黄果茄果实的灭螺活性及其有效成分的提取分离

测定黄果茄(Solanum xanthocarpum,SX)果实原粉浸杀钉螺和斑马鱼的活性,并提取分离其有效成分.研究结果:水温25 ℃,13μm SX原粉浸泡96 h,钉螺和斑马鱼的LC50值分别为7.61、54.4 mg/L(P<0.05);酸水提取与CCL分离得到碱性物SX Ⅰ、Ⅱ、Ⅲ,HPLC检测其纯度分别为97.89%、98.71%、96.12%,熔点仪测定其熔点分别为310.0、301.7、256.5℃,MS分析其相对分子质量分别为883、867、721;用其浸泡24 h抑杀钉螺100%的剂量分别为100.0、8.0、200.0 mg/L.结果表明SX果实原粉具有灭螺活性高和对鱼毒性低的生物效应且含有抑杀钉螺高活性的生物碱.     

吉祥草中杀灭钉螺有效成分的分离及结构解析

吉祥草为新发现的灭螺化合物,从水相提取物中分离出了杀螺有效成分晶体,进行了熔点、晶体衍射、元素分析、核磁共振C谱(13C NMR)、气-质谱等测定晶体性质的测试,证明为环己六醇.环己六醇的质量浓度为2.50 mg/L,72 h浸杀钉螺死亡率达93.3%;当杀螺成分质量浓度为5.00 mg/L时,72 h浸杀,其死亡率达100%.     

杀虫磺缓释剂杀钉螺试验报告

杀虫磺缓释剂浸杀成螺、幼螺、螺卵效果好，现场应用缓释片６３克／米＾２，半年后活螺平均密度下降９３．２％，春季施药１次，可达到控制当年钉螺的扩散。     

顶空固相微萃取-气质联用分析黄果茄果实的挥发性成分

为探究黄果茄果实中挥发性物质的具体成分及相对含量,了解其成分的功效及用途,实现黄果茄果实的开发利用。对黄果茄果实中的未知挥发性物质,采用顶空固相微萃取技术与气相色谱-质谱检测结合的方法进行检测分析。黄果茄果实中共鉴定出22种挥发性物质,醇类化合物有2种、醛类化合物2种、酮类化合物3种、酯类化合物10种、4种烷烃类和其他化合物。从相对含量方面上看,醛类和脂类化合物是黄果茄果实中主要的挥发性物质组成,是黄果茄果实提取物中主要的呈味物质。黄果茄挥发性物质中成分的大部分主要作为香料使用,应用于食品、日化、医药,少部分还可用作杀虫剂灭菌剂,以及化工溶剂、润滑剂等。     

植物源灭钉螺成分提取研究

以38种药用植物为试验材料,对石螺、钉螺进行了浸杀试验。其中植物水浸液浓度为1％(10000mg/l)石螺杀灭率达80％以上的植物有12种,复筛植物果茄(Slolanum xantho-carpum)果实的有机溶剂提取物浓度为33mg/l时48h的浸杀钉螺效果达100％。     

乌桕干叶乙醇提取液与链霉菌协同灭螺效果研究

研究了乌桕干叶乙醇提取液与链霉菌协同灭螺效果。结果表明,用乌桕鲜叶乙醇提取液和干叶乙醇提取液浸杀钉螺72 h后的LC_(50)分别为160.21 mg·L~(-1)、131.40 mg·L~(-1),表明乌桕于叶乙醇提取液的灭螺活性更高;将乌桕干叶乙醇提取液与链霉菌稀释液联合浸杀钉螺24 h,LC_(50)为53.95 mg·L~(-1),表明乌桕干叶乙醇提取液与链霉菌稀释液联合灭螺具有很明显的协同效应。为生态灭螺植物资源的合理使用及探索新的高效生态灭螺方法提供了理论依据。     

合成N-（4-碘胺苯基）-2-羟基-5-氯苯甲酰胺

研究单位： 湖南理工学院化学化工系柳一呜、易健民、张小勇。 技术简介： 相关文献显示，在近年的杀螺与杀精剂的筛选中，水杨酸衍生物研究较多，目前应用较多的杀螺与杀精剂是酰胺化合物，如N-（4-硝基苯基）-5-氯水杨酰胺（俗称硝苯柳胺）不但可以作为一种杀灭血吸虫中间宿主钉螺的杀螺剂，而且在计划生育和抗妇科感染方面也有广泛的用途。由于其在合成中所用原料对硝基苯胺为剧毒物质，其应用受限制。     

多噻烷杀钉螺实验研究

多噻烷杀钉螺实验研究谈佩萍，夏全斌，张楚霜，朱金华（湖南省寄生虫病防治研究所，岳阳４１４０００）多噻烷系贵州省化工研究院研制的一种新农药，在杀螺筛选中，发现该药有较好的杀螺作用。为进一步观察其效果，我们进行了室内和现场杀螺和杀螺卵试验，结果报告如下。...     

N-亚甲基磷酸壳聚糖有机锡酯的合成、表征及杀螺活性研究

用磷酸和甲醛在稀醋酸介质中对壳聚糖(CTS)进行N-亚甲基磷酸化改性,得到N-亚甲基磷酸壳聚糖(MPCS),用自制的MPCS在苯或甲苯介质中与有机锡发生反应,合成了3个新的N-亚甲基磷酸壳聚糖有机锡酯化合物:MPCS-SnPh3、MPCS-Sn(PhCH2)3、MPCS-SnBu3。通过IR、13C NMR、TG/DTA和X-ray对其结构和性质进行了表征和测试。杀钉螺实验结果表明,当其浓度在1.00 mg/L以上时,浸杀48 h后,钉螺的死亡率达100%。     

黄果茄果实生物碱的提取工艺

研究了黄果茄果实生物碱提取的最佳条件.采用正交实验方法,以黄果茄果实中2种生物碱SXⅡ和SXⅢ为考察指标,对影响黄果茄果实生物碱提取的因素进行了探讨.结果表明:SXⅡ最佳提取条件为浸提温度40℃、浸提时间15 h、水与原料配比10L/kg、pH值3.0;SXⅢ最佳提取条件为浸提温度10℃、浸提时间15h、水与原料配比10 L/kg、pH值3.0.     

食品专业化学动力学创新实验教学探索

针对传统化学动力学实验项目难以满足食品专业教学需求的实际情况,我们通过龙葵红色素热降解反应,开展食品专业化学动力学创新实验教学探索。通过实验教学,学生了解了天然食品色素的热稳定性,掌握了色素热降解动力学参数的测定方法,加深了对化学动力学知识的理解,实现了实验项目与专业问题的有机结合,有效地调动了学习积极性。教改在培养学生创造性思维和解决专业实际问题能力方面,收到了十分理想的效果。     

Green Synthesis of Silver Nanoparticles through Reduction with Solanum xanthocarpum L. Berry Extract: Characterization, Antimicrobial and Urease Inhibitory Activities against Helicobacter pylori

A green synthesis route for the production of silver nanoparticles using methanol extract from Solanum xanthocarpum berry (SXE) is reported in the present investigation. Silver nanoparticles (AgNps), having a surface plasmon resonance (SPR) band centered at 406 nm, were synthesized by reacting SXE (as capping as well as reducing agent) with AgNO(3) during a 25 min process at 45 °C. The synthesized AgNps were characterized using UV-Visible spectrophotometry, powdered X-ray diffraction, and transmission electron microscopy (TEM). The results showed that the time of reaction, temperature and volume ratio of SXE to AgNO(3) could accelerate the reduction rate of Ag(+) and affect the AgNps size and shape. The nanoparticles were found to be about 10 nm in size, mono-dispersed in nature, and spherical in shape. In vitro anti-Helicobacter pylori activity of synthesized AgNps was tested against 34 clinical isolates and two reference strains of Helicobacter pylori by the agar dilution method and compared with AgNO(3) and four standard drugs, namely amoxicillin (AMX), clarithromycin (CLA), metronidazole (MNZ) and tetracycline (TET), being used in anti-H. pylori therapy. Typical AgNps sample (S1) effectively inhibited the growth of H. pylori, indicating a stronger anti-H. pylori activity than that of AgNO(3) or MNZ, being almost equally potent to TET and less potent than AMX and CLA. AgNps under study were found to be equally efficient against the antibiotic-resistant and antibiotic-susceptible strains of H. pylori. Besides, in the H. pylori urease inhibitory assay, S1 also exhibited a significant inhibition. Lineweaver-Burk plots revealed that the mechanism of inhibition was noncompetitive.     

白英化学成分及生物活性研究进展

综述了近年来自英的化学成分和药理作用的研究概况.到目前为止,从白英中分离出的化合物有皂甙类、有机酸类、萜类、多酚类、黄酮类、甾醇类、香豆素类、多糖类和其他类型的化合物;白英具有良好的抗癌、抗菌、抗过敏等作用,在临床上具有广泛的应用价值.     

Enhanced Deep-Learning Prediction of Molecular Properties via Augmentation of Bond Topology

Deep learning has made great strides in tackling chemical problems, but still lacks full-fledged representations for three-dimensional (3D) molecular structures for its inner working. For example, the molecular graph, commonly used in chemistry and recently adapted to the graph convolutional network (GCN), is inherently a 2D representation of 3D molecules. Herein we propose an advanced version of the GCN, called 3DGCN, which receives 3D molecular information from a molecular graph augmented by information on bond direction. While outperforming state-of-the-art deep-learning models in the prediction of chemical and biological properties, 3DGCN has the ability to both generalize and distinguish molecular rotations in 3D, beyond 2D, which has great impact on drug discovery and development, not to mention the design of chemical reactions.     

Molecular Conditional Generation and Property Analysis of Non-Fullerene Acceptors with Deep Learning

The proposition of non-fullerene acceptors (NFAs) in organic solar cells has made great progress in the raise of power conversion efficiency, and it also broadens the ways for searching and designing new acceptor molecules. In this work, the design of novel NFAs with required properties is performed with the conditional generative model constructed from a convolutional neural network (CNN). The temporal CNN is firstly trained to be a good string-based molecular conditional generative model to directly generate the desired molecules. The reliability of generated molecular properties is then demonstrated by a graph-based prediction model and evaluated with quantum chemical calculations. Specifically, the global attention mechanism is incorporated in the prediction model to pool the extracted information of molecular structures and provide interpretability. By combining the generative and prediction models, thousands of NFAs with required frontier molecular orbital energies are generated. The generated new molecules essentially explore the chemical space and enrich the database of transformation rules for molecular design. The conditional generation model can also be trained to generate the molecules from molecular fragments, and the contribution of molecular fragments to the properties is subsequently predicted by the prediction model.     

Attraction and Oviposition of <Emphasis Type="Italic">Tuta absoluta</Emphasis> Females in Response to Tomato Leaf Volatiles

The tomato leafminer Tuta absoluta (Lepidoptera: Gelechiidae) is a devastating pest of cultivated tomato Solanum lycopersicum throughout South and Central America and Europe. We aimed to characterize the behavioral mechanisms and the chemical cues involved in host selection of T. absoluta females by chemical analysis of tomato leaf volatiles, wind tunnel attraction assays, and oviposition bioassays. Tomato leaf odor elicited in mated females upwind orientation flight followed by landing as well as egg-laying, demonstrating the essential role of plant volatiles in T. absoluta host-finding behavior. In wind tunnel and oviposition choice experiments, T. absoluta females significantly preferred tomato S. lycopersicum over wild tomato Solanum habrochaites, which is resistant to larval feeding. This indicates that leaf volatiles provide information on the suitability of plants as larval hosts. Mated females also discriminated three cultivars of S. lycopersicum according to their volatile profiles. Headspace collections from leaves of these three cultivars contained large amounts of β-phellandrene, followed by limonene, 2-carene, and (E)-β-caryophyllene, which together accounted for more than 70% of tomato foliage headspace. Most leaf volatiles were released by all three cultivars, but they showed significant differences with respect to the presence of a few minor compounds and blend proportion. This is an initial study of the volatile signatures that mediate attraction and oviposition of tomato leafminer T. absoluta in response to its main host, tomato.     

反应型乳化剂的合成及其与丙烯酸酯的乳液共聚

用聚乙二醇、芳香族二异氰酸酯和甲基丙烯酸羟乙酯为原料,制备了反应型乳化剂(RE),应用FTIR表征了RE的化学结构。进一步以RE为反应性单体与丙烯酸酯进行自由基共聚,制备了聚氨酯-丙烯酸酯共聚乳液,讨论了RE分子链中PEG链段的相对分子质量对乳液粒径及分布的影响。     

GPC-messungen von polymeren an oberflächenmodifizierten silikagelen

The fractionation of homo- and copolymers by GPC-experiments was investigated, using surface modified silica gels as porous supports. Linear polystyrenes, poly-α-methyl-styrenes, and polybutadienes have been analysed. Methods are shown which consider the hydrodynamic broadening effects due to GPC. A computer program of PROVDER and ROSEN has been improved by a subsequentiteration method. With this program good results for molecular weightdistributionscould be obtained. “True” molecular weight averages and polydispersities have been measured with a recycle method of WATERS and with extrapolation by HAMIELEC. By comparison with results from sedimentation transport runs and ?-fractionations a good agreement has been achieved within the limits of error of these methods. The (α-methyl styrene methacrylonitrile)-copolymers have been analysed fortheir heter-ogeneity of chemical composition. These polymers show an unusual elution behaviour,and exhibit more chemical heterogeneity than is computed by kinetic data.     

Combining Raman Chemical Imaging and Scanning Electron Microscopy to Characterize Ambient Fine Particulate Matter

Raman chemical imaging and scanning electron microscopy (Raman/SEM) have been used in a preliminary study to determine the size, morphology, elemental and molecular composition, and molecular structure of fine particulate matter in several test samples and one ambient air sample. Raman chemical imaging and SEM, respectively, provide a way to spatially characterize a sample based on its molecular and elemental makeup. When combined, Raman chemical imaging and SEM provide detailed spatial, elemental, and molecular information for particulate matter as small as 250 nm. Initial studies demonstrate the potential of Raman/SEM for molecular and elemental determination of organic and inorganic fine particulate matter. This has been accomplished by analyzing samples with fine particulate matter using each method independently. Since both techniques are nondestructive, particles of interest can be relocated between instruments. Practical issues such as filter substrate compatibility and instrumentation compatibility are addressed. In addition, first results showing Raman/SEM chemical images from several standard materials, as well as ambient PM_2.5 samples, are reported.