含芳硫醚结构的新型酰胺衍生物的设计、合成和生物活性（英文）

在前期工作中,含芳硫醚(砜)结构的系列酰胺衍生物在200μg/mL浓度下显示出了优异的杀线虫活性.为了细致研究氟吡菌酰胺中酰胺桥结构修饰对生物活性的影响,通过采取酰胺键翻转、引入N-磺酰基取代的酰胺键,设计、合成了两系列结构新颖的含芳硫醚的酰胺化合物.生物活性测定显示,酰胺桥结构修饰对目标化合物的杀线虫活性和杀菌活性影响较大.其中,相对于化合物Ⅰ,化合物Ⅱ中酰胺键上N-磺酰基的引入有利于改善杀线虫活性.分子对接发现,酰胺桥中羰基或者磺酰基与芳香环直接相连对杀线虫活性是有利的.     

2-酰基-氰基乙酸衍生物的合成及生物活性

设计并合成了21个新型2-酰基-氰基乙酸类化合物,应用氢核磁共振谱、元素分析和红外光谱验证了它们的结构,并测试了其生物活性.部分化合物对朱砂叶螨(Tetranychus cinnabarinus)具有活性,化合物4e和4k在600mg/L浓度下呈现100%的杀螨活性;部分化合物具有一定杀菌和除草活性,化合物4k和4s在400mg/L浓度下对小麦白粉病(Blumeria graminis)的抑制率达到100%,化合物4m在1000mg/L浓度下可以很好地防治苘麻(Abutilon theophrasti).初步探讨了化合物结构与生物活性关系.     

8-氮杂双环[3.2.1]辛烷-3-异噁唑肟类衍生物的合成及其杀线虫活性

基于具有潜在杀线虫活性的托烷衍生物结构,通过1,3-偶极环加成反应,设计合成了19个未见报道的8-氮杂双环[3.2.1]辛烷-3-异噁唑肟类衍生物,通过~1H NMR,~(13)C NMR和高分辨质谱对目标化合物的结构进行表征.初步的生物活性测试表明:在浓度25 mg/L下,目标化合物对南方根结线虫表现出良好的抑制活性,活性最好的化合物8-甲基-8-氮杂双环[3.2.1]辛烷-3-酮-O-((3-(4-硝基苯基)-4,5-二氢异噁唑-5-基)甲基)肟(9e)在1 mg/L浓度下对根结线虫的抑制率达55.6%.     

六(乙氧基吡咯烷酮)三聚磷腈的合成与表征

以N-羟乙基吡咯烷酮与氢化钠作用生成相应的钠盐,再将此钠盐与六氯三聚磷腈(HCCP)发生亲核取代反应,合成了六(乙氧基吡咯烷酮)三聚磷腈,用IR、31P NMR、1H NMR、13C NMR、DEPT、FABMS等现代谱学技术对其结构进行了表征。生物活性试验表明,此化合物1mg/mL时对腐生线虫Panagrellus redivivus的72h致死率为52·7%。     

四降三萜solanoeclepin A的合成研究进展

Solanoeclepin A是由Mulder等从茄科植物马铃薯根部分离得到,是一种具有非常独特骨架结构的四降三萜类天然产物.研究表明,其对造成土豆大量减产的土豆包囊线虫(PCN, Globodera rostochiensis and G. pallida)的孵化过程具有极强的诱导活性(0.3 g/ha土地).结合Corey教授关于glycinoeclepin的仿生合成工作,提出了solanoeclepin A可能的生源合成途径,综述了目前已报道的solanoeclepin A的全合成及片段合成策略.     

Hirsutellide A立体异构体的单晶结构与抗分支杆菌生物活性研究

研究了hirsutellide A立体异构体的X衍射单晶结构及其抗分支杆菌活性. 该化合物具有扭曲马鞍型18元大环结构; 在体外生物活性测试中, 化合物未表现出明显的抗分支杆菌活性. 由实验结果可以看出在天然环酯肽hirsutellide A中3'-C手性中心是其生物活性关键位点之一.     

蓖麻毒素A链(RTA)功能域突变体构效关系的量子化学研究

结合对蓖麻毒素A链(RTA)功能域氨基酸(Tyr80,Trr123,Gln177,Arg180)点突变后对其生物活性影响的实验研究,利用半经验量子化学AMI方法对RTA功能域及其点突变进行了理论计算.通过分析前线分子轨道性质和能级,从理论上探讨了其功能域点突变对其生物活性的影响,并预测了突变体(Tyr123→TrP)比RTA生物活性高.     

取代芳烃对某些生物急性毒性的拓扑学研究

提出了成键原子的生物活性值(ai),并建立其连接性指数(mA).其中的0A、1A与取代芳烃对斜生栅列藻、日本长腿蛙蝌蚪、绿藻等三种生物的急性毒性关连,相关系数(R)依次为0.9516、0.9564、0.9335,优于相应文献的研究成果.证明mA与取代芳烃生物活性的相关性优于著名的Kier指数(mXv).     

敌敌畏及其代谢产物对青海弧菌和秀丽线虫的联合毒性

实际环境中农药与其代谢产物常常共存, 农药和代谢产物之间的联合毒性(协同或拮抗)直接影响农药的环境风险评估. 农药敌敌畏(A)在环境中主要有三种代谢产物(二氯乙醇(B)、二氯乙酸(C)、磷酸二甲酯(D)), 在不同环境条件下其浓度组成有多种变化, 与敌敌畏形成多种混合物. 本文应用优化实验设计方法从中优选5条具有不同浓度配比的混合物射线, 选择水生生物青海弧菌(Vibrio qinghaiensis sp.-Q67)和土壤生物秀丽线虫(Caenorhabditis elegans)为受试生物, 通过微板毒性分析方法测试母体A及其代谢产物B、C、D以及它们的混合物射线在不同暴露时间及不同浓度水平下对青海弧菌的发光抑制毒性和对秀丽线虫的致死毒性, 应用含95%观测置信区间的组合指数评估各混合物射线在不同暴露时间下联合毒性随混合物浓度水平的变化. 结果表明: 对青海弧菌, 母体A及2个代谢产物C和D对Q67的发光抑制毒性不随时间变化而变化, 但代谢产物B在12 h的毒性显著大于0.25 h, 且母体A无论在哪个暴露时间其毒性都大于代谢产物. 对秀丽线虫, A与B、C及D的致死毒性不随时间而变化. A、C及D的毒性基本相同, 且均显著大于B. 5条混合物射线在不同浓度水平下, 在12 h对青海弧菌的发光抑制毒性显著大于0.25 h. 无论在0.25 h或12 h, 混合物射线对青海弧菌的联合毒性均是低浓度加和与高浓度拮抗. 对于秀丽线虫, 5条射线的毒性均不随时间而变化. 在2个时间点的联合毒性除射线R2和R5具有轻微拮抗外, 其它都是浓度加和.     

一类新型大环内酯衍生物的合成及其生物活性研究

为了寻找高效、广谱的杀虫、杀菌剂,以去糖基或部分去糖基的多杀菌素为母体进行结构修饰,合成了8种大环内酯酰化衍生物,其结构经1H NMR,13C NMR和MS表征.对合成的化合物进行了生物活性测试.结果表明,这类化合物对鳞翅目、鞘翅目、双翅目、半翅目及线虫等害虫有较好的杀灭活性,其中化合物3e在100 mg/L浓度下对桃蚜的24 h杀灭率达到100%,化合物3f和3h在上药量为200μg时对假单胞菌有一定的抑制作用.     

Glycinoeclepins B and C,nortriterpenes related to glycinoeclepin a

The structure of two new nortriterpenes, glycinoeclepins B and C, isolated from the aqueous extracts of roots of kidney bean and related structurally to glycinoeclepin A, a natural hatching stimulus for the soybean cyst nematode, has been elucidated to be formulas 2 and 3, respectively.     

Novel Potential Application of Chitosan Oligosaccharide for Attenuation of Renal Cyst Growth in the Treatment of Polycystic Kidney Disease

Chitosan oligosaccharide (COS), a natural polymer derived from chitosan, exerts several biological activities including anti-inflammation, anti-tumor, anti-metabolic syndrome, and drug delivery enhancer. Since COS is vastly distributed to kidney and eliminated in urine, it may have a potential advantage as the therapeutics of kidney diseases. Polycystic kidney disease (PKD) is a common genetic disorder characterized by multiple fluid-filled cysts, replacing normal renal parenchyma and leading to impaired renal function and end-stage renal disease (ESRD). The effective treatment for PKD still needs to be further elucidated. Interestingly, AMP-activated protein kinase (AMPK) has been proposed as a drug target for PKD. This study aimed to investigate the effect of COS on renal cyst enlargement and its underlying mechanisms. We found that COS at the concentrations of 50 and 100 µg/mL decreased renal cyst growth without cytotoxicity, as measured by MTT assay. Immunoblotting analysis showed that COS at 100 µg/mL activated AMPK, and this effect was abolished by STO-609, a calcium/calmodulin-dependent protein kinase kinase beta (CaMKKβ) inhibitor. Moreover, COS elevated the level of intracellular calcium. These results suggest that COS inhibits cyst progression by activation of AMPK via CaMKKβ. Therefore, COS may hold the potential for pharmaceutical application in PKD.     

Development of a bionematicide with Paecilomyces lilacinus to control Meloidogyne incognita

Root-knot disease caused by Meloidogyne incognita is a matter of grave concern because it affects several economically important crop plants. The use of solid-state fermentation (SSF) may help to elaborate efficient formulations with fungi to be employed in the biologic control of nematodes. Attempts were made to select low-cost substrates for spore production of a strain of Paecilomyces lilacinus with known nematicide capacity. Coffee husks, cassava bagasse, and defatted soybean cake were utilized as substrates, and sugarcane bagasse was used as support. Fermentations were carried out in flasks covered with filter paper at 28°C for 10 d. The products obtained by SSF were evaluated for their nematicide activity in pot experiments containing one seedling of the plant Coleus inoculated with the nematode M. incognita. The plants were evaluated 2 mo after inoculation. Fermented products showed a reduction in the number of nematodes. The best results were obtained with defatted soybean cake, which showed almost 100% reduction in the number of nematodes; the reduction with coffee husk was 80% and with cassava bagasse was about 60%.     

Comparison of ESI‐MS/MS and APCI‐MS methods for the quantification of folic acid analogs in C. elegans

Folic acid (FA) plays a vital role in central metabolism, including the one carbon cycle, nucleotide, and amino acid biosynthesis. The development of sensitive, accurate analytical methods to measure FA intermediates in tissues is critical to understand their biological roles in diverse physiological and pathological contexts. Here, we developed a highly sensitive method for the simultaneous quantification of FA intermediates in the nematode Caenorhabditis elegans as a model to dissect metabolic networks. The method was further validated by analyzing the worm folate pool upon RNAi knockdown of the dihydrofolate reductase gene dhfr‐1. Comparative mass spectrometry behavior of the FA analogs using two different ion sources, electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), revealed ESI‐MS/MS to be more sensitive, but APCI‐MS provided more detailed structure inferences, which can elucidate chemical investigation and synthesis of FA analogs. Finally, we report on the use of in vitro oxidation coupled with high‐resolution mass spectrometry as a tool to discover new endogenous FA derivatives in the nematode.     

Profiling of Caenorhabditis elegans proteins using two-dimensional gel electrophoresis and matrix assisted laser desorption/ionization-time of flight-mass spectrometry

The nematode Caenorhabditis elegans (C. elegans) is the first animal whose whole 97 Mb genome sequence, encoding ca. 19000 open reading frames (ORF's), has been essentially determined. We tried to establish a 2-DE map of the nematode proteome by means of two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). A soluble protein fraction of mixed stages of the worm, wild-type strain N2, was applied to 2-D PAGE. After Coomassie Brilliant Blue (CBB) staining, 1200 spots were detected and 140 major spots were excised from the gel and subjected to in-gel digestion with Achromobacter protease I (lysyl endopeptidase). Resulting peptides were analyzed by matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) followed by peptide mass fingerprinting for protein identification. With this approach we have obtained a two-dimensional electrophoresis (2-DE) protein map in which 69 spots were localized as landmarks for comparison of expression profiles to elucidate the basis of various biological events.     

Fourier-transform mid-infrared FPA imaging of a complex multicellular nematode

Here we report on the application of mid-IR imaging to a complex multicellular organism, a nematode. Despite the increase in sample complexity and sample thickness from previously measured cells and tissue sections, it is still possible, through the application of hierarchical cluster analysis, to elucidate biochemical information and spatial distribution information that can be linked to different tissue types in the nematode, namely somatic and non-striated muscle and the collagen rich cuticle. Comparison of HCA clusters from individuals from different species shows clusters can be associated specifically to a particular species, but that few clusters are shared between individuals from different species. In addition, using a synthetic fibre as a model for the nematode, we also show that the IR spectra can be affected by Mie scattering type baseline oscillations which are especially severe towards the edges of the fibre/nematode, but that these can be, to some extent, corrected for using currently available correction algorithms prior to cluster analysis.     

Redox active metal-induced oxidative stress in biological systems

A number of studies performed on biological systems have shown that redox-active metals such as iron and copper as well as other transition metals can undergo redox cycling reactions and produce reactive free radicals termed also reactive oxygen species (ROS) or reactive nitrogen species (RNS). The most representative examples of ROS and RNS are the superoxide anion radical and nitric oxide, respectively, both playing a dual role in biological systems. At low/moderate concentrations of ROS and RNS, they can be involved in many physiological roles such as defense against infectious agents, involvement in a number of cellular signaling pathways and other important biological processes. On the other hand, at high concentrations, ROS and RNS can be important mediators of damage to biomolecules involving DNA, membrane lipids, and proteins. One of the most damaging ROS occurring in biological systems is the hydroxyl radical formed via the decomposition of hydrogen peroxide catalyzed by traces of iron, copper and other metals (the Fenton reaction). The hydroxyl radical is known to react with the DNA molecule, forming 8-OH-Guanine adduct, which is a good biomarker of oxidative stress of an organism and a potential biomarker of carcinogenesis. This review discusses the role of iron and copper in uncontrolled formation of ROS leading to various human diseases such as cancer, cardiovascular disease, and neurological disorders (Alzheimer’s disease and Parkinson’s disease). A discussion is devoted to the various protective antioxidant networks against the deleterious action of free radicals. Metal-chelation therapy, which is a modern pharmacotherapy used to chelate redox-active metals and remove toxic metals from living systems to avoid metal poisoning, is also discussed.     

傅里叶变换红外吸收光谱识别五种植物油的研究

以花生油、大豆油、芝麻油、棉籽油和米糠油为样品,采用傅里叶变换红外光谱仪,采集傅里叶变换红外吸收光谱,对光谱预处理后,提取红外特征信息,以1746cm-1和2855cm-1处的吸收峰面积比值为横坐标,1099cm-1处与1119cm-1处的吸收峰面积比为纵坐标,在Origin6.0上做出二维分布图,对各种油脂进行识别分析。结果显示,大豆油与其它4种油脂之间有明显区分;大豆油、花生油和芝麻油分布效果好,但棉籽油各样品点之间比较分散;能与其它油脂区分开的有以下几种分布花生油明显区别于芝麻油、棉籽油和大豆油;米糠油明显区别于棉籽油和大豆油。分布有交叉的油脂有米糠油与花生油或芝麻油有交叉,棉籽油与芝麻油有交叉。     

Analysis of soybean sapogenins by high-performance liquid chromatography

A method for the analysis of soybean sapogenins is described. The method is based on the extraction of soybean saponins from a defatted sample. The triterpene glycosides are then hydrolysed with subsequent analysis of the liberated sapogenins by high-performance liquid chromatography using gradient elution and mass detection. By use of a sapogenin/carbohydrate ratio, an estimate of the total saponin content can be made.     

A novel approach to identify plant parasitic nematodes using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Plant parasitic nematodes are difficult to identify because different species are morphologically similar, and this makes their control more difficult. The aim of this work was to develop a rapid, simple method to identify plant parasitic nematodes, based on analysis of protein profiles of nematodes generated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Two methods have been used: grinding and direct analysis of intact nematodes. Both methods were standardised using the nematode Anguina tritici (wheat seed-gall nematode) as a model. Development of the approach involved optimisation of experimental parameters to generate reproducible diagnostic protein profiles for plant parasitic nematodes. With alpha-cyano-4-hydroxycinnamic acid (CHCA) as the matrix, the most effective solvent extraction was with 90% acetone. With sinapinic acid (SA) as matrix, 90% ethanol was most effective. When intact nematodes were analysed directly by mixing with the matrix solution, 40 min extraction with CHCA matrix solution generated the best protein profiles. The standardised methods were applied to analyse the seed-gall nematodes A. tritici and A. funesta and to the root-knot nematode, Meloidogyne javanica, which infects many horticultural crops. Typical protein profiles and diagnostic peaks were identified for these nematode species and for mixtures of Anguina species. The results provide 'proof-of-concept' that these nematode species can be identified by protein profiling using MALDI-TOFMS. This new approach could be extended to identify other plant and non-plant parasitic nematodes.