光谱采集方式对AOTF-近红外光谱技术分析烟草主要化学成分的影响

初步探讨了不同光谱采集方式对AOTF-近红外光谱技术检测烟草主要化学成分及建模的影响。结果表明,以旋转方式采集光谱可以得到更多的样品信息,所建立的模型精度较高。从模型的各项指标来看,总糖、还原糖和总烟碱的相关系数很高,说明化学成分含量数据和光谱数据间有较好的相关性。实验结果表明AOTF-近红外光谱技术可用于烟草样品主要化学成分的常规分析。     

A method toward constituents with weak response in mass spectra for comprehensively characterizing constituents in traditional Chinese medicine formula,Kangfuxiaoyanshuan as a case

How to identify the traces with weak response and poor mass spectrometry data is still a barrier to comprehensively characterize chemical constituents of traditional Chinese medicine formula. Thus, we took Kangfuxiaoyanshuan as a carrier to perform a method toward these weak response constituents in mass spectra. Chemical constituents profiling spectra of each herb and formula were firstly obtained by an ultra‐high‐performance liquid chromatography coupled with linear ion trap‐Orbitrap mass spectrometry. Next, the high response constituents in the formula were identified and suspicious constituents with weak response were classified preliminarily according to the reflection of chemical components from each herb. In order to clarify the suspicious, a method increasing detection concentration, optimizing chromatographic separation conditions, and online parameters in mass was established. As a result, a total of 123 chemical components including 43 suspicious components in Kangfuxiaoyanshuan were classified and characterized unambiguously.     

Qualitative Analysis and Componential Differences of Chemical Constituents in Taxilli Herba from Different Hosts by UFLC-Triple TOF-MS/MS

Taxilli Herba (TH) is a well-known traditional Chinese medicine (TCM) with a wide range of clinical application. However, there is a lack of comprehensive research on its chemical composition in recent years. At the same time, Taxillus chinensis (DC) Danser is a semi parasitic plant with abundant hosts, and its chemical constituents varies due to hosts. In this study, the characterization of chemical constituents in TH was analyzed by ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry (UFLC-Triple TOF-MS/MS). Moreover, partial least squares discriminant analysis (PLS-DA) was applied to reveal the differential constituents in TH from different hosts based on the qualitative information of the chemical constituents. Results showed that 73 constituents in TH were identified or tentatively presumed, including flavonoids, phenolic acids and glycosides, and others; meanwhile, the fragmentation pathways of different types of compounds were preliminarily deduced by the fragmentation behavior of the major constituents. In addition, 23 differential characteristic constituents were screened based on variable importance in projection (VIP) and p-value. Among them, quercetin 3-O-β-D-glucuronide, quercitrin and hyperoside were common differential constituents. Our research will contribute to comprehensive evaluation and intrinsic quality control of TH, and provide a scientific basis for the variety identification of medicinal materials from different hosts.     

固相微萃取气质联用技术对卷烟烟丝和卷烟烟气总粒相物中挥发性和半挥发性成分的研究

采用固相微萃取－气相色谱－质谱（SPME－GC－MS）法对成品卷烟烟丝和卷烟烟气总粒相物中挥发性和半挥发性成分进行了分析鉴定，并对鉴定出的70种成分和96种成分进行了比较。     

Influence of the Molecular Structure of Constituents and Liquid Phase Non-Ideality on the Viscosity of Deep Eutectic Solvents

Hydrophobic deep eutectic solvents (DES) have recently been used as green alternatives to conventional solvents in several applications. In addition to their tunable melting temperature, the viscosity of DES can be optimized by selecting the constituents and molar ratio. This study examined the viscosity of 14 eutectic systems formed by natural substances over a wide range of temperatures and compositions. The eutectic systems in this study were classified as ideal or non-ideal based on their solid–liquid equilibria (SLE) data found in the literature. The eutectic systems containing constituents with cyclohexyl rings were considerably more viscous than those containing linear or phenyl constituents. Moreover, the viscosity of non-ideal eutectic systems was higher than that of ideal eutectic systems because of the strong intermolecular interactions in the liquid solution. At temperatures considerably lower than the melting temperature of the pure constituents, non-ideal and ideal eutectic systems with cyclohexyl constituents exhibited considerably high viscosity, justifying the kinetic limitations in crystallization observed in these systems. Overall, understanding the correlation between the molecular structure of constituents, SLE, and the viscosity of the eutectic systems will help in designing new, low-viscosity DES.     

Simultaneous analysis of multiple bioactive constituents in Rheum tanguticum Maxim. ex Balf. by high-performance liquid chromatography coupled to tandem mass spectrometry

A simple, rapid method was developed using on-line high-performance liquid chromatography (HPLC)-diode array detection (DAD)/electrospray ionization mass spectrometry (ESI-MS) to simultaneously analyze multiple bioactive constituents in the extract of Rheum tanguticum Maxim. ex Balf. (Dahuang), a traditional Chinese medicine (TCM). Many bioactive constituents gave prominent [M-H]- ions in the negative ion ESI mass spectra. Among them, 41 different constituents including 16 anthraquinone derivatives, 7 phenylbutanone glucopyranosides, 4 stilbenes and 14 tannins were unambiguously identified or tentatively characterized based on their retention times, UV spectra and mass spectra in comparison with the data from standards or references. Meanwhile, some principles of fragmentation behavior for different types of constituents were proposed, which could contribute to the elucidation of these constituents in Rheum tanguticum.     

Rapid separation and identification of phenolic and diterpenoid constituents from Radix Salvia miltiorrhizae by high-performance liquid chromatography diode-array detection, electrospray ionization time-of-flight mass spectrometry and electrospray ionization quadrupole ion trap mass spectrometry

High-performance liquid chromatography-diode array detection (HPLC-DAD), electrospray ionization time-of-flight mass spectrometry (HPLC-ESI-TOF-MS) and electrospray ionization quadrupole ion trap mass spectrometry (HPLC-ESI-MSn) were used for the isolation, identification and structural analysis of water-soluble phenolic and nonpolar diterpenoid constituents in Dan-shen (Radix Salvia miltiorrhizae) which was prepared by sonication in 70% methanol. Mass spectra were obtained by ESI-TOF-MS and electrospray ionization quadrupole ion trap mass spectrometry (ESI-QIT-MS). A formula database of known constituents in Dan-shen was established and most constituents were rapidly identified by HPLC-DAD/ESI-TOF-MS by matching their accurate molecular masses with the formulae of the compounds in the database. Compounds with the same molecular formula could not be differentiated by TOF-MS; however, QIT-MS could differentiate those compounds and elucidate their structures based on their characteristic fragmentation. HPLC-DAD, HPLC/ESI-TOF-MS and HPLC/ESI-MSn provided complementary information for the identification of the constituents in Dan-shen. Forty constituents were identified in 30 min based on their positive and negative ion ESI mass spectra and liquid chromatographic information. Thus the method described is useful for the rapid analysis of multiple constituents in Dan-shen.     

气相色谱-质谱联用分析花椒挥发油的成分

 采用气相色谱 质谱联用技术对陕西富平产花椒挥发油的成分进行了分析 ,分离出了 17个峰 ,鉴定出了相对峰面积大于 1 0 %的组分共 16个 ,用峰面积归一化法定量测定了已确定组分的相对含量 ,其占挥发油总质量的95 %以上。     

GC／MS法测定木香挥发油化学成分

用气相色谱-质谱法对木香挥发油进行化学成分的分析。采用水蒸气馏法从木香中提取挥发油。试用不同类型的毛细管柱进行分析,找出最佳分析条件,用归一化法测定其含量,并用气相色谱-质谱法对化学成分进行鉴定。共鉴定了38个成分,占挥发油总成分的86%以上。方法稳定可靠。重现性好,适用于中药挥发油的化学成分分析。     

Identification and screening of chemical constituents with hepatoprotective effects from three traditional Chinese medicines for treating jaundice

The constituents with hepatoprotective activity were investigated in three traditional Chinese medicine formulae for treating jaundice, namely, Zhi‐Zi‐Da‐Huang‐Tang, Yin‐Chen‐Hao‐Tang, and Da‐Huang‐Xiao‐Shi‐Tang. By using liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry and liquid chromatography coupled with ion trap mass spectrometry, 79 chemical constituents were identified unambiguously or tentatively in three formulae based on the accurate molecular weight, mass spectrometric fragmentation behavior, and comparison with reference standards. Then the hepatoprotective activities of 27 constituents were evaluated on tert‐butylhydroperoxide‐injured BRL‐3A cells. The results indicated that 11 constituents, including protocatechic acid ( 19 ), epijasminoside A ( 56 ), rutin ( 71 ), tetrahydropalmatine ( 76 ), rhaponticin ( 80 ), 3,4‐dicaffeoylquinic acid ( 82 ), 3,5‐dicaffeoylquinic acid ( 85 ), diosmetin‐7‐O‐glucoside ( 90 ), jatrorrhizine ( 93 ), berberine ( 100 ), and daidzein ( 101 ) exerted hepatoprotective activities. Interestingly, most of the crude drugs in three formulae contained hepatoprotective active constituents, and the combinations of constituents from different crude drugs exhibited greater effects. This result provided evidence to the traditional Chinese medicine theory of combining several drugs together to exert synergistic efficacy.     

Study on Angelica and its different extracts by Fourier transform infrared spectroscopy and two-dimensional correlation IR spectroscopy

In order to develop a rapid and effective analysis method for studying integrally the main constituents in the medicinal materials and their extracts, discriminating the extracts from different extraction process, comparing the categories of chemical constituents in the different extracts and monitoring the qualities of medicinal materials, we applied Fourier transform infrared spectroscopy (FT-IR) associated with second derivative infrared spectroscopy and two-dimensional correlation infrared spectroscopy (2D-IR) to study the main constituents in traditional Chinese medicine Angelica and its different extracts (extracted by petroleum ether, ethanol and water in turn). The findings indicated that FT-IR spectrum can provide many holistic variation rules of chemical constituents. Use of the macroscopical fingerprint characters of FT-IR and 2D-IR spectrum can not only identify the main chemical constituents in medicinal materials and their different extracts, but also compare the components differences among the similar samples. This analytical method is highly rapid, effective, visual and accurate for pharmaceutical research.     

Identification of chemical constituents in traditional Chinese medicine formula using HPLC coupled with linear ion trap‐Orbitrap MS from high doses of medicinal materials to equivalent doses of formula: Study on Xiang‐Sha‐Liu‐Jun‐Zi‐Jia‐Jian granules

High‐resolution mass spectrometry has been a powerful tool for the research of chemical constituents in traditional Chinese medicine (TCM) formulas. However, the chromatographic peaks were difficult to discriminate clearly in data collection or analysis because of the complexity and the greatly different content of the constituents in TCM formula, which increased the difficulty of identification. In this study, a high‐performance liquid chromatography coupled with linear ion trap‐Orbitrap mass spectrometry based strategy focused on the comprehensive identification of TCM formula constituents was developed. Identification was carried out from a high dose of medicinal materials to equivalent dose of formula. Meanwhile, combined with mass spectrometry data, chromatographic behaviors, reference standards and previous reports, the identification of constituents in Xiang‐Sha‐Liu‐Jun‐Zi‐Jia‐Jian granules was described. 169 compounds were unambiguously or tentatively characterized, mainly including flavonoids, alkaloids, triterpenic acids, triterpene saponins, lactones, sesquiterpenoids and some other compounds. Among them, 11 compounds were unambiguously confirmed by comparing with reference standards. These results demonstrated that the method was effective and reliable for comprehensive identification of constituents of Xiang‐Sha‐Liu‐Jun‐Zi‐Jia‐Jian granules extracts and reveal the material basis of its therapeutic effects. This strategy might propose a research idea for the characterization of multi‐constituents in TCM formula.     

Photo‐Induced Electron Transfer from Excited Tris[2,2′‐bipyridine‐κN1,κN1′]ruthenium(2+) Ions to Dyadic Electron Acceptors That Can Be Protected by Host‐Guest Interaction against Fast Back Electron Transfer,Characterization of the Guest Molecules

Anthraquinone and viologen moieties were combined to dyadic molecules with two redox centers. These dyades and their constituents were used as acceptors in photo‐induced electron‐transfer reactions. The experiments show that a caveat is necessary if one tries to derive the properties and the reactions of the dyades from those of their constituents: the spectral properties appear to be independent superpositions of those of the constituents. However, the redox potentials of the two redox centres in the dyades deviate from that of their constituents, the methylene bridge can not suppress a considerable interaction between the two redox centres. This is especially true when the redox potentials of the constituents are close to one another. From the quenching experiments, it can be concluded that electrolyte cations like Na⁺ are engaged in the transition states of the electron‐transfer reactions. In this way, they can control the fate of the transferred electron.     

Variability of volatile constituents in Artemisia maritima in western Himalaya

Chemical composition of the essential oil of Artemisia maritima, collected from three different high altitude locations in western Himalaya was studied by gas-chromatography mass spectrometry. Twenty-five constituents were identified in the oil distilled from the sample from Pooh, of which 1,8-cineole (23.8%) and chrysanthenone (17.54%) were the major constituents. Twenty volatile constituents were identified from the sample collected from Rhongtong pass, of which chrysanthenone (38.1%) and 1,8-cineole (37.3%) were the major constituents. In the oil distilled from the sample collected from Lahaul-Spiti 28 constituents were identified, of which 1,8-cineole (44.22%), camphor (9.16%) and borneol (10.94%) were the major constituents. In this sample chrysanthenone was present in very low percentage.     

Computer-assisted choice of discrete spacers for anionic isotachophoresis separations

In isotachophoresis (ITP), the sample constituents migrate, depending on their concentrations in the loaded sample, either in fully developed zones or in the boundary layers between the zones of constituents of the corresponding effective mobilities. The latter (spike) migration mode is analytically beneficial in selective detections of trace analytes, especially, when appropriately chosen discrete spacers minimize detection interferences due to matrix constituents. To facilitate a search for suitable mixtures of discrete spacers, a two-step calculation procedure was developed in this work. Using a pool of discrete spacers consisting of 42 anionic and zwitterionic constituents, this procedure was shown effective in the anionic ITP separations performed at pH = 6.5-10.0. Besides the predictions of the migration orders, it was helpful in identifying the spacing constituents that could cause resolution problems due to an uncertainty with which pH of the leading electrolyte solution is known. The ionic mobility and pKa data, taken for the spacing constituents from the literature and the ones obtained from the ITP experiments carried out in this work, were used in the calculations performed in a context with the choice of spacers. Although the data obtained from the ITP experiments provided better results, small uncertainties with which they were acquired (attributable to fluctuations in the experimental conditions) set practical limits in the calculation based choice of multi-component mixtures of the spacing constituents.     

色谱-质谱联用技术在我国3种柚子组分鉴定及指纹图谱建立中的应用

利用色谱-质谱联用技术对我国主要的3个品种柚子果实的不同部位(外表皮、内表皮、内果皮、果肉、种子)的化学组分进行结构鉴定及种类和含量的差异性分析,结果表明,沙田柚、琯溪蜜柚、玉环柚果实5个部位共鉴定出68种不同化学组分物质,包括醇类19种、酯类15种、烯烃类9种、有机酸类8种、酮类7种、烷烃类4种、其他物质6种。其中3个品种柚子外表皮共有的化学组分有7种,含量最高的是柠檬烯(44.03%);内表皮共有的化学组分有6种,含量最高的是油酸酰胺(44.62%);内果皮共有的化学组分有10种,含量最高的是谷甾醇(30.75%);果肉共有的化学组分有11种,含量最高的是软脂酸(20.02%);种子中共有的化学组分有15种,含量最高的是亚油酸(45.83%)。化学组分差异性分析结果表明,沙田柚、琯溪蜜柚、玉环柚3种柚子的外表皮独有的化学组分分别有3种、6种、4种,内表皮分别有3种、4种、8种,内果皮分别有1种、4种、6种,果肉分别有4种、4种、2种,沙田柚、玉环柚种子独有的化学组分均为1种,并对化学组分进行聚类分析和相似度分析。研究结果说明不同品种柚子同一部位的化学组分种类和含量均存在相似性和差异性,特有物质较多,色谱指纹图谱特异性显著,这可为柚类品种鉴定、品质质量控制、原产地溯源等提出一种新的色谱指纹图谱思路。     

Analysis of the Volatile Constituents of Schisandra chinesis (Turz.) Bail by Gas Chromatography-Mass Spectrometry, Using Headspace Solid-Phase Microextraction

Summary Headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry was developed for the analysis of the volatile constituents of a traditional Chinese medicine, the fruits of Schisandra chinensis (Turz.) Bail. Two different fibers of polydimethylsiloxane and carbowax-divinylbenzene were used for the absorption of the volatile constituents of the fruits. Thirty-three volatile compounds were separated and identified. The optimum absorption and desorption conditions were also studied. Relative standard deviation values less than 6.5% showed that the method has a good reproducibility. The volatile constituents were also analyzed by steam distillation and thirty-five compounds were identified. The similar results obtained by the two methods showed that SPME is a simple, rapid and solvent-free method for the analysis of volatile constituents of plant materials.     

高效液相色谱法研究黄连生物碱与吴茱萸黄酮配伍时成分含量的变化

为了研究中药配伍过程中是否发生化学反应,先从单味药材中提取不同的组分或大类化合物,然后对其进行配伍，用高效液相色谱法（HPLC）测定其在配伍前后的成分变化。实验采用HPLC对黄连生物碱与吴茱萸黄酮配伍后的各色谱峰进行检测和分析，结果表明黄连生物碱与吴茱萸黄酮配伍后色谱峰具有加和性,各成分的相对峰面积未见明显变化,且未见新的色谱峰产生，说明黄连生物碱与吴茱萸黄酮配伍后没有发生化学反应。     

Electronic and molecular structures of (HCN)n polymers

The CNDO/2 method, using the tight-binding approximation, for polymers, has been applied to several constituents of (HCN)_n polymers. Contributions of the intrasegment and intersegment energies to the total energy are discussed in connection with the relative stabilities of these various constituents. The stabilities of the (NCN)_n polymers as protein ancestors are discussed on the basis of the calculations. Band structures of the typical polymer constituents are very briefly discussed.