左金丸及类方HPLC指纹图谱与生物热活性的“谱-效”关系研究

HPLC法建立左金丸及类方水提液的特征指纹图谱,计算各特征峰的相对峰面积,并采用中药色谱指纹图谱相似度评价系统A版(2004 A)计算类方间的相似度;微量热法测定大肠杆菌在左金丸及类方水提液作用下的热谱曲线,得到相应的热动力学参数,如生长速率常数k,最大产热功率Pm,最高峰的出峰时间tm和总产热量Qt等,并对这些热动力学参数进行主成份分析.典型相关分析法对左金丸及类方HPLC指纹图谱中特征峰的相对峰面积与其类方作用下大肠杆菌生长代谢的主要热动力学参数相关联,研究"谱-效"相关性.结果表明,HPLC指纹图谱与生物热活性存在很好的相关性,类方中吴茱萸次碱、盐酸巴马汀、盐酸小檗碱的含量差异是导致其生物热活性不同的主要原因.

芦根亲水共有成分及解酒护肝的“谱⁃效⁃味”关系研究

目的分析芦根亲水共有成分及解酒护肝“谱-效-味”关系。方法以12个不同产地芦根饮片,单个产地芦根鲜品、饮片、水提冻干粉为样品。采用反相/亲水色谱串联四极杆-飞行时间质谱法分析样品共有成分,网络药理学-分子对接技术分析共有成分活性,分子排阻色谱串联示差折光法分析样品糖类成分分子量。通过大鼠急性酒精性肝损伤实验测定大鼠血清ALT、AST、LDH、TG、VLDL水平,偏最小二乘法和皮尔逊相关分析芦根糖类共有成分峰面积与药效指标浓度,电子舌分析味觉值相关性。结果从芦根中得到290种成分,筛选出12种共有成分,芦根中糖类成分分子量集中分布在1~2 kDa及100~200 kDa这2个区间段,共有成分分子量为1600、1000 Da(命名为芦根多糖1600、1000)。腺苷环磷酸酯、鸟嘌呤核糖苷-3,5-环磷酸酯能够降低ALT、AST水平,对香豆酸能够降低LDH水平,芦根多糖1600能够降低TG、VLDL水平。糖类成分含量越高,甜味值越高;酚酸类成分含量越高,酸味值越高,药效越高。结论芦根多糖1600、对香豆酸、腺苷环磷酸酯、鸟嘌呤核糖苷-3,5-环磷酸酯可以作为芦根解酒护肝活性成分。

Electronic Structures, DNA-binding, SAR, and Spectral Properties of Ruthenium Methylimidazole Complexes [Ru（MeIm）4L]^2＋（L=iip,tip,2ntz）

Theoretical studies on the electronic and geometric structures, the trend in DNA-binding affinities as well as the the structure-activity relationship （SAR） of a series of water-soluble Ru（II） methylimidazole complexes, i.e. [Ru（Mehn）4iip]^2＋ （1） （MeIm=l-methylimidazole, iip=2-（1H-imidazo-4-group）-lH-imidazo[n,5-f][1,10]phenanthroline）, [Ru（MeIm）4tip]^2＋ （2） （tip=2-（thiophene-2-group）-lH-imidazo[4,5-f] [i,10]phenanthroline）, and [Ru（Melm）42ntz]^2＋ （3） （2ntz=2-（2-nitro-l,3-thiazole-5-group）-lH-imidazo[4,5-f][1,10]phenanthroline）, were car- ried out using the density functional theory （DFT）. The electronic structures of these Ru（II） complexes were analyzed on the basis of their geometric structures optimized in aqueous solution, and the trend in the DNA-binding constants （Kb） was reasonably explained. The results show that the replacement of imidazole ligand by thiophene ligand can effectively improve the DNA-binding affinity of the complex. Meanwhile, it was found that introduc- ing the stronger electronegative N atom and NO2 group on terminal loop of intercalative ligand can obviously reduce the complex＇s LUMO and HOMO-LUMO gap energies. Based on these findings, the designed complex [Ru（MeIm）42ntz]^2＋ （3） can be expected to have the greatest Kb value in complexes 1-3. In addition, the structure-activity relationships and antitumor mechanism were also carefully discussed, and the antimetastatic activity of the designed complex 3 was predicted. Finally, the electronic absorption spectra of this series of complexes in aqueous solution were calculated, simulated and assigned using DFT/TDDFT methods as well as conductor-like polarizable continuum model （CPCM）, and were in good agreement with the experimental results.

Surface-enhanced vibrational spectroscopies in electrocatalysis:Fundamentals,challenges,and perspectives

Electrocatalysis offers a promising approach towards chemical synthesis driven by renewable energy.Molecular level understanding of the electrochemical interface remains challenging due to its compositional and structural complexity.In situ interfacial specific characterization techniques could help uncover structure-function relationships and reaction mechanism.To this end,electrochemical surface-enhanced Raman spectroscopy(SERS)and surface-enhanced infrared absorption spectroscopy(SEIRAS)thrive as powerful techniques to provide fingerprint information of interfacial species at reaction conditions.In this review,we first introduce the fundamentals of SERS and SEIRAS,followed by discussion regarding the technical challenges and potential solutions.Finally,we highlight future directions for further development of surface-enhanced spectroscopic techniques for electrocatalytic studies.

中药质量评价关键问题与分析方法探讨

该文针对我国目前中药质量评价体系现状,总结了中药质量评价的关键科学问题,并围绕“发现”与“控制”有效成分的中药质量评价方法进行探讨。笔者结合多年中药质量分析研究工作经验,分析了中药“谱-效”关系研究、全时段等基线多波长融合指纹图谱、生物活性测定法3种质量评价与检测方法的研究内容、手段、适用范围等,为丰富、完善中药质量控制方法和中药质量标准体系的提升提供了借鉴。

Support effect of zinc tin oxide on gold catalyst for CO oxidation reaction

Nanostructured gold catalyst supported on metal oxide is highly active for the CO oxidation reac‐tion. In this work, a new type of oxide support, zinc tin oxide, has been used to deposit 0.7 wt%Au via a deposition‐precipitation method. The textural properties of Zn2SnO4 support have been tuned by varying the molar ratio between base （N2H4＆#183;H2O） and metal ion （Zn2＋） to be 4/1, 8/1 and 16/1. The catalytic tests for CO oxidation reaction revealed that the reactivity on Au‐Zn2SnO4 with N2H4＆#183;H2O/Zn2＋ = 8/1 was the highest, while the reactivity on Au‐Zn2SnO4 with N2H4＆#183;H2O/Zn2＋ =16/1 was almost identical to that of the pure support. Both fresh and used catalysts have been characterized by multiple techniques including nitrogen adsorption‐desorption, X‐ray diffraction, transmission electron microscopy, high‐angle annular dark‐field scanning transmission electron microscopy, X‐ray photoelectron spectroscopy, X‐ray adsorption fine structure, and tempera‐ture‐programmed reduction by hydrogen. These demonstrated that the textural properties, espe‐cially pore volume and pore size distribution, of Zn2SnO4 play crucial roles in the averaged size of gold nanoparticles, and thus determine the catalytic activity of Au‐Zn2SnO4 for CO oxidation.

Fundamental aspects in CO_(2) electroreduction reaction and solutions from in situ vibrational spectroscopies

Using renewable energy to drive carbon dioxide reduction reaction(CO_(2)RR)electrochemically into chemicals with high energy density is an efficient way to achieve carbon neutrality,where the effective utilization of CO_(2) and the storage of renewable energy are realized.The reactivity and selectivity of CO_(2)RR depend on the structure and composition of the catalyst,applied potential,electrolyte,and pH of the solution.Besides,multiple electron and proton transfer steps are involved in CO_(2)RR,making the reaction pathways even more complicated.In pursuit of molecular-level insights into the CO_(2)RR processes,in situ vibrational methods including infrared,Raman and sum frequency generation spectroscopies have been deployed to monitor the dynamic evolution of catalyst structure,to identify reactive intermediates as well as to investigate the effect of local reaction environment on CO_(2)RR performance.This review summarizes key findings from recent electrochemical vibrational spectrosopic studies of CO_(2)RR in addressing the following issues:the CO_(2)RR mechanisms of different pathways,the role of surface-bound CO species,the compositional and structural effects of catalysts and electrolytes on CO_(2)RR activity and selectivity.Our perspectives on developing high sensitivity wide-frequency infrared spectroscopy,coupling different spectroelectrochemical methods and implementing operando vibrational spectroscopies to tackle the CO_(2)RR process in pilot reactors are offered at the end.

HPLC Analysis of Egg Yolk Phosphatidylcholine by Evaporative Light Scattering Detector

Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).

Alternaria toxin-induced resistance in rose plants against rose aphid(Macrosiphum rosivorum): effect of tenuazonic acid

Many different types of toxins are produced by the fungus, Alternaria alternata （Fr.） Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography （HPLC） analyses demon- strated that tenuazonic acid （TEA） was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 IJg/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated re- sponses in rose plants to intensively enhance the plant＇s resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants.