链霉菌S227抗耐药菌活性成分的研究

本论文以从四川峨嵋山森林土壤中分离筛选获得的一株产抗耐药性活性化合物的链霉菌S227为材料，对发酵液中活性物质的分离纯化及抗耐药性活性进行了研究。 建立了抗耐药性活性的定性、定量检测方法。建立的管蝶法活性定量检测的标准回归方程为：D=4.8229Ln(C)+3.6326 R=0.9972 ；纸片法活性定量检测的标准回归方程为：D=5.5Ln(C)-12.794 R=0.999。 根据建立的样品活性的检测方法，测定了发酵液的初始活性。实验证明活性物质的温度、pH稳定性好。 通过活性的定性、定量追踪方法，分别利用等体积的石油醚、乙酸乙酯、正丁醇在不同的pH梯度下萃取，确定了pH3条件下正丁醇能最大程度的萃取活性物质，说明活性物质极性很大。对正丁醇萃取相经过两次硅胶柱层析及薄层层析分离得到具有抗耐药菌活性的纯化样品S227-4。 经过核磁共振氢谱、碳谱数据分析初步确定S227-4为四聚糖，通过糖的水解实验初步确定S227-4由葡萄糖和半乳糖组成。 纸片法活性检测表明S227-4具有抗耐药菌活性。采用MIC测定法对该样品抗耐药活性进行研究。在证明该样品本身不具有抗菌活性的基础上，以临床分离的耐药性金黄色葡萄球菌为指示菌，考察了该样品与抗生素联合使用时对耐药菌抗生素MIC（最小抑菌浓度）值的影响，结果表明在不影响菌体生长的浓度条件下，该样品能明显降低多株耐药菌对多种抗生素的MIC值，不同程度地恢复所测试耐药菌对相应抗生素的敏感性。如S227-4与青霉素钠联用可以使S. aureus 12352的MIC降低8倍，而与红霉素联用可以使S. aureus 12334的MIC降低128倍。 The purification process and the activity of the anti bacterial drug resistance compounds produced by Streptomyces S227 isolated from the forest soil sample of the Mountain E’MEI in Sichuan Province were studied in this thesis. Quantitative and qualitative activity assay methods of the active compounds were established. The regression equation of the tube method was D=4.8229Ln(C)+3.6326, R=0.9972. The regression equation of the paper method was D=5.5Ln(C)-12.794, R=0.999. According to the established activity assay method, the incipient activity of the broth was evaluated. And it was proved that the stability of the active compounds was good. By quantitative and qualitative activity tracing method, petroleum ether, ethyl acetate and butanol were used to extract the active compounds at different pH. The result showed that butanol was the most effective agent for active component recovery at pH3. From the butanol extraction a purified sample, S227-4, was isolated by silica gel column chromatography and thin-layer chromatography . S227-4 was proved to be a tetra- saccharide by 1H-NMR and 13C-NMR. And its monosaccharides include glucose and galactose by hydrolysate analysis. The anti-drug resistant activity of S227-4 was tested in vitro by MICs assay using different drug resistant Staphylococcus aureus strains isolated clinically. The sample itself showed no anti-microbial activity in growth inhibitory experiment, but when it was used together with different antibiotics, it could remarkably decrease the MICs of different clinically isolated drug-resistant bacterial strains to these antibiotics. For example, when S227-4 was used with penicillin, the MIC of S. aureus 12352 decreased 8 times compared with that when penicillin was used alone. Meanwhile when it was used with erythromycin the MIC of S. aureus 12334 deceased 128 times compared with erythromycin alone.

重离子反应中质子与中子转移对超重元素合成的影响

研究了采用类弹碎片质量数为变量的一维(1D)主方程(ME)描述重离子熔合反应时的受限制条件,建立了以类弹碎片中子和质子数为独立变量的二维(2D)ME,并采用分步差分格式法数值解(2D)ME得到了熔合几率。新的方法适用于研究任何弹靶组合系统,给出了与实验符合更好的结果,为寻求合成超重核的反应道提供了更为宽阔的选择空间。同时也研究了弹靶的不同同位旋组合对复合核形成截面的影响。

A study of fucoidan from the brown seaweed Chorda filum

Fucoidan fractions from the brown seaweed Chorda filum were studied using solvolytic desulfation.Methylation analysis and NMR spectroscopy were applied for native and desulfated polysaccharides.Homefucan sulfate from C.filum was shown to contain poly-a-(1-3)-fucopyranoside backbone with a high degree of branching,mainly of a-(1-2)-linked single units.Some fucopyranose residues are sulfated at O-4(mainly) and O-2 positions.Some a-(1-3)-linked fucose residues were shown by NMR to be 2-O-acetylated.The 1H and 13C NMR spectra of desulfated,deaceylated fucan were complerely assigned.THe spectral data obtained correspond to a quasiregular polysaccharide structure with a branched hexasaccharide repeating unit.Other fucoidan frations from C.filum have more complex carbohydrate composition and give rather complex methvlation patterns.

Polymerization of Lactide Using Achiral Bis(pyrrolidene) Schiff Base Aluminum Complexes

A series of aluminum ethyls and isopropoxides based on a bis(pyrrolidene) Schiff base ligand framework has been prepared and characterized. NMR studies of the dissolved complexes indicate that they adopt a symmetric structure with a monomeric, five-coordinated aluminum center core. The aluminum ethyls used as catalysts in the presence of 2-propanol as initiator and the aluminum isopropoxides were applied for lactide polymerization in toluene to test their activities and stereoselectivities. All polymerizations are living, as evidenced by the narrow polydispersities and the good fit between calculated and found number-average molecular weights of the isolated polymers. All of these aluminum complexes polymerized (S,S)-lactide to highly isotactic PLA without epimerization of the monomer, furnished isotactic-biased polymer from rac-lactide, and gave atactic polymer from meso-lactide.

CIAC-综合结构信息系统

介绍了CIAC-综合结构信息系统， 它由两个部分组成， 即CIAC-13CNMR谱图数据库和结构解析专家系统ESESOC ESESOC可从未知化合物的分子式、光谱数据(IR,MS,1HNMR,2D-NMR等)及其它化学信息自动地推衍出与已知信息相一致的候选化合物结构。

Sesquiterpenes from the red alga Laurencia tristicha

Seven new sesquiterpenes (1-7), together with seven known sesquiterpenes, aplysin (8), aplysinol (9), gossonorol (10), 7,10-epoxy-ar-bisabol-11-ol (11), 10-epi-7,10-epoxy-ar-bisabol-11-ol (12), johnstonol (13), and laurebiphenyl (14), have been isolated from the red alga Laurencia tristicha. The structures of new compounds were established as laur-11-en-2,10-diol (1), laur-11-en-10-ol (2), laur-11-en-1,10-diol (3), 4-bromo-1,10-epoxylaur-11-ene (4), cyclolauren-2-ol (5), laurentristich-4-ol (6), and ar-bisabol-9-en-7,11-diol (7) by means of spectroscopic methods including IR, HRMS, and ID and 21) NMR techniques. Compound 6 possessed a novel rearranged skeleton. All compounds were tested against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), hepatoma (Bel 7402), colon cancer (HCT-8), and HELA cell lines. Laurebiphenyl (14) showed moderate cytotoxicity against all tested cell lines, with IC50 values of 1.68, 1.22, 1.91, 1.77, and 1.61 mu g/mL, respectively. Other compounds were inactive (IC50 > 10 mu g/mL).

An ent-Kaurane Diterpene from Euphorbia wallichii

One known ent- kaurane diterpene, ent- 16α, 17- dihydroxykauran- 3-one, were isolated from the roots of Euphorbia wallichii for the first time. Its structure was elucidated on the basis of spectral methods. And the NMR assignments of the compound in CD3OD were given for the first time.

A New Triterpenoid from Amoora dasyclada

Five compounds were isolated from the EtOH extraction of the stem of Amoora dasyclada (How et T. Chen) C. Y. Wu (Meliaceae). On the basis of spectroscopic methods, their structures were elucidated as 24, 25-epoxy-tirucall-7-ene-3, 23-dione (1), 24, 25, 26, 27-tetranortirucall-7-ene-3-oxo-23(21)-lactone (2), taraxerone (3), taraxerol (4) and b-sitosterol (5). Among them, compound 1 was a new triterpenoid, compounds 3-5 were firstly obtained from this plant; compound 2, an tetranortriterpenoid, was firstly isolated from natural sources, and its NMR data were assigned for the first time. Moreover, the D7-bond and the Me-14 in compound 2 were never changed, which has never been found in other tetranortriterpenoids. And the biosynthetic pathway of tetranortriterpenoid was further discussed.

Chemical constituents from euphorbia wallichii

Eleven known compounds were isolated from the roots of Euphorbia wallichii for the first time. They were elucidated to be three triterpenoids, β-amyrin (1), β-amyrin acetate (2) and 3β-acetoxy-lupenol (3), one nor-triterpene peroxide baccatin (4), two caffeic esters (5a, 5b), palmitic acid-2,3-dihydroxypropanenyl ester (6), palmitic acid (7), scopoletin (8), β-sitosterol (9) and daucosterol (10) on the basis of spectral methods. Among them, compound 5a, 5b were reported firstly in the spurge family. And the NMR assignments of compounds 5a and 5b were given for the first time.

A new daphnane diterpene from Daphne tangutica

A new daphnane diterpene was isolated from the root barks of Daphne tangutica Maxim. Its structure was elucidated as 1, 2 alpha-dihydro-20-palimoyldaphnetoxin by the spectroscopic evidence including 2D-NMR.

基于波动方程的层间多次波预测方法研究

In exploration geophysics，velocity analysis and migration methods except reverse time migration are based on ray theory or one-way wave-equation. So multiples are regarded as noise and required to be attenuated. It is very important to attenuate multiples for structure imaging, amplitude preserving migration. So it is an interesting research in theory and application about how to predict and attenuate internal multiples effectively. There are two methods based on wave-equation to predict internal multiples for pre-stack data. One is common focus point method. Another is inverse scattering series method. After comparison of the two methods, we found that there are four problems in common focus point method: 1. dependence of velocity model; 2. only internal multiples related to a layer can be predicted every time; 3. computing procedure is complex; 4. it is difficult to apply it in complex media. In order to overcome these problems, we adopt inverse scattering series method. However, inverse scattering series method also has some problems: 1. computing cost is high; 2. it is difficult to predict internal multiples in the far offset; 3. it is not able to predict internal multiples in complex media. Among those problems, high computing cost is the biggest barrier in field seismic processing. So I present 1D and 1.5D improved algorithms for reducing computing time. In addition, I proposed a new algorithm to solve the problem which exists in subtraction, especially for surface related to multiples. The creative results of my research are following: 1. derived an improved inverse scattering series prediction algorithm for 1D. The algorithm has very high computing efficiency. It is faster than old algorithm about twelve times in theory and faster about eighty times for lower spatial complexity in practice; 2. derived an improved inverse scattering series prediction algorithm for 1.5D. The new algorithm changes the computing domain from pseudo-depth wavenumber domain to TX domain for predicting multiples. The improved algorithm demonstrated that the approach has some merits such as higher computing efficiency, feasibility to many kinds of geometries, lower predictive noise and independence to wavelet； 3. proposed a new subtraction algorithm. The new subtraction algorithm is not used to overcome nonorthogonality, but utilize the nonorthogonality's distribution in TX domain to estimate the true wavelet with filtering method. The method has excellent effectiveness in model testing. Improved 1D and 1.5D inverse scattering series algorithms can predict internal multiples. After filtering and subtracting among seismic traces in a window time, internal multiples can be attenuated in some degree. The proposed 1D and 1.5D algorithms have demonstrated that they are effective to the numerical and field data. In addition, the new subtraction algorithm is effective to the complex theoretic models.

北部湾盆地迈陈凹陷地震勘探方法研究

Maichen Depression lie between Leizhou Peninsula and Qiongzhou Strait. Oil and gas have been discovered in Weixinan Depression, Wushi Depression and Fushan Depression, which pertain to a same basin — North Sea Basin along with Maichen Depression.Jiangsu Oil started exploration at 2002. The first well began to drill at November, 2004 after gravity survey, electric method prospecting and 2D seismic exploration had been finished. Generating rock and hydrocarbon shows have been verified by the drilling. Low yield oil stream has been tested. And we started 3D seismic exploration at November, 2005. My thesis topic came from the actual needs of our exploration in the Maichen Depression. In the thesis, I give emphasis to analyse the own seismic geologic conditions of Maichen Depression. By real tests, we choosed the means to overcome or weaken the unfavorably impress owing to the own coditions in Maichen Depression. Finally, we obtained the usable seismic data. 1. Owing to the multiphase eruptive rock during the Quaternary Period, the near surface layers are very inhomogeneous. By simultaneous testing at same point with short refraction, uphole surveys of radial source and of surface source, the most appropriate method had been sorted out. Radial source uphole survey has been regarding the best practicable means in the complex area. Accurate surficial geology was very helpful to choosing of acquirement means and parameters. Basically the appropriate method of seismic acquirement has been built at Maichen area. 2. The seismic primary data has many, very strong and complex noise. By noise characteristic analysis in different domain, many means of denoising had been paralleled individual and joint application researched. As a result, the pre-stack multidomain joint denoise flow was the appropriate method. It can improve the seismic signal-to-noise ratio. 3. The problem of seismic static correction at Maichen Depression is very conspicuous. Many static correction methods had been tested individual and joint researched. The seismic data quality has been improved after choosing the appropriate combination of static correction flows. 4. Although the above-mentioned process are resultful, the seismic profile quality is just passable. Some reflector continuity and fault zone imagery are ambiguity. So it was the useful method to reduce the structural ambiguity during seismic interpretation that built-up geologic model in accord with real geologic character by areal structure study upon backbone seismic profiles. In the same way, traps have been assessed and drill targets have been selected.

青藏高原东部电性结构特征及地球动力学意义

As the largest and highest plateau on the Earth, the Tibetan Plateau has been a key location for understanding the processes of mountain building and plateau formation during India-Asia continent-continent collision. As the front-end of the collision, the geological structure of eastern Tibetan Plateau is very complex. It is ideal as a natural laboratory for investigating the formation and evolution of the Tibetan Plateau. Institute of Geophysics, Chinese Academy of Sciences (CAS) carried out MT survey from XiaZayii to Qingshuihe in the east part of the plateau in 1998. After error analysis and distortion analysis, the Non-linear Conjugate Gradient inversion(NLCG), Rapid Relaxation Inversin (RRI) and 2D OCCAM Inversion algorithms were used to invert the data. The three models obtained from 3 algorithms provided similar electrical structure and the NLCG model fit the observed data better than the other two models. According to the analysis of skin depth, the exploration depth of MT in Tibet is much more shallow than in stable continent. For example, the Schmucker depth at period 100s is less than 50km in Tibet, but more than 100km in Canadian Shield. There is a high conductivity layer at the depth of several kilometers beneath middle Qiangtang terrane, and almost 30 kilometers beneath northern Qiangtang terrane. The sensitivity analysis of the data predicates that the depth and resistivity of the crustal high conductivity layer are reliable. The MT results provide a high conductivity layer at 20~40km depth, where the seismic data show a low velocity zone. The experiments show that the rock will dehydrate and partially melt in the relative temperature and pressure. Fluids originated from dehydration and partial melting will seriously change rheological characteristics of rock. Therefore, This layer with low velocity and high conductivity layer in the crust is a weak layer. There is a low velocity path at the depth of 90-110 km beneath southeastern Tibetan Plateau and adjacent areas from seismology results. The analysis on the temperature and rheological property of the lithosphere show that the low velocity path is also weak. GPS measurements and the numerical simulation of the crust-mantle deformation show that the movement rate is different for different terranes. The regional strike derived from decomposition analysis for different frequency band and seismic anisotropy indicate that the crust and upper mantle move separately instead of as a whole. There are material flow in the eastern and southeastern Tibetan Plateau. Therefore, the faults, the crustal and upper mantle weak layers are three different boundaries for relatively movement. Those results support the "two layer wedge plates" geodynamic model on Tibetan formation and evolution.

人工源频率域大地电磁法正反演研究

The CSAMT method is playing an important role in the exploration of geothermal and the pre-exploration in tunnel construction project recently. In order to instruct the interpretation technique for the field data, the forward method from ID to 3D and inversion method in ID and 2D are developed in this paper for the artificial source magnetotelluric in frequency domain. In general, the artificial source data are inverted only after the near field is corrected on the basis of the assumption of half-homogeneous space; however, this method is not suitable for the complex structure because the assumption is not valid any more. Recently the new idea about inversion scheme without near field correction is published in order to avoid the near field correction error. We try to discuss different inversion scheme in ID and 2D using the data without near field correction.The numerical integration method is used to do the forward modeling in ID CSAMT method o The infinite line source is used in the 2D finite-element forward modeling, where the near-field effect is occurred as in the CSAMT method because of using artificial source. The pseudo-delta function is used to modeling the source distribution, which reduces the singularity when solving the finite-element equations. The effect on the exploration area is discussed when anomalous body exists under the source or between the source and exploration area; A series of digital test show the 2D finite element method are correct, the results of modeling has important significant for CSAMT data interpretation. For 3D finite-element forward modeling, the finite-element equation is derived by Galerkin method and the divergence condition is add forcedly to the forward equation, the forward modeling result of the half homogeneous space model is correct.The new inversion idea without near field correction is followed to develop new inversion methods in ID and 2D in the paper. All of the inversion schemes use the data without near field correction, which avoid introducing errors caused by near field correction. The modified grid parameter method and the layer-by-layer inversion method are joined in the ID inversion scheme. The RRI method with artificial source are developed and finite-element inversion method are used in 2D inversion scheme. The inversion results using digital data and the field data are accordant to the model and the known geology data separately, which means the inversion without near field correction is accessible. The feasibility to invert the data only in exploration area is discussed when the anomalous body exists between the source and the exploration area.

Badania właściwości fotochemicznych azydonukleozydów purynowych w kontekście ich potencjalnego wykorzystania jako czynników fotozszywających w dwuniciowych układach oligonukleotydowych

Wydział Chemii: Zakład Fizyki Chemicznej