高效毛细管电泳法测定石杉碱甲片中石杉碱甲含量

提出了毛细管电泳法分离测定石杉碱甲片中石杉碱甲含量的方法。以pH为4.6的乙酸盐溶液为电解质溶液,运行电压13kV,于波长310nm处进行紫外检测。石杉碱甲的质量浓度在5.0～60mg.L-1范围内与峰面积呈线性关系。采用该方法对石杉碱甲片样品中石杉碱甲的浓度进行了测定,所得加标回收率在97.8%～98.7%之间,测定值的相对标准偏差(n=5)在0.53%～0.85%之间。     

微波预处理提取蛇足石杉中总生物碱的工艺优化

蛇足石杉为厥类植物,属石松类石杉科(Huperziacease)石杉属(Huperzia),又名千层塔、蛇足草.从蛇足石杉中提取分离得到的石杉碱甲(Hup A),是一种强效的可逆性胆碱酯酶抑制剂,在临床上主要用于治疗重症肌无力、改善老年性记忆功能减退 [1-2].     

石杉碱甲的合成及结构改造研究进展*

石杉碱甲是一高效、高选择性乙酰胆碱酯酶抑制剂, 由于其独特的药理特征和低毒性, 引起了人们的广泛注意。本文系统地综述了石杉碱甲的全合成方法、结构改造工作及构效关系的研究。     

石杉碱甲和石杉碱乙的化学研究

从石杉科植物千层塔中分得两个新生物碱:石杉碱甲和石杉碱乙,经光谱测定和化学降解阐明它们的结构分别如1和2所示.它们都具有很强的抑制胆碱酯酶活性和提高学习,记忆效率的功能,其中石杉碱甲经临床试验证明对重症肌无力,老年性健忘症和老年性痴呆症有一定疗效.     

石杉碱甲类似物的合成及药理研究Ⅰ.(±)-14-氟石杉碱甲

用两种方法合成了(±)-14-氟石杉碱甲(6),并测定了其抑制乙酸胆碱酯酶的生物活性.其抑制活性是(-)-石杉碱甲(1)的1/62.     

石松生物碱(+)-Fawcettimine,(+)-Fawcettidine和(-)-8-Deoxyserratinine的全合成

Angew.Chem.Int.Ed.2012,51,491～495石松类生物碱(Lycopodium alkaloids)是从蕨类植物石松和其近缘植物中分得的结构类似,具有相同生源的一类结构奇特且骨架变化多样的生物碱.这类生物碱具有很多重要的生物学功能,最具代表性的如石杉碱甲对治疗老年痴呆症有显著疗效.由于该类生物碱具有新颖复杂的化学结构和重要的生物功能,对于该天然产物的全合成研究已经成为近十年内国际有机合成领域的难点和热点.天津大学药学院和北京生命科学研究所雷晓光教授课题组最近报道完成了该家族中三个天然产物(+)-Fawcettimine,     

石杉碱甲分子印迹聚合物的制备、表征及其吸附性能

以硅胶为牺牲载体,石杉碱甲为模板分子,甲基丙烯酸为功能单体,二乙烯基苯为交联剂,偶氮二异丁腈为引发剂,首次制备了石杉碱甲分子印迹聚合物,并用红外光谱、扫描电子显微镜和热重分析研究了印迹聚合物的结构特征,用静态吸附法和Scatchard分析法研究了印迹聚合物的识别效能和表面位点分布特征。 结果表明,石杉碱甲印迹聚合物对模板分子具有较好的选择吸附性能,选择系数为1.399。Scatchard分析表明,印迹聚合物基体中主要存有两类吸附位点,对高亲和位点：平衡离解常数Kd1=0.776 g/L,最大表观结合量Qmax1=0.213 mg/g;对低亲和位点：平衡离解常数Kd2=0.169 g/L,最大表观结合量Qmax2=0.832 mg/g。 当该聚合物用于微固相萃取蛇足石杉粗提液中的石杉碱甲时,石杉碱甲回收率为93.5%,显示了较好的富集效果。     

石杉碱甲引湿性的研究

分析和比较石杉碱甲干燥前和干燥后的引湿性。使用动态水分吸附分析法（Dynamic Vapor Sorption,DVS）对石杉碱甲的引湿性进行研究。采用卡式水分测定方法测定了石杉碱甲干燥前和干燥后的水分。石杉碱甲干燥前与干燥后均有引湿性,导致含量结果测定存在误差。DVS结果显示引湿增重7%即可达到平衡。将样品置于相对湿度75%、温度15℃恒温恒湿箱中15天引湿后测得水分为7.30%,经DVS考察不再引湿,能准确地测定石杉碱甲的含量。并用高效液相色谱法测定石杉碱甲的含量的均一性。     

高效液相色谱法定量测定中药千层塔提取物中的石杉碱甲

建立了高效液相色谱快速定量测定中药千层塔提取物中石杉碱甲含量的分析方法。千层塔提取物经甲醇/水/甲酸(10/90/0.2, v/v/v)提取并定容后,过滤膜后直接分析。色谱分离选用XCharge C18色谱柱(150 mm×4.6 mm, 5 μm),以水(含0.1%三氟乙酸)和乙腈(含0.09%三氟乙酸)为流动相进行梯度洗脱,流速为2 mL/min,于310 nm波长下检测,可在10 min内完成石杉碱甲的快速分离分析。结果表明,石杉碱甲在2.12～106 mg/L范围内线性关系良好(相关系数为0.9999);平均加标回收率为102.34%,相对标准偏差(RSD)为0.46%;日内及日间精密度均小于2%,满足定量要求。该方法简便、快速,结果可靠,重现性好,可作为千层塔提取物质量评价的依据。     

A New Flavonol Oligosaccharide from the Seeds of Aesculus chinensis

Aesculus chinensis is a traditional chinese medicinal plant widely distributed in China, which has been used to treat stomach disease. From recent research its seeds contain many flavonoids and proanthocyanidin A2, which have potential venotonic and vasoprotective action and powerful antioxidant activity. In this paper, we report the isolation and the structure elucidation of a new flavonol oligosacchride. Bioassay results showed that the compound exhibited an antivirus activity. …     

Ultrafast Single-Scan 2D NMR Spectroscopic Detection of a PHIP-Hyperpolarized Protease Inhibitor

Two-dimensional NMR spectroscopy is one of the most important spectroscopic tools for the investigation of biological macromolecules. However, due to the low sensitivity of NMR spectroscopy, it takes usually from several minutes to many hours to record such spectra. Here, the possibility of detecting a bioactive derivative of the sunflower trypsin inhibitor-1 (SFTI-1), a tetradecapeptide, by combining parahydrogen-induced polarization (PHIP) and ultrafast 2D NMR spectroscopy is shown. The PHIP activity of the inhibitor was achieved by labeling with O-propargyl-l -tyrosine. In 1D PHIP experiments a signal enhancement of a factor of approximately 1200 compared to standard NMR was found. This enhancement permits measurement of 2D NMR correlation spectra of low-concentrated SFTI-1 in less than 10 seconds, employing ultrafast single-scan 2D NMR detection. As experimental examples PHIP-assisted ultrafast single-scan TOCSY spectra of SFTI-1 are shown.     

Monofunctionalized pillar[5]arene-based stable [1]pseudorotaxane

A new monofunctionalized pillar[5]arene bearing imidazolium moiety that formed stable [1]pseudorotaxane even at high concentration (100 mmol/L) was reported. [1]Rotaxane was obtained effi ciently through thiol-ene reaction from [1]pseudorotaxane which further confi rmed the formation of [1]pseudorotaxane.     

Petatrichol B： A Pentacyclic Triterpenoid with Unusual Skeleton from Petasites tricholobus

A novel pentacyclic triterpenoid, petatrichol B, was isolated from the rhizome of Petasites tricholobus. Its structure was established by means of spectroscopic analysis （EIMS, HRSIMS, IR, 1D NMR and 2D NMR）.     

利用选择性激发核磁共振对混合物中的两种化合物进行结构解析

利用现代NMR的1D、2D技术对一个混合物进行了分析。结果表明：混合物由两种化合物组成。为了同时准确确定两种化合物的结构，本工作应用了1D-TOCSY技术，利用该技术选择性强的特点来补充常规的1D、2DHMR实验所提供的分子结构的信息。在没有进行预分离的条件下，顺利地完成了样品中两种化合物的核磁信号归属，并最终确定了它们的结构。     

Preparation and study on the solid inclusion complex of cloxacillin sodium with beta-cyclodextrin

The interaction of cloxacillin sodium with beta-cyclodextrin (beta-CD) has been studied by several analytical techniques, including (1)H NMR, fluorescence spectroscopy, infrared spectroscopy. In this paper, solid inclusion complex of cloxacillin sodium with beta-CD was synthesized by the coprecipitation method. In addition, the characterization of the inclusion complex has been proved by fluorimetry, infrared spectroscopy and 1D, 2D NMR. The experimental results confirmed the existence of 1:1 inclusion complex of cloxacillin sodium with beta-CD. The formation constant of complex was determined by fluorescence method and (1)H NMR. Spacial configuration of complex has been proposed on 2D NMR technique.     

Bishyoscyamine, one unusual dimeric tropane alkaloid from Anisodus acutangulus

One unusual dimeric tropane alkaloid, bishyoscyamine, was isolated from the roots of Anisodus acutangulus, whose structure including the absolute stereochemistry was unambiguously determined based on extensive 1D NMR and 2D NMR, HR-ESI-MS [α]D and CD spectroscopic analyses. To our knowledge, bishyoscyamine is the first example of tropane alkaloid dimer condensed by a C-N bond.     

A new lignan from the seeds of Sphaerophysa salsula

A novel lignan: sphaerophyside SC was isolated from ethanolic extract of the seeds of Sphaerophysa salsula (Pall.) DC. The structure of the compound was elucidated mainly on the basis of the 1D NMR and 2D NMR data.     

1H and 13C NMR assignments for four triterpenoid saponins from Albizziae cortex

Four triterpenoid saponins were isolated from Albizziae cortex, and a complete assignment of their (1)H and (13)C NMR spectra was carried out using 1D and 2D NMR ((1)H-(1)H COSY, HSQC, HMBC, and HSQC-TOCSY) methods. Their (1)H NMR assignments were reported for the first time and some of their (13)C NMR spectral data reported in literature were corrected.     

Automated structure verification based on a combination of 1D (1)H NMR and 2D (1)H - (13)C HSQC spectra

A method for structure validation based on the simultaneous analysis of a 1D (1)H NMR and 2D (1)H - (13)C single-bond correlation spectrum such as HSQC or HMQC is presented here. When compared with the validation of a structure by a 1D (1)H NMR spectrum alone, the advantage of including a 2D HSQC spectrum in structure validation is that it adds not only the information of (13)C shifts, but also which proton shifts they are directly coupled to, and an indication of which methylene protons are diastereotopic. The lack of corresponding peaks in the 2D spectrum that appear in the 1D (1)H spectrum, also gives a clear picture of which protons are attached to heteroatoms. For all these benefits, combined NMR verification was expected and found by all metrics to be superior to validation by 1D (1)H NMR alone. Using multiple real-life data sets of chemical structures and the corresponding 1D and 2D data, it was possible to unambiguously identify at least 90% of the correct structures. As part of this test, challenging incorrect structures, mostly regioisomers, were also matched with each spectrum set. For these incorrect structures, the false positive rate was observed as low as 6%.