 36% yield, respectively.

Research paper thumbnail of Synthesis of 9-(2,3-Dideoxy-2,3-Difluoro-β-D- Arabinofuranosyl)Adenine

Nucleosides, Nucleotides and Nucleic Acids, 2007

Convergent synthesis of 9-(2,3-dideoxy-2,3-difluoro-beta-D-arabinofuranosyl)adenine is described ... more Convergent synthesis of 9-(2,3-dideoxy-2,3-difluoro-beta-D-arabinofuranosyl)adenine is described starting from methyl 5-O-benzyl-2-deoxy-2-fluoro-alpha-D-arabinofuranoside.

Research paper thumbnail of 5'-Phosphorylation of natural nucleosides and their modified analogs by intact Erwinia herbicola cells: specificity with respect to donors and acceptors of phosphate group

Biopolymers & Cell, May 20, 1989

Conformation of plasma fibronectin was determined by circular dichroism and thermal perturbation ... more Conformation of plasma fibronectin was determined by circular dichroism and thermal perturbation differential spectroscopy with different ionic strength of the solution. It was found that conformational transition in fibronectin molecule, induced by an increase of the ionic solution strength was followed by no changes in secondary and tertiary structure of protein but was a result of changes in relative arrangement and domain-domain interaction in space.

Research paper thumbnail of Synthesis And Spectral Properties of Uric Acid Ribosides

Nucleosides, Nucleotides & Nucleic Acids, Feb 1, 1986

Abstract Ribosylation of trimethylsilyl uric acid by tetra O-acetyl-β-D-ribofuranose in the prese... more Abstract Ribosylation of trimethylsilyl uric acid by tetra O-acetyl-β-D-ribofuranose in the presence of trimethylsilyl trifluoromethanesulfonate as the condensing agent was studied at various ratio of the reactants. As a result uric acid N7-monoriboside and N7, N7, N7-diriboside were obtained and their spectral properties examined.

Research paper thumbnail of Synthesis of uracil nucleosides of D-xyluronic acid derivatives

Carbohydrate Research, Aug 1, 1975

Research paper thumbnail of Synthesis of 2,6-Dihalogenated Purine Nucleosides by Thermostable Nucleoside Phosphorylases

Advanced Synthesis & Catalysis, Mar 25, 2015

The enzymatic transglycosylation of 2,6‐dichloropurine (26DCP) and 6‐chloro‐2‐fluoropurine (6C2FP... more The enzymatic transglycosylation of 2,6‐dichloropurine (26DCP) and 6‐chloro‐2‐fluoropurine (6C2FP) with uridine, thymidine and 1‐(β‐D‐arabinofuranosyl)‐uracil as the pentofuranose donors and recombinant thermostable nucleoside phosphorylases from G. thermoglucosidasius or T. thermophilus as biocatalysts was studied. Selection of 26DCP and 6C2FP as substrates is determined by their higher solubility in aqueous buffer solutions compared to most natural and modified purines and, furthermore, synthesized nucleosides are valuable precursors for the preparation of a large number of biologically important nucleosides. The substrate activity of 26DCP and 6C2FP in the synthesis of their ribo‐ and 2′‐deoxyribo‐nucleosides was closely similar to that of related 2‐amino‐ (DAP), 2‐chloro‐ and 2‐fluoroadenines; the efficiency of the synthesis of β‐D‐arabinofuranosides of 26DCP and 6C2FP was lower vs. that of DAP under similar reaction conditions. For a convenient and easier recovery of the biocatalysts, the thermostable enzymes were immobilized on MagReSyn® epoxide beads and the biocatalyst showed high catalytic efficiency in a number of reactions. As an example, 6‐chloro‐2‐fluoro‐(β‐D‐ribofuranosyl)‐purine (9), a precursor of various antiviral and antitumour drugs, was synthesized by the immobilized enzymes at 60 °C under high substrate concentrations (uridine:purine ratio of 2:1, mol). The synthesis was successfully scaled‐up [uridine (2.5 mmol), base (1.25 mmol); reaction mixture 50 mL] to afford 9 in 60% yield. The reaction reveals the great practical potential of this enzymatic method for the efficient production of modified purine nucleosides of pharmaceutical interest.magnified image

Research paper thumbnail of Synthesis of oligoriboadenylates and their thiophosphate analogues using salicylchlorophosphite

Collection of Czechoslovak Chemical Communications, 1990

Research paper thumbnail of ChemInform Abstract: UNUSUAL REACTION OF 3-CARBOMETHOXY-Δ2-PYRAZOLINE IN THE PRESENCE OF LEAD TETRAACETATE

Chemischer Informationsdienst, 1977

ChemInform Abstract Der Pyrazolincarbonsäuremethylester (I) reagiert mit Bleitetraacetat in Benzo... more ChemInform Abstract Der Pyrazolincarbonsäuremethylester (I) reagiert mit Bleitetraacetat in Benzol zu einem Gemisch der Verbindungen (II) und (III).

Research paper thumbnail of ChemInform Abstract: EINE NEUE RK. VON ACETYLSALICYLSAEURECHLORID MIT 1,2‐, 1,3‐ UND 1,4‐DIOLEN UND ALKOHOLEN

Chemischer Informationsdienst, 1973

Acetylsalicylsäurechlorid (I) reagiert mit den Diolen (II) in Pentan, Benzol, Acetonitril oder Di... more Acetylsalicylsäurechlorid (I) reagiert mit den Diolen (II) in Pentan, Benzol, Acetonitril oder Dioxan in 60‐90%iger Ausbeute zu den Chlor‐acetaten (III) und Salicylsäure (IV).

Research paper thumbnail of Nucleoside 5'-triphosphates modified in the sugar moiety as substrates for DNA polymerases

Collection of Czechoslovak Chemical Communications, 1996

Research paper thumbnail of ChemInform Abstract: MODIFIED NUCLEOSIDES. V. SYNTHESIS OF PYRAZOLE NUCLEOSIDES

Chemischer Informationsdienst, 1976

Durch Anlagerung des Diazoessigesters (II) an das Acetat des Propargylalkohols (I) entsteht bevor... more Durch Anlagerung des Diazoessigesters (II) an das Acetat des Propargylalkohols (I) entsteht bevorzugt das Pyrazol (III) neben der isomeren Verbindung (IV).

Research paper thumbnail of Methyl 1-deoxy-1-( N 1 -thyminyl)-�- D -psicofuranoside

Acta Crystallogr E Struct Rep, 2007

Research paper thumbnail of ChemInform Abstract: DEOXY ANALOGS OF CARBOXYAMINOIMIDAZOLE RIBOTIDE

Chemischer Informationsdienst, 1980

Bei Einwirkung des Säurechlorids (II) auf das Ribonucleosid (I) entsteht ein Gemisch der isomeren... more Bei Einwirkung des Säurechlorids (II) auf das Ribonucleosid (I) entsteht ein Gemisch der isomeren Chlorderivate (III) und (IV).

Research paper thumbnail of (2'-5') Oligoadenylate Analogues Useful as Inhibitors of HOST-V5.-GRAFT Response

Research paper thumbnail of ChemInform Abstract: GLYCOSYLATION OF N4-BENZOYLCYTOSINE BY ACETYLATED GLYCALS

Chemischer Informationsdienst, 1980

Research paper thumbnail of Recognition of Artificial Nucleobases by E. coli Purine Nucleoside Phosphorylase versus its Ser90Ala Mutant in the Synthesis of Base-Modified Nucleosides

Chemistry (Weinheim an der Bergstrasse, Germany), Jan 31, 2015

A wide range of natural purine analogues was used as probe to assess the mechanism of recognition... more A wide range of natural purine analogues was used as probe to assess the mechanism of recognition by the wild-type (WT) E. coli purine nucleoside phosphorylase (PNP) versus its Ser90Ala mutant. The results were analyzed from viewpoint of the role of the Ser90 residue and the structural features of the bases. It was found that the Ser90 residue of the PNP 1) plays an important role in the binding and activation of 8-aza-7-deazapurines in the synthesis of their nucleosides, 2) participates in the binding of α-D-pentofuranose-1-phosphates at the catalytic site of the PNP, and 3) catalyzes the dephosphorylation of intermediary formed 2-deoxy-α-D-ribofuranose-1-phosphate in the trans-2-deoxyribosylation reaction. 5-Aza-7-deazaguanine manifested excellent substrate activity for both enzymes, 8-amino-7-thiaguanine and 2-aminobenzothiazole showed no substrate activity for both enzymes. On the contrary, the 2-amino derivatives of benzimidazole and benzoxazole are substrates and are converted...

Research paper thumbnail of Synthesis of 2,6‐Dihalogenated Purine Nucleosides by Thermostable Nucleoside Phosphorylases

Advanced Synthesis & Catalysis, 2015

The enzymatic transglycosylation of 2,6‐dichloropurine (26DCP) and 6‐chloro‐2‐fluoropurine (6C2FP... more The enzymatic transglycosylation of 2,6‐dichloropurine (26DCP) and 6‐chloro‐2‐fluoropurine (6C2FP) with uridine, thymidine and 1‐(β‐D‐arabinofuranosyl)‐uracil as the pentofuranose donors and recombinant thermostable nucleoside phosphorylases from G. thermoglucosidasius or T. thermophilus as biocatalysts was studied. Selection of 26DCP and 6C2FP as substrates is determined by their higher solubility in aqueous buffer solutions compared to most natural and modified purines and, furthermore, synthesized nucleosides are valuable precursors for the preparation of a large number of biologically important nucleosides. The substrate activity of 26DCP and 6C2FP in the synthesis of their ribo‐ and 2′‐deoxyribo‐nucleosides was closely similar to that of related 2‐amino‐ (DAP), 2‐chloro‐ and 2‐fluoroadenines; the efficiency of the synthesis of β‐D‐arabinofuranosides of 26DCP and 6C2FP was lower vs. that of DAP under similar reaction conditions. For a convenient and easier recovery of the biocat...

Research paper thumbnail of ChemInform Abstract: Phosphonate Isostere of Nucleoside 3′- and 2′-Phosphates as Precursors of the Related Oligonucleotides

Research paper thumbnail of ChemInform Abstract: Nucleotides. Part. 58. Synthesis and Biological Activity of (2′→5′) Oligoadenylate Trimers Containing a 5′‐Terminal 5′‐Amino‐5′‐deoxy‐ or 5′‐Amino‐3′,5′‐dideoxyadenosine Derivative

ChemInform, 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Research paper thumbnail of ChemInform Abstract: Synthesis of 9-(2,3-Dideoxy-2,3-difluoro-β-D-arabinofuranosyl)adenine

Research paper thumbnail of Reactions of (Diethylamino)Sulfur Trifluoride (DAST) with Methyl-5-O-Benzyl-β-D-arabino- and -xylo-furanosides

Synlett, 1996

Reaction of (diethylamino)sulfur trifluoride (DAST) with methyl-5-O-benzyl-β-D-arabinofuranoside ... more Reaction of (diethylamino)sulfur trifluoride (DAST) with methyl-5-O-benzyl-β-D-arabinofuranoside (1) in CH2Cl2 at room temperature for 3-5 h, followed by silica gel column chromatography afforded ribo2 and lyxo3 fluorides in 41 and 21% yield, respectively. Under similar conditions with xylo-isomer 4 as starting material, epoxide 5 and ribo fluoride 6 were isolated in 33 and 36% yield, respectively.

Research paper thumbnail of Synthesis of 9-(2,3-Dideoxy-2,3-Difluoro-β-D- Arabinofuranosyl)Adenine

Nucleosides, Nucleotides and Nucleic Acids, 2007

Convergent synthesis of 9-(2,3-dideoxy-2,3-difluoro-beta-D-arabinofuranosyl)adenine is described ... more Convergent synthesis of 9-(2,3-dideoxy-2,3-difluoro-beta-D-arabinofuranosyl)adenine is described starting from methyl 5-O-benzyl-2-deoxy-2-fluoro-alpha-D-arabinofuranoside.