Antiviral activity of some 5-arylethynyl 2'-deoxyuridine derivatives

5-(3-Perylenylethynyl)-2'-deoxyuridine was prepared by cross-linking 5-iodo-2'-deoxyuridine derivatives with 3-ethynylperylene followed by deprotection. 5-(1-Perylenylethynyl)-, 5-(3-perylenylethynyl)-, and 5-[4-(2-benzoxazolyl)phenylethynyl]-2'-deoxyuridine were found to inhibit in Vero cells the replication of type 1 herpes simplex virus and its drug-resistant strains.     

Contribution to the determination of the chemotherapeutic drug G1 in biological fluids

A sensitive gas chromatographic method for the quantitative determination of the new antibacterial and antifungal drug G1, 1-(5-bromofuran-2-yl)-2-bromo-2-nitroethene, has been optimized. The method involves a fast and single extraction step from spiked serum and urine samples. The G1 drug was quantified using an internal standard method and by means of a nitrogen-selective detector. The results are statistically significant and show that mean levels of G1 as low as 1 μg ml⁻¹ can be measured accurately.     

Regiospecific hydroxylation of 3-(methylaminomethyl) pyridine to 5-(methylaminomethyl) -2 (1H) -pyridinone byArthrobacter ureafaciens

Microbial production of a 6-hydroxy-3-pyridylmethyl compound from 3-pyridylmethyl compound was investigated. The hydroxylation of 3-(methylaminomethyl)pyridine to 5-(methylaminomethyl)-2(1H)-pyridinone, tautomer of 2-hydroxy-5(methylaminomethyl)pyridine, by resting cells ofArthrobacter ureafaciens JCM3873 was found to proceed regio- and chemo-selectively with an almost quantitative yield. The addition of molybdate ion and nicotine as an inducer to the culture medium was required for the preparation of cells containing high hydroxylation activity. The optimal temperature and pH for the hydroxylation by using resting cells were 35°C and around 7, respectively. This hydroxylation enzyme does undergo inhibition by the substrate. The inhibitory effect could be eliminated by stepwise feeding of the substrate. Under adequate conditions, 23 mg/ml of 5-(methylaminomethyl)-2(1H)-pyridinone was produced with a molar yield of nearly 100% from 3-(methylaminomethyl)pyridine.     

单纯性先天性心脏病中TBX5基因表达异常的机制

为探讨人类单纯性先天性心脏病患者中TBX5基因表达下调的可能原因, 应用变性高效液相色谱(DHPLC)方法检测100例单纯性先天性心脏病患者中TBX5基因上游1 200 bp调控区的突变情况; 应用甲基化敏感性限制性内切酶(MS-RE)法检测50例单纯性先天性心脏病患者和5例非先天性心脏病患者心肌组织TBX5基因启动子区两个CpG岛(转录起始点上游-49~-188 bp和-247~-464 bp处)的甲基化情况; 应用P-match软件预测小鼠Tbx5基因上游转录因子Nkx2-5的结合位点, 构建Nkx2-5表达载体转染小鼠H9C2(2-1)心肌细胞, RT-PCR及Western blotting检测Tbx5基因表达, 凝胶阻滞实验(EMSA)验证Nkx2-5和Tbx5基因的作用。结果在100例单纯性先天性心脏病患者中, 未检测到TBX5基因上游1 200 bp调控区突变; 非先天性心脏病患者和单纯性先天性心脏病患者在两个CpG岛存在相同的甲基化; 小鼠Tbx5基因转录起始点上游-312~-315 bp可能存在Nkx2-5的结合位点, 转染Nkx2-5表达载体后Tbx5基因在mRNA及蛋白质水平均有表达增高趋势, Nkx2-5在体外可以与Tbx5基因上游-312~-315 bp序列相结合。以上结果提示TBX5基因调控区突变和两个CpG岛的甲基化不是单纯性先天性心脏病患者心肌组织中TBX5基因表达下调的原因, TBX5基因表达下调可能由于NKX2-5的表达异常引起。     

Measurement of 5-fluoro-2'-deoxyuridine serum levels by gas chromatography chemical ionization mass spectrometry

Serum levels of 5-fluoro-2'-deoxyuridine in cancer treated patients were measured by gas chromatography mass spectrometry under chemical ionization conditions; 1-(2-deoxy-beta-D-lyxofuranosyl)-5-fluorouracil (3'-epi-5-fluoro-2'-deoxyuridine) was used as an internal standard. The drug and internal standard were quantitatively isolated from the serum sample by a mini-column anion exchange method and the extract permethylated using potassium-tert-butoxide in dimethylsulphoxide and methyl iodide. The derivatized nucleosides were then re-extracted from the reaction mixture and analysed on a glass capillary column coated with Superox-4. The column was coupled directly to the chemical ionization source of the mass spectrometer; NH3 was used as the reagent gas. The gas chromatographic effluent was monitored at m/z 289, the [MH]+ ion of the N,O-permethyl derivatives of 5-fluoro-2'-deoxyuridine and the internal standard. Recovery of 5-fluoro-2'-deoxyuridine from serum in the 0-1 microgram ml-1 concentration range averaged 93 +/- 2% (SD); a linear detector response was observed up to 50 ng 5-fluoro-2'-deoxyuridine ml-1. At the 10 ng ml-1 level, a within-run assay precision of 10% (CV) (n = 5) was found, while a detection limit of about 1 ng 5-fluoro-2'-deoxyuridine ml-1 of serum was attained. The method was applied to the measurement of disappearance curves of 5-fluoro-2'-deoxyuridine in the serum of treated patients.     

CircDUS2L (circ_0039908) promotes lung adenocarcinoma progression by upregulating PGAM1 by acting as a miR-590-5p molecular sponge

Lung adenocarcinoma (LUAD) is usually found at the metastatic stage. Circular RNA dihydrouridine synthase 2-like (DUS2L) (circDUS2L) has been discovered to be upregulated in LUAD. Nevertheless, the function of circDUS2L in LUAD has not been verified. Levels of circDUS2L, microRNA-590-5p (miR-590-5p), and phosphoglycerate mutase 1 (PGAM1) mRNA were analyzed using quantitative real-time polymerase chain reaction (RT-qPCR). Cell proliferation, apoptosis, metastasis, and invasion were assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT), colony formation, 5-ethynyl-2′-deoxyuridine (Edu), flow cytometry, and transwell assays. Protein levels were detected by western blotting. Cell glycolysis was analyzed by measuring cell glucose consumption, lactate production, and extracellular acidification rate (ECAR). The regulatory mechanism of circDUS2L in LUAD cells was analyzed by bioinformatics analysis, dual-luciferase reporter, RNA pull-down, and RNA immunoprecipitation (RIP) assays. Xenograft assay was conducted to confirm the function of circDUS2L in vivo. CircDUS2L was highly expressed in LUAD tissues and cells. CircDUS2L silencing constrained xenograft tumor growth in vivo. CircDUS2L knockdown induced apoptosis, repressed viability, colony formation, proliferation, metastasis, invasion, and glycolysis of LUAD cells in vitro by releasing miR-590-5p via functioning as a miR-590-5p sponge. MiR-590-5p was lowly expressed in LUAD tissues and cells, and miR-590-5p mimic curbed malignant behaviors and glycolysis of LUAD cells by targeting PGAM1. PGAM1 was overexpressed in LUAD tissues and cells, and circDUS2L sponged miR-590-5p to regulate PGAM1 expression. CircDUS2L elevated PGAM1 expression through functioning as a miR-590-5p sponge, thus driving malignant behaviors and glycolysis of LUAD cells.     

Synthesis and biological evaluation of 2-(5-methyl-4-phenyl-2-oxopyrrolidin-1-yl)-acetamide stereoisomers as novel positive allosteric modulators of sigma-1 receptor

Novel positive allosteric modulators of sigma-1 receptor represented by 2-(5-methyl-4-phenyl-2-oxopyrrolidin-1-yl)-acetamide enantiomers were synthesised using an asymmetric Michael addition of 2-nitroprop-1-enylbenzene to diethyl malonate. Following the chromatographic separation of the methyl erythro- and threo-4-nitro-3R- and 3S-phenylpentanoate diastereoisomers, target compounds were obtained by their reductive cyclisation into 5-methyl-4-phenylpyrrolidin-2-one enantiomers and the attachment of the acetamide group to the heterocyclic nitrogen. Experiments with electrically stimulated rat vas deference contractions induced by the PRE-084, an agonist of sigma-1 receptor, showed that (4R,5S)- and (4R,5R)-2-(5-methyl-4-phenyl-2-oxopyrrolidin-1-yl)-acetamides with an R-configuration at the C-4 chiral centre in the 2-pyrrolidone ring were more effective positive allosteric modulators of sigma-1 receptor than were their optical antipodes.     

Mutagenic activity of carcinogenic and noncarcinogenic nitrofurans and of urine of rats fed these compounds

The nitrofurans, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (AF-2), N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide (FANFT), nitrofurantoin, 5-nitro-2-furoic acid, 5-nitro-2-furamidoxime, 5-nitrofurfurylidene diacetate and the urine of rats fed these compounds, were assayed for mutagenic activity in Salmonella typhimurium strains TA100 and TA100FR1. All the nitrofurans were mutagenic in the order: AF-2 and FANFT > nitrofurantoin > 5-nitro-2-furamidoxime > 5-nitrofurfurylidene diacetate > 5-nitro-2-furoic acid. Strain TA100 was more sensitive than TA100FR1 to the mutagenic influence of these nitrofurans. Only the urine of rats fed AF-2, FANFT and nitrofurantoin had mutagenic activity. Again, TA100 was more sensitive than TA100FR1. The mutagenicity of the urine was not increased by treatment with β-glucuronidase. AF-2, 2-amino-4-(5-nitro-2-furyl)thiazole (deformylated product of FANFT) and nitrofurantoin were excreted in the urine of rats fed these compounds; whereas the other nitrofurans were not excreted.     

Lilac alcohol epoxide: a linalool derivative in Actinidia arguta flowers

Lilac alcohol epoxide (2-(5-methyl-5-(oxiran-2-yl)-tetrahydrofuran-2-yl)propan-1-ol), a previously unreported monoterpene, was identified in the solvent extract of the flowers of seven Actinidia arguta genotypes. The diastereomeric lilac alcohol epoxides co-occurred with the lilac aldehydes and alcohols. Another compound, the lilac diol (2-(5-(1-hydroxyethyl)-5-methyl-tetrahydrofuran-2-yl)propan-1-ol) was synthesised as part of our efforts to identify the lilac alcohol epoxide.     

Cis-trans isomerization of nitrofuran derivatives by xanthine oxidase

Enzymatic cis-trans isomerization of nitrofuran derivatives was 3-(5-Nitro-2-furyl)-2-(2-furyl)-demonstrated with milk xanthine oxidase. acrylamide (AF-2) and 3-(5-nitro-2-furyl)-2-(5-bromo-2-furyl)acrylamide (NFBFA) were mainly converted from the cis to the trans form by this enzyme supplemented with an electron donor. This enzymatic reaction was further characterized with respect to its cofactor requirements. Finally, a new cis-trans isomerization mechanism, which is based on transfer of a single electron by a nitroreductase such as xanthine oxidase to a nitrofuran derivative to give the anion free radical, was proposed.     

Perylene attached to DNA through stiff or flexible linker: duplex stability and FRET

Two fluorescent nucleosides, 5-(perylen-3-ylethynyl)-2'-deoxyuridine and 5-[(perylen-3-yl)methoxypropyn-1-yl]-2'-deoxyuridine, were incorporated into synthetic oligodeoxyribonucleotides and spectral properties of the conjugates and their duplexes were studied.     

Long noncoding RNA FOXD2-AS1 promotes glioma malignancy and tumorigenesis via targeting miR-185-5p/CCND2 axis

Glioma is the most aggressive malignant tumor in the adult central nervous system. Abnormal long noncoding RNA (lncRNA) FOXD2-AS1 expression was associated with tumor development. However, the possible role of FOXD2-AS1 in the progression of glioma is not known. In the present study, we used in vitro and in vivo assays to investigate the effect of abnormal expression of FOXD2-AS1 on glioma progression and to explore the mechanisms. FOXD2-AS1 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of FOXD2-AS1 was correlated with poor prognosis of glioma. Downregulation of FOXD2-AS1 decreased cell proliferation, migration, invasion, stemness, and epithelial-mesenchymal transition (EMT) in glioma cells and inhibited tumor growth in transplanted tumor. We also revealed that FOXD2-AS1 was mainly located in cytoplasm and microRNA (miR)-185-5p both targeted FOXD2-AS1 and CCND2 messenger RNA (mRNA) 3′-untranslated region (3′-UTR). miR-185-5p was downregulated in glioma tissue, cells, and sphere subpopulation. Downregulation of miR-185-5p was closely correlated with poor prognosis of glioma patients. In addition, miR-185-5p mimics decreased cell proliferation, migration, invasion, stemness, and EMT in glioma cells. CCND2 was upregulated in glioma tissue, cells, and sphere subpopulation. Upregulation of CCND2 was closely correlated with poor prognosis of glioma patients. CCND2 knockdown decreased cell proliferation, migration, invasion, and EMT in glioma cells. In glioma tissues, CCND2 expression was negatively associated with miR-185-5p, but positively correlated with FOXD2-AS1. FOXD2-AS1 knockdown and miR-185-5p mimics decreased CCND2 expression. Inhibition of miR-185-5p suppressed FOXD2-AS1 knockdown-induced decrease of CCND2 expression. Overexpression of CCND2 suppressed FOXD2-AS1 knockdown-induced inhibition of glioma malignancy. Taken together, our findings highlight the FOXD2-AS1/miR-185-5p/CCND2 axis in the glioma development.     

Angiotensin-(1-5), an active mediator of renin-angiotensin system,stimulates ANP secretion via Mas receptor

Angiotensin-(1-5) [Ang-(1-5)], which is a metabolite of Angiotensin-(1-7) [Ang-(1-7)] catalyzed by angiotensin-converting enzyme (ACE), is a pentapeptide of the renin-angiotensin system (RAS). It has been reported that Ang-(1-7) and Ang-(1-9) stimulate the secretion of atrial natriuretic peptide (ANP) via Mas receptor (Mas R) and Ang II type 2 receptor (AT₂R), respectively. However, it still remains unknown whether Ang-(1-5) has a similar function to Ang-(1-7). We investigated the effect of Ang-(1-5) on ANP secretion and to define its signaling pathway using isolated perfused beating rat atria. Ang-(1-5) (0.3, 3, 10 μM) stimulated high pacing frequency-induced ANP secretion in a dose-dependent manner. Ang-(1-5)-induced ANP secretion (3 μM) was attenuated by the pretreatment with an antagonist of Mas R (A-779) but not by an antagonist of AT₁R (losartan) or AT₂R (PD123,319). An inhibitor for phosphatidylinositol 3-kinase (PI3K; wortmannin), protein kinase B (Akt; API-2), or nitric oxide synthase (NOS; L-NAME) also attenuated the augmentation of ANP secretion induced by Ang-(1-5). Ang-(1-5)-induced ANP secretion was markedly attenuated in isoproterenol-treated hypertrophied atria. The secretagogue effect of Ang-(1-5) on ANP secretion was similar to those induced by Ang-(1-9) and Ang-(1-7). These results suggest that Ang-(1-5) is an active mediator of renin-angiotensin system to stimulate ANP secretion via Mas R and PI3K-Akt-NOS pathway.     

Synthesis of N,N-dialkylaniline-2'-deoxyuridine conjugates for DNA-mediated electron transfer studies

Syntheses of two analogs of deoxyuridine with N,N-dialkylaniline chromophores are reported. 5-[3-(N-methylphenylamino)propanoyl]-2'-deoxyuridine (1) and 5-[2-(4-N,N-dimethylaminophenyl)ethyl)]-2'-deoxyuridine (2) are prepared by palladium-mediated coupling. Preparation of 2 was facilitated by in situ transient O4-trimethylsilyl protection during alkynylation which suppressed secondary cyclization of the coupling adduct.     

毕赤酵母不对称合成阿托伐他汀中间体

阿托伐他汀可通过抑制HMG-CoA还原酶与底物的结合来抑制胆固醇的合成,而 (R)-3-羟基-5-邻苯二甲酰亚胺基戊酸乙酯是阿托伐他汀合成的重要中间体。通过对实验室保藏菌种进行筛选,得到一株巴氏毕赤酵母X-33可将5-邻苯二甲酰亚胺-3-氧代戊酸乙酯还原为 (R)-3-羟基-5-邻苯二甲酰亚胺基戊酸乙酯。在磷酸盐缓冲液体系中考察了初始底物浓度、反应时间、辅助底物、葡萄糖添加量、pH、温度等因素对产物收率和对映体选择性的影响,获得了较佳的反应条件。选择底物投料量为7 g/L时,当菌体浓度120 g/L,葡萄     

Characterization of human phosphodiesterase 12 and identification of a novel 2'-5' oligoadenylate nuclease - The ectonucleotide pyrophosphatase/phosphodiesterase 1

The vertebrate 2-5A system is part of the innate immune response and central to cellular antiviral activities. Upon activation by viral double-stranded RNA, 5′-triphosphorylated, 2′-5′-linked oligoadenylate polyribonucleotides (2-5As) are synthesized by one of several 2′-5′ oligoadenylate synthetases. The 2-5As bind and activate RNase L, an unspecific endoribonuclease, resulting in viral and cellular RNA decay. Given that most endogenous RNAs are degraded by RNase L, continued enzyme activity will eventually lead to cell growth arrest and cell death. This is averted, when 2-5As and their 5′-dephosphorylated forms, the so-called 2-5A core molecules, are cleaved and thus inactivated by 2′-5′-specific nuclease(s), e.g. phosphodiesterase 12, thereby turning RNase L into its latent form. In this study, we have characterized the human phosphodiesterase 12 in vitro focusing on its ability to degrade 2-5As and 2-5A core molecules. We have found that the enzyme activity is distributive and is influenced by temperature, pH and divalent cations. This allowed us to determine V_max and K_m kinetic parameters for the enzyme. We have also identified a novel 2′-5′-oligoadenylate nuclease; the human plasma membrane-bound ectonucleotide pyrophosphatase/phosphodiesterase 1, suggesting that 2-5A catabolism may be a multienzyme-regulated process.     

Identification of 5-Hydroxytryptamine1A Receptor Proteins in Bovine Frontal Cortex

5-Hydroxytryptamine1A (5-HT1A) receptor proteins were identified by a novel approach in which photoaffinity labeling technique was used in conjunction with affinity column chromatography. 5-HT1A receptors were solubilized from bovine frontal cortical membranes with 0.3% digitonin and 0.1% Nonidet P-40, and bound effectively to 1-[2-(4-aminophenyl)ethyl]-4-(3-trifluoromethylphenyl)piperazine (PAPP)-coupled Affi-Gel 10 in a time-dependent manner. PAPP was shown previously to be a selective ligand for the 5-HT1A receptor. Two protein bands with molecular masses of approximately 55,000 and 38,000 daltons revealed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis were eluted from the affinity column with either 1 mM 5-HT or 1 microM [3H]1-[2-(4-azidophenyl)ethyl]-4-(3-trifluoromethyl-phenyl)piperazine ([3H]p-azido-PAPP). [3H]p-Azido-PAPP is a selective photoaffinity labeling probe for the 5-HT1A receptor. The intensity of these two protein bands and the incorporation of [3H]p-azido-PAPP into these two proteins decreased significantly when the solubilized fraction was preincubated with excess 5-HT or PAPP (saturating all 5-HT1A receptors) prior to affinity column chromatography. These results suggest strongly that these two proteins are related to the 5-HT1A receptor protein. The isoelectric points of the photolabeled 5-HT1A receptor proteins were 6.0 and 6.5.     

1-(3,4-Dihydroxy-5-Methoxyphenyl-3-Methylbut-2-Ene from The Liverworth Plagiochila Rutilans

Extraction of the liverwort Plagiochila rutilans afforded 1-(3,4-dihydroxy-5-methoxyphenyl)3-methylbut-2-ene, the structure of which was confirmed by synthesis.