Study on Antibacterial Activity of 2-Methyl-3-(methylthio)Pyrazine Against Three Strains of Spoilage Bacteria

Previous studies have shown that glycine and proline are pharmacophores that display antibacterial activity.In the present study,glycine and proline were derivated to diketopiperazine compounds by chemical synthesis method,and their antibacterial activities were evaluated by three strains of spoilage bacteria,Escherichia coli,Pseudomonas aeruginosa and Shewanella putrefaciens,and the relationship of their antibacterial activities and structures was also investigated.Uv-vis spectrophotometry was used to determine the growth curves of three kinds of active indicator bacteria.Minimum inhibitory concentration(MIC)was determined by micro broth dilution method.The results showed that 2-methyl-3-(methylthio)pyrazine had significant antibacterial activity against three strains of the bacteria,and its MIC was 1.25%.It indicates 2-methyl-3-(methylthio)pyrazine has the potential to be developed as a kind of preservative in future.

Synthesis, Crystal Structure and Antitumor Activity of 2-(3-Methyl-5-(methylthio)-4H-1,2,4-triazol-4-yl)isoindoline-1,3-dione

The title compound 2-（3-methyl-5-（methylthio）-4H-1,2,4-triazol-4-yl）isoindoline- 1,3-dione （C12H10NaO2S, Mr= 274.30） has been synthesized by a three-step procedure including the cyclization, hydrazinolysis and substitution reactions, and its crystal structure was determined by X-ray single-crystal diffraction. The crystal belongs to the monoclinic system, space group P2/c with a = 12.264（3）, b = 14.646（3）, c = 14.349（4） A,β = 91.69（3）°,μ = 0.255 mm1, Mr = 274.30, V = 2576.2（10） A3, Z =8, Dc = 1.414 g/cm3, F（000） = 1136, R = 0.0487 and wR = 0.1329 for 4048 observed reflections with I 〉 2σ（I）. In addition, the preliminary bioassay suggested that the title compound 6 exhibits relatively good antitumor activity against HT-29 and MCF-7.

TD-DFT Calculation on the UV-Vis Spectra of Complex 8-((Trimethoxysilyl)methylthio)quinoline·SnCl_4

Electronic structures and absorption spectra properties of complex 8-（（trimethoxysilyl）methylthio）quinoline.SnCh in gas phase and MeCN media have been investigated by using DFT/TD-DFT method. The calculated lowest-energy absorption band shows different mechanisms under these two conditions, and it bears LMCT/LLCT/ILCT character in MeCN solution and LLCT/ILCT character in gas phase. The calculated absorption bands of the title complex in MeCN solvent are in good agreement with the experimental results, and calculation results indicate that the very weak experimentally observed lowest-energy absorption band of the title complex in MeCN solvent originates from the spin-forbidden singlet-triplet transitions.

Synthesis and Crystal Structure of cis-Dichloro-(tetrakis(methylthio)-ethylene) Palladium(Ⅱ)

The crystals of the title complex, cis-dichloro-(tetrakis(methylthio)-ethylene) palladium(Ⅱ) (C6H12Cl2PdS4, Mr = 389.70 ) have been synthesized and analyzed structurally by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P with a = 8.211(1), b = 8.443(1), c = 10.134(2) ? a = 78.34(1), b = 89.02(2), g = 71.06(1)? V = 649.9(2) 3, Z = 2, Dc = 1.991 g/cm3, m (MoKa) = 2.437 mm-1, F(000) = 384, R = 0.0246 and Rw = 0.0621 for 2417 observed reflections with I > 2s(I). The X-ray crystal structure analysis revealed that the palladium (Ⅱ) is coordinated to two chloride anions and one chelate ligand TMTE in a quasi-square coordination geometry. Two molecules pack in face to face forming a dimmer structure with PdPd distance 3.424 ? Detailed discussions for the structure data of the complex were given by comparing with that of the free TMTE.

Synthesis,Crystal Structure and Biological Activity of 2-[(Pyridin-2-yl)methylthio]-1H-benzimidazole Derivatives

In order to discover the novel anti-tumor agents, a series of 2-[（pyridin-2-yl）methylthio]-1 H-benzimidazole derivatives were designed and synthesized, and the structures were characterized by IR, MS, and proton NMR. 2-[（3,4-Dimethoxypyridin-2-yl）methylthio]-1 Hbenzimidazole was investigated with X-ray crystallography, and the molecule is in orthorhombic system, space group P212121, with a = 9.1828（16）, b = 11.625（2）, c = 13.463（2） ？, Z = 4, R = 0.0231 and wR = 0.0596. The antitumor activities of target compounds were evaluated against human liver cancer cell line HepG2, and human liver normal cell line HL7702 using MTT assay. The target compounds have demonstrated weak or moderate anti-tumor activity against HepG2, while all the target compounds exhibit no cytotoxic effects on HL7702.

Synthesis,Crystal Structure and Antitumor Activity of(E)-N-(4-Fluorobenzylidene)-3-(methylthio)-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazol-4-amine

The crystal structure of the title compound（E）-N-（4-fluorobenzylidene）-3-（methylthio）-5-（3,4,5-trimethoxyphenyl）-4 H-1,2,4-triazol-4-amine（C_（19）H_（19）FN_4O_3S,Mr = 402.44） was synthesized,and its structure was characterized by 1 H-NMR,13 C-NMR,ESI-MS and single-crystal X-ray diffraction.The crystal belongs to the triclinic system,space group P1 with a = 9.228（13）,b = 10.364（14）,c = 10.641（14） ？,α = 85.323（3）,β = 75.172（2）,γ = 80.903（3）°,μ = 0.20 mm^（-1）,M_r = 402.44,V = 970.64（10） ？~3,Z = 2,D_c = 1.377 g/cm^3,F（000） = 420,R = 0.0484 and wR = 0.1474 for 3181 observed reflections with I 〉 2σ（I）.In addition,the preliminary bioassay indicated that the title compound 5 exhibits better inhibitory activity against Hela than 5-fluorouracil.

Synthesis and Crystal Structure of 5-Diazo-4-ethoxycarbonyl-3-methylthio Pyrazol

The crystal of the title compound, 5-diazo-4-ethoxycarbonyl-3-methylthio pyrazole, has been prepared and determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group C2/c with a = 29.174(8), b = 4.7592(12), c = 15.956(4) ? b = 117.632(4), C7H8N4O2S, Mr = 212.23, V = 1962.7(9) ?, Z = 8, Dx = 1.436 g/cm3, S = 1.000, m(MoKa) = 0.31 mm-1, T = 298(2) K, F(000) = 880, R = 0.0658 and wR = 0.1741 for 1091 independent reflections with I ≥ 2s(I). The crystal of the title compound is formed with p-p interactions through electrostatic attractions. Moreover, no HSO4- exists in the crystal structure. Therefore, only diazo pyrazole was obtained rather than either diazonium salt of the corresponding pyrazole or diazoaminopyrazole when 5-amino-4-ethoxycarbonyl-3-methylthio pyrazole was diazotized with sodium nitrite, catalyzed by sulfuric acid at 0 ℃.

Synthesis and Crystal Structure of 1-Methylsulfinyl-1-methylthio-2-cyano-2-phenylethylene

The crystal of the title compound (C_ 11H_ 11NOS_2, M_r =237.33) has been prepared and determined by X-ray single crystal diffraction. The crystal is monoclinic, space group P2_1/c with parameters : a=5.484 (1), b=7.793(2), c=28.295(6), β=90.277(4)°, V=1209.2(5)3, Z=4, D_c=1.034 g/cm3, μ(MoKα)= 0.413 mm -1, F(000)=496, the final R=0.0390 and wR=0.1051 for 1500 observed reflections with I>2σ(I). The X-ray analysis result shows that the orientation of methylsulfinyl and phenyl is the cis and confirms the E-stereochemistry of the title compound.

Synthesis and Crystal Structure of 2-[(4-Methoxy- 6-methylthio-2-pyrimidinyl)aminocarbonyl- aminosulfonyl] Benzoic Acid Methyl Ester

The title compound 2-[(4-methoxy-6-methylthio-2-pyrimidinyl)aminocarbonyl- aminosulfonyl]benzoic acid methyl ester (C15H16N4O6S2, Mr = 412.44) was obtained by the reaction of (4-methoxy-6-methylthio-2-pyrimidinyl)amine with 2-methoxylcarbonylbenzene-sulfonylisocya- nate. The crystal is of monoclinic, space group P21/c with a =11.169(3), b = 9.508(3), c = 17.690(5) ? b = 91.593(5), Z = 4, V = 1877.9(10) 3, Dc = 1.459 g/cm3, F(000) = 856, m(MoKa) = 0.324 mm-1, R = 0.0690 and wR = 0.1368 for 3301 observed reflections (I > 2s(I)). The N(1)H…N(3) and N(2)H…O(4) hydrogen bonds can be observed. In the molecule the phenyl plane(I), pyrimi- din-2-yl-urea bridge plane(Ⅱ) and ester plane(Ⅲ) form three conjugated systems.

Rational Synthesis of Crystalline Covalent Triazine Framework with Methylthio Pendant Arms for Efficient Mercury(Ⅱ)Adsorption

The interest in curtailing environmental pollution issues through physical separation processes has inspired an extensive search for novel nanoporous materials with exceptional adsorption capabilities.Covalent triazine frameworks(CTFs),emerged as a class of crystalline covalent organic frameworks(COFs),have been widely examined for various separation applications,owing to their large porosity,high stability,and rich nitrogen(N)doping.The development of CTFs for efficient adsorption of mercury(Ⅱ)(Hg^(2+))is of great importance for the field,whereas it is rarely attempted,on account of limited synthetic strategies and unknown structural-property relations of conventional CTFs derived from ionothermal approaches.Herein,we report rational synthesis of a crystalline CTF with methylthio pendant arms for efficient removal of Hg^(2+)with an exceptional capacity of 751 mg·g^(-1),ranking at the top among previously-reported adsorbents.This work may open up new possibility in the synthesis of COFs for various separations.

苜蓿链霉菌TX21抑菌作用确定及促生物质的鉴定

链霉菌是一种重要的微生物资源,具有广泛的应用价值。本研究从土壤中筛选出一株对多种病原菌有抑制效果的菌株,编号TX21,其中对玉蜀黍平脐蠕孢的抑菌效果最优,为50.0%。采用浸种及喷施的方法探究了菌株TX21发酵上清液对水稻种子和黄瓜幼苗的促生效果,结果显示发酵上清液能使水稻种子胚根和胚芽分别增长48.5%和47.1%,黄瓜幼苗根系和鲜重分别增加了37.6%和47.0%,表现出良好的促生作用;通过形态学观察、生理生化和16S r RNA分子生物学鉴定苜蓿链霉菌Streptomyces alfalfae。利用黄瓜子叶叶绿素试验及UHPLC-MS方法明确了发酵上清液的有效促生物质,证实其中含有2-甲硫顺式玉米素核苷(ms^(2)io^(6)A,分子式:C_(16)H_(23)N_(5)O_(5)S)。

Methylation of 5-Amino-3-methylthio-1 H-pyrazole Derivatives and Two Related Crystal Structures

5-Amino-3-methylthio-1H-pyrazoles are very important building blocks from which a wide variety of pyrazole de-rivatives can be prepared. When substituted 5-amino-3-methylthio-1H-pyrazole was treated with CH3I, the methy-lation occurres at endocyclic two nitrogens at the same time. The ratio of isomers in products was depended upon the nature of 4-position substituent in the pyrazole ring. The products were characterized by X-ray diffraction analysis, and the ratios of isomer were explained by means of the results of ab inito calculation.

萝卜苗中异硫氰酸盐的动态变化及体外抗氧化活性

测定不同生长时期的6种萝卜苗(长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗、抚顺红萝卜苗及满堂红萝卜苗)正己烷提取物的总异硫氰酸盐和4-methylthio-3-butenyl isothiocyanate(MTBITC)含量,分别用FRAP法、ABTS法、抗超氧阴离子自由基(O-2·)和抗羟自由基(.OH)能力4种方法测定提取物的体外抗氧化性能。结果显示:萝卜苗中MTBITC含量占总异硫氰酸盐的80%以上;5～10d的萝卜苗中含有较高的MTBITC含量;同生长期的苗中,长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗的MTBITC含量比抚顺红萝卜苗和满堂红萝卜苗高。长春白萝卜苗、盛丰白萝卜苗、象牙白萝卜苗、德国特白萝卜苗4种萝卜苗的抗氧化性能与MTBITC含量呈正相关。而满堂红和抚顺红萝卜苗中MTBITC含量较低,但却表现出较强的抗氧化性能。

3-(4-溴苯基)吡咯烷-2,5-二酮的合成

以4-溴苯乙腈和1,1-二(甲硫基)-2-硝基乙烯为原料,二甲基亚砜为溶剂,经过4步反应,获得3-(4-溴苯基)吡咯烷-2,5-二酮。反应时间为24、2、48、3.5 h时,收率分别为75.2%、76.8%、77.8%、78.5%,纯度分别为95.6%、96.6%、97.5%、97.8%(HPLC)。对终产物和标准样对比测定熔点、~1H NMR进行表征。

萝卜苗中异硫氰酸盐的提取工艺

以正己烷和二氯甲烷为溶剂,4-methylthio-3-butenyl isothiocyanate(MTBITC)和4-methylsulfinyl-3-butenyl isothiocyanate(Sulforaphene)的总量为提取效率研究萝卜苗中异硫氰酸盐的提取工艺。结果表明:提取萝卜苗中异硫氰酸盐的最佳工艺条件为自身酶解时间3～5min、液固比2:1(mL/g)、按正己烷-二氯甲烷-二氯甲烷的溶剂顺序各提取1次、提取时间3min/次。

甲基硫醚基团的官能化研究

本研究以甲基硫醚与溴代烷为原料,以生成热力学更稳定的硫醚为驱动力,在相对温和的条件下通过一锅法直接制备新的硫醚衍生物。该方法避免了使用过渡金属,额外的添加剂以及严格的无水无氧条件,而且底物范围广,平均收率大于70%。通过本研究发展的硫醚官能化方法,成功对一系列的芳香/脂肪烷基甲基硫醚衍生物实现了进一步烷基化,包括非天然甲硫氨酸单体合成子的制备。

CH_3S自由基H迁移异构化及脱H_2反应的直接动力学研究

采用密度泛函方法(MPW1PW91)在6-311G(d,p)基组水平上研究了CH3S自由基H迁移反应CH3S→CH2SH(R1),脱H2反应CH3S→HCS+H2(R2)以及脱H2产物HCS异构化反应HCS→CSH(R3)的微观动力学机理.在QCISD(t)/6-311++G(d,p)//MPW1PW91/6-311G(d,p)+ZPE水平上进行了单点能校正.利用经典过渡态理论(TST)与变分过渡态理论(CVT)分别计算了各反应在200～2000K温度区间内的速率常数kTST和kCVT,同时获得了经小曲率隧道效应模型(SCT)校正后的速率常数kCVT/SCT.结果表明,反应R1,R2和R3的势垒?E≠分别为160.69,266.61和241.63kJ/mol,R1为反应的主通道.低温下CH3S比CH2SH稳定,高温时CH2SH比CH3S更稳定.另外,速率常数计算结果显示,量子力学隧道效应在低温段对速率常数的计算有显著影响,而变分效应在计算温度段内对速率常数的影响可以忽略.

高浓度有机硫废水的厌氧生物除臭处理

采用升流式厌氧污泥床反应器(UASB)去除蛋氨酸合成时产生的恶臭有机硫废液的恶臭气味.试验结果显示,UASB可以有效地去除废水中的主要恶臭物质甲硫基丙醛.在进水中甲硫基丙醛浓度高达8000mg/L的情况下,经两级串联的UASB处理后,其去除率达100%,而且使废水的恶臭消失.

蛋氨酸羟基异丙酯对犊牛生长、血清生化指标和激素水平的影响

本试验旨在通过在犊牛日粮精料补充料中添加蛋氨酸羟基异丙酯（ HMBi）,研究其对犊牛生长、血清生化指标以及激素水平的影响。选择3.5月龄、体质量相近的雪龙黑牛与徐州黄牛杂交肉犊牛12头,进行配对,随机分为对照组和试验组,每组6头,在相同的条件下饲养。对照组在精料补充料中不添加 HMBi,试验组每头犊牛分别在精料补充料中添加4 g/d的 HMBi。试验期间,记录犊牛每天的采食量和粪便形态。试验期1 d、28 d、49 d早晨空腹称量每头牛的体质量,测量体高、体长、胸围和管围等体尺指标。试验期开始和结束前颈静脉采血测定血液指标和激素水平。结果显示,与对照组相比,试验组犊牛的体质量变化不显著（P〉0.05）；在第1~7 d时的粗料采食量显著高于对照组（P〈0.05）；腹泻率极显著低于对照组（P〈0.01）；第28 d的胸深显著高于对照组（P〈0.05）。血清生化指标方面,试验组血清甘油三酯（TG）显著降低（P〈0.05）；血清尿素氮（BUN）在试验后较试验前显著降低（P〈0.05）。血液激素方面,试验组犊牛血清胰岛素（INS）、瘦素（LEP）以及生长激素（GH）、类胰岛素生长因子1（IGF-1）水平与对照组相比,差异不显著（P〉0.05）。表明,在日粮精料补充料中添加4 g/d 的 HMBi能降低犊牛腹泻率,促进胸深发育,促进机体脂肪和蛋白沉积,但对血液激素水平影响不显著。

含甲硫基和肟醚基的N-甲氧基氨基甲酸酯类化合物的合成及生物活性研究

为了寻找高效、低毒的农药,设计合成了一系列新的含甲硫基和肟醚基的N-甲氧基氨基甲酸酯类化合物5a～5q,其结构经IR,1HNMR,LC/MS和元素分析确认.生物活性测定表明,部分化合物在50mg/L下对稻瘟病菌(Pyriculariaoryzae)、灰霉病菌(Botrytiscinerea)、水稻纹枯病菌(Rhizoctoniasolani)和小麦白粉病菌(Blumeriagriminis)有很好的抑菌活性.