超滤亲和结合液相色谱-质谱联用和分子对接技术筛选毛菊苣种子中高亲和性α-葡萄糖苷酶抑制剂

采用超滤亲和结合液相色谱-质谱联用(UF-LC-MS) 和分子对接技术筛选毛菊苣种子中高亲和α-葡萄糖苷酶抑制剂.以4-硝基苯-α-D-吡喃葡萄糖苷(PNPG)为底物,阿卡波糖为阳性对照,评价毛菊苣种子提取物对α-葡萄糖苷酶的抑制活性,其中阿卡波糖IC50为0.003 mg/mL,毛菊苣种子IC50为0.447 mg/mL.利用UF-LC-MS技术对毛菊苣种子提取物进行筛选鉴定,获得4种化合物;通过Autodock软件筛选出2种与α-葡萄糖苷酶有较高亲和力的化合物,分别是绿原酸和异绿原酸A.结合体外酶活实验,验证了绿原酸、异绿原酸A对α-葡萄糖苷酶的抑制活性.结果表明,各化合物对α-葡萄糖苷酶的抑制活性由大到小依次是:阿卡波糖>异绿原酸A>绿原酸,其中异绿原酸A与阿卡波糖抑制率相近.     

Yttrium-catalyzed heterocyclic formation via aerobic oxygenation: A green approach to benzothiazoles

The YCl₃-catalyzed aerobic oxidative cyclization reaction for the synthesis of benzothiazoles has been developed.This method provides a practical,effective and green synthetic approach to benzothiazoles which are important units in many biologically active compounds.     

光电二极管阵列等离子体原子发射光谱分析背景智能化实时校正研究

提出了用于光电二极管阵列等离子体原子发射光谱分析背景智能化实时校正的方法。采用二次微分结合原ICP光谱法,在不经微分噪声过滤的基础上,实现快速准确的谱线识别。简单背景采用多项式模型,结构背景及翼展干扰采用概率统计模型。通过对高浓度Ca存在下A₁及La的测定,表明本方法能够准确地校正背景干扰。     

New Exact Solutions to Dispersive Long-Wave Equations in (2+1)-Dimensional Space

New exact solutions expressed by the Jacobi elliptic functions are obtained to the (2+1)-dimensional dispersive long-wave equations by using the modified F-expansion method. In the limit case, new solitary wave solutions and triangular periodic wave solutions are obtained as well.     

Symmetry Groups and New Exact Solutions of （2＋1）-Dimensional Dispersive Long-Wave Equations

Using the modified CK＇s direct method, we derive a symmetry group theorem of （2＋1）-dimensional dispersive long-wave equations. Based upon the theorem, Lie point symmetry groups and new exact solutions of （2＋1）- dimensional dispersive long-wave equations are obtained.     

(±)-3,5-二羟基-7,4′-二甲氧基二氢黄酮醇和(±)-3,5,7-三羟基-4′-甲氧基二氢黄酮醇的全合成

3,5 -二羟基 - 7,4′-二甲氧基二氢黄酮醇 ( 1 )从 Cephalanthus spathelliferus中分离得到后 [1] ,又在H aplopappus bayahuen[2 ] 和 L annea coromandelica[3] 等植物中被发现 ,在印度一直被用于治疗象皮病、阳痿、溃疡、阴道炎、口臭、痢疾和风湿病等 . 3,5 ,7-三羟基 - 4′-甲氧基二氢黄酮醇 ( 2 )首次从 Prunusdonestica[4 ] 中分离出来后 ,又从 Salix caprea L.,Brazilian propolis中得到 .研究表明 ,该化合物具有抗菌、抗肿瘤活性 .我们用与文献 [5 ]类似的方法以 2 ,4,6-三羟基苯乙酮和茴香醛为起始原料 ,经选择性保护、缩合、…     

煤中汞,砷,硒赋存形态的研究

本文利用连续化学浸提法对三种典型煤进行连续浸提,根据不同形态的溶解度,将煤中的汞,砷,硒分为可交换态,硫化物形态,有机物结合态及残渣态四种形态。结果表明不同的煤有不同的形态分布特征。但总体来看,汞主要以硫化物形态和残渣态存在。砷主要以硫化物形态存在。硒赋存在硫化物,有机物及残渣态中。     

4-(1,2,4-三唑-5-酮-4-基)-3-硫代脲酸乙酯的合成、晶体结构及理论计算

4-氨基-1,2,4-三唑-5-酮(ATO)与硫氰酸钾、氯甲酸乙酯在乙酸乙酯中反应, 合成了4-(1,2,4-三唑-5-酮-4-基)-3-硫代脲酸乙酯, 在室温下采用缓慢蒸发溶剂二甲基甲酰胺得到合适的可用于X射线衍射的单晶. 晶体属六方系, 空间群为R-3, 晶体结构参数为a＝2.60524(7) nm, b＝2.60524(7) nm, c＝0.82579(6) nm, γ＝120°, V＝4.8540(4) nm³, D_c＝1.442 g/cm³, μ＝0.300 mm^－1, F(000)＝2190, Z＝18, R₁＝0.0569, wR₂＝0.1424. 选取标题化合物的一个结构单元作为初始模型, 运用Gaussian 03程序对化合物进行了HF/6-311G, MP2/6-311G和B3LYP/6-311G水平的几何全优化,并对其原子电荷及自然键轨道(NBO)进行了分析.     

Synthesis and Crystal Structure of 4-（4,6-dimethoxyl -pyrimidin-2-yl）-3-thiourea Carboxylic Acid Methyl Ester

1 INTRODUCTION Pyrimidinyl thioureas have been studied for many years because of their broad antibiosis and sterilibza- tion properties. Recent years’ study shows that pyri- midinyl thioureas not only can be used to kill insects and adjust plant growth, but also have anti-viral ac- tivities[1, 2]. From our early quantum study on these compounds, we find that they have several active cen- ters and can form polyligand complexes with metals easily[3]. These complexes are widely used as ant…     

Effects of pairing correlation on neutron drop

In this work, the effects of the pairing correlation on the properties of neutron drops N=6-50 trapped in a harmonic oscillator potential with ω = 10 Me V are investigated by comparing the results given by the Skyrme Hartree-Fock and Hartree-FockBogoliubov theories with the density-dependent delta interaction(DDDI) pairing force. The results showed that the pairing correlation slightly made the neutron drops more bound, and increased the central neutron density, the spin-orbit and pseudo spin-orbit splittings. Thus, the pairing correlation must be accounted for to improve the Skyrme functional compared with the ab initio calculations. Furthermore, although the single-particle energy gaps with or without pairing were similar, the shell closures varied due to pair scattering. Here, the shell closures in neutron drops using the Sk M* parameter set and DDDI pairing force were found at N=8, 16, and 32.