Negentropy and the evolution of chemical recruitment in ants (Hymenoptera: Formicidae)

The applicability of the concept of negentropy to the study of evolution is tested by tracing the phylogeny of the information content of the communication systems used for recruitment in the Formicidae. Data from the literature is reviewed and ordered around theoretical evolutionary routes based on increasing negentropy of the chemical communication systems used. One pathway presupposes the development of chemical orientation prior to chemical attraction, i.e. signalling the presence of food; whereas the others begin with the chemical attraction of nestmates without orientation with chemical cues to the food. The results suggest that the Myrmicinae, Ponerinae, Dolichoderinae, Pseudomyrmycinae and possibly Dorylinae evolved chemical recruitment via chemical attraction, whereas the Formicinae evolved chemical recruitment via chemical orientation. These alternative patterns permit the establishment of phyletic trends based on glandular evolution for chemical recruitment. The results are compared with phylogenetic studies based on morphological and chemical characters, and it emerges that the recruitment behaviour proves to be a particularly conservative characteristic, in that it is evident in the same form in a wider range of species. The conclusion is reached that the negentropy content of living systems is a powerful tool in phylogenetic studies, even of small taxonomic groups.     

PPM: a side-chain and backbone chemical shift predictor for the assessment of protein conformational ensembles

The combination of the wide availability of protein backbone and side-chain NMR chemical shifts with advances in understanding of their relationship to protein structure makes these parameters useful for the assessment of structural-dynamic protein models. A new chemical shift predictor (PPM) is introduced, which is solely based on physical?Cchemical contributions to the chemical shifts for both the protein backbone and methyl-bearing amino-acid side chains. To explicitly account for the effects of protein dynamics on chemical shifts, PPM was directly refined against 100?ns long molecular dynamics (MD) simulations of 35 proteins with known experimental NMR chemical shifts. It is found that the prediction of methyl-proton chemical shifts by PPM from MD ensembles is improved over other methods, while backbone C??, C??, C??, N, and H^N chemical shifts are predicted at an accuracy comparable to the latest generation of chemical shift prediction programs. PPM is particularly suitable for the rapid evaluation of large protein conformational ensembles on their consistency with experimental NMR data and the possible improvement of protein force fields from chemical shifts.     

21世纪植物化学生态学前沿领域

植物和其它有机体通过次生物质为媒介的化学作用关系近年引入注目,其中植物的诱导化学防御,植物的化学通讯,植物次生物质和进化的关系,植物与人类的化学关系和海洋植物化学生态学是21世纪植物化学生态学值得关注的前沿领域。植物化学生态学前沿领域的进展将为实现21世纪的持续,发展是在生态安全条件下提高农业产量并达到对病虫草害的有效控制方面具有重要意义。     

Prediction of intracellular targets of a small compound by analyzing peptides presented on MHC class I

In chemical biology, the elucidation of chemical target is crucial for successful drug development. Because MHC class I molecules present peptides from intracellular damaged proteins, it might be possible to identify targets of a chemical by analyzing peptide sequences on MHC class I. Therefore, we treated cells with the autophagy-inducing chemical TMD-457 and identified the peptides presented on MHC class I. Many of the peptides were derived from molecules involved in ER trafficking and ER stress, which were confirmed by morphological and biochemical analyses. Therefore, our results demonstrate that analyzing MHC class I peptides is useful for the detection of chemical targets.     

An Analysis of Chemical Ingredients Network of Chinese Herbal Formulae for the Treatment of Coronary Heart Disease

As a complex system, the complicated interactions between chemical ingredients, as well as the potential rules of interactive associations among chemical ingredients of traditional Chinese herbal formulae are not yet fully understood by modern science. On the other hand, network analysis is emerging as a powerful approach focusing on processing complex interactive data. By employing network approach in selected Chinese herbal formulae for the treatment of coronary heart disease (CHD), this article aims to construct and analyze chemical ingredients network of herbal formulae, and provide candidate herbs, chemical constituents, and ingredient groups for further investigation. As a result, chemical ingredients network composed of 1588 ingredients from 36 herbs used in 8 core formulae for the treatment of CHD was produced based on combination associations in herbal formulae. In this network, 9 communities with relative dense internal connections are significantly associated with 14 kinds of chemical structures with P<0.001. Moreover, chemical structural fingerprints of network communities were detected, while specific centralities of chemical ingredients indicating different levels of importance in the network were also measured. Finally, several distinct herbs, chemical ingredients, and ingredient groups with essential position in the network or high centrality value are recommended for further pharmacology study in the context of new drug development.     

Random coil chemical shift for intrinsically disordered proteins: effects of temperature and pH

Secondary chemical shift analysis is the main NMR method for detection of transiently formed secondary structure in intrinsically disordered proteins. The quality of the secondary chemical shifts is dependent on an appropriate choice of random coil chemical shifts. We report random coil chemical shifts and sequence correction factors determined for a GGXGG peptide series following the approach of Schwarzinger et al. (J Am Chem Soc 123(13):2970–2978, 2001). The chemical shifts are determined at neutral pH in order to match the conditions of most studies of intrinsically disordered proteins. Temperature has a non-negligible effect on the ¹³C random coil chemical shifts, so temperature coefficients are reported for the random coil chemical shifts to allow extrapolation to other temperatures. The pH dependence of the histidine random coil chemical shifts is investigated in a titration series, which allows the accurate random coil chemical shifts to be obtained at any pH. By correcting the random coil chemical shifts for the effects of temperature and pH, systematic biases of the secondary chemical shifts are minimized, which will improve the reliability of detection of transient secondary structure in disordered proteins.     

化学基因组学和化学蛋白质组学用于细胞自噬研究

化学基因组学和化学蛋白质组学作为后基因组时代的新技术,是以化学小分子为工具,对细胞的生理过程进行精确干扰,研究有机体和细胞的功能,同时也是新药开发的重要手段。本文综述了化学基因组学和化学蛋白质组学征自噬相关靶点的特异性小分子的发现,及小分子存自噬机理研究中的应用。     

九节属药用植物化学成分及药理作用研究进展

九节属植物(Psychotria)是我国南方常用中草药。文献调研表明,关于我国境内本属植物相关化学成分及药理作用研究报道很少。为进一步研究开发Psychotria属药用植物资源,对其化学成分及药理作用进行综述,为其深入开发打下基础。     

化学杀虫剂对菜田节肢动物多样性的影响

分析了化学杀虫剂对菜田节肢动物结构组成、多样性变化等的影响,结果表明化学杀虫剂对菜田节肢动物的影响主要表现在物种组成、多样性指数及物种分布的均匀性等方面,尤其是对害虫类、捕食性天敌和蜘蛛类的影响尤为明显。停止化学杀虫剂使用后,菜田优势害虫种群趋势指数降低,天敌的控制作用明显增强,节肢动物多样性指数增大。因此,限制和停止化学杀虫剂的使用,恢复由于杀虫剂使用而破坏了的菜田环境,逐步增强天敌对优势害虫的控制能力,这在菜田害虫生态控制中具有重要作用。     

土壤因子对关黄柏10种化学成分含量的影响

为了揭示不同产地土壤因子对关黄柏酚酸类、生物碱类和柠檬苦素类化学成分含量的影响,本研究对31个样点的15个土壤因子及所产药材的10种化学成分含量进行检测。通过冗余分析考察土壤因子与化学成分间的相关性,用t-value双序图解读各土壤因子对各化学成分含量的影响,并通过聚类分析考察样点土壤特征对药材化学特征的影响。结果显示：土壤中的盐分、速效磷、阳离子交换量、速效氮、速效钾、有机质、有效锰、硫和有效铜对关黄柏化学成分含量有显著影响;3-O-阿魏酰奎尼酸、4-O-阿魏酰奎尼酸、5种生物碱、黄柏内酯含量随上述土壤因子含量的上升呈下降趋势;紫丁香酚苷和黄柏酮主要呈上升趋势。研究结果表明环境土壤因子的差异会导致关黄柏多种化学成分的含量发生显著性改变。     

Role of herbaceous plant communities in biogenic cycles of chemical elements

The role of ecological factors in the formation of biogenic cycles of chemical elements has been studied. It has been shown that, both under background conditions and chemical pollution, biogeochemical and biocenotic factors contribute to this process. These are the species structure of a community, specific features of chemical element accumulation, biomass of individual species, and productivity of phytocenosis. The accumulation of chemical elements in the phytomass depends not so much on their increasing concentrations in the soils as on degradation of the environment caused by their toxic effect and manifested in transformation of species composition and reduction of the total phytomass of the phytocenosis.     

植物-微生物联合修复化学农药污染土壤的研究进展

化学农药的高毒性、生物积累性和扩散性极易对环境及人类健康造成危害,环境中化学农药的去除尤为重要。植物-微生物联合修复技术因其高效、环境友好和修复成本低等优点受到越来越多的关注,植物-微生物联合修复化学农药污染土壤是一种很有前景的方法。植物为根际和内生细菌提供养分,而细菌通过化学农药的降解和解毒来支持植物生长。本文综述了影响化学农药在植物体内吸收和转运的因素以及植物-微生物修复技术的原理,并讨论了植物与微生物在化学农药污染土壤修复中的协同效应,并对植物-微生物联合修复法在化学农药污染土壤修复中的应用前景进行了展望。     

The origin of an unusually large 19F chemical shift difference between the diastereomeric alpha-cyano-alpha-fluoro-p-tolylacetic acid (CFTA) esters of 3',4',5,7-tetra-O-methylepicatechin

During a study on the relationship between the (19)F chemical shift difference for the diastereomeric alpha-cyano-alpha-fluoro-p-tolylacetic acid (CFTA) esters of chiral secondary alcohols and the absolute configurations of the alcohols, an unusually large 19F chemical shift difference has been observed for the CFTA esters of 3',4',5,7-tetra-O-methylepicatechin. This large chemical shift difference has been reproduced by ab initio calculations of molecular geometry and GIAO calculations of 19F chemical shifts on the stable conformations of the diastereomeric alpha-cyano-alpha-fluorophenylacetic acid (CFPA) esters of cis-flavan-3-ol as model systems. The origin of the large chemical shift difference has been further investigated using NBO analysis. This revealed that the interaction between pi(C=C) of the aryl group in the chiral auxiliary and sigma*(C--F) is a very important determinant of the 19F chemical shifts and this interaction depends on the torsion angle between the plane of aryl group and the C--F bond.     

Chemical defensive substances of soft corals and gorgonians

Despite lack of efficient physical protection in the highly competitive and hostile environment, the marine invertebrates including soft corals and gorgonians can survive, mainly relying on their chemical defensive system by a series of secondary metabolites accumulating in their bodies or releasing to their surroundings. The chemical defensive functions of these secondary metabolites were found to serve as antipredatory, antimicrobial, allelopathy and antifouling agents. Study on chemical defensive substances from corals and gorgonians is one of the most important topics in marine chemical ecology. The research results could help us to understand the chemical ecological relationships between corals and their surrounding organisms. The research strategy and methodology played an enlightening role in the discovery of bioactive natural products and the generation of new drug lead compounds from marine sources. The chemical defensive substances from soft corals and gorgonians were reviewed. This review focused on the structures of these secondary metabolites as well as their functions including antipredatory, allelopathy and antifouling activities.     

Chemical defensive substances of soft corals and gorgonians

Despite lack of efficient physical protection in the highly competitive and hostile environment, the marine invertebrates including soft corals and gorgonians can survive, mainly relying on their chemical defensive system by a series of secondary metabolites accumulating in their bodies or releasing to their surroundings. The chemical defensive functions of these secondary metabolites were found to serve as antipredatory, antimicrobial, allelopathy and antifouling agents. Study on chemical defensive substances from corals and gorgonians is one of the most important topics in marine chemical ecology. The research results could help us to understand the chemical ecological relationships between corals and their surrounding organisms. The research strategy and methodology played an enlightening role in the discovery of bioactive natural products and the generation of new drug lead compounds from marine sources. The chemical defensive substances from soft corals and gorgonians were reviewed. This review focused on the structures of these secondary metabolites as well as their functions including antipredatory, allelopathy and antifouling activities.     

Discrimination of toxic impacts of various chemicals using chemical–gene expression profiling of Escherichia coli DNA microarray

The expression levels of 96 genes were characterized and differentiated using a cDNA microarray after the bacterium Escherichia coli was exposed to numerous toxic chemicals. In all, the effects of 14 different chemicals and 1 mixture were investigated using 1-h exposure data to provide information about physiological changes brought on by the stress experienced and interaction of chemical–gene expression. Hierarchical clustering analysis showed that the genes could be sub-grouped based upon their expression patterns while each also showed unique signatures to each chemical tested when examined using a principal component analysis (PCA). By constructing a chemical–gene expression profiling based on changes in the expression of the genes for each chemical, we were able to identify the chemicals effects and gene targets more systematically. Despite the fact that only a small number of genes were used for gene expression analysis, they were sufficient to discriminate between the effects of each exposure. It was found that the use of a single time point for expression analysis was insufficient for interpreting the effects a given chemical has on the bacterium. Such information cannot be obtained from conventional toxicity studies, demonstrating that chemical–gene expression profiling method based on the hierarchical clustering analysis and principal component analysis (PCA) in toxicity monitoring offers a new perspective for bio-monitoring and information on dynamic changes occurring at the sub-cellular level.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism     

Behavioural response of bullfrog tadpoles to chemical cues of predation risk are affected by cue age and water source

When confronted by signals of predators presence, many aquatic organisms modify their phenotype (e.g., behaviour or morphology) to reduce their risk of predation. A principal means by which organisms assess predation risk is through chemical cues produced by the predators and/or prey during predation events. Such responses to predation risk can directly affect prey fitness and indirectly affect the fitness of species with which the prey interacts. Accurate assessment of the cue will affect the adaptive nature, and hence evolution, of the phenotypic response. It is therefore, important to understand factors affecting the assessment of chemical cues. Here I examined the effect of the age of chemical cues arising from an invertebrate predator, a larval dragonfly (Anax junius), which was fed bullfrog tadpoles, on the behavioural response (activity level and position) of bullfrog tadpoles. The bullfrog response to chemical cues declined as a function of chemical cue age, indicating the degradation of the chemical cue was on the order of 2–4 days. Further, the decay occurred more rapidly when the chemical cue was placed in pond water rather than well water. These results indicate a limitation of the tadpoles to interpret factors that affect the magnitude of the chemical cue and hence accurately assess predation risk. These findings also have implications for experimental design and the adaptation of phenotypic responses to chemical cues of predation risk.     

复方安神精油吸入给药的镇静催眠作用及化学成分的GC-MS分析

为研究复方安神精油吸入给药的镇静催眠作用,本实验采用动物自主活动测试和戊巴比妥钠诱导的睡眠潜伏期与睡眠时间实验:GC-MS分析复方安神精油的挥发性化学成分与入脑的主要化学成分;基于网络药理学预测和筛选出治疗失眠症相关靶蛋白与活性成分,旨在为复方安神精油治疗与改善失眠症提供理论依据。研究发现,复方安神精油具有镇静催眠作用,可显著减少动物自主活动,缩短睡眠潜伏期,延长睡眠时间;复方安神精油主要化学成分与入脑主要化学成分中含有多种具有神经中枢镇静催眠作用以及抗焦虑、抗抑郁作用的化学成分;基于网络药理学预测和筛选出25个治疗失眠症相关活性成分作用于39个治疗失眠症相关作用靶点,体现复方安神精油多成分、多靶点发挥镇静催眠作用的特点。     

Arrestment responses of the parasitoid, Nemeritis canescens, to a contact chemical produced by its host, Plodia interpunctella

ABSTRACT. The locomotory response of walking parasitoids to a contact chemical from their host is reviewed, and in particular the response of the ichneumonid, Nemeritis canescens Grav., to the mandibular gland secretion of its host, Plodia interpunctella Hubn., is investigated. In response to the presentation of the host chemical on a surface, a walking Nemeritis exhibits a complex ortho-kinetic response involving stopping, walking at a reduced speed and probing with the ovipositor. In response to the removal of the chemical following presentation, as would occur when the insect left the edge of the chemical patch, the wasp exhibits a klinotactic response which directs it back to the patch at an average angle of 157° relative to the orientation at the moment of stimulation. This turning-back response at the patch edge greatly increases the time spent on a patch of contact chemical. The waning of this response determines when a host patch is abandoned. This waning is retarded by increasing the concentration of contact chemical on the patch and by opposition while on the patch.