癌基因MDM2阻断剂的分子结构的NMR研究

根据P53-MDM2复合物晶体结构,设计合成了非肽类小分子作为MDM2的阻断剂.利用超导核磁共振波谱仪,测定了化合物的¹H谱、¹³C谱、¹H-¹H COSY谱、HMQC和HMBC谱,确定了化合物的结构,归属了化合物的¹H、¹³C化学位移,为筛选抗癌活性化合物提供了理论依据.     

雷酚萜甲醚和雷酚萜的2DNMR研究

从雷公藤分离出二种新的萜化合物,利用¹H-¹H COSY,¹H-¹³H COSY和COLOC等2DNMR技术,分析了雷酚萜甲醚和雷酚萜的¹H和¹³C NMR谱,明确地指认出这三种化合物的全部¹H和¹³C共振峰.     

两个C19-二萜生物碱的结构鉴定和NMR信号归属

从剑川乌头（Aconitum handelianum）的根中分离得到两个C₁₉-二萜生物碱：高展花乌头宁（homochasmanine,化合物1）和14-去苯甲酰大渡乌碱（14-debenzoylfranchetine,化合物2）.采用1D和2D核磁共振（NMR）技术（包括¹H NMR、¹³C NMR、DEPT、¹H-¹H COSY、HSQC、HMBC和NOESY）对其进行结构鉴定,完整归属了这两个化合物的¹H和¹³C NMR信号.     

β-二氢沉香呋喃倍半萜的1H和13C化学位移全指定及13C化学位移与立体化学之间的关系

采用¹H,¹³C-COSY和COLOC谱,对三个(1-3)β-二氢沉香些喃倍半萜的¹H和¹³C化学位移进行了全指定.经过考察和比较上述化合物及十九个文献报导化合物的立体化学和C-14化学位移的关系,得出一个新的,非常重要的构型判断方法.     

苯基哌嗪衍生物的NMR波谱研究

通过¹H NMR、¹³C NMR、及HMBC、HSQC、¹H-¹H DQFCOSY等2D NMR方法对新合成的10个苯基哌嗪衍生物类抗高血压药物进行结构鉴定, 并对这些化合物的¹H NMR和¹³C NMR信号进行了全归属. 初步探讨了取代基对分子¹³C化学位移的影响.      

一种新型的莪术醇衍生物的波谱学分析

莪术醇进行环外双键断裂氧化和酸催化氧桥开环加成2步反应后,经硅胶柱层析分离,得到一种新型的莪术醇衍生物（2）. 应用1D NMR和2D NMR测试了化合物2的¹H NMR、¹³C NMR、¹H-¹H COSY、gHSQC、gHMBC,对化合物2的¹H和¹³C化学位移进行了全归属,结合其红外光谱和质谱,推得化合物2为8-羟基-12-异丙基-2-甲基-三环[6.2.2.0^1,5]十二烷-10-氧杂-6,9-二酮,并比较了莪术醇,莪术醇双键断裂氧化产物(化合物1),化合物2的¹H NMR、¹³C NMR数据变化.     

狭苞橐吾内酯A的2D NMR研究

报道了从狭苞橐吾根中分离得到的一个新的倍半萜内酯,命名为狭苞橐吾内酯A,利用¹³C-¹H COSY、¹H-¹H COSY、¹H-¹H NOESY和¹³C-¹H COLOCLR等2D NMR技术归属了所有质子和碳的化学位移信号,并探讨了该化合物的相对构型.     

Lasiodonin Acetonide的NMR数据解析

对lasiodonin acetonide进行了¹H和¹³C NMR检测,参考lasiodonin, maoecrystal T, wikstroemioidin B和rabdocoetsin A的¹H、¹³C NMR数据,通过DEPT和¹H-¹H COSY、HSQC、HMBC等2D NMR技术对该化合物所有的¹H和¹³C NMR信号进行了全归属和详细解析.     

应用E.COSY型的13C-1H相关谱准确测定果糖-1,6-二磷酸根离子中异核31P-1H和31P-13C偶合常数

建议了一种E.COSY型的¹³C-¹H相关实验.在相应的¹³C-¹H相关谱中,³¹P核对¹³C,¹H核的被动偶合给出E.COSY型的谱峰裂分,可用于准确测定含磷化合物中的³¹P-¹H和³¹P-¹³C偶合常数及其相对符号.测定了果糖-1,6-二磷酸根离子的³¹P-¹H和³¹P-¹³C偶合常数。     

草苁蓉中2个单萜苷类化合物的NMR研究

从草苁蓉75%乙醇提取物中分离得到了2个单萜苷类化合物,结合其理化性质,并通过1D NMR（¹H NMR,¹³C NMR）及¹H-¹H COSY、HSQC、HMBC、NOESY等多种波谱学方法进行结构鉴定,鉴定2个化合物分别为β-D-glucopyranose 1-(3,7-dimethyl-2-trans-6-octadienoate)(化合物1)和6,7-dihydrofoliamenthoic acid diglucoside（化合物2）,其中化合物1为新化合物,化合物2为第1次从列当科植物中获得.     

Effect of nitro groups and alkyl chain length on the negative ion tandem mass spectra of alkyl 3-hydroxy-5-(4'-nitrophenoxy) and alkyl 3-hydroxy-5-(2', 4'-dinitrophenoxy) benzoates

Tandem mass spectrometric behaviour was studied for a small combinatorial library of alkyl 3-hydroxy-5-(4'-nitrophenoxy) benzoates (A1-A5) and alkyl 3-hydroxy-5-(2', 4'-dinitrophenoxy) benzoates (B1-B5). The spectra were recorded by negative ion electrospray low-energy collision induced dissociation (CID) tandem mass spectrometry. The product ion spectra of [M - H](-) of the benzoates A1-A5 are similar, as are those of benzoates B1-B5. However, the spectra of the B series compounds differ significantly from those of the A series owing to the second electron-withdrawing nitro substituent in the B compounds. In addition, the length of the alkyl chain has an effect on the fragmentation. However, both series of compounds exhibit an abundant nitrophenoxy ion formed by the loss of 3-hydroxybenzoate. This is at m/z 138 in A1-A5 and at m/z 183 in B1-B5. A precursor ion scan of the nitrophenoxy ion provides a rapid method to identify the synthesised compounds in this type of combinatorial mixture. Copyright 1999 John Wiley & Sons, Ltd.     

二正丁基锡(IV)基羧酸酯的谱学表征

合成了10个二正丁基锡(IV)基羧酸酯化合物{[ⁿBu₂Sn (O₂CR)]₂O}₂(A1~A5)和ⁿBu₂Sn (O₂CR)₂(B1~B5)(R=1:CCl₃;2:CHCl₂;3:CH₂Cl;4:PhCH=CH;5:2,2,3,3-四甲基环丙基),其中A4、A5和B5为新化合物,对它们进行了元素分析和IR及、¹H、¹³C、¹¹⁹Sn NMR谱表征,重点讨论了¹³C和¹¹⁹Sn NMR谱的谱学特征及化学位移值与母体酸的PKa值大小的关系,并在此基础上推测了它们分子结构。     

Enhancing the superconducting transition temperature of CeRh 1-x IrxIn5 due to the strong-coupling effects of antiferromagnetic spin fluctuations: an 115In nuclear quadrupole resonance study

We report on systematic evolutions of antiferromagnetic (AFM) spin fluctuations and unconventional superconductivity (SC) in heavy-fermion (HF) compounds CeRh(1-x)Ir(x)In(5) via an (115)In nuclear-quadrupole-resonance experiment. The nuclear spin-lattice relaxation rate 1/T(1) has revealed the marked development of AFM spin fluctuations as approaching an AFM ordered state. Concomitantly, the superconducting transition temperature T(c) and the energy gap Delta0 increase drastically from T(c)= 0.4K and 2Delta0/k(B)T(c)=5 in CeIrIn(5) up to T(c) =1.2K and 2Delta0/k(B)T(c) =8.3 in CeRh(0.3)Ir(0.7)In5 , respectively. The present work suggests that the AFM spin fluctuations in close proximity to the AFM quantum critical point are indeed responsible for the strong-coupling unconventional SC in HF compounds.     

若干多钒硼酸盐簇合物的光谱研究

合成了具有[(VO)₁₂O₆B₁₈O₄₂]簇骼的4种新颖的多钒硼酸盐簇合物：(enH₂)₆H₃[(VO)₁₂O₆B₁₈O₄₂]·13H₂O(1),[Ni(en)₂]₆H₃[(VO)₁₂O₆B₁₈O₄₂]·8H₂O(2),[Cu(en)₂]₅H₃[(VO)₁₂O₆B₁₈O₄₂][B(OH)₃]₂·16H₂O(3)和(enH₂)₄Na₄H₃[(VO)₁₂O₆B₁₈O₄₂]·8H₂O(4)。通过FTIR, UV-Vis DRS和荧光光谱等手段对其进行了研究,探讨了结构和性能的关系。其中,化合物(1)含有[(VO)₁₂O₆B₁₈O₄₂]的分立结构,环状B₁₈O₄₂通过8个B—(μ₃—O)—V键被两个V₆O₁₈簇夹在中间;而化合物(2)是在(1)的基础上,由6个[Ni(en)₂]各自通过两个Ni—(μ₃—O)—B与B₁₈O₄₂的桥氧配位形成另一类新的分立型结构;化合物(3)和(4)的[(VO)₁₂O₆B₁₈O₄₂]构筑单元间分别通过[Cu(en)₂]2+和无机Na+离子桥联形成二维层状结构。多钒硼酸盐簇合物的特征振动频率和这些化合物的结构相关;UV-Vis DRS表明,在205和260 nm附近出现金属氧簇化合物的荷移跃迁;用310 nm光激发, 在约415 nm处能引起由O_μ→Mo的荧光发射, 同时还研究了其荧光寿命。     

高压下钡的硫化物的结构相变和光学性质研究(英文)

利用基于密度泛函的第一性原理,计算了高压下钡的硫化物(BaS、BaSe和BaTe)的结构相变和光学性质。计算结果表明,这些化合物的压致结构相变是从NaCl型结构转变为CsCl型结构;对于结构转变压力和金属化转变压力,BaS为8.57 GPa和45.4 GPa,BaSe为7.44 GPa和36.5 GPa,BaTe则分别为5.67 GPa和16.7 GPa。光学性质计算结果显示:随着压力的增加,静态介电常数ε0不断增加,介电常数虚部ε2的峰值向高能方向移动(蓝移)。     

First principles study of structural phase transition of YSb and ScSb compounds

High pressure induced phase transition of YSb and ScSb compounds have been studied using Density Functional Theory method within Generalized Gradient Approximation. It was found that the phase transition from the NaCl-type (B1) to a CsCl-type structure (B2) began to occur at around 29 GPa for YSb compound, agreeing well with available experiments and theoretical calculations. For ScSb compound it was suggested that structural phase transition from B1 to B2 will occur at about 40 GPa, differing greatly with experimental and theoretical results. The finding that the transition pressures increase with decreasing lattice constant in the NaCl-type structure for YSb and ScSb compounds was found to be similar to the phenomena observed for LnSb (Ln: lanthanide) compounds. Mulliken charge and overlap population analysis revealed that YSb and ScSb compounds in B1 structure show similar interaction between anion and cation, while in B2 structure a higher degree of covalency was found for ScSb than that in YSb. Also, DOS and band structure of these two compounds in B1 and B2 structures were presented and analyzed.     

Phase stability and electronic behavior of MgS,MgSe and MgTe compounds

Ab initio calculations based on density functional theory using the full-potential linearized augmented plane wave method have been carried out to find the structural stability of different crystallographic phases, the pressure-induced phase transition and the electronic properties of the magnesium chalcogenides MgS, MgSe and MgTe. The zinc blende (B3), wurtzite (B4), rock salt (B1), CsCl (B2), NiAs (B8), β-BeO, 5-5 and TiP crystal structures are considered and the exchange and correlation potential is treated by the generalized-gradient approximation using the Perdew–Burke–Ernzerhof parameterization. Moreover, the modified Becke-Johnson (mBJ) scheme is also applied to optimize the corresponding potential for the band structure calculations. Results show that the wurtzite phase is the stable structure in the ground state adopted by MgSe and MgTe compounds while MgS adopts the rock-salt one. Moreover, the band structure calculations reveal a metallic behavior in the CsCl structure for all the compounds, whereas for the other structures, a semiconducting behavior is observed.     

First-principles lattice dynamical study of ScAs and ScSb at zero and high pressure

A first-principles pseudopotential method is used to investigate the structural and elastic properties of ScAs and ScSb in their ambient B1(NaCl) and in high pressure B2 (CsCl) phases and phonon structures at zero and close to phase transition pressure. The calculated lattice constants, static bulk modulus, first order pressure derivative of the bulk modulus and the elastic constants are reported in B1 and B2 structures and compared with available experimental and other theoretical results. The phonon properties of these two compounds are compared among themselves which reveal that these compounds are predominantly metallic, due to degeneracy of optical frequencies at the zone centre. At high pressure, near the B1 to B2 transition, the LA mode at X-point softens leading to structural instability.     

MgB2超导体掺Au的研究

分析不同烧结温度及时间和不同掺金量的名义组分为Mg1-xAuxB2样品的X射线衍射图后发现，很难得到单相的Mg1-xAuxB2样品，名义组分为Mg1-xAuxB2（x=1/16,2/16,0.146)的样品都是多相混合物，X射线衍射图显示主要是Au和Mg的化合物，样品的起始超导转变温度仍然由MgB2决定。     

系列甲基苯基卟啉-5-氟尿嘧啶化合物的合成与表征

设计合成了6种甲基苯基卟啉-5-氟尿嘧啶化合物。通过红外光谱、紫外-可见光谱、核磁共振谱和质谱对所合成的化合物结构进行了确认。探索出了合成反应的最佳条件和目标化合物的分离纯化方法。实验结果表明,选择DMF为溶剂,反应温度在115℃,反应时间2h,产率较高,A1、A2,B1、B2、C1和C2分别为25.66%、25.02%,24.89%、26.17%、28.43%和24.19%;采用硅胶G(粒径为48—75μm)柱层析,分离效果较好。