New alkaloid isolated from Fritillaria pallidiflora

目的 确证从伊贝母中分离得到一种新的生物碱的结构。方法 IR,MS及 NMR。结果 其结构被鉴定为N- ( 1′,4′-二羟基 - 1′,2′,3′,4′-四氢化萘基 ) -丙基 - N-二苯基甲基 - N- 3 ,3 -二甲基丁胺。结论 这种生物碱为首次从植物中分离得到 ,它在骨架结构上与已知的贝母生物碱截然不同。

Hepatocyte transformation and tumor development induced by hepatitis C virus NS3 c-terminal deleted protein

AIM: To study the effect of hepatitis C virus nonstructural protein 3 c-terminal deleted protein (HCV NS3-5') on hepatocyte transformation and tumor development.METHODS: QSG7701 cells were transfected with plasmid pRcHCNS3-5' (expressing HCV NS3 c-terminal deleted protein) by lipofectamine and selected in G418. The expression of HCV NS3 gene and protein was determined by PCR and immunohistochemistry respectively. Biological behavior of transfected cells was observed through cell proliferation assay, anchorage-independent growth and tumor development in nude mice. The expression of HCV NS3 and c-mycproteins in the induced tumor was evaluated by immunohistochemistry.RESULTS: HCV NS3 was strongly expressed in QSG7701 cells transfected with plasmid pRcHCNS3-5' and the positive signal was located in cytoplasm. Cell proliferation assay showed that the population doubling time in pRcHCNS3-5' transfected cells was much shorter than that in pRcCMV and nontransfected cells (24 h, 26 h, 28 h respectively). The cloning ratio of cells transfected with pRcHCNS3-5; pRcCMV and nontransfected cells was 33 %, 1.46 %, 1.11%, respectively,the former one was higher than that in the rest two groups (P＜0.01). Tumor development was seen in nude mice inoculated with pRcHCNS3-5' transfected cells after 15 days.HE staining showed its feature of hepatocarcinoma, and immunohistochemistry confirmed the expressions of HCV NS3and c-mycproteins in tumor tissue. The positive control group inoculated with HepG2 also showed tumor development, while no tumor developed in the nude mice injected with pRcCMV and non-transfected cells after 40 days.CONCLUSION: 1.HCV NS3 c-terminal deleted protein has transforming and oncogenic potential. 2. Human liver cell line QSG7701 may be used as a good model to study HCV NS3 pathogenesis.

Existence of Heme Oxygenase-carbon Monoxide-cyclic Guanosine Monophosphate Pathway in Human Trabecular Meshwork Cells In Vitro

To confirm the existence of heme oxygenase (HO)-carbon monoxide (CO)- cyclic guanosine monophosphate (cGMP) pathway in the cultured human trabecular meshwork cells (HTMCs) in vitro, and to evaluate the inductive role of hemin on this pathway, HTMCs of the third to fourth generation were cultured in vitro. Reverse transcripase-polymerase chain reaction (RT-PCR) was employed for detection of HO-1 and HO-2 mRNA. Immunohistochemical staining was used to detect HO-1 and HO-2 proteins. Hemin was added into the culture solution. The HO-1 mRNA levels were quantified by RT-PCR. The relative amount of carbon monoxide released into the media was measured with the quantifying carbon monoxide hemoglobin (HbCO) by spectrophotometry. Radioimmunoassay was used to determine changes of cGMP in HTMCs. The results showed that cultured cells had the specific characteristics of HTMCs. Both HO-1 and HO-2 genes were expressed in HTMCs, as well as HO-1 and HO-2 proteins in HTMCs. Hemin induced HO-1 mRNA, HbCO and cGMP in a dose-dependent manner. In conclusion, HO-CO-cGMP pathway exists in the cultured HTMCs and can be induced by hemin. Pharmacological stimulation of HO-CO-cGMP pathway may constitute a novel therapeutic approach to rescuing glaucoma.

Sequence variability of the 5, UTR in isolates of hepatitis C virus in China

Background: Hepatitis C virus infection is a great is- sue in China; however, there is very little informa- tion on genotyping investigations based on sequence variability in the 5' untranslated (5'UTR) reported. The present study was to define the sequence varia- bility based on the sequence divergences of the 5' UTR of the virus. Methods: Sequences of 91 isolates from patients with chronic hepatitis C from Yunnan, southwest China, were sequenced and genotypes were defined accord- ing to the sequence divergences of the 5' UTR of the virus. Results: Eighty-six isolates were classified into 3 clades (previously termed groups or major types) by the methods proposed by Chan et al in 1992 and phy- logenetic analysis based on nucleotide sequence diver- gences within the 5' UTR. Fifty-six percent of the i- solates were classified into clade 3, 35% into clade 1, and 34.9% into clade 2. New genotypes 1f, 2h, 3h and 3i were defined. In addition, 3 novel sequences were discovered, respectively with an 18-nt sequence deletion (corresponding to nucleotide position -173 to -156), a 28-nt sequence insertion, and a 40-nt se- quence insertion, between -56 and -55. Of these i- solates, 56% possessed a 'G' at position -66 in place of the 'T' that is present in all previously re- ported sequences. Conclusions: These HCV variants, evolved or re- mained in this area, may be of great significance in diagnosis and treatment of hepatitis C patients.

Infinite Three-Dimensional Coordination Polymers: Synthesis and Structures of [Cd (4,4'-bpy)_2 (H_2O)_2]_n (pic)_(2n),[Zn (4,4'-bpy)_2 (H_2O)_2]_n(pic)_(2n) (H_2O)_(2n), and [Zn (4,4'-bpy)_2 (H_2O)_2]_n (4,4'-bpy)_n(H_2O)_n (pic)_(2n)

Three Complexes of the formula [Cd (4,4'-bpy)_2 (H_2O)_2]_n. (pic)_(2n) (1) [Zn (4,4'-bpy)_2 (H_2O)]_n (4,4'-bpy)_n(H_2O)_n (pic)-(2n) (2) and [Zn (4,4'-bpy)_2 (H_2O)]_n (4,4'-bpy)_n (pic)-(2n)(H_2O)_n (3) (4.4'-bpy = 4.4'-bipyridine. pic = picric anion ) have been synthesized and characterized by elemental analysis and single-crystal x-ray diffraction. They all have infinite three-dimensional network structure. crystallizing in the monoclinic space group C2/c (1) and Cc (2.3).

4＇, 6-Dihydroxy-4-methoxyisoaurone inhibits TNF-α-induced NF-KB activation and expressions of NF-KB-regulated target gene products

The nuclear factor-KB （NF-KB） transcription factors control many physiological processes including in- flammation, immunity, apoptosis, and angiogenesis. In our search for NF-KB inhibitors from natural resources, we identified 4＇,6-dihydroxy-4-methoxyisoaurone （ISOA） as an inhibitor of NF-KB activation from the seeds of Tricho- santhes kirilowii. However, the mechanism by which ISOA inhibits NF-KB activation is not fully understood. In the present study, we demonstrated the effect of ISOA on NF-KB activation in TNF-α-stimulated HeLa cells. This com- pound suppressed NF-KB activation through the inhibition of IKB kinase （IKK） activation. ISOA also has an influ- ence on upstream signaling of IKK through the inhibition of expression of adaptor proteins, TNF receptor-associated factor 2 （TRAF2） and receptor interacting protein 1 （RIP1）. Consequently, ISOA blocked the phosphorylation and degradation of the inhibitor of NF-KB alpha （IKBα） , and subsequent phosphorylation and nuclear translocation of p65. The suppression of NF-KB activation by ISOA led to the down-regulation of target genes involved in inflam- mation, proliferation, angiogenesis and invasion, as well as potentiation of TNF-α-induced apoptosis at least in part through activation of caspase-8. Taken together, this study extends our understanding on the mechanisms underly- ing the anti-inflammatory and anti-cancer activities of ISOA. Our findings provide new insight into the molecular mechanisms and a potential application of ISOA for inflammatory diseases as well as certain cancers associated with abnormal NF-KB activation.

Adenosine 5'triphosphate transport and accumulation during the cold preservation of rat hepatocytes in University of Wisconsin solution

AIM: We used isolated hepatocytes to investigate how different concentrations of ATP in the University of Wisconsin (UW) solution affected both cellular ATP content and cell viability during the cold storage and the rewarming step. The mechanism involved in ATP transport and accumulation in hypothermia was also determined.METHODS: The cells were preserved up to 72 h in different conditions: UW solution without ATP (a-group),UW+5 mmol/L ATP (b-group), and UW+10 mmol/L ATP (c-group). The ATP content and the cell viability (LDH release) were determined during the cold storage and the rewarming step. In the groups a and c, the respiratory function of the cells at rewarming was studied. In addition,the cell volume of hepatocytes and the mechanism involved in ATP transport and accumulation were assessed. The extracellular degradation of exogenous nucleotides during transport experiments was investigated by a HPLC technique.RESULTS: After three days of cold storage a loss of cellular ATP content was observed in hepatocytes preserved either without nucleotides (a-group) or with 5 mmol/L ATP (b-group). In contrast, 10 mmol/L ATP (c-group) was able to maintain a normal ATP cellular content, with only a 6% diminution after 72 h of cold storage. The respiratory function was significantly different in hepatocytes preserved with 10 mmol/L ATP than without ATP. No significant change was detected for the three groups in cellular volume during the cold storage. We also report that the time course accumulation of [3H]-ATP by cold stored hepatocytes is a rapid process that is completed after 180 s with linear dependence on the extracellular ATP concentration (linear fitting results in a slope of 0.5624±0.1179 mmol/L ATP intracell/mmol/L ATP extracell).CONCLUSION: Our results show that, during hypothermic storage in UW solution, hepatocytes are permeable to ATP by a diffusive mechanism. Also, we found that it is ATP the main extracellular nucleotide available for transport and it is not the breakdown products.

Acute Toxicity Effects of 2,2',4,4',5,5'-Hexabromodiphenyl Ether on Chlorella vulgaris

[Objectives] This study was conducted to investigate the toxic effects of 2,2',4,4',5,5'-hexabromobiphenyl ether on Chlorella vulgaris and provide basic data for protecting aquatic ecosystems. [Methods] The acute toxicity effects of 2,2',4,4',5,5'-hexabromodiphenyl ether on C. vulgaris was investigated by the semi-static water contacting acute toxicity method. [Results] The 48,72 and 96 h-EC(50) of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris were23. 58,18. 71 and 14. 75 μg/L,respectively,and the safe concentration of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris was 1. 475μg/L. For the water solubility of 2,2',4,4',5,5'-hexabromodiphenyl ether is extremely low( 1 μg/L),it could not cause the acute poisoning death of C. vulgaris. According to the grading standards for the assessment of the toxicity on algae,2,2',4,4',5,5'-hexabromodiphenyl ether was extremely highly toxic to C. vulgaris. [Conclusions]The extremely high toxicity of 2,2',4,4',5,5'-hexabromodiphenyl ether to C. vulgaris shows that it has heavy potential harm to aquatic ecosystems and the maximum residue limit standards of 2,2',4,4',5,5'-hexabromodiphenyl ether in water should be formulated to better protect aquatic ecosystems.

Search for New AntiphytovirucidesⅣ.Synthesis of 2-(2'-Hydroxyphenyl)-5(6)-substituted benzimidazole Derivatives

A convenient method to synthesize substituted 2 (2' hydroxyphenyl) benzimidazoles is reported. Six title compounds have been synthesized by the reaction of salicylic acid and 4 substituted o phenylenediamine in the presence pyridine POCl 3 . Three compounds were tested as plant virucide against tobacco mosaic virus and they exhibited some activities.

Synthesis of a dithieno[3,2-b∶2',3'-d]silole-based conjugated polymer and characterization of its short wave near-infrared fluorescence properties

Short wave near-infrared(SWIR,900-1700 nm)fluorescence imaging has attracted extensive research interest from scientists due to its high imaging quality.However,the variety of SWIR fluorescence imaging agents are quite limited and the corresponding quantum efficiency is rela-tively low.In this work,a novel conjugated polymer PDTSDTBT was reported,consisting of a donor unit with a tetrahedral Si(sp3)named DTS and an acceptor unit named DTBT with branched side chains.The design approach of endowing the donor-acceptor structure with the branched side chains successfully increase the fluorescence quantum efficiency.The polymer was prepared into nanoparticles by nanoprecipitation.The PDTSDTBT nanoparticles showed an absorption peak of 626 nm and fluorescence emission peak of 924 nm.The quantum efficiency of the nanoparticles is 0.53%,which is higher than that of nanotube fluorophores(0.4%).The nanoparticles also demonstrate a photothermal effect,the temperature of nanoparticles solution could reach 45℃under excitation by 660 nm laser.Therefore,the PDTSDTBT nanoparticles is an excellent fluorescent imaging agent with potential photothermal applications.

The 5'-flanking cis-acting elements of the human ε-globin gene associates with the nuclear matrix and binds to the nuclear matrix proteins

The nucleax mains attachment regions(MARs) and the binding nuclear matrix proteins in the 5’-flalildng cisacting elements of the humanε-globin gene have been examined. Using in vitro DNA-matrix binding assay,it has been shown that the positive stage-specific regulatory element (ε-PREII, -446bp-419bp) upstream of this gene could specifically associate with the nuclear matrix from K562 cells, indicating thatε-PREII mad be an erythroidspecilic facultstive MAR. In gel mobility shift assay and Southwestern blotting assal an eothroid-specific nuclear matrix protein (ε-NMPk) in K562 cells has been revealed to bind to this positive regulatory element (E-PREII). Furthermore, we demonstrated that the silencer (-392hp -177bp) uP8tream of the humanε-globin gene could associate with the nuclear matrices from K562, HEL and Raji cells. In addition, the nucleax matrix proteins prepared from these three cell lines could also bind to this silencer, suggesting that this silencer element linght be a constitutive nuclear mains attachment region (constitutive MAR). Our results demonstrated that the nucleax madrid and nuclear mains proteins lxilght play an important role in the regulation of the human 5-globin gene expression.

Research undertaken by CAS scientists with support of "973 Program"

The National Basic Research Program (dubbed as the " 9 73 Program" is China's on-going national keystone basic research program, which was approved by the Chinese government in June 1997 and is organized and implemented by the Ministry of Science and Technology. The strategic objectives of the Program are to strengthen the original innovations and to address the important scientific issues concerning the national economic and social development at a deeper level and in a wider scope, so as to improve China's capabilities of independent innovations and to provide scientific support for the future development of the country. The followings are some of the" 9 73 projects" initiated in 2006 under the coordination of CAS scientists.

SYNTHESIS OF POLYSTYRENE-BLOCK-POLYCAPROLACTAM WITH 1,1-BIS-(1′-NAPHTHYL) ETHYLENE AS A DEACTIVATING AGENT

The insertion of 1,1-bis (1′-naphthyl) ethylene monomer unit into the active polystyrene chain end greatly decreased the reactivity of the active chain end to the carbonyl group, and allowed the polymeric chain end to react only with the double bond in N-methacryloyl caprolactam, resulting in N-acylcaprolactam functionalized polystyrene in 100% conversion. New diblock copolymer of polystyrene with polycaprolactam was synthesized by direct reaction of the functionalized polymer with caprolactam without adding additional alkali metal or their caprolactam salts.

X-ray Structure of 1- (3' -Phenyl-4' -morpholinyl-2' 5' - dithiole-1' - ylidene)-3, 4-biscarboethoxy-2-thionaphthalene

The title compound (C28H27NO5S3, Mr= 553. 69) was prepared bythe reaction of a-thiobenzoylthioformmorholine with diethyl acetylene dicarboxylate.The crystal is monoclinic, space group P21/n with a= 9. 160(3), b= 17. 726(3), c=16. 602(3) A ; β= 100. 375(13)°; V=2651. 4(10) A3, Z=4, Dc= 1. 387 g/cm3, μ(MoKa) =0. 319 mm-1, F(000) =1160, R=0. 0428, wR(F2) =0. 0910 for 2438 observed reflections (I>2(I)). X-ray analysis reveals that interatomic distances for C(5)-C(6), C(13)-C(14) and C(21)-C(22) are 1. 331(4), 1. 351(4), 1. 344(4)A respectively, which show that they are normal C=C double bonds. All S-C bondlengths are similar to typical S-C single bonds (1. 75 - 1. 78 A ). The five-membered ring A (C(5) -C(6) -S(2)-C(13) -S(1) ) (Fig. 1) and six-membered ringB (C(14) -C(15) -C(20) -C(21)-C(22)-S(3) ) (Fig. 1) adopt the flat twist conformation. Furthermore, the morpholine ring adopts chair conformtion.

激光焊接及焊后热处理K439B合金的显微组织与力学性能

对应用于发动机涡轮上的新型镍基合金K439B进行激光焊接实验,研究焊后热处理对接头显微组织和力学性能的影响。半定量分析结果表明,热处理后接头各区域γ′相均发生长大,一次γ′相和二次γ′相半径分别约为25和150 nm。力学性能测试结果表明,焊后热处理可使焊缝区硬度提高约HV 100,由γ′相提供的临界恢复剪应力从4.8 MPa提高到92 MPa;另一方面,热处理后接头的抗拉强度和屈服强度与母材的相当,大量碳化物的存在导致接头在拉伸过程中优先断裂于母材处。

2'⁃岩藻糖基乳糖功能及其微生物生产菌种构建研究进展

2'⁃岩藻糖基乳糖(2'⁃fucosyllactose,2'⁃FL)在人乳寡糖中含量最高,占比可达30%。2'⁃FL能够有效促进婴儿大脑发育、提高婴儿免疫力,对青少年、成年人、老年人也大有裨益,已被广泛应用于婴幼儿配方奶粉、功能性食品饮料及医疗辅剂中。微生物合成2'⁃FL具有易实现大规模生产、可使用廉价原料作为底物等优势。目前2'⁃FL最主要的工业生产菌种为大肠杆菌,其他食品安全级菌株如酿酒酵母、枯草芽孢杆菌等也陆续被改造用来生产2'⁃FL,并已取得一定成效。该文对2'⁃FL作用于人体的机制、应用领域及2'⁃FL合成菌种构建现状等进行综述,并对未来发展趋势进行展望。

正交设计对‘红阳’猕猴桃ISSR反应体系的优化研究

以‘红阳’猕猴桃及其杂交F1代为试材,通过正交设计对ISSR-PCR扩增反应的影响因子进行优化,初步确立了适合‘红阳’猕猴桃ISSR-PCR反应体系：总体积20μL,10×PCR buffer2.0μL,Mg2＋0.75 mmol/L,Taq酶1.5 U,模板DNA 60 ng,引物1.25μmol/L,dNTPs 0.15mmol/L。扩增程序：94℃预变性7 min,94℃变性30 s,50-58℃退火45 s,72℃延伸2 min,45个循环,72℃延伸7 min。引物UBC841的最佳退火温度为58.5℃。应用该优化反应体系,用UBC835对35份杂交F1代DNA进行ISSR-PCR扩增,结果显示优化后的反应体系具有较高的稳定性。

肌肉因子Irisin与运动

Irisin是新近在骨骼肌中发现的肌肉因子,可促进白色脂肪细胞'棕色化',增加能量消耗、降低体重。运动通过影响Irisin、UCP1的表达来调控脂代谢进而改善肥胖、糖尿病等代谢性疾病,但不同运动方式和运动强度对Irisin表达的影响规律并不相同。将深入探讨运动调控Irisin表达变化的作用机制,旨为防治肥胖等代谢性疾病提供新视角。