Deoxyguanylic Acid Research Articles

Fructus gardeniae ameliorates anxiety-like behaviors induced by sleep deprivation via regulating hippocampal metabolomics and gut microbiota.

Fructus gardeniae (FG) is a traditional Chinese medicine and health food for thousands of years of application throughout Chinese history and is still widely used in clinical Chinese medicine. FG has a beneficial impact on anxiety, depression, insomnia, and psychiatric disorders; however, its mechanism of action requires further investigation. This study aimed to investigate the effects and mechanisms of FG on sleep deprivation (SD)-induced anxiety-like behavior in rats. A model of SD-induced anxiety-like behavior in rats was established by intraperitoneal injection of p-chlorophenylalanine (PCPA). This was accompanied by neuroinflammation and metabolic abnormalities in thehippocampus and disturbance of intestinal microbiota. However reduced SD-induced anxiety-like behavior and decreased levels of pro-inflammatory cytokines including TNF-α and IL-1β were observed in the hippocampus of rats after 7 days of FG intervention. In addition, metabolomic analysis demonstrated that FG was able to modulate levels of phosphatidylserine 18, Phosphatidylinositol 18, sn-glycero-3-phosphocholine, deoxyguanylic acid, xylose, betaine and other metabolites in the hippocampus. The main metabolic pathways of hippocampal metabolites after FG intervention involve carbon metabolism, glycolysis/gluconeogenesis, pentose phosphate, and glycerophospholipid metabolism. 16S rRNA sequencing illustrated that FG ameliorated the dysbiosis of gut microbiota in anxious rats, mainly increased the abundance of Muribaculaceae and Lactobacillus, and decreased the abundance of Lachnospiraceae_NK4A136_group. In addition, the correlation analysis demonstrated that there was a close relationship between hippocampal metabolites and intestinal microbiota. In conclusion, FG improved the anxiety behavior and inhibited of neuroinflammation in sleep-deprived rats, and the mechanism may be related to the FG regulation of hippocampal metabolites and intestinal microflora composition.

One-pot process of 2′-deoxyguanylic acid catalyzed by a multi-enzyme system

2′-Deoxyguanylic acid (deoxyguanosine-5′-monophosphate, dGMP) is a substance required by living cells that is used extensively in reagents, fine chemicals and other industrial fields. Traditionally, dGMP is separated from DNA degradation products, which is low-yielding and time-consuming. Herein, we investigated a novel, one-pot multi-enzymatic cascade reaction to produce dGMP. This reaction involved purine nucleoside phosphorylase (PNPase) and acetate kinase (ACKase) from Escherichia coli, N-deoxyribosytransferase II (NDT-II) from Lactobacillus delbrueckii and deoxyguanosine kinase (dGKase) from Bacillus subtilis. During the reaction, the initial guanosine substrate was cleaved into guanine and ribose-1-phosphate by PNPase. Then, deoxyguanosine (dGR) was subsequently produced from a reaction between guanine and thymidine catalysed by NDT-II. Finally, the intermediate dGR was phosphorylated to dGMP by dGKase and a cytidine triphosphate (CTP) regeneration system that utilised acetyl phosphate via ACKase. A very small amount of CTP was added because CTP regeneration was efficient to transfer a phosphate group from acetyl phosphate to dGR. After 12 h of incubation, a maximal dGMP yield of up to 76% was obtained based on the addition of 5 mM guanosine and 5 mM thymidine.

A Thymine Tetrad Assembly Templated from Thymidylic Acid

A template tetra-coupled with thymidylic acid through a phosphate linkage was characterized in methanol for emergent properties of nucleobase tetrad formation. Intramolecular hydrogen bonded base pairing in the absence of a cation was indicated for the thymidylic acid species supporting a monomeric template-assembled structure. Thus, an initial report of a stabilized individual thymine tetrad assembly is presented here. Consistent with previous investigations, a deoxyguanylic acid variant templated an analogous methanolic monomeric G-tetrad in comparison to the thymine species.

Квантово-механічне дослідження конформаційних можливостей молекули 5'-дезоксигуанілової кислоти

Квантово-механічне дослідження конформаційних можливостей молекули 5'-дезоксигуанілової кислоти

Synthesis, structure and interactions with DNA of novel tetranuclear, [Mn4(II/II/II/IV)] mixed valence complexes

Reaction of Mn(II) with phenoxyalkanoic acids and di-2-pyridyl ketone oxime (Hpko) leads to neutral tetranuclear complexes of the general formula Mn4(O)(pko)4(phenoxyalkanoato)4 (phenoxyalkanoic acids: H-mcpa=2-methyl-4-chloro-phenoxy-acetic acid, H-2,4,5-T=2,4,5-trichloro-phenoxy-acetic acid or H3,4-D=3,4-dichloro-phenoxy-acetic acid). The compounds were synthesized by adding di-2-pyridyl ketone oxime to MnCl2 in the presence of the sodium salts of the alkanoic acids in methanol. The crystal structure of Mn4(II/II/II/IV)(O)(pko)4(2,4,5-T)4·2.5CH3OH·0.25H2O 1 shows that the complex consists of a [Mn4(μ4-O)]8+ core with a Mn(IV) and 3 Mn(II) ions in octahedral environment and a μ4-O atom bridging the four manganese ions. Spectroscopic studies of the interaction of these tetranuclear clusters with DNA showed that these compounds bind to dsDNA. The binding strength of the Mn4(II/II/II/IV)(O)(pko)4(2,4,5-T)4 complex for calf thymus DNA is equal to 1.1×104M−1. Among the deoxyribonucleotides they bind preferentially to deoxyguanylic acid (dGMP). Competitive studies with ethidium bromide (EthBr) showed that the Mn4(II/II/II/IV)(O)(pko)4(2,4,5-T)4 complex exhibited the ability to displace the DNA-bound EthBr indicating that the complex binds to DNA via intercalation in strong competition with EthBr for the intercalative binding site. Additionally, DNA electrophoretic mobility experiments showed that all three complexes, at low cluster concentration, are obviously capable of binding to pDNA causing its cleavage (relaxation) at physiological pH and temperature. At higher cluster concentration, catenated dimer forms of pDNA was formed.

3‘-H-Phosphonate Synthesis of Chiral Benzo[a]pyrene Diol Epoxide Adducts at N2 of Deoxyguanosine in Oligonucleotides

A synthetic route to oligonucleotides containing N(2)-deoxyguanosine adducts at C-10 of the enantiomeric 7,8-diol 9,10-epoxides of 7,8,9,10-tetrahydrobenzo[a]pyrene in which the epoxide oxygen and the 7-hydroxyl group are trans is described. The present adducts result from the trans addition of N(2) of deoxyguanosine to the epoxide at C-10. Our synthesis proceeds via preparation of the 3'-H-phosphonate of a suitably protected deoxyguanosine N(2)-adduct. The blocking groups consisted of O(6)-allyl on the deoxyguanosine, acetates on the 7-, 8-, and 9-hydroxyl groups of the hydrocarbon moiety, and dimethoxytrityl on the 5'-hydroxyl group of the sugar. These blocking groups are well suited to oligonucleotide synthesis on solid supports. The free 3'-hydroxyl group of this nucleoside adduct was readily converted to its 3'-H-phosphonate with diphenyl phosphite in pyridine in high yield for both the 10R and 10S isomers. For synthesis of oligonucleotides, the first several nucleotides were incorporated onto the solid support with an automated synthesizer using standard phosphoramidite chemistry. The adducted deoxyguanilic acid residue was introduced as the H-phosphonate in a manual step (80% yield), followed by completion of the sequence on the synthesizer. Although a 10-fold excess of the 3'-H-phosphonate was used in the manual coupling step, as much as 70% of the reactant could be recovered. The 3'-H-phosphonate of the protected 10S nucleoside adduct was converted to the unblocked nucleotide adduct, various salts of which failed to form crystals suitable for X-ray analysis. Although submilligram quantities of this compound have been formed as mixed diastereomers by direct reaction of deoxyguanylic acid with racemic diol epoxide, the present study represents the first actual synthesis of the major DNA adduct formed from benzo[a]pyrene in mammals as its 3'-phosphate.

DNA Adducts Formed by the Fjord-Region Dihydrodiol Epoxide of Benzo[S]Picene

Anti benzo[s]picene 9,10-dihydrodiol 11,12-epoxide was reacted with calf thymus DNA and with its constituent deoxyribonucleotides. The origin of DNA adducts was established by comparison of their HPLC retention times and UV spectra with those of the nucleotide-derived adduct-markers. The low binding of the dihydrodiol epoxide to DNA (2%) and to deoxyguanylic and deoxyadenylic acids precluded an NMR study, and assignment of cis or trans epoxide ring opening was made by analogy to other anti dihydrodiol epoxide adducts. The adduct ratio for dGuo/dAdo in DNA was 24/76 and the ratios of dGuo cis/dGuo trans and dAdo cis/dAdo trans were 40/60 and 6/94, respectively.

DNA Adducts from syn 7-Methylbenz[A]anthracene 3,4-Dihydrodiol 1,2-Epoxide

DNA adducts derived from reaction of the racemic bay region syn 7-methylbenz[a]anthracene 3,4-dihydrodiol 1,2-epoxide with calf thymus DNA in vitro were tentatively identified. Eight markers (four deoxyguanosine and four deoxyadenosine adducts) were obtained from separate reactions of the racemic syn dihydrodiol epoxide with deoxyguanylic and deoxyadenylic acids. The nucleoside of origin of individual DNA products was established by comparing HPLC retention times and UV spectra of DNA adducts with those of the adduct markers. All DNA adducts eluted with retention times and had UV spectra that corresponded to the purine nucleoside adducts. Circular dichroism spectra of the marker adducts allowed assignment of S and R configuration at C1, the site of attachment of the hydrocarbon residue to the nucleoside. The CD spectra were comprised of four pairs of spectra that were mirror images of one another. Each pair consisted of the two cis or two trans products resulting from epoxide ring opening of each dihydrodiol epoxide enantiomer by the exocyclic amino group of the deoxyguanosine or deoxyadenosine residues. Since the adducts obtained were insufficient for NMR studies, assignment of cis and trans structures was made by comparison of elution sequence and circular dichroism data with those of the known syn benz[a]anthracene dihydrodiol epoxide adducts. The ratio of dGuo/dAdo adducts in DNA was 1.5, close to the ratio reported for syn benz[a]anthracene dihydrodiol epoxide. DNA adducts accounted for 27% of the original dihydrodiol epoxide used. The ratios of dGuo/dAdo modifications were 58/42 and 69/31 for the 3S,4R-dihydrodiol 1S,2R-epoxide and the 3R,4S-dihydrodiol 1R,2S-epoxide enantiomers, respectively. Approximately 75% of total DNA adducts was derived from the 3S,4R-dihydrodiol 1S,2R-epoxide enantiomer and these were largely cis adduets.

A chemiluminescence derivatization method for detecting nucleic acids and DNA probes using a trimethoxyphenylglyoxal reagent that recognizes guanine

A chemiluminescence derivatization method using a novel reagent, 3′,4′,5′-trimethoxyphenylglyoxal (TMPG) was studied for the quantitative detection of nucleic acids and deoxyguanylic acid oligomers on a nylon membrane. In the method, TMPG rapidly converted guanine of a nucleic acid to a chemiluminescent derivative in an alkaline phosphate solution at a room temperature. A cooled, charge-coupled device camera was used to detect the chemiluminescence emitted at room temperature from the derivatives on the membrane after the TMPG reaction. The detection signal was increased by increasing the amount of deoxyguanylic acid in the analyte molecule. When a DNA probe having a 5′-(G) 15TT(G) 15TT deoxyoligomer at its 3′ terminus was hybridized with a target complementary DNA fragment on the membrane, an increased chemiluminescence from the hybrid was detected by the proposed method. The lower limit of detection is approximately 1.0 pmol of the target DNA fragment bound to the probe in the hybridization assay.

Trans -en 2 Os ( η -H 2 )] 2 + as an 1 H NMR probe for the coordination of some anticancer metal complexes to deoxyguanotide

The molecular hydrogen complex of osmium, [trans-en2Os (ŋ-H2)]2+ (en, entlylendediamine) is a new1H NMR recognition probe for biomolecules. By using this probe, the coordination between deoxyguanylic acid (dGMP) and four metal anticancer complexes, titanocene dichloride, (C2H5)2SnCl2(phen). (C2H5)2SnCl2 and cisplatin are studied in D2O under the condition near the physiological one. The results show that the former three complexes mainly and strongly coordinate with the phosphate oxygen of dGMP, while cisplatin mainly coordinates with N(7) of dGMP.

Enzymatic production of 5′-deoxyribonucleotides from salmon milt

A new enzymatic method for production of 5′-deoxyribonucleotides from salmon milt with microbial enzymes has been studied. For efficient hydrolysis of salmon milt, we found that a two-step hydrolysis procedure was necessary. Streptomyces griseus protease, Actinase AS, and nuclease “Amano” from Penicillium citrinum were used to obtain 5′-deoxyribonucleotides. The total amount of 5′-deoxyribonucleotides in the final enzymatic hydrolysate was about 47% yield of the total DNA in the starting material. The yields of 5′-deoxyadenylic acid (5′-dAMP) and 5′-deoxyguanylic acid (5′-dGMP) were 17 and 10%, respectively.

Study of the fluorescence system deoxyguanylic acid-Tb (III) and the determination of deoxyguanylic acid

It was found that deoxyguanylic acid (dGMP) can form a complex with Tb(III) at pH 6.9–7.5, which then emits the strong characteristic fluorescence of Tb(III). Excitation is at 290 nm and emission wavelengths are 490 nm and 545 nm. A linear relation is obtained between the fluorescence intensity and dGMP concentration in the range 2.0 × 10 −7 to 1.0 × 10 −5 mol l −1. The detection limit is 3.0 × 10 −8 mol l −1. This method can determine dGMP selectively in the presence of other nucleotides (not including GMP).

Characterization of DNA Adducts Formed by anti-Benzo[g]chrysene 11,12-Dihydrodiol 13,14-Epoxide

The anti-11,12-dihydrodiol 13,14-epoxide of benzo[g]chrysene, a fjord-region-containing hydrocarbon, was found to react with DNA in vitro to yield, as the major product, an adduct in which the epoxide of the 11R, 12S, 13S, 14R enantiomer was opened trans by the amino group of deoxyadenosine. The structures of this adduct and other deoxyadenosine and deoxyguanosine adducts were established by spectroscopic methods. In reactions with deoxyguanylic acid, a product tentatively identified as a 7-substituted guanine was also detected. The mutagenic properties of this dihydrodiol epoxide in shuttle vector pSP189 showed that mutation at AT pairs accounted for 39% of base change mutations whereas chemical findings indicated that about 60% of adducts formed in calf thymus DNA involved adenines. Since calf thymus DNA is 56% AT and the target supF gene is 41% AT, the findings represent a fairly close relationship between adduct formation and mutagenic response. Overall, the chemical and mutagenic selectivities for the two purine bases in DNA were similar, though not identical, to those for the only other fjord-region-containing hydrocarbon studied in depth, i.e., benzo[c]phenanthrene. A major difference for these two hydrocarbon derivatives, however, is that benzo[c]phenanthrene dihydrodiol epoxides react to much higher extents (approximately 4-fold) with DNA than did the benzo[g]chrysene derivative.

Antiviral Action of Oligodeoxyguanylic Acids against Human Immunodeficiency Virus Type 1

Deoxyguanylic acids, but not other deoxynucleotides, as short as 3- to 4-mer, were effective in preventing HIV-1-induced cytopathicity. In addition, they prevented giant cell formation of infected Sup-T1 cells, and p24 production in HIV-1 infected H9 cells. Phosphorylation at either the 5'- or 3'-end enhanced these activities. Furthermore, 5'-phosphorylated phosphorothioate tetradeoxyguanylic acid was effective in reducing HIV production in chronically infected cells (H9/IIIB). The search for the target steps of this compound revealed that it inhibits at least 3 steps in the life cycle of HIV: interaction with CD4 (measured by inhibitory effect on the syncytia formation between Sup-T1 and H9/IIIB cells), reverse transcriptase, and step(s) after integration. These results suggest that phosphorylated phosphorothioate tetradeoxyguanylic acid may be a novel candidate for a therapeutic agent of AIDS.

Alkylation of DNA by the nitrogen mustard bis(2-chloroethyl)methylamine.

Alkylation of DNA by the nitrogen mustard bis(2-chloroethyl)methylamine (mechlorethamine; HN2) gave four principal products, derived by mono-alkylation of guanine at N-7 and adenine at N-3 and by cross-linking of guanine to guanine or guanine to adenine at these positions. These products were isolated by hydrolysis from DNA at neutral pH, followed by ion-exchange chromatography on SP-Sephadex and reversed phase chromatography on ODS. They were characterized by identification with products from the reaction of nitrogen mustard with adenine or deoxyguanylic acid, and by their UV, mass, and proton magnetic resonance spectra.

The reaction of melphalan with deoxyguanosine and deoxyguanylic acid

The reaction of melphalan (phenylalanine mustard, I) with 2′-deoxyguanosine, followed by removal of the sugar in acid, yielded two products. The major product was identified as 4-( N-(2-guanin-7-ylethyl)- N-(2-hydroxyethyl)amino)phenylalanine (II) by ultra-violet absorption, mass and NMR spectroscopy. The minor product has already been identified as the corresponding bis-guaninyl adduct III (Tilby et al., Chem.-Biol. Interact., 73 (1990) 183–194). The reaction of melphalan with 5′-deoxyguanylic acid yielded the deoxyribonucleotide of II and products resulting from reaction with the phosphate group. The initial products, which were formed with a half-life of ∼40 min at 37°, still had a reactive chloroethyl group; this was displaced more slowly, by reaction with water or with another molecule of dGMP. The products of reaction of melphalan with DNA were released by treatment with acid (0.1 M HCl, 70°, 30 min) and separated from each other on a cation exchange column. They were identified as II, III and an adenine adduct, in a ratio of approximately 3:1:2.

DNA damage induced by hypocrellin-A photosensitization.

Hypocrellin-A (HC-A) isolated from Hypocrellia bambusae Sacc., is a new and effective photosensitizer. Illumination of sarcoma 180 cells with visible light in the presence of HC-A leads to a decrease in cell viability and 3H-TdR incorporation, causes DNA strand breakage, and results in the selective destruction of guanine moieties in DNA. HC-A photosensitization causes an increase in the theta 260/theta 280 ratio in the circular dichroism spectra of DNA in vitro. Of the four usual 2'-deoxynucleotides illuminated in the presence of HC-A only 2'-deoxyguanylic acid was destroyed.

Effect of condensed tannins and related compounds on reverse transcriptase

AbstractInhibitory effects of 18 condensed tannins and related compounds on reverse transcriptase from an RNA tumour virus were examined in the presence of poly(riboadenylic acid) oligo(deoxythymidylic acid) ((rA)n(dT)12–18) or poly(ribocytidylic acid) oligo(deoxyguanylic acid) ((rC)n(dG)12–18) as a template‐primer. A potent inhibitory effect was found in galloylated monomers and oligomers as well as non‐galloylated tetramer, trimer and two of three dimers. The mode of the inhibition of one of them, procyanidin B‐2, was competitive with regard to the template‐primer.

Medium dependence of the spectroscopic and photophysical properties of Ru(bpy) 2(HAT) 2+. The effect of solvent, pH and binding to polyelectrolytes

In order to assess its usefulness as a probe for medium properties, the absorption, emission and excited state decay behaviour of Ru(bpy) 2(HAT) 2+ (bpy,2,2′-bipyridyl; HAT, 1,4,5,8,9,12-hexaazatriphenylene) were studied in various solvents, low temperature ethanol—methanol glasses, perfluorinated ionomer membranes (Nafion), in the presence of DNA or synthetic polynucleotides and in a solution of sodium polystyrenesulphonate (PSSS). The emission intensity and lifetime are quenched in acid solution and in protic solvents, increasing in the order H 2O < ethanol (EtOH) < dimethylsulphoxide) DMSO) < CH 3CN. The p K a values for the first two protonations of the HAT ligand in Ru(bpy) 2(HAT) 2+ (p K a1 = − 2.5, p K a2 = −4.3) have been determined. The spectroscopic and emission lifetime properties of the complex in Nafion membranes depend markedly on the swelling solvent and membrane hydration. The acidity of the H +-form membrane at different degrees of hydration was estimated by comparison with the absorption behaviour in acid solution. In the presence of DNA in aqueous solutions, the absorption of the complex is markedly altered, resembling that in low temperature glasses, and a 400% increase in the emission intensity and lifetime is observed. Spectroscopic changes are less marked with single-stranded than with double-stranded polynucleotides and very sensitive to the presence of salt cations. They increase in the order poly(dG).poly(dC) < poly[d(GC)] < poly(dA).poly(dT) < calf thymus DNA (CT-DNA) < poly[d(AT)] (dG, deoxyguanylic acid; dC, deoxycytidylic acid; dA, deoxyadenylic acid; dT, deoxythymidylic acid). Results are consistent with the partial intercalation of the complex into DNA, with a preference for AT stretches.

A comparative study of adenylic, guanylic and deoxyguanylic acids and their sodium salts as solid and in solution: structural information and conformational features

The solid and solution states of adenosine-5′-monophosphoric acid (H 2-AMP), guanosine-5′-monophosphoric acid (H 2-GMP), 2′-deoxyguanosine-5′-monophosphoric acid (H 2-dGMP) and their sodium salts (Na 2-AMP, Na 2-GMP and Na 2-dGMP) have been studied by Fourier Transform infrared spectroscopy, 1H-NMR spectroscopy and X-ray powder diffraction measurements, and correlations between structural modifications, sugar conformational changes and spectroscopic properties have been established. Spectroscopic and other evidence has indicated that the H 2-dGMP acid is isomorphous with that of the known H 2-GMP acid, with a C 3′- endo/anti sugar conformation. The Na 2-GMP and the Na 2-dGMP are not structurally similar, with the sugar moiety showing the C 2- endo/anti conformation in the Na 2-GMP and theO 4′- endo/anti, in the Na 2-GMP salt. The H 2-AMP acid can have either C 2′- endo/anti or C 3′- endo/anti conformation, whereas the Na 2-AMP salt has C 2′- endo/anti conformer. In aqueous solution, each mononucleotide contains mixtures of C 2′- endo/anti and C 2′- endo/anti conformations. The marker infrared band for the C 2′- endo/anti was observed at 824–817 cm −1, while a strong band centered at 800–806 cm −1 is the characteristic feature of the C 3′- endo/anti conformation. The O 4′- endo/anti sugar pucker has two bands with medium intensities at 800 and 822 cm −1. Metal ions such as Cd(II), Ni(II) and Co(II) favor C 3′- endo/anti conformer, while the Cu(II) ion interaction produces both C 2′- endo/anti and C 3′- endo/anti sugar puckers in coexistence.