共查询到20条相似文献,搜索用时 31 毫秒
1.
Shih Hsi Chu Lynn Ho Edward Chu Todd Savarese Zhi Hao Chen Elizabeth Claflin Rowe 《Nucleosides, nucleotides & nucleic acids》2013,32(2):185-200
Abstract A series of 5′-halogenated formycins, including the chloro-, bromo- and iodo- derivatives, were synthesized. These compounds are competitive inhibitors of 5′-deoxy-5′-methylthioadenosine phosphorylase (MTAPase) with Ki values in the range of 10?7 M, making them the most potent inhibitors of MTAPase reported to date. These compounds protect cells from the growth-inhibitory action of 5′-halogenated adenosines, which must be activated by MTAPase. The syntheses of 5′-halogenated formycin B derivatives, which inhibit purine nucleoside phosphorylase, are also described. 相似文献
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Abstract The synthesis of several new 5′-deoxy-5′-nucleosideacetic acid derivatives by the reactions of alkoxycarbonylmethylene triphenylphosphoranes with nucleoside 5′-aldehydes is described. 相似文献
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Negi Sanjana Tak Himanshu Madari Steffi Bhakta Subham Ganapathi T. R. 《Protoplasma》2023,260(2):391-403
Protoplasma - Generation of crops with broad-spectrum tolerance to biotic and abiotic stress conditions depends upon availability of genetic elements suitable for varied situations and diverse... 相似文献
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《Phytochemistry》1996,42(5):1259-1262
Methyl 5′,5′,5′-trifluorojasmonate was synthesized as an antimetabolic analogue of methyl jasmonate. It induced potato tuber formation more effectively than methyl jasmonate and inhibited the growth of rice seedlings and the germination of lettuce and radish seeds. These results suggest that epijasmonic acid itself has potato tuber-inducing activity and that the hydroxyl group of tuberonic acid is not necessary for this activity. 相似文献
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Abstract 5-Ethyl-2′-deoxyurldine (EDU) is phosphorylated to a much greater extent by herpes simplex virus (HSV)-infected Vero cells than by mock-infected cells. Within the infected cells, EDU is preferentially incorporated into viral DNA and more inhibitory to viral than cellular DNA synthesis 相似文献
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J. Matulic-Adamic I. Rosenberg A. A. Arzumanov N. B. Dyatkina E. A. Shirokova A. A. Krayevsky 《Nucleosides, nucleotides & nucleic acids》2013,32(10):1085-1092
Abstract Treatment of 3′-fluoro-3′-deoxythymidine (FLT), 3′-azido-3′-deoxythymidine (AZT) and 2′,3′-dideoxyadenosine (ddA) with tris(1,1,1,3,3,3-hexafluoro-2-propyl)phosphite or phosphorous acid and N,N'-dicyclohexylcarbodiimide produced the corresponding nucleoside 5′-hydrogenphosphonates. Reaction of FLT, AZT and 3′-deoxythymidine (ddT) with fluorophosphoric acid and 2,4,6-triisopropylbenzenesulfonyl chloride lead to the corresponding nucleoside 5′-phosphorofluoridates also on a multi-gram scale. All the compounds were isolated in high pure state by chromatographic technique. 相似文献
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A kinetic analysis of the labeling of the methylated components of messenger RNA and heterogeneous nuclear RNA in mouse L cells indicates that the 5′ terminal cap I structures (m7GpppXmpYp) of mRNA are derived from 5′ terminal cap structures of hnRNA. Most of the hnRNA caps are conserved during processing, whereas only a portion of the internal m6A residues in hnRNA are conserved. The cap II structures (m7GpppXmpYmpZp), which constitute the 5′ termini of some mRNAs, arise by a “secondary” methylation that occurs after the mRNAs have entered the cytoplasm. This secondary methylation is apparently restricted to a particular subclass of mRNAs having a high frequency of pyrimidine nucleotides at position Y, a composition at position X which differs from that of the bulk of the cap I-terminated mRNAs, and a relatively slow rate of turnover. 相似文献
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Subha R. Das 《Nucleosides, nucleotides & nucleic acids》2013,32(10):668-677
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. 相似文献
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5-Deoxy-5-nucleosideacetic acids II–V are isostructural analogues of nucleotides with a carboxylate group in the place of the 5-phosphate group. We have studied their oligomerization in aqueous solution using a water-soluble carbodiimide as the condensing agent in the presence or absence of an appropriate polynucleotide template. Condensation of adenylic acid analogues IIa, IIIa, and Va in the presence of polyuridylic acid were found to be the most efficient reactions. Cyclization of the activated monomers to lactones and the insolubility of the oligomers in aqueous solution were found to be obstacles to the efficient formation of long oligomers. 相似文献
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Robert Van Ostrand Casey Jacobsen Alicia Delahunty Carley Stringer Ryan Noorbehesht Haidi Ahmed 《Nucleosides, nucleotides & nucleic acids》2017,36(3):181-197
Reported is an efficient synthesis of adenyl and uridyl 5′-tetrachlorophthalimido-5′-deoxyribonucleosides, and guanylyl 5′-azido-5′-deoxyribonucleosides, which are useful in solid-phase synthesis of phosphoramidate and ribonucleic guanidine oligonucleotides. Replacement of 5′-hydroxyl with tetrachlorophthalimido group was performed via Mitsunobu reaction for adenosine and uridine. An alternative method was applied for guanosine which replaced the 5′-hydroxyl with an azido group. The resulting compounds were converted to 5′-amino-5′-deoxyribonucleosides for oligonucleotide synthesis. Synthetic intermediates were tested as antimicrobials against six bacterial strains. All analogs containing the 2′,3′-O-isopropylidine protecting group demonstrated antibacterial activity against Neisseria meningitidis, and among those analogs with 5′-tetrachlorophthalimido and 5′-azido demonstrated increased antibacterial effect. 相似文献
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Summary This study was undertaken to investigate the mechanism of chemical radiosensitization by halogenated bases incorporated into DNA. Radiation-induced base and sugar-phosphate backbone damage to 5-bromouridine-5-monophosphate (5-BrUMP) was monitored using a flow system connected in series with a recording spectrophotometer, a bromide (Br–)-specific ion analyzer and a Technicon auto-sampler. The system was used to assay loss of UV-absorbing 5,6 double-bond, release of Br– and inorganic phosphate (Pi) release using an automated colorimetric method, as a function of gamma-ray dose. Results obtained with radical scavengers indicate that, unlike non-halogenated nucleotides where the hydroxyl radical (· OH) is the principal damaging species, 5-BrUMP is damaged by the hydrated electron (e
aq
–
), hydrogen atom (H·) and · OH, producing a high yield of base damage and Br– and Pi release in anoxia. Another novel feature of 5-BrUMP radiolysis is that oxygen, by convertinge
aq
–
and H· to the unreactive superoxide radical anion (0
2
–
), has a protective effect on both base and phosphate ester damage. Under · OH-scavenging conditions, where the radiation yield of reductive debromination is 3.8, there is some Pi release, suggesting the possibility of intramolecular hydrogen atom transfer from the sugar ring to the 5-uracilyl radical and subsequent sugar-phosphate bond cleavage. This hypothesis is supported by the action of oxygen and thiols in modifying thee
aq
–
-mediated sugar-phosphate damage. 相似文献
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Hisanori Suzuki Yasuharu Tanaka Daniela Tornese Buonamassa Benedetta Farina Enzo Leone 《Molecular and cellular biochemistry》1987,74(1):17-20
The effects of analogs of diadenosine 5,5-p1,p4-tetraphosphate (Ap4A) were examined on the ADP-ribosylation reaction of histone Hl catalysed by purified bovine thymus poly(ADP-ribose)transferase. Among the compounds tested, Ap4A and ApCH2PPPA were shown to be the most efficient inhibitors of the enzyme. From kinetic studies of their action, it appears that Ap4A and ApCH2pppA might be mixed type inhibitors.Abbreviations ADP-ribose
adenosine diphosphate ribose
- ADPRT
poly-(ADP-ribose)transferase
- Ap4A
diadenosine 5,5-p1,p4-tertraphosphate
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Ap4A
diadenosine 5,5-p1,p4(-1,N6-ethenyl-)tetra-phosphate
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ApAA
diadenosine 5,5-p1,p4(-N6(-1,N6-)bisethenyl-)tetraphosphate
- ApCH2pppA
diadenosine 5,5-p1,p4(-p1,p2-methylene-)tetraphosphate
- AppCH2ppA
diadenosine 5,5-p1,p4(-p2,p3methylene-)tetraphosphate
- AppNHppA
diadenosine 5,5-p1,p4(-p2,p3-amino-)tetraphosphate
- AppCHBrppA
diadenosine 5,5-p1,p4(-p2,p3-bromine methyno-)tetraphosphate
- CpCH2ppCH2PC
dicytidine 5,5-p1,p4(-p1,p2-p3,p4-bismethylene-)tetraphosphate
- ApCH2ppCH2pA
diadenosine 5,5-p1,p4(-p1,p2-p3,p4-bismethylene-)tetraphosphate. 相似文献
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William M. Mahoney Jr Jagadambika Gunaje Guenter Daum Xiu Rong Dong Mark W. Majesky 《PloS one》2013,8(4)
Hedgehog (Hh) signaling plays fundamental roles in morphogenesis, tissue repair, and human disease. Initiation of Hh signaling is controlled by the interaction of two multipass membrane proteins, patched (Ptc) and smoothened (Smo). Recent studies identify Smo as a G-protein coupled receptor (GPCR)-like protein that signals through large G-protein complexes which contain the Gαi subunit. We hypothesize Regulator of G-Protein Signaling (RGS) proteins, and specifically RGS5, are endogenous repressors of Hh signaling via their ability to act as GTPase activating proteins (GAPs) for GTP-bound Gαi, downstream of Smo. In support of this hypothesis, we demonstrate that RGS5 over-expression inhibits sonic hedgehog (Shh)-mediated signaling and osteogenesis in C3H10T1/2 cells. Conversely, signaling is potentiated by siRNA-mediated knock-down of RGS5 expression, but not RGS4 expression. Furthermore, using immuohistochemical analysis and co-immunoprecipitation (Co-IP), we demonstrate that RGS5 is present with Smo in primary cilia. This organelle is required for canonical Hh signaling in mammalian cells, and RGS5 is found in a physical complex with Smo in these cells. We therefore conclude that RGS5 is an endogenous regulator of Hh-mediated signaling and that RGS proteins are potential targets for novel therapeutics in Hh-mediated diseases. 相似文献
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Kôichi Ogata Akira Imada Yoshio Nakao 《Bioscience, biotechnology, and biochemistry》2013,77(9):586-623
A Bacillus accumulated 5′-nucleotides in the culture fluid during cultivation. These nucleotides consisted mainly of ribonucleoside 5′-monophosphates and of traces of nucleoside 5′-diphosphates. The composition of the accumulated nucleotides resembled that of the nucleotides of intracellular RNA. Therefore an intimate relationship between the accumulation of nucleotides and the metabolism of endogenous RNA was suggested.The excretion of 5′-nucleotides into the culture fluid took place in parallel with the reduction of intracellular RNA, and it was presumed that the accumulated nucleotides were products of degradation of intracellular RNA. 相似文献
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Lysosome-solubilized pig liver NADH-cytochrome b5 reductase is inactivated by 5′-p-fluorosulfonylbenzoyladenosine (5′-FSBA) following pseudo-first-order kinetics. A double reciprocal plot of 1/K obs versus 1/[5′-FSBA] yields a straight line with a positiveY intercept, indicative of reversible binding of the analogue prior to an irreversible incorporation.K d or the initial reversible enzyme-analogue complex is estimated at 185 µM withK 2=0.22 min?1 (atpH 8.0 and 25°C). A stoichiometry of 1.2 moles of analogue bound/mole of enzyme at 100% inactivation has been determined from incorporation studies using 5′-p-fluorosulfonylbenzoyl-[14C]adenosine. The irreversible inactivation as well as the covalent incorporation could be completely prevented by the presence of NADH, the substrate of enzyme, during the incubation. Four 5′-FSBA-labeled peptides were isolated by reverse-phase high-performance liquid chromatography of tryptic digest of the modified NADH-cytochrome b5 reductase and their amino acid sequences were determined. These peptides appear to be related to the NADH binding site of the enzyme. 相似文献