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《农药》2017,(11)
[目的]为了发现醌类化合物中具有潜在修饰价值的抑菌先导化合物。[方法]采用菌丝生长速率法分别测定了10种醌类化合物a~j对番茄灰霉病菌和小麦赤霉病菌的室内抑菌活性。[结果]初步构效关系表明:化合物a~j对所测2种病原真菌均表现出不同程度的抑菌活性,其中菲醌(i)对番茄灰霉病菌表现出优于阳性对照霉灵(EC_(50)值为38.0 mg/L)的抑菌活性,其对应EC_(50)值为37.3 mg/L;茜素(b)和菲醌(i)对小麦赤霉病菌均表现出超过霉灵(EC_(50)值为76.1 mg/L)的抑菌活性,其对应EC_(50)值分别为18.6、5.3 mg/L。[结论]化合物b、c、d和i对番茄灰霉病菌和小麦赤霉病菌表现出较好的抑菌活性,初步拟定将这4种化合物作为下一步开发抑菌剂的先导化合物。 相似文献
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金丝桃蒽酮素(HYP)是有多个羟基的醌类衍生物.在极性溶剂乙腈中,电子给体N,N-二乙基苯胺和电子受体甲基紫精、蒽醌均能有效猝灭其荧光.说明它既具有酚羟基的给电子性能,又有醌类化合物的受电子性能.HYP与平面构型的蒽醌可能形成基态复合物,以不同的方式与其发生光致相互作用. 相似文献
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金丝桃蒽酮素(HYP)是有多个羟基的Bei醌类衍生物。在极性溶剂乙腈中,电子给体N,N-二乙基苯胺和电子受体甲紫精、蒽醌均能有效猝灭其荧光。说明它既具有酚羟基的给电子性能,又有醌类化合物的受电子性能。HYP与平面构型的蒽醌可能形成基态复合物,以不同的方式与其发生光致相互作用。 相似文献
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丙酮-丁醇发酵生产菌的快速筛选方法 总被引:8,自引:0,他引:8
建立了高效丙酮-丁醇生产菌的快速筛选方法,采用氮离子注入诱变技术选育丙酮-丁醇发酵生产菌,以2-脱氧-D-葡萄糖作为抗代谢阻遏物,筛选高淀粉酶活性的突变株. 首次根据丙酮-丁醇发酵代谢途径中先产酸后产溶剂及高活力厌氧发酵细胞具有较强还原力的特点,设计了溴甲酚绿和刃天青2种筛选平板,所筛突变株经发酵验证丁醇和总溶剂产生能力均有显著提高,I4-28突变菌株总溶剂产量和丁醇产量分别较出发菌株提高了27.96%和40.66%,丁醇/总溶剂比由63.39%提高到71.94%,突变菌株具有较好的传代稳定性. 相似文献
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Antisolvent crystallization of fosfomycin phenylethylamin (FPEA) by acetone is demonstrated by measuring its solubility in binary solvents of (ethanol + acetone) and (water + acetone) at 293.15 K. The solubility (g/g) of FPEA always decreased with the increase of acetone composition and correlations were proposed to sufficiently represent the data. Excess solubilities (mole fraction) of FPEA were always positive with maximum and well correlated by the simplified-modified-Wilson equation. Effects of various solvent properties on the solubility were analyzed by the solvatochromic KAT linear solvation energy relationship, which revealed the decrease of solvent's hydrogen bond donation ability should be the most essential characteristics of the antisolvent. Finally, by analyzing its surrounding solvent composition using the inverse Kirkwood–Buff integrals method, we found FPEA was preferentially solvated by water in acetone–water due to the strong acidic behavior of water, while, because of different competing interactions in acetone–ethanol, FPEA was preferentially solvated by acetone in ethanol-rich region while by ethanol in acetone-rich region. 相似文献
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采用丙酮稀释含有促进剂DMP-30的环氧树脂(E-51)胶液,并以此胶液对E玻璃纤维进行包覆。通过示差扫描量热法、凝胶化实验和傅里叶变换红外光谱研究了DMP-30作用下环氧树脂的固化特性;通过弯曲强度实验和扫描电子显微镜分析探讨了丙酮对该树脂胶液包覆玻纤的增强效果。结果表明:环氧树脂E-51/固化剂甲基六氢苯酐/促进剂DMP-30质量比为100/72.9/1.5,固化工艺为102℃/0.5 h+124℃/1 h+141℃/1 h,丙酮质量分数为5%(以环氧树脂为基准)时,体系的弯曲强度比无丙酮稀释时提高了24.7%。这是由于丙酮降低了树脂胶液粘度,改善了树脂胶液与玻纤的界面结合,形成均匀的结合状态。 相似文献
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Ethyl acrylate was graft-copolymerized from acetone–water systems with γ-irradiated, purified cotton cellulose. The scavenging of the free radicals in the irradiated cellulose by water, acetone, and water–acetone systems was determined by electron spin resonance spectroscopy. The ESR spectra of free radicals, scavenged by water and acetone, were recorded by the use of a time-averaging computer attached to the ESR spectrometer, in which the ESR spectrum of the irradiated cellulose, which had been immersed in water and/or acetone, was electronically subtracted from the ESR spectrum of the irradiated cellulose control. For both water and acetone, the ESR spectra of the scavenged free radicals were singlets. This indicated that free radical sites formed on carbon C1 or C4 on radiation-initiated depolymerization, which would generate singlet ESR spectra, were readily accessible to these solvents. The maximum scavenging of the radicals was observed when irradiated cellulose was immersed in acetone–water solution which had a composition of 25/75 vol-%. The scavenging of the free radicals in irradiated cellulose when immersed in acetone–water solutions was less than when immersed in methanol–water solutions. Also, the extent of graft copolymerization of ethyl acrylate from acetone solutions with irradiated cellulose was less than that of ethyl acrylate from methanol solutions. These differences were probably due to differences in the diffusion rates of acetone and methanol into the cellulosie structure. The Trommsdorff-type effect in the acetone solutions would be less than in the methanol solutions, since acetone is a better solvent for poly(ethyl acrylate) than methanol. 相似文献
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以KH2PO4/Al2O3为催化剂,针对以甲醇为烷基化试剂的酚油醚化体系,研究了5种混配组分(乙酸、甲酸、丙酮、呋喃、乙酸乙酯)对酚油醚化反应规律的影响。结果表明,丙酮对促进烷基酚转化为芳醚的作用效果最强。基于丙酮混配组分,500℃下探究了丙酮质量配比的影响,基于最佳丙酮添加量(50wt%),进一步考察了温度对反应体系的影响,并进行机理分析。结果表明,丙酮含量不高于70wt%时,液体收率随丙酮含量升高而降低,进一步提高丙酮含量时液体收率基本稳定。各丙酮含量下,液体产物中均未检出邻甲氧基苯酚或其它任何烷氧基酚。较高丙酮含量时烷基酚含量显著降低。丙酮含量为50wt %时,芳醚含量出现极大值(29.06area%),进一步提高丙酮含量,芳烃及其它组分显著增加,导致产物中芳醚含量降低。随反应温度升高,产物中的芳醚和芳烃含量分别在500和450℃时出现极大值。综合考虑液体收率和产物极性两方面因素,确定该反应体系的最佳反应温度为450℃,丙酮添加量为50wt%,最佳条件下产物中芳醚与芳烃总量达52.90area%。丙酮分子中的羰基与酚系物中的羟基发生作用,分解产生CO2,同时烷基酚与烷氧基酚脱羟基后分别得到芳烃和芳醚两类主要液相产物。 相似文献
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Xuesong Wang Yu Li Li Liu Lianyuan Wang Han Wang Xuexin Guo 《Journal of Porous Materials》2017,24(2):463-468
Flower-like porous ZnO was successfully synthesized by a simple hydrothermal method followed by calcination. The morphologies of the as-prepared materials were characterized by scanning electron microscopy (SEM) and the crystal structures were determined by X-ray diffraction. It can be seen in SEM images that each flower-like ZnO unit is composed of randomly arranged ZnO thin flakes which makes the materials extremely porous. Meanwhile, there are numerous through-holes distributed on the surface of ZnO flakes. The gas-sensing properties of the as-prepared materials were investigated, and the results indicate the ultrahigh sensing properties of flower-like porous ZnO to acetone. The response of flower-like porous ZnO sensors to 50 ppm acetone is about 97.8 at the optimum operating temperature of 280 °C. The response and recovery times to 50 ppm acetone are about 2 and 23 s, respectively. Moreover, even at low concentrations of 0.25, 1 and 10 ppm acetone high responses can be observed with the values of 6.7, 15.8 and 30.1. In addition, the as-synthesized flower-like ZnO shows excellent selectivity to acetone and the response to 50 ppm acetone (97.8) is about 4.43 times larger than ethanol (22.1) at the same concentration, which can successfully distinguish acetone and ethanol. 相似文献
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《Journal of Industrial and Engineering Chemistry》2014,20(5):2761-2768
In this study, a packed-bed dielectric barrier discharge (DBD) reactor was developed for acetone removal. The effects of packing materials were investigated in terms of discharge characteristics, removal efficiency and byproducts formation. The identification of organic byproducts was conducted. The results indicated the presence of packing materials enhanced the energy density and exhibited a positive effect on acetone removal, while high oxygen concentration inhibited the removal of acetone. The formations of byproducts were significantly reduced in the presence of packing materials. The degradation pathways and mechanisms were discussed, showing CH3 radicals played a crucial role in the acetone degradation process. 相似文献
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气相色谱法应急监测空气中丙酮 总被引:1,自引:0,他引:1
目的:建立了空气中丙酮的气相色谱应急监测方法。方法:利用便携式大气采样器采集空气中气态丙酮,水吸收后经气相色谱分离,并用氢火焰离子化检测器(FID)测定。结果:本方法操作方便快捷,平均回收率大于95%,相对标准偏差小于3%。结论:本方法适合环境空气及工作场所空气中丙酮浓度的应急监测。 相似文献
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固体碱催化丙酮和碳酸二甲酯合成乙酰乙酸甲酯 总被引:2,自引:0,他引:2
以碳酸二甲酯(DMC)与丙酮为原料,在固体碱上合成乙酰乙酸甲酯,并考察了反应温度、反应时间、催化剂用量和原料摩尔比等因素对反应结果的影响。结果表明,以固体酸为催化剂时,无乙酰乙酸甲酯的生成,而具有中强碱位的K/MgO对反应具有较好的催化性能。当以K/MgO为催化剂,在反应温度为240℃,反应时间5h,催化剂用量为反应物总质量的1.5%,原料摩尔比为n(丙酮)∶n(DMC)=1∶4时,丙酮的转化率和乙酰乙酸甲酯的选择性分别达到41.2%和50.3%。反应的主要副产物为丙酮自身缩合的产物(二丙酮醇、4-甲基-3-烯基-2-戊酮、4-甲基-4-烯基-2-戊酮)以及醚化产物(2-甲氧基丙烯)等。 相似文献
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Ya-Lun Su Lai Kwok Leung Yu-Rong Bi Yu Huang Zhen-Yu Chen 《Journal of the American Oil Chemists' Society》2000,77(8):807-813
The present study examined the antioxidant activity in heated canola oil of hexane, acetone, and methanol extracts of dry
roots of gansu huangqin (Scutellaria rehderiana) as well as six flavonoids isolated from the acetone and methanol extracts. The oxidation was conducted at 95°C by monitoring
oxygen consumption and decreases in both linoleic and α-linolenic acids. The acetone extract was most effective in inhibiting
oxidation of canola oil, followed by the methanol extract. The antioxidant activity of gansu huangqin acetone extract was
dose-dependent. Among the six flavonoids, baicalein and ganhuangenin were more effective than butylated hydroxytoluene (BHT)
in protecting canola oil from oxidation. The present results suggest that the acetone extract of this root may be a potential
source of natural antioxidants for use in processed foods. 相似文献