Synthesis of 5-Azacytidine Nucleosides with Rigid Sugar Moiety as Potential Antitumor Agents

Abstract

The bicyclic 3′-O,5′-C-methylene-linked and 2′-O,5′-C-methylene-linked 5-azacytidine derivatives were readily synthesized from 1,2;5,6-di-O-isopropylidene-d-glucose and evaluated against several cancer cell lines.     

Synthesis of Novel Bicyclic Nucleosides with 3,6-Anhydro Sugar Moiety

Based on the biological importance of conformationally restricted nucleoside analogues, we have efficiently synthesized 3,6-anhydro sugar moiety with 3-C-hydroxymethyl substituent from 1,2;5,6-di-O-isopropylidene-D-glucose and condensed 15 with silylated nucleobases to afford the bicyclic nucleoside with 3,6-anhydro skeleton as potential antiviral agent.     

New Trends in Synthesis of Pyrazole Nucleosides as New Antimetabolites

Pyrazole nucleosides and condensed pyrazole nucleosides exhibit various biological activities. This article describes recent synthetic approaches to their preparation, chemical properties, biological activities, and structure-activity relationships, with emphasis to selected drugs or drug candidates. Two pyrazole C-nucleoside compounds pyrazofurin (pyrazomycin) and its α-epimer pyrazofurin B are active components of potent antivirals approved for therapeutic use in human medicine aimed against various diseases caused by DNA viruses.     

Studies on the Chemical Synthesis of Potential Antimetabolites. 35.1 Synthesis of 2-Chloro-1-deazaadenosine and 2-Chloro-1-deazainosine as Candidate Inhibitors for S-Adenosylhomocysteinases and Methyltransferases

Abstract

The syntheses of 2-chloro-1-deazaadenosine (2) and 2-chloro-1-deazainosine (3) are described. Conversion of 7-ribosylated 6-chloro-1-deazapurine 3-oxide to the desired 2,6-disubstituted 9-ribosyl-1-deazapurines was effected by a series of reactions involving “deoxygenative chlorination” and transglycosylation in satisfactory yields.     

Synthesis of Modified Nucleosides. Palladium-Catalysed Couplings of Organostannanes or Organoboranes with Pyrimidine Nucleosides

Abstract

Coupling of suitably protected 5-iodouridine or 5-iodo-2′-deoxyuridine with either arylboronic acids or aryltrimethylstannanes in the presence of a palladium catalyst gave moderate yields of the corresponding 5-aryluridines and 5-aryC2′-deoxyuridines. 5-Hydroxyuridine was converted into 5-(trifluoromethanesulphonyl)uridine in good yield and the triacetate of this modified nucleoside also underwent palladium-catalysed couplings with a variety of organostannanes to produce the 5-substituted uridine in excellent yield.     

Synthesis of Sugar Modified Nucleosides Containing Nicotinic,Quinaldic, Indol-3-ylpropionic or 1-Nitroanthraquinone-2-carboxylic Acid Residue

Abstract

The nucleoside derivatives were synthesized with arylcarbonic acid residue as an anchor group at the sugar moiety coupled by an ester or an amide bond. Their cytotoxic properties and effects on DNA structure were studied.     

A Mild Procedure for O-Deacylation of the Fully Acylated Sugar Moiety of Nucleosides in the Presence of Cyanide

Abstract

The solvolytic O-deacylation of the fully acylated sugar moiety of uridine and thymidine was found to take place readily in the presence of KCN in methanol at room temperature.     

Homologues of Isomeric Dideoxynucleosides as Potential Antiviral Agents: Synthesis of Isodideoxy-Nucleosides with a Furanethanol Sugar Moiety

Abstract

The synthesis of a homologues series of compounds related to (R, S)-isodideoxynucleosides has been completed by coupling a variety of natural purine and pyrimidine bases with a modified sugar intermediate. This sugar precursor was prepared regiospecifically and stereospecifically from D-glucose.     

Synthesis and Biological Activity of Modified Thiopyrimidine Nucleosides

Abstract

N³ -β-D-glucopyranosyl, galactopyranosyl and xylopyranosyl 6-methyl-2-methylthiouracil and their 5-bromo derivatives have been synthesized by coupling an a-acetobromosugar with the corresponding thiouracil. The new modified thiouridine analogues were evaluated for their inhibitory activity against Human Immunodeficiency Virus (HIV) replication in MT-4 cells as well as for their cytotoxicity.     

Studies on Disaccharide Nucleoside Synthesis. Mechanism of the Formation of Trisaccharide Purine Nucleosides

Abstract

The unexpected formation of trisaccharide nucleosides during synthesis of purine 5′-O-β-D-ribofuranosylnucleosides in the presence of Lewis acids was observed.     

Studies on Nucleotide Chemistry 15. Synthesis of Oligodeoxynucleotides Using Amidine Protected Nucleosides

Abstract

An in situ method is described for synthesizing DNA which incorporates a new series of amidine protected deoxy-nucleosides and bis-dialkylaminophosphines as phosphitylating agents. These procedures were used to synthesize d(GGGAATTCCC) which was digested by EcoRI.     

Synthesis and Antiviral (RNA) Evaluation of Nucleoside Analogs of Tiazofurin Modified at the Carboxamide Moiety

Abstract

The carboxamide functionality of tiazofurin 1a has been modified to produce the following analogs: carboximidates 5a,b, carboxamidines 6, 10, tetrahydropyrimidine 7, N-glycine 8 and N-glutamine 9. These structural modifications abolished the in vitro antiviral (RNA) activity exhibited by tiazofurin against the flaviviruses (yellow fever and Japanese encephalitis viruses), bunyavirus (Punta Toro virus) and togavirus (Venezuelan equine encephalomyelitis virus). Only carboximidates 5a,b retained marginal activity against bunyaviruses.     

Synthesis of a Novel,Optically Active Uridine Analog Containing a 1,4-Dioxane Sugar Moiety. Synthesis of the Corresponding Dinucleotide

A new optically active uridine nucleoside analogue in which a substituted 1,4-dioxane ring functioned as the sugar analogue was prepared from L-tartaric acid. The nucleoside analogue was further converted into the corresponding protected dinucleotide.     

Synthesis of Nucleosides Having Unusual Branched Sugars as Potential Antiviral Agents

Abstract

Enantiomerically pure novel nucleosides having unusual branched sugars were synthesized in a stereospecific manner from a common chiral pool of (S, S)-1,4-bis(benzyloxy)-2,3-epoxybutane and evaluated for antiviral activity.     

Synthesis and Antiviral Activity of Carbocyclic Nucleosides Incorporating a Modified Cyclopentane Ring. Part 3: Adenosine and Uridine Analogues

Abstract

Six new carbocyclic nucleosides were prepared by mounting a purine (compounds 4–6), 8-azapurine (7 and 8) or undine (9) base on the ammo group of (1S,3R)-3-amino-2,2,3-trimethylcyclopentylmethanol (10). At subtoxic concentrations, compounds 5-9 showed at best marginal antiviral activity.     

Synthesis of Modified Thiopurine Nucleosides for Structural Characterization of Human Thiopurine S-Methyltransferase

Abstract

Synthesis of a number of photoactive thiopurine-containing nucleosides was described. S-methylation of the synthesized compounds in the course of the reaction catalyzed by recombinant human thiopurine S-methyltransferase was studied by UV-spectroscopy.     

Synthesis of Novel 3-Butylphthalide Derivatives Containing Isopentenylphenol Moiety as Potential Antiplatelet Agents for the Treatment of Ischemic Stroke

In order to find novel antiplatelet drugs for the treatment of ischemic stroke, a series of 3-butylphthalide derivatives containing isopentenylphenol moiety were designed, synthesized and characterized with spectroscopic analyses. The in vitro antiplatelet activity results indicated that compound 3 better inhibited the arachidonic acid (AA) induced platelet aggregation than aspirin (ASP) and 3-butylphthalide (NBP). Additionally, compared with precursor NBP, compound 3 possessed outstanding antithrombotic activity in the animal experiment model, which could effectively alleviate the formation of tail thrombus and carotid artery thrombus in mice. More importantly, intraperitoneal administration of compound 3 can well protected the rats against ischemia/reperfusion-induced brain injury. Further pharmacokinetic (PK) assay indicated that compound 3 had good absorption characteristics and metabolic stability in vivo. Overall, the present research provides a new candidate compound for the treatment of ischemic stroke caused by platelet aggregation.     

Raman and Infrared Studies of Nucleosides at High Pressures: I. Adenosine

Abstract

Room temperature Raman and infrared (IR) spectra of crystalline adenosine at pressures between 1 atm and 10 GPa are reported. Vibrational modes were identified through assignments in the literature. Many modes were found to increase in frequency with pressure; however, some irregularities were observed. Discontinuities were observed in numerous Raman and IR modes near 2.5 GPa, indicating a phase transition. The modes associated with the glycosidic bond shift significantly down in frequency near this pressure, suggesting a weakening of the associated bond. The IR modes associated with hydrogen-stretching motions were found to decrease in frequency with pressure.     

Synthesis of Amide Linked Nucleosides at the 6 Position of Deoxy Inosine and Their application to DNA synthesis,Hybridization Studies.

Abstract

Synthesis of amide linked nucleosides at the 6 position of the purine base to recognize “G:C” base pair in a DNA duplex is described. Here we describe the synthesis of amide linked nucleosides containing heteroatoms N, O and C and their application to DNA synthesis and hybridization studies.