Design,synthesis, quantum chemical studies and biological activity evaluation of pyrazole–benzimidazole derivatives as potent Aurora A/B kinase inhibitors

Novel pyrazole–benzimidazole derivatives have been designed and synthesized. The entire target compounds were determined against cancer cell lines U937, K562, A549, LoVo and HT29 and were screened for Aurora A/B kinase inhibitory activity in vitro. The compounds 7a, 7b, 7i, 7k and 7l demonstrated significant cancer cell lines and Aurora A/B kinase inhibitory activities. Molecular modeling studies suggested the derivatives have bound in the active site of Aurora A kinase through the formation of four hydrogen bonds. Quantum chemical studies were carried out on these compounds to understand the structural features essential for activity. The cellular activity of 7k was also tested by immunofluorescence.     

Synthesis and acrosin inhibitory activities of 5-phenyl-1H-pyrazole-3-carboxylic acid amide derivatives

A series of novel 5-phenyl-1H-pyrazole-3-carboxylic acid amide derivatives were designed, synthesized, and their acrosin inhibitory activities in vitro were evaluated. The results of the acrosin inhibitory activity showed that all target compounds were more potent than control TLCK. Compounds AQ-A1, AQ-D3, AQ-D4, AQ-E4 and AQ-E5 exhibited stronger acrosin inhibitory activities than control ISO-1. Especially, compound AQ-E5 displayed the most potent acrosin inhibitory activity in all the compounds, with an IC₅₀ of 0.01 μmol/mL. This study provided a new structural class for the development of novel acrosin inhibitory agents.     

Bicyclic and tricyclic heterocycle derivatives as histamine H3 receptor antagonists for the treatment of obesity

A novel series of non-imidazole bicyclic and tricyclic histamine H₃ receptor antagonists has been discovered. Compound 17 was identified as a centrally penetrant molecule with high receptor occupancy which demonstrates robust oral activity in rodent models of obesity. In addition compound 17 possesses clean CYP and hERG profiles and shows no behavioral changes in the Irwin test.     

Discovery of a small molecular compound simultaneously targeting RXR and HADC: Design,synthesis, molecular docking and bioassay

Retinoid X receptor (RXR) and Histone deacetylase (HDAC) are considered important targets for anti-cancer therapy due to their crucial roles in genetic or epigenetic regulations of cancer development and progression. Here, we have designed and synthesized a novel compound which targets both RXR and HADC. This dual-targeting agent is derived from bexarotene and suberoylanilide hydroxamic acid (SAHA), prototypical RXR agonist and HDAC inhibitor, respectively. Molecular docking studies demonstrate that this agent has a relatively strong affinity to RXR and HADC. Importantly, it presents the potentials of activation of RXR and inhibition of HDAC in both cell-free and whole-cell assays, and displays anti-proliferative effect on representative cancer cell lines and drug-resistant cancer cell lines.     

Genetic diversity of Bartonella quintana in macaques suggests zoonotic origin of trench fever

Bartonella quintana is a bacterium that causes a broad spectrum of diseases in humans including trench fever. Humans were previously considered to be the primary, if not the only, reservoir hosts for B. quintana. To identify the animal reservoir and extend our understanding of the ecological and evolutionary history of B. quintana, we examined blood samples from macaques and performed multilocus sequence typing (MLST) analysis. We demonstrated the prevalence of B. quintana infection was common in macaques from main primate centres in mainland China. Overall, 18.0% (59/328) of rhesus macaques and 12.7% (39/308) of cynomolgus macaques were found to be infected with B. quintana by blood culture and/or polymerase chain reaction. The infection was more frequently identified in juvenile and young monkeys compared with adult animals. In contrast with the relatively low level of sequence divergence of B. quintana reported in humans, our investigation revealed much higher genetic diversity in nonhuman primates. We identified 44 new nucleotide variable sites and 14 novel sequence types (STs) among the B. quintana isolates by MLST analysis. Some STs were found only in cynomolgus macaques, while some others were detected only in rhesus macaques, suggesting evidence of host‐cospeciation, which were further confirmed by phylogenetic analysis and Splits decomposition analysis. Our findings suggest that trench fever may primarily be a zoonotic disease with macaques as the natural hosts.     

Conformational stability of CopC and roles of residues Tyr79 and Trp83

CopC is a periplasmic copper Chaperone protein that has a β‐barrel fold and two metal‐binding sites distinct for Cu(II) and Cu(I). In the article, four mutants (Y79F, Y79W, Y79WW83L, Y79WW83F) were obtained by site‐directed mutagenesis. The far‐UV CD spectra of the proteins were similar, suggesting that mutations did not bring any significant changes in secondary structures. Meanwhile the effects of mutations on the protein's function were manifested by Cu(II) binding. Fluorescence lifetime measurement and quenching of tryptophan fluorescence by acrylamide and KI showed that the microenvironment around Trp83 was more hydrophobic than that around Tyr79 in apoCopC. Unfolding experiments induced by guanidinium chloride (GdnHCl), urea provided the conformational stability of each protein. The Δ<ΔG⁰_element> obtained using the model of structural elements was used to show the role of Tyr79 and Trp83. On the one hand, the <ΔG⁰_element> induced by urea for Y79F, Y79W have a loss of 6.51, 2.03 kJ/mol, respectively, compared with apoCopC, proving that replacement of Tyr79 by Phe or Trp all decreased the protein stability, meaning that the hydrogen bonds interactions between Tyr79 and Thr75 played an important role in stabilizing apoCopC. On the other hand, the <ΔG⁰_element> induced by urea for Y79WW83L have a loss of 11.44 kJ/mol, but for Y79WW83F did a raise of 1.82 kJ/mol compared with Y79W. The replacement of Trp83 by Phe and Leu yields opposite effects on protein stability, which suggested that the aromatic ring of Trp83 was important in maintaining the hydrophobic core of apoCopC.     

Establishment and characterization of fetal fibroblast cell lines for generating human lysozyme transgenic goats by somatic cell nuclear transfer

This study was performed to qualify goat fetal fibroblast (GFF) cell lines for genetic modification and somatic cell nuclear transfer (SCNT) to produce human lysozyme (hLYZ) transgenic goats. Nine GFF cell lines were established from different fetuses, and the proliferative lifespan and chromosomal stability were analyzed. The results suggested that cell lines with a longer lifespan had stable chromosomes compared with those of cells lines with a shorter lifespan. According to the proliferative lifespan, we divided GFF cell lines into two groups: cell lines with a long lifespan (GFF1/2/7/8/9; group L) and cell lines with a short lifespan (GFF3/4/5/6; group S). Next, a hLYZ expression vector was introduced into these cell lines by electroporation. The efficiencies of colony formation, expansion in culture, and the quality of transgenic clonal cell lines were significant higher in group L than those in group S. The mean fusion rate and blastocyst rate in group L were higher than those in group S (80.3 ± 1.7 vs. 65.1 ± 4.2 % and 19.5 ± 0.6 vs. 15.1 ± 1.1 %, respectively, P < 0.05). After transferring cloned embryos into the oviducts of recipient goats, three live kids were born. PCR and Southern blot analyses confirmed integration of the transgene in cloned goats. In conclusion, the lifespan of GFF cell lines has a major effect on the efficiency to produce transgenic cloned goats. Therefore, the proliferative lifespan of primary cells may be used as a criterion to characterize the quality of cell lines for genetic modification and SCNT.     

琥珀酸脱氢酶或琥珀酰辅酶A合成酶缺失促进大肠杆菌积累5-氨基乙酰丙酸

5-氨基乙酰丙酸 (ALA) 是生物体内四吡咯类化合物的合成前体,在农业及医药领域应用广泛,是极具开发价值的高附加值生物基化学品。目前利用外源C4途径的重组大肠杆菌发酵生产ALA的研究主要利用LB培养基并添加葡萄糖和琥珀酸、甘氨酸等合成前体,成本较高。琥珀酸在C4途径中以琥珀酰辅酶A的形式直接参与ALA的合成。文中在以葡萄糖为主要碳源的无机盐培养基中研究了琥珀酰辅酶A下游代谢途径琥珀酸脱氢酶编码基因sdhAB和琥珀酰辅酶A合成酶编码基因sucCD缺失对ALA积累的影响。与仅表达异源ALA合成酶的对照菌株相比,sdhAB和sucCD缺失菌株ALA的产量分别提高了25.59%和12.40%,且ALA的积累不依赖于琥珀酸的添加和LB培养基的使用,从而大幅降低了生产成本,显示出良好的工业应用前景。     

淹水-控温模式下砷污染水稻土溶液中砷形态的变化

以水稻种植区的砷污染土壤为研究对象,采用高效液相色谱(HPLC)-电感耦合等离子体质谱(ICP-MS)联用分析测试系统,研究了不同培养温度(5、27和50 ℃)对灭菌和不灭菌的土壤淹水后其溶液中砷赋存形态变化的影响.结果表明： 在土壤溶液中检测到的砷形态只有无机三价砷(As^Ⅲ)、无机五价砷(As^V)和有机的二甲基砷(DMA^V),未检测到单甲基砷(MMA^V)的存在;在不同控温条件下随淹水时间的延长,As^Ⅲ逐渐转变为砷的主要赋存形态,平均比例约为64%;As^V次之,约占35%,DMA^V的含量相对最低,约占1%;土壤灭菌与否对土壤溶液中五价砷的水平没有明显影响,但明显影响了五价砷的还原和促进了无机三价砷的甲基化,并且灭菌的促进效果随着淹水及培养时间的延长而逐渐降低;50 ℃、淹水23 d时,灭菌土壤溶液中DMA^V浓度最高,为23.7 ng·mL^-1,这说明灭菌土壤中残留的某些嗜热微生物成为优势菌群并促进了土壤溶液中砷的甲基化.结合水稻生长的实际环境条件对该研究结果进行分析,培养温度27 ℃淹水23 d后不灭菌的自然土壤溶液中砷浓度处于较低水平,因此在砷污染的水稻种植区建议采用短周期干湿交替的水分管理模式,在保障产量的情况下可尽量降低土壤溶液中砷的水平.     

正痘病毒基因结构及功能研究的几项进展

正痘病毒载体在重组疫苗研究中有广泛前景,但其罕见但较为严重的副反应阻碍了发展。正痘病毒属中具有较宽宿主范围的痘苗病毒和牛痘病毒具有典型的宿主范围基因K1L、CP77和C7L。这三个基因对不同宿主细胞具有选择性,可以扰乱宿主细胞信号通路,并且与病毒的毒力相关。