A biochemometrics strategy combining quantitative determination,bioactivity evaluation and relationship analysis for identification of analgesic alkaloids of raw and vinegar‐processed Corydalis turtschaninovii

A biochemometrics strategy combining quantitative determination, bioactivity evaluation, and relationship analysis was proposed for identification of analgesic components of herbs. First, a robust liquid chromatography tandem mass spectrometry method was developed for simultaneous determination of nine major alkaloids in crude and vinegar‐processed Corydalis turtschaninovii. Nine alkaloids were separated on a BEH C₁₈ column with a mobile phase consisting of acetonitrile and water spiked with 0.1% formic acid and then detected by multiple reactions monitoring in the positive ion mode. Nitidine chloride was employed as the internal standard. The method displayed good linearity and the precisions of intra‐day and inter‐day were all within 3.0%. The recovery rates of each alkaloid ranged from 97.1 to 102.9%. The method was successfully applied for quantitative analysis of nine alkaloids in ten batches of crude and vinegar‐processed Corydalis turtschaninovii. Second, the analgesic effects of crude and vinegar‐processed Corydalis turtschaninovii were evaluated in mice. Third, principle component analysis, canonical correlation analysis, and partial least squares regression were used to analysis the relationship between the contents of nine major alkaloids and the analgesic effect of different crude and vinegar‐processed samples. Tetrahydropalmatine, coptisine, and dehydrocorydaline have a close positive correlation with the analgesic effect.     

PVCH-PE-PVCH三嵌段共聚物在超临界CO2中的熔融再结晶行为

本研究组在前期研究中发现, 改变溶剂的挥发速率可以调节体系中PE结晶和PVCH玻璃化之间的竞争, 进而调节PE结晶的受限程度. 超临界二氧化碳(scCO2)是一种非极性溶剂, 其对无定形聚合物(如PS)有很强的溶胀作用, 可显著降低聚合物的玻璃化转变温度, 提高原来被冻结的高分子链的活动能力. PVCH的分子结构与PS相似, 研究结果表明, scCO2对PVCH组分也有很强的溶胀能力, 导致PVCH的玻璃化转变温度降低, 从而可以改变PE嵌段的受限状态. 本文研究了PVCH-PE-PVCH在scCO2中的熔融再结晶行为.     

高速逆流色谱法对废次烟草中茄尼醇的分离制备

高速逆流色谱法(HSCCC)是80年代初期发展起来的一种无需使用任何固态支持介质的液液分配色谱分离技术,样品的各组分是根据其在两相中的分配系数不同被分离开的.由于不使用固态支持介质,避免了因不可逆吸附而引起的样品损失、失活变性等.高速逆流色谱法已广泛应用于天然产物有效成分的分离.     

单、双核钌羰基化合物Ru（CO）n（n=5，4，3）和Ru2（CO）n（n=9，8）的理论研究

采用两种密度泛函方法对中性单核Ru（CO）n（n=5,4,3）和双核Ru2（CO）n（n=9,8）化合物进行理论计算,优化出16个稳定异构体．研究发现,和Os（CO）5类似,Ru（CO）5存在两个能量接近的最低异构体．Ru（CO）4的能量最低异构体为C2v对称性的单态构型．Ru（CO）3能量最低异构体为G对称性的单态构型．Ru2（c0）。的两个能量接近的最低异构体分别含有单个桥羰基和3个桥羰基．双核不饱和Ru2（CO）8的能量最低异构体为含有两个桥羰基的单态Q构型．通过比较M2（CO）n（M=Fe,Ru,Os;n=9,8）的能量最低构型,发现Fe和Ru倾向于形成含有多个桥配位羰基的构型,而Os则更倾向于形成不含桥配位羰基的构型．对离解能的研究表明,和失去一个羰基生成Ru2（CO）8相比,Ru2（CO）9更容易离解为Ru（CO）5和Ru（CO）4．     

溶剂对聚氯乙烯-聚乙二醇-KOH体系脱氯行为的影响

废旧塑料的回收利用是当今研究的热点之一.据报道,2007年中国聚氯乙烯(PVC)产量高达960万吨[1],如何合理利用相应产生的废旧PVC是一个十分重要的课题.     

4-[(E)-2-(3,4,5-三甲氧基苯基)乙烯基]苯氧基羧酸酯的合成及抗肿瘤活性研究

二苯乙烯的多种衍生物表现出一系列的生理活性,如3,4,5.三羟基二苯乙烯(白藜芦醇)具有预防心脏病,抑制血小板凝聚,调控脂质和脂蛋白代谢,抗氧化及对癌症的治疗等作用[1-3].     

Novel facile detection of persistent organic pollutants using highly sensitive gas sensor

Persistent organic pollutants (POPs) are greatly noxious chemicals in environment, and they can cumulate in organisms and transfer between different species. Therefore, it is significant to detect POPs for both environmental evaluation and further treatment. However, developing facile approach for the detection of POPs still remains a challenge so far. In this paper, we report an innovative method for facile detection of POPs using gas sensor for the first time. Porous SnO₂ nanostructures with a special tri-walled structure prepared via hydrothermal route and annealing process, were employed as gas-sensing materials. Through gas measurements, it was revealed that the as-fabricated gas sensor exhibited highly sensitive performance towards target POPs, including methoxychlor, mirex, p,p′-DDT, and aldrin. Moreover, we found that target POPs were distinguishable by extracting characteristics in kinetic curves of gas adsorption-desorption. As the presented detecting approach is facile without the requirements of complex operations, expensive and bulky instruments, it is expected that it would be developed as a promising method for the detection of POPs, and thereby showing its significance for environmental monitoring.     

Structure of aqueous sodium metaborate solutions: X-ray diffraction study

A structural analysis of aqueous sodium metaborate solutions (NaBo₂ · nH₂O, n = 10, 15, 20) at 298 ± 0.5 K by a rapid liquid ??-?? X-ray diffractometry with a highly effective X??celerator detector is reported in present paper. The radial distribution functions (RDF) and theoretical partial radial distribution functions for B-O, O-O, Na-O, Na-B, and Na-Na atom pairs were obtained from precisely diffraction data processing. Structure of aqueous sodium metaborate solutions was given through model calculation and described in three different items: hydrated sodium ion, hydrated metaborate ion and ion association. Effects of concentration on the structure of the solutions were discussed in detail. The mechanisms of ion aggregation and the formation of crystal nuclei in the solution are proposed. The results show that a clear picture of the structure of aqueous sodium metaborate solution has been acquired.     

Liquid chromatography-mass spectrometry identification of imidacloprid photolysis products

Photolysis of imidacloprid by near ultraviolet (UV) radiation was investigated using reversed phase liquid chromatography (RPLC) and liquid chromatography-electrospray ionization/mass spectrometry (LC-ESI/MS) operated in the positive ion mode. The decomposition of imidacloprid by near UV light is first order with a half life of 10.18 h. Photo-degradation products of imidacloprid identified in this study included imidacloprid urea, imidacloprid olefin, and imidacloprid desnitro. A degradation pathway is proposed for imidacloprid from an examination of the product decay curves obtained in this monitoring study which was performed in a batch test mode.