黄芩及其制剂中黄芩素和黄芩甙的

用毛细管区带电泳 -电化学检测法测定了黄芩及其制剂中黄芩素和黄芩甙的含量。研究了电极电位、电解液酸度和浓度、电泳电压及进样时间等对电泳的影响 ,得到了较为优化的测定条件。以直径为300μm的碳圆盘电极为检测电极 ,电极电位为0.90V(vsSCE) ,在100mmol/L硼酸盐缓冲液(pH9.0)中 ,上述两组分在8min内完全分离。黄芩素和黄芩甙浓度与电泳峰电流分别在5.0×10 -7～1.0×10 -3mol/L和1.0×10 -6～1.0×10 -3mol/L范围内呈良好线性 ,检出限分别为2.24×10 -7mol/L和5.48×10 -7mol/L。7次测定分别含5.0×10 -4mol/L黄芩素和黄芩甙试样溶液 ,峰高的相对标准偏差分别为3.53%和4.03%。     

黄芩素和黄芩苷与人血清白蛋白相互作用的光谱研究

采用荧光光谱、紫外-可见光谱和表面增强拉曼光谱研究了黄芩素和黄芩苷与人血清白蛋白的相互作用, 得到了分子间的结合状态和吸附形态方面的信息. 通过比较黄芩素和黄芩苷的普通拉曼和表面增强拉曼光谱, 确立了黄芩素和黄芩苷的正常构象, 同时考察了结合上人血清白蛋白后不同浓度黄芩素和黄芩苷的吸附方式差别.     

紫外分光光度法测定黄芩中黄芩苷的含量

从黄芩中提取黄芩苷,并用紫外分光光度法对纯化后的黄芩苷进行测定。建立了一种以乙醇为溶剂、超声溶解制样、检测波长为278nm的测定黄芩苷含量的新方法。纯化后黄芩苷纯度达98．76％,黄芩苷乙醇溶液的含量在1～18μg／mL之间与吸光度呈良好的线性关系,相关系数为0．9993,平均回收率为99．49％,相对标准偏差为0．328％（n=4）。该方法适用于黄芩苷的定量测定。     

黄芩及其制剂中黄芩素和黄芩甙的毛细管区带电泳—电化学检测

用毛细管区带电泳－电化学检测法测定了黄芩及其制剂中黄芩素和黄芩甙的含量。研究了电极电位、电解液酸度和浓度、电泳电压及进样时间等对电泳的影响,得到了较为优化的测定条件。以直径为300μm的碳圆盘电极为检测电极,电极电位为0.90V(vsSCE),在100mmol/L硼酸盐缓冲液(pH9.0)中,上述两组分在8min内完全分离。黄芩素和黄芩甙浓度与电泳峰电流分别在5.0×10     

Cu-NIC-TMED富集黄芩中黄芩苷的规律及机理

以烟酸(NIC)为配体制备了金属-有机骨架材料(MOFs)铜-烟酸-四甲基乙二胺配位聚合物(Cu-NICTMED),并将其用于黄芩中黄芩苷的吸附、分离和纯化,建立了一种无毒无害、环境友好、流程简化且效率较高的提取方法.采用溶剂热法合成Cu-NIC-TMED,然后对其进行结构表征,以实现适当的配位及准确合成.研究了Cu-NIC-TMED吸附黄芩苷的规律和机理:该吸附符合准二级动力学方程,平衡吸附数据符合Langmuir吸附等温模型.同时,通过对响应面(RSM)进行优化得到最佳吸附参数.在最佳吸附参数条件下, Cu-NIC-TMED对黄芩中黄芩苷的吸附率高达84.08%,且对黄芩中其它成分的吸附效果微乎其微.使用pH=6.8的磷酸盐缓冲溶液（PBS）作为解吸溶液, Cu-NIC-TMED解吸黄芩苷的解吸率为41.24%,黄芩苷的纯度由吸附前的21.55%提高到解吸后的75.77%, Cu-NIC-TMED在吸附前后具有良好的稳定性,回收率达到78.64%.因此, Cu-NIC-TMED在黄芩苷的吸附纯化中具有应用价值.     

若干极性树脂对黄芩甙及黄芩黄素的吸附性能研究

测定了35种具有不同极性的吸附树脂对黄芩甙及黄芩黄素的吸附量,发现弱碱树脂具有较大的吸附量,研究了弱碱树脂对黄芩黄素的吸附动力学,观察到该树脂对黄芩黄素的吸附较快,5h已基本达到吸附平衡。     

黄芩苷元的Mannich反应

利用天然产物黄芩苷元（baicalein)在A环8－位碳上进行Mannich反应，合成 了11个新的Mannich碱化合物。反应温和，产物易纯化，收率达80％以上。同时考 察了伯胺与甲醛配比为1：2时，产物为二氢苯并E嗪类化合物和黄芩苷元A环上5－ ，6－，7－位羟基对8－位氢进行Mannich反应活性的影响。并对Mannich碱化合物 2b和2j进行盐酸成盐4b和4j，初步考察了它们的溶解度与黄芩苷元的差别。     

金属有机骨架材料ZIF-8富集黄芩中黄芩苷的新方法

本工作旨在探索MOFs材料高效富集黄芩中黄芩苷的新方法,拓展MOFs在吸附领域的用途.溶剂热法合成了沸石咪唑酯骨架-8（ZIF-8）,并进行了结构表征,以确保其准确合成.研究了ZIF-8对黄芩苷的吸附规律和作用机理：ZIF-8对黄芩苷的吸附符合准二级动力学方程,平衡吸附数据符合Langmuir吸附等温模型.采用响应面法（RSM）得到优化后的最佳吸附参数,在此条件下,ZIF-8对黄芩中黄芩苷的吸附率高达98.22%,且对黄芩中其它成分吸附效果不显著,以pH 6.8的PBS溶液作解吸液,ZIF-8对黄芩苷的解吸率为62.46%,而黄芩苷的纯度由吸附前的21.55%提高到解吸后的64.27%,且ZIF-8在吸附前后稳定性良好,回收率达到83.50%.因此,ZIF-8在吸附纯化黄芩苷方面具有潜在的应用价值.     

不同产地黄芩中黄芩甙及元素的含量比较

用高效液相色谱法和原子吸收光谱法分别对１０个不同产地正品黄芩中黄芩甙及元素的含量进行了分析比较。     

D241树脂分离纯化黄芩总黄酮的研究

本文研究了用241树脂分离纯化黄芩总黄酮的方法和工艺。实验结果表明：D241树脂对黄芩总黄酮的静态交换容量是77mg/ml树脂。在pH11.0、流速2.0BV/h、提取液中总黄酮浓度17.5mg/ml条件下，D241树脂对黄芩总黄酮的动态交换容量为43.8mg/ml。用60％甲醇作为黄芩总黄酮洗脱剂，在PH4.0、洗脱流速1.5BV/h条件下，4．5BV洗脱剂即可完全洗脱被D241树脂交换的黄芩总黄酮。与酸沉淀法相比较，经过除去果胶，总黄酮纯度由33．34％提高到74．9％，粗品收得率由11.52%降低至4.83%；经过D241树脂分离纯化，其纯度达到91.5%，产品收得率3.54%。     

Chemical profiling and marker characterization of Huangqin decoction prepared with three types of peony root by liquid chromatography with electrospray ionization mass spectrometry

Clarification of the quality and biological effect equivalence of traditional Chinese medicines containing multi‐origin species is essential to improve their current quality standards, and also is the core problem to clarify the origins of single herbs with multi‐species in Chinese formulas that will guarantee their clinical application. Huangqin decoction is the typical one of multi‐origin formulas frequently used in traditional Chinese medicine and Kampo medicine. An ultra high performance liquid chromatography with electrospray ionization–tandem mass spectrometry was developed for chemical profiling and marker quantification of Huangqin decoction prepared with two different original types of peony root, white and red peony root. Forty‐seven main peaks in chemical profiling of Huangqin decoction prepared with white and red peony root were identified: nine were from peony root, 20 from baical skullcap root, 17 from licorice root, and one from jujubae fruit. The markers characteristics of the respective types of peony root in Huangqin decoction differ from that in single herbs, especially in terms of monoterpenoids and hydrolysable tannins. Subsequently, 17 representative markers in Huangqin decoction prepared with three types of peony root and their chemical characteristics and content distribution were carried out.     

黄芪中微量锌的测定

用分光光度法测定了黄芪中锌的含量,该法的平均回收率为99.01%.变异系数为1.50%.     

Ligand- and protein-based modeling studies of the inhibitors of human cytochrome P450 2D6 and a virtual screening for potential inhibitors from the Chinese herbal medicine, Scutellaria baicalensis (Huangqin,Baikal Skullcap)

We have previously examined the binding patterns of various substrates to human cytochrome P450 2D6 (CYP2D6) using a series of molecular modeling methods. In this study, we further explored the binding modes of various types of inhibitors to CYP2D6 using a combination of ligand- and protein-based modeling approaches. Firstly, we developed and validated a pharmacophore model for CYP2D6 inhibitors, which consisted of two hydrophobic features and one hydrogen bond acceptor feature. Secondly, we constructed and validated a quantitative structure-activity relationship (QSAR) model for CYP2D6 inhibitors which gave a poor to moderate prediction accuracy. Thirdly, a panel of CYP2D6 inhibitors were subject to molecular docking into the active site of wild-type and mutated CYP2D6 enzyme. We demonstrated that 8 residues in the active site (Leu213, Glu216, Ser217, Gln244, Asp301, Ser304, Ala305, and Phe483) played an important role in the binding to the inhibitors via hydrogen bond formation and/or π-π stacking interaction. Apparent changes in the binding modes of the inhibitors have been observed with Phe120Ile, Glu216Asp, Asp301Glu mutations in CYP2D6. Finally, we screened for potential binders/inhibitors from the Chinese herbal medicine Scutellaria baicalensis (Huangqin, Baikal Skullcap) using the established pharmacophore model for CYP2D6 inhibitors and molecular docking approach. Overall, 18 out of 40 compounds from S. baicalensis were mapped to the pharmacophore model of CYP2D6 inhibitors and most herbal compounds from S. baicalensis could be docked into the active site of CYP2D6. Our study has provided insights into the molecular mechanisms of interaction of synthetic and herbal compounds with human CYP2D6 and further benchmarking studies are needed to validate our modeling and virtual screening results.     

The accessibility of antigenic determinants of ribosomal protein S4 in situ.

Antibodies to Escherichia coli ribosomal protein S4 react with S4 in subribosomal particles, eg, the complex of 16S RNA with S4, S7, S8, S15, S16, S17, and S19 and the RI reconstitution intermediate, but they do not react with intact 30S subunits. Antibodies were isolated by three different methods from antisera obtained during the immunization of eight rabbits. Some of these antibody preparations, which contained contaminant antibodies directed against other ribosomal proteins, reacted with subunits, but this reaction was not affected by removal of the anti-S4 antibody population. Other antibody preparations did not react with subunits. It is concluded that the antigenic determinants of S4 are accessible in some protein deficient subribosomal particles but not in intact 30S subunits.     

表活性单体NaAMCnS及其聚合物的合成及性能研究

针对疏水缔合聚合物水溶性不足的问题，本文合成了三种含烷基磺酸根的阴离子型表面活性单体2-丙烯酰胺基辛烷基磺酸钠（NaAMC₈S）、2-丙烯酰胺基十二烷基磺酸钠(NaAMC₁₂S)和2-丙烯酰胺基十八烷基磺酸钠(NaAMC₁₈S),通过氢谱、碳谱、高分辨质谱对其结构进行了表征。通过表面张力法和电导率法测定了NaAMC₈S和NaAMC₁₂S的临界胶束浓度；用荧光探针技术研究了其增溶作用；以偶氮二异丁脒盐酸盐（AIBA）为引发剂，在水溶液中研究了丙烯酰胺（AM）分别与NaAMC₈S、NaAMC₁₂S的二元共聚反应，通过控制AM与NaAMC₈S、NaAMC₁₂S的投料比制备得到两个系列聚合物P（AM/NaAMC₈S）、P(AM/NaAMC₁₂S),研究了表面活性单体含量对聚合物疏水缔合作用及耐温抗盐性能的影响。实验结果表明，NaAMC₈     

Preparation of D-Phenylalanine by Asymmetric Transformation

The method of preparing D-phenylalanine by asymmetric transformation is reported.D-phenylalanine was prepared from DL-phenylalanine by two-step reaction.D-phenylalanine(2S,3S)-tartrate was prepared by heating DL-phenylalanine,salicylaldehyde,and (2S,3S)-tartaric acid in propionic acid;the obtained D-phenylalanine(2S,3S)-tartrate was treated with triethylamine in ethanol giving D-phenylalanine with 98% optical purity in 69% yield.     

Fatty Acid Composition of Sideritis Species

Seed oils of 15Sideritisspecies collected from different regions in Turkey(S. athoa, S. brevidens, S. caesarea, S. condensata, S. congesta, S. dichotoma, S. erythrantha var. cedretorum, S. germanicopolitana ssp. germanicopolitana, S. hololeuca, S. lanata, S. libanotica ssp. violascens, S. lycia, S. niveotomentosa, S. perfoliata, S. phrygia, S. pisidica)were obtained by a Soxhlet apparatus using hexane. The oil yields were found to be between 5.6-36.3%. Fatty acids in the oils were converted to methyl esters and their compositions were determined by GC/MS. The main fatty acid components of the oils from all the species are linoleic (45.4-64.0%), oleic (12.3-26.5%), 6-octadecynoic (4.5-26.8%), palmitic (0.3-9.4%), and linolenic (0.8-2.0%) acids.     

Luminescence properties of the mixed J-aggregate of oxacyanine dye and thiacyanine dye. Formation of a persistence-type aggregate

The monolayer assemblies incorporating the J-aggregates of oxacyanine dye, N,N'-dioctadecyloxacyanine perchlorate (S9), and thiacyanine dye, N,N'-dioctadecylthiacyanine perchlorate (S11), S9(J) + S11(J), have been fabricated by the Langmuir-Blodgett (LB) technique. The mole fraction X of S11, X = [S11]/([S9] + [S11]), was varied from 0 to 1. Steady-state absorption spectra, fluorescence spectra, and picosecond fluorescence decay curves of the monolayer assemblies have been measured. Spectroscopic properties of the monolayer assemblies incorporating the individual dye aggregates, S9 J-aggregate (S9(J), X = 0) or S11 J-aggregate (S11(J), X = 1), are characterized by a distinct J-band and resonance fluorescence at lambda(ab) = 403 nm and lambda(em) = 403 nm for S9(J) and lambda(ab) = 456 nm and lambda(em) = 463 nm for S11(J). On the other hand, absorption spectra of the S9(J) + S11(J) assemblies for X = 0.1-0.9 display two absorption bands, a shorter wavelength one and a longer wavelength one, whose peak positions are blue-shifted from those of the corresponding J-bands of the S9 J-aggregate and the S11 J-aggregate, respectively. Furthermore, fluorescence spectra are characterized by a single band (longer wavelength fluorescence) which is somewhat blue-shifted from the resonance fluorescence of the S11 J-aggregate. The fluorescence lifetimes of the S11 J-aggregate and isolated S11 molecules in LB films appear to be tau = 110 and 1900 ps, respectively, while the fluorescence lifetime of the longer wavelength fluorescence of the S9(J) + S11(J) assemblies takes practically a constant value of tau = 170-180 ps for X = 0.2-0.8. These observations would indicate that S9 and S11 molecules in the S9(J) + S11(J) assembly can form a specific mixed aggregate distinct from the individual S9 and S11 J-aggregates. From detailed considerations of the former works on luminescence properties of the S9 J-aggregate doped with isolated S11 molecules, as well as the mosaic-type mixed J-aggregate (M-aggregate) composed of a certain thiacyanine dye, 3,3'-disulfopropyl- 5,5'-dichlorothiacyanine sodium salt, and thiacarbocyanine dye, meso-substituted 3,3'-disulfopropyl-5,5'-dichlorothiacarbocyanine potassium salt, it is suggested that S9 and S11 can form a homogeneous aggregate of the persistence type (HP-aggregate). The HP-aggregate is distinguished from the M-aggregate because it is characterized by homogeneous mixing of two component dyes and persistence of two absorption bands.     

Synthesis of new chiral sulfinyldiacetic acid derivatives and attempt at chemoselective asymmetric Pummerer reaction

(R(S))-1 (85% ee) was prepared by utilizing a porcin pancreatic lipase-promoted hydrolysis of sulfinyldiacetic acid dimethyl ester (8) which was derived from thiodiacetic acid (7). (R(S))-1 (99% ee) and (S(S))-1 (99% ee) were readily obtained by methanolysis of (R(S),S)-12 and (S(S),S)-12 with MeONa in MeOH. (R(S),S)-12 and (S(S),S)-12 were furnished by chromatographic separation of the diastereomeric mixture, obtained by oxidation of thiodiacetic mono-carboxylic acid (11) with 30% H2O2 followed by dehydrative condensation of the resultant sulfinyldiacetic mono-carboxylic acid with 4(S)-isopropyl-1,3-thiazolidine-2-thione. (R(S))-1 (99% ee) was successively treated with (TMS)2NLi, Ac2O, and TMSOTf to give a major chiral-3 product in 75% ee and in a highly chemoselective manner (chiral-3:chiral-2=93:7).     

Total synthesis of (-)- and (+)-dysibetaine

Glycidamides 6R and 6S were elaborated to (R,R)- and (S,S)-dysibetaines (1R and 1S) by intramolecular alkylation and functional group modification in 23% overall yield. The absolute stereochemistry of natural dysibetaine was established as S,S by comparison of the optical rotation of the natural product with that of the synthetic materials.