3′-3′,3′-5′ and 5′-5′ TpT-Amides: Synthesis,Characterization and Alkaline Hydrolysis

Abstract

A simple procedure is described for the preparation of the title compounds 1, 8 and 9. 3′-3′ or 3′-5′ or 5′-5′ TpT was reacted with a twofold molar excess of TPS in anhydrous DMF, at room temperature, for 5 min, followed by a 1 min in situ treatment of the reaction mixture with excess 7.0 N NH₄OH, at 0°C. The alkaline hydrolysis of 1, 8 and 9 proceeds without the assistance of 3′- and 5′-hydroxyl groups resulting in equimolar mixtures of thymidine (4) and thymidine 3′-phosphoramidate (6) (for the 3′-3′ isomer) or thymidine 5′-phosphoramidate (7) (for the 5′-5′ isomer) or 6 and 7 in equal quantities (for the 3′-5′ isomer).     

用固定化5′-磷酸二酯酶工业生产5′-核苷酸

自从固定化氨基酰化酶在日本获得工业应用以来,已引起各国广泛注意,至今已有近10个固定化酶在一些先进国家投入工业使用。我们自1970年开展固定化酶研究以来,已将我     

Synthesis and Biological Effects of 5′-Deoxy-5′-(Cyclo-Propylmethylthio)Adenosine

Abstract

A novel synthesis of the nucleoside analog, 5′-deoxy-5′-(cyclopropylmethylthio)adenosine (CPMTA, 1) has been developed. CPMTA is a closely related structural analog of 5′-deoxy-5′-(isobutylthio)-adenosine (SIBA, 2), which has been widely studied and shown to exert a multitude of biological effects. The in vitro and in vivo antitumor (L1210 leukemia) activity of CPMTA has been found to be comparable to that of SIBA, whereas its in vitro antiviral (HSV and VSV) activity is diminished. These agents are being developed as inhibitors of methylation and/or polyamine synthesis.     

Interaction of (2′ -5′) and (3′ -5′) Linked 2-Aminoadenylyl-3-aminoadenosines with Polyuridylic Acid

Abstract

2′-5′ and 3′-5′ linked 2-aminoadenylyl-2-aminoadenosines [(2′-5′)n²Apn²A (1) and (3′-5′)n²Apn²A (2)] were synthesized by condensation of 5′-O-monomethoxytrityl-N ² N ⁶-dibenzoyl-2-aminoadenosine and N ²,N ⁶,2′,3′-O-tetrabenzoyl-2-aminoadenosine 5′-phosphate using dicyclohexylcarbodiimide (DCC). The conformational properties of these dimers 1 and 2 were examined by UV, NMR and CD spectroscopy. The results reveal that the 2′-5′-isomer 1 takes a stacked conformation, which contains a larger base-base overlap and is more stable against thermal perturbation with respect to the 3′-5′-isomer 2. Interactions of 1 and 2 with polyuridylic acid (Poly (U)) were also examined by Tm, mixing curves, UV and CD spectra. Both the dinucleoside isomers 1 and 2 formed a complex of 1 : 2 stoichiometry with poly(U), which was much more stable than that of the corresponding ApA isomer     

Microbiological synthesis of 5-ethyl- and (E)-5-(2-bromovinyl)-2′-deoxyuridine

Summary The title compounds were prepared by an enzymatic transdeoxyribosylation from 2 dGuo or 2 dThd to the respective heterocyclic bases, 5-ethyluracil and (E)-5-(2-bromovinyl)uracil, using the whole bacterial cells ofEscherichia coli as a biocatalyst.     

Oligomerizations of deoxyadenosine bis-phosphates and of their 3′-5′, 3′-3′, and 5′-5′ dimers: Effects of a pyrophosphate-linked,poly(t) analog

A pyrophosphate-linked polynucleotide analog based on thymidine 3,5 bis-phosphate (pTp) catalyzes the oligomerization of activated dimers of pdAp in the presence of MgCl₂. Although no catalysis of the oligomerization of the activated monomer (ImpdAplm) was observed in the presence of MgCl₂, there was a significant stimulation of oligomerization by the template in the presence of MnCl₂.     

The 5′-Nor Aristeromycin Analogues of 5′-Deoxy-5′-Methylthioadenosine and 5′-Deoxy-5′-Thiophenyladenosine

To extend the potential of 5′-noraristeromycin (and its enantiomer) as potential antiviral candidates, the enantiomers of the carbocyclic 5′-nor derivatives of 5′-methylthio-5′-deoxyadenosine and 5′-phenylthio-5′-deoxyadenosine have been synthesized and evaluated. None of the compounds showed meaningful antiviral activity.     

Synthesis and Antiviral Activity Assay of Novel (E)-3′,5′-Diamino-5-(2-bromovinyl)-2′,3′,5′-trideoxyuridine

Abstract

(E)-3′,5′-diamino-5-(2-bromovinyl)-2′,3′,5′-trideoxyuridine (5), the diamino analogue of BVDU (1), was synthesized from BVDU. In contrast with BVDU, compound 5 did not show activity against herpes simplex virus or varicella-zoster virus.     

Chemoenzymatic Synthesis of 3′-Deoxy-3′-(4-Substituted-Triazol-1-YL)-5-Methyluridine

An efficient protocol has been developed for the synthesis of a small library of 3′-deoxy-3′-(4-substituted-triazol-1-yl)-5-methyluridine using Cu(I)-catalyzed Huisgen–Sharpless–Meldal 1,3-dipolar cycloaddition reaction of 3′-azido-3′-deoxy-5-methyluridine with different alkynes under optimized condition in an overall yields of 76%–92%. Here, the azido precursor compound, i.e., 3′-azido-3′-deoxy-5-methyluridine was chemoenzymatically synthesized from D-xylose in good yield. Some of the alkynes used in cycloaddition reaction were synthesized by the reaction of hydroxycoumarins or naphthols with propargyl bromide in acetone using K₂CO₃in excellent yields. All synthesized compounds were unambiguously identified on the basis of their spectral (IR, ¹H-, ¹³C NMR spectra, and high-resolution mass spectra) data analysis.     

Structure and Conformation of the Branch Core Triribonucleotide Containing 2′-5′ and 3′-5′ Phosphodiester Linkages (A2′p5′G 3′p5′C) in Solution,Essential for Yeast mRNA Splicing,Deduced from 1H-NMR

Abstract

The non-exchangeable ¹H-NMR signals of the branch core trinucleotide of the lariat branch site (A^2′p5′G _3′p5′C), 1) and its derivatives 2 and 3 are completely assigned using one- and two- dimensional NMR techniques including NOE, COSY, NOESY, ¹H-¹HINADEQUATE and 2D-J-resolved spectroscopy. From the vicinal coupling constants in the individual ribose rings, NOE data and T₁ measurements, the following properties of the trimers are deduced.(i)The unique stacking behavior of the trimers is S^1′N _3′N, and the sugar rings exist predominantly in the N-conformation (3′-endo-2′-exo).(ii)The sugar-base orientations appear to be anti.(iii) The branched trimers exist in solution as single-stranded right-handed conformations resembling A-RNA with stacking between the adenine and guanine residues in aqueous solution at 21°C and pH 7.2.(iv) The calculated values for the torsion angles ε^t andγ⁺ for the trimers are 201–203° and 71–86%, respectively, while the percent β¹ values are higher for the guanine (87–92%) than the cytosine residues (73–77%). The computer generated depiction of the triribonucleotide 1 is also shown. These subtle structural features may act as recognition signals for this critical lariat branch site which is essential for the second step in yeast mRNA splicing.     

Phosphonoformate Esters of Anti-HIV Nucleosides: 3′-Azido-3′-deoxythymidine and 2′,3′-Dideoxycytidine Derivatives Containing a Small 5′-(0-Alkoxycarbon-ylphosphinyl) or 5′-(O-Cholesterylcarbonylphosphinyl) Substituent

Abstract

A convenient general method of synthesis of 5′-O-(alkoxycarbonyl)phosphonate esters of 2′,3′-dideoxyribonucleosides is presented, using the 5′-O-(methoxycarbonyl)phosphinyl, 5′-0-(ethoxycarbonyl)phosphinyl, and 5′-O-(cholesterylcarbonyl)phosphinyl derivatives of 3′-azido-3′-deoxythymidine (AZT) and the 5′-0-(ethoxycarbonyl)phosphinyl derivative of 2′,3′-dideoxycytidine (ddC) as examples. Reaction of trimethyl phosphonoformate, methyl phosphonoformate, or dimethyl cholesterylcarbonylphosphonate with phosphorus pentachloride in carbon tetrachloride, followed by direct condensation of the resulting phosphonyl chloride with the nucleoside, gave the fully esterified phosphonoformate derivatives, which on treatment with sodium iodide in tetrahydrofuran underwent selective cleavage of the P-OMe or P-OEt groups, leaving the carboxylate esters intact. The resulting products were converted from sodium salts to ammonium salts by ion-exchange chromatography.     

癌变过程中酪氨酸转氨酶(TAT)和5′-核苷磷酸二酯酶(5′-NPDase)的变化

本文测定了大鼠及人体胚胎发育和癌变过程中TAT和5′-NPDase活力变化,所得结果表明: (一)5′-NPDase快速同工酶区带在甲胎蛋白(AFP)阴性肝癌患者血清中阳性率较高。(二)TAT,5′-NPDase和AFP也许可作为研究癌、胚以及肝癌癌变过程中基因表达的三个互补生化指标。     

5′-O-Dephosphorylated 2′,5′-oligoadenylate (2-5A) with 8-methyladenosine at the 2′-terminus activates human RNase L

Human ribonuclease L (RNase L), an interferon-induced endoribonuclease, becomes enzymatically active after binding to 2-5A. The 5′-phosphoryl group of 2-5A is reportedly necessary for the conformational change leading to RNase L activation. However, we found that 5′-O-dephosphorylated 2-5A tetramer analogs with 8-methyladenosine at the 2′-terminus were more effective as an activator of RNase L than the parent 2-5A tetramer. Introduction of 8-methyladenosine is thought to induce a dramatic shift of 2-5A in the binding site of RNase L.     

麦芽根中5′-磷酸二酯酶和5′-磷酸单酯酶的提取

建立一种高效快速的从麦芽根中提取5′-磷酸二酯酶和磷酸单酯酶的方法。通过将麦芽根粉碎后,取一定粒度的麦芽根加一定量的去离子水浸泡,过滤后得粗酶液。用紫外分光光度法测定5′-磷酸二酯酶和5′-磷酸单酯酶的酶活,研究粉碎粒度、料液比、抽提温度、抽提时间等因素对麦芽根中5′-磷酸二酯酶和5′-磷酸单酯酶提取的影响。将原料粉碎至100目,以去离子水为提取剂,于4℃提取20h,料液质量比为1:10,5′-磷酸二酯酶的酶活力可达160U/ml。该法简单、快速、准确、适应性强,为5′-磷酸二酯酶的提取与检测提供了有效的工具。     

利用5′-RACE法扩增到钙通道基因的5′-端片段

钙除了是人体牙和骨中的重要组成成份之外,吠”还是细胞内的第二信使。电压激活的钙离子通道在调节细胞内钙离子水平中有至关重要的作用。作者曾报道过用丁一RAC法克隆到钙通道基因3’一端3000多hp的大片段［1］,最近利用已知序列提供的信息,设计基因特异性引物,利用RT－PCR及5’－RACE法,我们又克隆到了此钙通道基因的丁一端约4．skb的大片段。1材料与方法1．亚总RNAN取用含10％／J‘牛血清的MEM培养基培养INS一1细胞。该细胞为鼠源胰腺9一细胞建株细胞（美国UniverstyofSouhAlabama的MingLi博士惠赠）,LVA钙通道基因高…     

Enantiospecific Synthesis of 5′-Noraristeromycin and its 7-Deaza Derivative and A Formal Synthesis of (-)-5′-Homoaristeromycin

Abstract

Beginning with the treatment of the diacetate of cis-3,5-cyclopentenediol (5) with Pseudomonas cepacia lipase, (-)-5′-noraristeromycin (1) and (-)-7-deaza 5′-noraristeromycin (3) have been prepared. Subjecting 5 to treatment with porcine liver esterase led to an efficient preparation of a substituted cyclopentane precursor which, following literature precedence, can be converted into (-)-5′-homoaristeromycin (4).     

SYNTHESIS OF 5-(2,2′-BIPYRIDINYL AND 2,2′-BIPYRIDINEDIIUMYL)-2′-DEOXYURIDINE NUCLEOSIDES: PRECURSORS TO METALLO-DNA CONJUGATES

ABSTRACT

The synthesis of 2,2′-bipyridinyl-2′-deoxyuridine metal-chelator nucleosides (Bipy-dU) with either ethynyl or ethylenyl linkers was now been accomplished. These new nucleosides will permit the construction of a number of corresponding metallo-DNA conjugates where many types of metals can be complexed to the 2,2′-bipyridinyl chelator group and the resulting metallo-dU conjugates incorporated into DNA oligonucleotides. Additionally this paper also reports the synthesis of a di-N-alkylated bipyridinediiumyl-2′-deoxyuridine nucleoside (Bipy²⁺-dU) with an ethylenyl linker. The Bipy²⁺-dU nucleoside was found to decompose under basic conditions precluding its use in standard automated DNA-synthesis by the phosphoramidite method. No such restrictions apply to the two Bipy-dU nucleosides reported here for use as metal chelators.