Highly potent and selective NaV1.7 inhibitors for use as intravenous agents and chemical probes

The discovery and selection of a highly potent and selective Na_V1.7 inhibitor PF-06456384, designed specifically for intravenous infusion, is disclosed. Extensive in vitro pharmacology and ADME profiling followed by in vivo preclinical PK and efficacy model data are discussed. A proposed protein–ligand binding mode for this compound is also provided to rationalise the high levels of potency and selectivity over inhibition of related sodium channels. To further support the proposed binding mode, potent conjugates are described which illustrate the potential for development of chemical probes to enable further target evaluation.     

The contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect

Katsuodashi, a dried bonito broth, is very basic and indispensable in Japanese cuisine and contains taste-exhibiting components and unique aroma. We previously reported that its unique aroma contributes to the preference and reinforcement effect associated with dried bonito. This study aims to elucidate the contribution of aromatic components in Katsuobushi to preference formation and reinforcement effect. Volatile components obtained from dried bonito were fractionated and the fractions were subjected to two-bottle choice test. The fractionation test suggested that the component responsible for the preference is not one but comprises multiple components. In the GC–MS analysis/reconstruction test, solution with aromatic flavor narrowed down to 125 compounds had preference, and also had reinforcement effect. Moreover, GC–MS–olfactometry analysis narrowed down the candidate components to 28 out of 125. Mice showed preference for the test solution with aromatic flavor reconstructed with 28 components but did not show reinforcement behavior.     

First principles study of the electronic structure and optical properties of chrysene under pressure

Structural parameters, electronic and optical properties of chrysene have been investigated using the plane-wave ultrasoft pseudopotential technique based on the first principles density functional theory. The pressure dependence of the electronic band structure, density of states and partial density of states of chrysene were presented. Meanwhile, the complex dielectric function, refractive index, absorption coefficient, reflectivity, and the extinction coefficient are calculated and analysed. According to our work, we found that the optical properties of chrysene undergo a red shift with increasing pressure.     

Deconvolution of the circular dichroism spectra of proteins: the circular dichroism spectra of the antiparallel beta-sheet in proteins.

A recently developed algorithm, called Convex Constraint Analysis (CCA), was successfully applied to determine the circular dichroism (CD) spectra of the pure beta-pleated sheet in globular proteins. On the basis of X-ray diffraction determined secondary structures, the original data set used (Perczel, A., Hollosi, M., Tusnady, G. Fasman, G.D. Convex constraint analysis: A natural deconvolution of circular dichroism curves of proteins, Prot. Eng., 4:669-679, 1991), was improved by the addition of proteins with high beta-pleated sheet content. The analysis yielded CD curves of the pure components of the main secondary structural elements (alpha-helix, antiparallel beta-pleated sheet, beta-turns, and unordered conformation), as well as a curve attributed to the "aromatic contribution" in the wavelength range of 195-240 nm. Upon deconvolution the curves obtained were assigned to various secondary structures. The calculated weights (percentages determining the contributions of each pure component curve in the measured CD spectra of a given protein) were correlated with the X-ray diffraction determined percentages in an assignment procedure and were evaluated. The Pearson product correlation coefficients (R) are significant for all five components. The new pure component curves, which were obtained through deconvolution of the protein CD spectra alone, are promising candidates for determining the percentages of the secondary structural components in globular proteins without the necessity of adopting an X-ray database. The CD spectrum of the CheY protein was interesting because it has the characteristic shape associated with the alpha-helical structure, but upon analysis yielded a considerable amount of beta-sheet in agreement with the X-ray structure.     

Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Shenfu Irrigation Area in China and their Application for Determining the Optimum Land Use Model

In order to use contaminated soil safely, risk and use planning of contaminated soils by 16 priority polycyclic aromatic hydrocarbons (PAHs) of the United States Environmental Protection Agency (USEPA) in Shenfu Irrigation Area (SIA) were investigated. The toxic equivalency factor (TEF) approach and the risk quotient (RQ) approach were used to assess the carcinogenic risk and ecological risk of PAHs in the current agricultural use, respectively, and the ecological risk of PAHs in SIA under residential, commercial, and industrial land uses which could be used in the future were also evaluated. The results were as follows: 95.9% of soils in SIA were heavily contaminated by PAHs; Benzo[a]pyrene (BaP), Benzo[a]anthrancene (BaA), Benzo[b]fluoranthene (BbF), Benzo[k]fluoranthen (BkF), Benzo[g,h,i]perylene, Chrysene, Dibenz[a,h]anthracene (Dba), and Indeno[1,2,3-c,d]pyrene (Ipy) were the dominated carcinogenic PAHs, and there were no carcinogenic concerns for 81.6% of SIA; Anthracene, BaP, Fluoranthene, Naphthalene, Phenanthrene, BaA, BbF, BkF, Dba, Ipyr and Pyrene were considered the major ecological risk drivers, and there were medium to high ecological risks in 56.3% of SIA under agricultural use. However, the ecological risk can be reduced markedly by changing the land use mode; under residential/parkland land use 65.1% of SIA faced low risk and the rest faced negligible risk, while all areas faced negligible risk under industrial/commercial usage. Based on the risk assessment results, an optimum land use model (both human health-based and eco-based in the SIA) was achieved and will be helpful for the local government to plan how to use the land under low risk in the SIA.     

三烷基取代芳香聚酮gombapyrones生物合成基因簇的确认及其生物合成推导

【目的】本研究旨在确认链霉菌Streptomyces rubellomurinus ATCC 31215来源芳香聚酮化合物(gombapyrones, GOMs)的生物合成基因簇(biosynthetic gene cluster, BGC),并对其生物合成途径进行推导。【方法】对链霉菌S. rubellomurinus ATCC 31215进行大规模发酵及提取分离,得到GOM-B和GOM-D;以三烷基取代芳香聚酮生物合成途径保守存在的P450单氧化酶的蛋白序列作为探针,在GOMs产生菌S. rubellomurinus基因组中进行BLAST搜索获得潜在的GOMs生物合成基因簇(gom BGC);通过对gom BGC中的聚酮合成酶(polyketide synthase, PKS)结构基因进行同框缺失突变,对突变株发酵产物进行高效液相色谱-质谱(highperformanceliquidchromatography-massspectrometry,HPLC-MS)分析以确认gomBGC与GOMs的产生相关;基于生物信息学分析,推导GOM-B的生物合成途径。【结果】从S. rubell...