Crystal and Molecular Structure of 2-(2-Methoxycarboxyl)phenyloxy-5 ,7-dim ethyl-1 ,2 ,4-triazolo〔1 ,5-a〕pyrimidine

The crystal structure of the title compound has been determined by single crystal X ray diffraction analysis. C 15 H 14 N 4O 3, M r =298.30, monoclinic, space group P2 1/n, a=9.483(9), b=11.078(9), c=13.700(9), β=100.19(7)°, V=1417(4) 3, Z=4, D x =1.399 g.cm -3 , μ =0.0942 mm -1 ; F (000)=624, final R =0.074 and R w =0.074 for 1502 observed reflections〔 I≥3σ(I )〕. The results show that all ring atoms in the triazolopyrimidinyl moiety were coplanar with strong tensile force, which might be an important active site.

A unique role of the pyrimidine de novo synthesis enzyme ODCase in Lysobacter enzymogenes

Bacterial species of the genus Lysobacter are environmentally ubiquitous with strong antifungal biocontrol potential.Heat-stable antifungal factor(HSAF)secreted by the biocontrol bacterium Lysobacter enzymogenes OH11 has broad-spectrum and highly efficient antifungal activity.Studying the biosynthetic regulations of HSAF would lay an important foundation for strain engineering toward improved HSAF production.In this work,we demonstrate that Le0752,an orotidine-5´-phosphate decarboxylase enzyme(ODCase)catalyzing a pivotal step of the UMP de novo biosynthesis pathway,is vital for HSAF-mediated antimicrobial activities and growth of L.enzymogenes OH11,but not for twitching motility.This gene regulates the production of HSAF by affecting the expression of lafB,a key gene in the HSAF biosynthesis operon,through the transcription factor Clp.Interestingly,bioinformatics analysis revealed that Le0752 belongs to the Group III ODCases,whereas its homologs in the closely related genera Xanthomonas and Stenotrophomonas belong to Group I,which contains most ODCases from Gram-positive bacteria,Gram-negative bacteria and cyanobacteria.Moreover,the Group I ODCase PXO_3614 from the Xanthomonas oryzae pv.oryzae PXO99A strain complemented the Le0752 mutant in regulating HSAF-mediated antagonistic activity.Together,these results highlight the important requirement of de novo pyrimidine biosynthetic enzymes for antibiotic HSAF production in L.enzymogenes,which lays an important foundation for improving HSAF production via metabolic flow design and for dissecting the regulatory functions of bacterial ODCases.

Cyclobutane Pyrimidine Dimer Accumulation in Relation to UV-B Sensitivity in Rice Cultivars

Five rice ( Oryza sativa L.) cultivars, widely planted in South China, were grown in greenhouse with or without supplemental UV_B radiation at level of 13.6 kJ·m -2 ·d -1 . After 15 day_UV_B treatment, significant intraspecific differences were observed in plant height, photosynthetic rate and total biomass. Based on the total biomass accumulation, cultivar “Tesanai” was found to be the most sensitive, and cultivar “Luhuangzhan” was the most tolerant species to UV_B radiation. UV_B induced cyclobutane pyrimidine dimer (CPD) in rice DNA were quantified by ELISA with specific monoclonal antibody. CPD accumulations in DNA extracted from 5 rice cultivars were remarkably increased by UV_B radiation, and it was confirmed that there was a strong positive correlation between CPD accumulation and the inhibition of total biomass. Photorepair was proved to be the predominant mode of CPD repair in UV_B irradiated rice. Light_dependent removal of CPD was very fast as compared with dark repair. Different levels of CPD accumulation among rice cultivars were related with different capacity of CPD photorepair. Capacity of light_dependent CPD removal may play an important role in UV_B resistance of rice.

Synthesis and Characterization of Nonlinear Optical Material of Substituted Diacetylenes with Azophenyl Group and Pyrimidine Ring

?-(2-methylthio -4 -methyl -5 -pyrimidinyl)-2. 4 - pentadiyn- 1 -ol- (4- N. N-dimethylamino-azobenzene -4' -sulfonate) (PDABS - 1 ). ②5 -(2 -methylthio -4 -methyl -5-pyrimidinyl)- 2.4 -pentadiyn- 1 -ol - (azobenzene - 4 -sulfonate) (PDABS -2 ). ③2. 4 -hexadiyn - 1 -ol-6- (4 - N, N-dimethylamino-azobenzene-4'-sulfonate) (HDABS - 1 ), ④2. 4 -hexadiyn - 1-ol -6 - (azobenzene4-sulfonate) (HDABS-2), the four new compounds are synthesize. The structures of the new compounds have been demonstrdted by elemental analysis. IR(KBr). 1H-NMR (CD3CO/TMS),MS. Their X(3), d33. βμ and the fabrication of their polarization orientated thin film also have ben reported in this paper.

The Synthesis of Some Novel Pyrimidine Compounds

Four novel pyridimine compounds were prepared. The yield of the intermediates was improved with new method making use of Pd(Ⅱ) catalyst and cuprous acetylide which were proved to be practital in the formation of the acetylide which were proved to be practical in the formation of the acetylides. Their nonlinear optical properties were briefly studied.

Synthesis and anti-inflammatory activity of imidazo[1,2-a]pyrimidine derivatives

A series of imidazo[1,2-a]pyrimidine derivatives substituted adjacently with two aryls at positions 2 and 3 were designed and synthesized in order to improve their anti-inflammatory activities. Biological tests suggested that these compounds have antiinflammatory activities with COX-2 selectivity to some extent.

Spectroscopic analysis on the binding interaction of biologically active pyrimidine derivative with bovine serum albumin

A biologically active antibacterial reagent, 2-amino-6-hydroxy-4-（4-N, N-dimethylaminophenyl）-pyr- imidine-5-carbonitrile （AHDMAPPC）, was synthesized. It was employed to investigate the binding in- teraction with the bovine serum albumin （BSA） in detail using different spectroscopic methods. It ex- hibited antibacterial activity against Escherichia cali and Staphylococcus aureus which are common food poisoning bacteria. The experimental results showed that the fluorescence quenching of model carrier protein BSA by AHDMAPPC was due to static quenching. The site binding constants and number of binding sites （n ≈ 1） were determined at three different temperatures based on fluorescence quenching results. The thermodynamic parameters, enthalpy change （AH）, free energy （AG） and entropy change （AS） for the reaction were calculated to be 15.15 kJ/mol, -36.11 kJ/mol and 51.26J/mol K according to van＇t Hoff equation, respectively. The results indicated that the reaction was an endothermic and spontaneous process, and hydrophobic interactions played a major role in the binding between drug and BSA. The distance between donor and acceptor is 2.79 nm according to Forster＇s theory. The alterations of the BSA secondary structure in the presence of AHDMAPPC were confirmed by UV-visible, synchronous fluorescence, circular dichroism （CD） and three-dimensional fluorescence spectra. All these results in- dicated that AHDMAPPC can bind to BSA and be effectively transported and eliminated in the body. It can be a useful guideline for further drug design.

Synthesis, Crystal Structure and Biological Activities of 3-[2-(4-Fluoro-phenyl)-ethyl]-5-methyl-4-hydroxyl-4-methyl-7-methylsulfanyl-3,4-dihydro-pyrido[4,3-d]pyrimidine-8-carbonitrile

The title compound, 3-[2-（4-fluoro-phenyl）-ethyl]-5-methyl-4-hydroxyl-4-methyl- 7-methylsulfanyl-3,4-dihydro-pyrido[4,3-d]pyrimidine-8-carbonitrile, has been prepared and detemined by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 6.8754（8）, b = 10.2617（12）, c = 13.3491（16） A, α = 93.163（2）, β = 96.704（2）, γ = 102.421（2）°, V= 910.35（19）A^3, Z= 2, Mr= 370.44, Dc= 1.351 g/cm^3,μ = 0.203 mm^-1,F（000） = 388, the final R = 0.0573 and wR = 0.1497. X-ray analysis reveals that the pyridine and pyrimidine rings are almost coplanar.

Synthesis, Structure and Biological Activity of 2-[2-(4-Fluorobenzylidene)hydrazinyl]-4-(1-methyl-1H-indol-3-yl)thieno[3,2-d]pyrimidine

The title compound 2-[2-(4-fluorobenzylidene)hydrazinyl]-4-(1-methyl-1 H-indol-3-yl)thieno[3,2-d] pyrimidine(8) was synthesized by the condensation of 4-fluorobenzaldehyde(7) with 2-hydrazinyl-4-(1-methyl-1 H-indol-3-yl)thieno[3,2-d]pyrimidine(6). This intermediate was prepared from methyl 3-aminothiophene-2-carboxylate(1) by the condensation with urea, chlorination with phosphorus oxychloride and then condensation with hydrazine hydrate. The crystal of 8 belongs to monoclinic system, space group P21/c with a = 14.0453(18), b = 17.436(2), c = 18.0982(17) ? and β = 122.969(7)°. In addition, 8 possesses marked inhibition against the proliferation of human colon cancer cell line HT-29(IC50 = 6.09 μM) and human gastric cancer cell line MKN45(IC50 = 3.04 μM), displaying promising anticancer activity.

Synthesis,Crystal Structure and Antitumor Activities of Ethyl 5-methyl-4-morpholino-2-(3-Methyl-phenylamino)-furo[2,3-d] pyrimidine-6-carboxylate

The title compound （C21H24N4O4, Mr = 396.44） has been synthesized by the func- tionalized ethyl 4-chloro-6-methyl-2-arylamino-furo[2,3-d]pyrimidine-5-carboxylates and mor- pholine. Its structure was confirmed by means of 1H NMR IR, MS and elemental analysis. The crystal structure of the title compound was determined by X-ray single-crystal diffraction. The compound crystallizes in triclinic system, space group P1, a = 7.9919（8）, b = 9.9312（1）, c = 12.9380（13） A, aα = 86.987（2）, β = 83.604（2）, γ = 89.641（2）°, V = 1019.08（18） A3, Z = 2, F（000） = 420, Dc = 1.292 g/cm3,μ = 0.091 mm-1, R = 0.0602 and wR = 0.1548 for 3943 independent （Rint = 0.0639） and 3414 observed （I 〉 2σ（I）） reflections, lntermolecular N-H…O and π-π stacking interactions contributed to the stability of the structure. The preliminary biological test indicated the title compound exhibited cytotoxicity against human lung cancer cell lines.

Synthesis of 2-Arylimidazo[l, 2-a]pyrimidines in Ionic Liquids

Room temperature ionic liquids were used as a "green" recyclable alternative to conventional solvents in the synthesis of pharmaceutically useful compounds 2-arylimidazo[1, 2-a] pyrimidines through Tschotschibabin reaction of a-bromoacetophenones with 2-aminopyrimidine in good yields.

Synthesis of 5-substituted benzyl-2,4-diamino pyrimidine derivatives as c-Fms kinase inhibitors

A serials of novel 5-substituted benzyl-2,4-diamino pyrimidine derivatives have been synthesized and evaluated as inhibitors of c-Fms kinase by the standard MTT method.The results showed that compound 15,5-[3-methoxy-4-（pyridine-3-yl）benzyl]-2,4-diamino pyrimidine,had an IC50 of 1.45μmol/L in inhibiting the proliferation of M-CSF-dependent myeloid leukemia cells in mice （NFS-60）,which was similar with GW2580,a selective inhibitor of c-Fms kinase.

An efficient and green preparation of 5-aminophosphonate substituted pyrimidine nucleosides under solvent-free conditions

An environmentally benign and highly efficient one-pot preparation of α-aminophosphonates under solvent-free conditions was developed. By employing this method, 5-aminophosphonate substituted pyrimidine nucleosides were synthesized in good to excellent yields starting from 5-forrnyl-2＇-deoxyuridine, aniline and dimethylphosphite.

Syntheses and Crystal Structures of Two New α-Aminophosphonate Derivatives Containing Thieno[2,3-d]pyrimidine

Two new a-aminophosphonate derivatives containing thieno[2,3-d]pyrimidine, diethyl（（（6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 （4H）-yl）amino）（4-methoxyphenyl）methyl） phosphonate （1） and diethyl（（4-bromophenyl）（（6-ethyl-2-methyl-4-oxothieno[2,3-d]pyrimidin-3 （4//）-yl）amino）methyl）phosphonate （2）, have been synthesized by a facial phosphorylated reaction, and their structures were characterized by NMR, IR, HRMS and X-ray single-crystal diffraction. Compound 1 （C21H28N3O5PS, Mr = 465.49） belongs to the orthorhombic system, space group P212121, with a = 10.83653（16）, b = 12.04906（19）, c = 18.0061（3） A, V= 2351.06（6） A3, Z= 4, Dc= 1.315 g/cm3, p = 2.177 mm-1, F（000） = 984.0, the final R = 0.0389 and wR = 0.0985 for all data. Compound 2 （C20H25BrN304PS, Mr = 514.37） belongs to the orthorhombic system, space group P212121, with a = 10.9187（5）, b = 11.9522（4）, c = 17.7667（7） A, V= 2318.60（16） A3, Z = 4, Dc= 1.474 g/cm3,μ = 4.175 mm^-1, F（000） = 1056.0, the final R = 0.0367 and wR = 0.0946 for all data.

Coupling Reaction of 4-Chloro-7-H-Pyrrolo[2,3-d]Pyrimidine with 2,3,5-Tri-O-Acetyl-b-D-Ribofuranosyl Chloride

Coupling reaction of 4-chloro-7-H-pyrrolo[2,3-d]pyrimidine with 2,3,5-tri-O-acetyl -β-D-ribofuranosyl chloride under the basic condition was investigated. An abnormal coupling reaction, in which the heterocyclic base attacked at the carbon of 1,2-O-methylidene moiety instead of anomeric carbon of ribose was observed and the structure of products 5a, 5b were identified by NMR and X-Ray diffraction.

Crystal and Molecular Structure of 2-(2, 6-Dinitro-4-Trifluoromethyl) phenylthio-5, 7-Dimethyl-1,2,4-Triazolo [1, 5-a] Pyrimidine

The crystal structure of the title compound has been determined bysingle crystal X-ray diffraction analysis. C14H9F3N6O4S, Mr = 414. 32, monoclinic,space group P21/n, a=8. 287(3), b= 24. 972(4), c= 8. 617(3)A, β= 108. 36(3)°,V= 1693(2) A3, Z=4, Dx=1. 626 g. cm-3, μ=0. 2481 mm-1; F(000) =840, finalR = 0. 057 and Rw= 0. 057 for 1169 observed reflections [I≥3σ(I)]. The results showthat all ring atoms in the triazolopyrimidinyl moiety were coplanar with strong tensileforce, which might be an important active site.

<i>β</i>-Oxoanilides in Heterocyclic Synthesis: Synthesis and Antimicrobial Activity of Pyridines, Pyrans, Pyrimidines and Azolo, Azinopyrimidines Incorporating Antipyrine Moiety

Condensation of β-Oxoanilide 1 with active methylene derivatives 2a,bafforded the pyridine derivative 5, and with crotononitrile afforded the pyridine 8. Compounds 9 and 11a-c were obtained by reaction of 1 with malononitrile dimer and arylidinemalononitrile 10a-10c. In contrast, when compound 1 reacted with ethoxymethylen malononitrile afforded the pyridine derivative 13. On the other hand, treatment of 1 with anthranilic acid gave the quinoline derivative 14. Also, reactions of 1 with isothiocyanate derivatives afforded compounds 16-18. The reaction of 1 with chalcone derivative afforded the pyridine derivative 22. Treatment of compound 1 with thiourea produced pyrimidine derivative 23. Furthermore, compound 1 converted into pyrimidinethione 24a and pyrimidinone 24b on treatment with a mixture of aromatic aldehydes and thiourea or urea respectively. Reaction of 24a with hydrazonyl halide, thiosemicarbazide and arylidinecyanothioacetamide afforded compounds 26, 28 and 29. Compound 29 was treated with chloroacetonitrile to afford compound 30. Six compounds from the newly synthesized were screened for antibacterial and antifungal activity against bacteria staphylococcus aureus, bacillus cereus and klebsiella pneumonia and fungi aspergillus flavus and aspergillus ochraceous, respectively. Some of the tested compounds showed significant antimicrobial activity. IR, 1H NMR, mass spectral data, and elemental analysis elucidated the structures of all the newly synthesized compounds.

Synthesis of Novel Heteropolycyclic Nitrogen Systems Bearing Fluorine Substituted Pyrazolo[3,4-d] Pyrimidine Derived from Polyfunctional π-Acceptor Compounds and Guanidine as Fungicidal Probes

Novel heteropolycyclic nitrogen systems bearing fluorine substituted pyrazolo[3,4-d] pyrimidine moiety have been synthesis by the interaction between N’-heteroaryl guanidine 4 with polyfunctional π-acceptors in different media and condition. The structures of the synthesis compounds were established by spectroscopic analysis and evaluated as antifungal probes in various concentration.

Induction of Recombinant Uridine Phosphorylase and Its Application in Biosynthesis of Pyrimidine Nucleosides

Recombinant Escherichia coli pUDP,which overexpressed uridine phosphorylase（UPase）,was constructed.0.5 mmol·L 1lactose had a similar induction effect as the commonly used inducer IPTG during 2.5-5.5 h of cell growth.The lactose-induced UPase was stable at 50°C.Wet cells of pUDP was used as catalyst to biosynthesize 5-fluorouridine from 30 mmol·L 1uridine and 5-fluorouracil in phosphate buffer（pH 7.0）catalyzed at 50°C for 1.5 h and the yield of 5-fluorouridine was higher than 68%.Under the optimum reaction conditions for production of 5-fluorouridine,5-methyluridine and azauridine were synthesized from uridine by pUDP,the yield was 61.7%and 47.2%respectively.Deoxynucleosides were also synthesized by pUDP,but the yield was only about 20%.

Efficient synthesis of pyrano[2,3-d]pyrimidinone and pyrido[2,3-d]pyrimidine derivatives in presence of novel basic ionic liquid catalyst

A basic ionic liquid, namely 1,1＇-（butane-1,4-diyl）bis（1,4-diazabicyclo [2.2.2]octan-1-ium） hydrox-ide, was prepared and characterized using Fourier-transform infrared spectroscopy, XH nuclear magnetic resonance spectroscopy, and pH measurements. The ionic liquid was used for efficient promotion of the synthesis of pyrano[2,3-d]pyrimidinone and pyrido[2,3-d]pyrimidine derivatives at room temperature under grinding conditions. A simple procedure, short reaction time, high yields, non-column chromatographic separation, commercial availability of the starting materials, and recyclability of the catalyst are attractive features of this process.