Organometallic Compounds: An Opportunity for Chemical Biology?

Organometallic compounds are renowned for their remarkable applications in the field of catalysis, but much less is known about their potential in chemical biology. Indeed, such compounds have long been considered to be either unstable under physiological conditions or cytotoxic. As a consequence, little attention has been paid to their possible utilisation for biological purposes. Because of their outstanding physicochemical properties, which include chemical stability, structural diversity and unique photo- and electrochemical properties, however, organometallic compounds have the ability to play a leading role in the field of chemical biology. Indeed, remarkable examples of the use of such compounds-notably as enzyme inhibitors and as luminescent agents-have recently been reported. Here we summarise recent advances in the use of organometallic compounds for chemical biology purposes, an area that we define as "organometallic chemical biology". We also demonstrate that these recent discoveries are only a beginning and that many other organometallic complexes are likely to be found useful in this field of research in the near future.     

Chemical Biology Approaches to Understanding Neuronal O−GlcNAcylation

O-linked β-N-acetylglucosamine (O−GlcNAc) is a ubiquitous post-translational modification in mammals, decorating thousands of intracellular proteins. O−GlcNAc cycling is an essential regulator of myriad aspects of cell physiology and is dysregulated in numerous human diseases. Notably, O−GlcNAcylation is abundant in the brain and numerous studies have linked aberrant O−GlcNAc signaling to various neurological conditions. However, the complexity of the nervous system and the dynamic nature of protein O−GlcNAcylation have presented challenges for studying of neuronal O−GlcNAcylation. In this context, chemical approaches have been a particularly valuable complement to conventional cellular, biochemical, and genetic methods to understand O−GlcNAc signaling and to develop future therapeutics. Here we review selected recent examples of how chemical tools have empowered efforts to understand and rationally manipulate O−GlcNAcylation in mammalian neurobiology.     

Northwest Chemical Says Goodbye to Jianlibao

Northwest Chemical Co., Ltd. has re-cently announced that as GuangdongJianlibao Group Co., Ltd. fails to signthe equity transfer agreement withNorthwest Paint Plant, the largestshareholder of the company, North-west Paint Plant has decided to termi-nate equity transfer with JianlibaoGroup.According to relevant data, North-west Paint Plant held 109.8 million     

ChemChina to Setup Large Chemical Pesticides Group

The signing ceremony for the contractbetween the National Development Bankand the Chem China financial advisoryboard was held in Beijing on March 3,2005.The two parties will speed up the regroup-     

Modulation of Cellular Fate of Vinyl Triarylamines through Structural Fine Tuning: To Stay or Not To Stay in the Mitochondria?

Mitochondria are involved in many cellular pathways and dysfunctional mitochondria are linked to various diseases. Hence efforts have been made to design mitochondria-targeted fluorophores for monitoring the mitochondrial status. However, the factors that govern the mitochondria-targeted potential of dyes are not well-understood. In this context, we synthesized analogues of the TP-2Bzim probe belonging to the vinyltriphenylamine (TPA) class and already described for its capacity to bind nuclear DNA in fixed cells and mitochondria in live cells. These analogues ( TP-1Bzim, TPⁿ-2Bzim, TP¹⁺-2Bzim, TN-2Bzim ) differ in the cationic charge, the number of vinylbenzimidazolium branches and the nature of the triaryl core. Using microscopy, we demonstrated that the cationic derivatives accumulate in mitochondria but do not reach mtDNA. Under depolarisation of the mitochondrial membrane, TP-2Bzim and TP¹⁺-2Bzim translocate to the nucleus in direct correlation with their strong DNA affinity. This reversible phenomenon emphasizes that these probes can be used to monitor ΔΨ_m variations.     

Chemical Ecology of the host searching behavior in an Egg Parasitoid: are Common Chemical Cues exploited to locate hosts in Taxonomically Distant Plant Species?

Parasitoids are known to exploit volatile cues emitted by plants after herbivore attack to locate their hosts. Feeding and oviposition of a polyphagous herbivore can induce the emission of odor blends that differ among distant plant species, and parasitoids have evolved an incredible ability to discriminate them and locate their hosts relying on olfactive cues. We evaluated the host searching behavior of the egg parasitoid Cosmocomoidea annulicornis (Ogloblin) (Hymenoptera: Mymaridae) in response to odors emitted by two taxonomically distant host plants, citrus and Johnson grass, after infestation by the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae), vector of Citrus Variegated Chlorosis. Olfactory response of female parasitoids toward plants with no herbivore damage and plants with feeding damage, oviposition damage, and parasitized eggs was tested in a Y-tube olfactometer. In addition, volatiles released by the two host plant species constitutively and under herbivore attack were characterized. Females of C. annulicornis were able to detect and significantly preferred plants with host eggs, irrespectively of plant species. However, wasps were unable to discriminate between plants with healthy eggs and those with eggs previously parasitized by conspecifics. Analysis of plant volatiles induced after sharpshooter attack showed only two common volatiles between the two plant species, indole and β-caryophyllene. Our results suggest that this parasitoid wasp uses common chemical cues released by many different plants after herbivory at long range and, once on the plant, other more specific chemical cues could trigger the final decision to oviposit.

     

Chemical microprocess technology—from laboratory-scale to production

Successful applications of the chemical microprocess technology in the field of screening and the synthesis of fine chemicals using also new preparation routes are presented. By means of these examples it is shown that the microprocess technology allows new screening methods for the preparation of compound libraries or the investigation of catalysts, breaks new ground for the preparation of fine chemicals and offer novel possibilities for the production of chemicals on an industrial-scale.     

Does Pheromone Biology of Lambdina athasaria and L. pellucidaria Contribute to Their Reproductive Isolation?

Recently, 7-methylheptadecane and 7,11-dimethylheptadecane have been reported as sex pheromone components of both spring hemlock looper (SHL), Lambdina athasaria, and pitch pine looper (PPL), Lambdina pellucidaria. Our objective was to test the hypothesis that SHL and PPL are reproductively isolated, in part, through species specificity in: (1) absolute configuration of pheromone components, (2) diel periodicity of pheromonal communication, and/or (3) seasonal flight period. In coupled gas chromatographic-electroantennographic detection (GC-EAD) analyses of stereoselectively synthesized (7S)- and (7R)-7-methylheptadecane [7S; 7R] as well as (7S,11S)-, (7R,11R)-, and (meso-7,11)-7,11-dimethylheptadecane [7S,11S; 7R,11R; meso-7,11], only 7S and meso-7,11 elicited responses by male SHL and PPL antennae. In field experiments, male SHL and PPL were attracted only to lures containing 7S plus meso-7,11. In hourly recordings of trap-captured males, SHL and PPL in their respective habitats were trapped between 24:00 and 03:00 hr. Capture of both SHL and PPL in pheromone-baited traps throughout June indicated overlapping seasonal flight periods. These findings of identical absolute configuration of pheromoal components, diel periodicity of pheromonal communication, and overlap of seasonal flight periods support synonymy of SHL and PPL. Finite taxonomic classification of PPL and SHL must await careful assessment of further criteria, such as morphometrics, molecular comparisons and ecological analyses.     

Chinese Journal of Chemical Engineering Author Index to 2005

A·A .Sabetskiy seeA启.Kholmogorov 91 A .G.Kholmogoro、· 一0 N.Kononova;G.L.Pashkov;L.V.Shashina;V.P. Plekhanov;A.A.Sabetskiy Reeovery of lead from sulfide eoneentrate after meehanoehemieal益、etivation using nitrie aeid 91 A .M.Meretskyis已全A.M.Meretskyi 102 BAI Peng see HUA Chao 144;QU Hongmei 548 BAO Fubing see LIU Yanhua 297 BAO Xiaojun see SUN Shulan 291 BAO Ying 一WANG Jingkang;WANG YOngli Simulation analysis of dilution erystallization of sPeetino- 1llyCin …     

Beyond Chemical Synthesis: Self-Organization?!

The present text presents briefly some general considerations on the steps from molecular synthesis to the development of chemistry beyond the molecule, towards mastering progressively the processes underlying the generation of complex matter by self-organization.     

Discussion on “Change-Points: From Sequential Detection to Biology and Back” by David Siegmund

Abstract

Motivated by Professor Siegmund's article and his other works in the area of change-point analysis and its biomedical applications, we discuss approaches to change-point–related problems that involve parameters of unknown dimension.     

Chinese Journal of Chemical Engineering Subject index to 2005

5一aminolevulinate synthase Expression of a new hemA gene from Agrobaeterfumra- d了obae七er in Esch.犷笼动fa eolf fors一aminolevulinate Produe- tion 13(4):522(2005) a/0 nitrogen rem~1 proeess Fuzzy eontrol of Iiitrate reeireulation and external earbon addition inA/o;、itrogen removal proeess 13(2):244(2005) absorPtion The analysis of gas absorption into a stationary droplet in atmospherie environment 13(6):837(2005) aeoustie eavitation Mass transfer dul·ing osmotie de坷dration using acoust…