石香薷挥发油提取的比较研究

利用GC-MS对石香薷挥发油进行了定性、定量分析。采取超临界CO2萃取、水蒸气蒸馏和有机溶剂石油醚萃取这三种方法提取石香薷挥发油。这三种方法提取石香薷挥发油的主要成分基本相似,主要为含氧化合物(香薷酮、百里香酚和香荆芥酚)等,采取超临界CO2萃取和水蒸气蒸馏的石香薷挥发油品质较优。超临界CO2萃取法为提取石香薷挥发油的理想方法。     

鱼腥草挥发油的化学成分

The volatile oils from Houttuynia cordata Thunb. were obtained with supereritical CO2, steam distillation and petroleum ether extraction and analyzed qualitatively and quantitatively by GC-MS. The results showed that the chemical constituents of the volatile oils by three different methods are very different. The extraction rates of volatile oil by above-mentioned three extraction methods are 1.764%, 0.040% and 0.082%, respectively. The volatile oil extracted by supercritical CO2 extraction, which the content of houttuyninum reached 14.393 %, is better than those with traditional methods.     

不同方法提取的荷叶挥发油化学成分分析

采取超临界CO2萃取和水蒸气蒸馏提取荷叶挥发油,利用GC-MS对它们进行了定性、定量分析。结果表明这两种方法提取荷叶挥发油的化学成分及含量皆有很大差别。超临界CO2萃取的荷叶挥发油更具天然性,超临界CO2萃取法为提取荷叶挥发油的理想方法。     

红蒿枝挥发油化学成分及其细胞毒性

In this paper, the volatile oil of 18 samples from Cyathod/ne purpurea were determined by seam distilling method. 27 constituents of volatih oil were identitied qualitativdy and quantitativdy by GC/MS. Three samples of volatih oll have been tested for cytotoxicity in cell growth inhibition against cultured L1210 murine leukemia cell.     

The quantitative analysis of three action modes of volatile anesthetics on purple membrane

We quantitatively assessed the spectroscopic changes of purple membrane in relation to the concentrations of a volatile anesthetic. As reported previously, volatile anesthetics show three modes of action on purple membrane. By using an anesthetic for which the concentration in solution could be determined spectroscopically and by applying modified analytical methods regarding the M-intermediate lifetime, we were able to clarify the quantitative relation between anesthetic concentration and each mode of action, a relation which in the past has only been described qualitatively. We also determined through the measurement of transient pH changes with pyranine that the proton pump efficiency per photochemical cycle in an action mode induced with low concentrations of anesthetic does not change from that of the native state. Moreover, we dynamically obtained the individual M-bacteriorhodopsin difference spectrum of each state at room temperature using our flash photolysis system equipped with a wavelength-tunable dye laser. These results demonstrated again that we should clearly distinguish different action modes of anesthetics according to their concentrations.     

萱草花瓣中类胡萝卜素分析样品的制备及UPCC-MS检测方法研究

以大苞萱草（Hemerocallis middendorfii Trautv.et Mey.）和‘原谅’萱草（H.‘Pardon Me’）为研究对象,对萱草属植物花瓣中类胡萝卜素的样品制备方法以及UPCC-MS定性和定量检测方法进行了研究。结果表明：（1）萱草花瓣类胡萝卜素样品制备过程中,不同的提取试剂、振荡方法及皂化方法对类胡萝卜素的提取效率均有显著影响,经过对提取结果的方差分析,确定最佳的样品制备方案为：提取试剂B丙酮：正己烷（3：5/V：V）、温控摇床振荡提取,常温皂化16 h;（2） UPCC-MS技术能在10 min内高效分离萱草花瓣中的类胡萝卜素,且使用的有毒化学试剂少,是检测类胡萝卜素的较好选择;（3）大苞萱草和原谅萱草花瓣中共含有20种类胡萝卜素物质,两者颜色不同,类胡萝卜素的组成和含量也存在差异。     

生姜的挥发性化学成分

用ＧＣ／ＭＳ方法,定性定量地分析了用３种不同方法提取的姜油的化学成分,分别鉴定了４６,５０,６１个化合物。蒸馏油主要含有单萜、倍半萜烯类化合物,未见生姜特有的辣味成分。冷榨油和超临界ＣＯ２萃取油除倍半萜类化合物外,主要含有辣味成分,含量分别为１８．６１％,２３．０９％。冷榨油及超临界ＣＯ２萃取油较好地保持了生姜的特征辛香气及辣味成分     

Pyrolytic Methylation-Gas Chromatography of Whole Bacterial Cells for Rapid Profiling of Cellular Fatty Acids

A novel, on-line derivatization technique has been developed which enables generation of fatty acid methyl ester (FAME) profiles from microorganisms by gas chromatography-mass spectrometry without the need for laborious and time-consuming sample preparation. Microgram amounts of bacterial cells are directly applied to a thin ferromagnetic filament and covered with a single drop of methanolic solution of tetramethylammonium hydroxide. After air drying, the filament is inserted into a special gas chromatograph inlet equipped with a high-frequency coil, thus enabling rapid inductive heating of the ferromagnetic filament. This so-called Curie-point heating technique is shown to produce patterns of bacterial FAMEs which are qualitatively and quantitatively nearly identical to those obtained from extracts of methylated lipids prepared by conventional sample pretreatment methods. Relatively minor differences involve the loss of hydroxy-substituted fatty acids by the pyrolytic approach as well as strongly enhanced signals of FAMEs derived from mycolic acids. This type of pyrolysis enables on-line derivatization and thermal extraction of volatile derivatives for analysis, whereas the residual components remain on a disposable probe (ferromagnetic wire) of a pyrolytic device. The reduced sample size (micrograms instead of milligrams) and the lack of sample preparation requirements open up the possibility of rapid microbiological identification of single colonies (thus overcoming the need for time-consuming subculturing) as well as analysis of FAME profiles directly from complex environmental samples.     

Comprehensive two‐dimensional gas chromatography–mass spectrometry analysis of volatile constituents in Thai vetiver root oils obtained by using different extraction methods

Introduction – Vetiver root oil is known as one of the finest fixatives used in perfumery. This highly complex oil contains more than 200 components, which are mainly sesquiterpene hydrocarbons and their oxygenated derivatives. Since conventional GC‐MS has limitation in terms of separation efficiency, the comprehensive two‐dimensional GC‐MS (GC × GC‐MS) was proposed in this study as an alternative technique for the analysis of vetiver oil constituents. Objective – To evaluate efficiency of the hyphenated GC × GC‐MS technique in terms of separation power and sensitivity prior to identification and quantitation of the volatile constituents in a variety of vetiver root oil samples. Methodology – Dried roots of Vetiveria zizanioides were subjected to extraction using various conditions of four different methods; simultaneous steam distillation, supercritical fluid, microwave‐assisted, and Soxhlet extraction. Volatile components in all vetiver root oil samples were separated and identified by GC‐MS and GC × GC‐MS. The relative contents of volatile constituents in each vetiver oil sample were calculated using the peak volume normalization method. Results – Different techniques of extraction had diverse effects on yield, physical and chemical properties of the vetiver root oils obtained. Overall, 64 volatile constituents were identified by GC‐MS. Among the 245 well‐resolved individual components obtained by GC × GC‐MS, the additional identification of 43 more volatiles was achieved. Conclusion – In comparison with GC‐MS, GC × GC‐MS showed greater ability to differentiate the quality of essential oils obtained from diverse extraction conditions in terms of their volatile compositions and contents. Copyright © 2009 John Wiley & Sons, Ltd.     

Pattern recognition and genetic algorithms for discrimination of orange juices and reduction of significant components from headspace solid‐phase microextraction

Introduction – Orange (Citrus sinensis L.) juice comprises a complex mixture of volatile components that are difficult to identify and quantify. Classification and discrimination of the varieties on the basis of the volatile composition could help to guarantee the quality of a juice and to detect possible adulteration of the product. Objective – To provide information on the amounts of volatile constituents in fresh‐squeezed juices from four orange cultivars and to establish suitable discrimination rules to differentiate orange juices using new chemometric approaches. Methodology – Fresh juices of four orange cultivars were analysed by headspace solid‐phase microextraction (HS‐SPME) coupled with GC‐MS. Principal component analysis, linear discriminant analysis and heuristic methods, such as neural networks, allowed clustering of the data from HS‐SPME analysis while genetic algorithms addressed the problem of data reduction. To check the quality of the results the chemometric techniques were also evaluated on a sample. Results – Thirty volatile compounds were identified by HS‐SPME and GC‐MS analyses and their relative amounts calculated. Differences in composition of orange juice volatile components were observed. The chosen orange cultivars could be discriminated using neural networks, genetic relocation algorithms and linear discriminant analysis. Genetic algorithms applied to the data were also able to detect the most significant compounds. Conclusions – SPME is a useful technique to investigate orange juice volatile composition and a flexible chemometric approach is able to correctly separate the juices. Copyright © 2009 John Wiley & Sons, Ltd.     

Metabolic profiling and phylogenetic analysis of medicinal Zingiber species: Tools for authentication of ginger (Zingiber officinale Rosc)

Phylogenetic analysis and metabolic profiling were used to investigate the diversity of plant material within the ginger species and between ginger and closely related species in the genus Zingiber (Zingiberaceae). In addition, anti-inflammatory data were obtained for the investigated species. Phylogenetic analysis demonstrated that all Zingiber officinale samples from different geographical origins were genetically indistinguishable. In contrast, other Zingiber species were significantly divergent, allowing all species to be clearly distinguished using this analysis. In the metabolic profiling analysis, the Z. officinale samples derived from different origins showed no qualitative differences in major volatile compounds, although they did show some significant quantitative differences in non-volatile composition, particularly regarding the content of [6]-, [8]-, and [10]-gingerols, the most active anti-inflammatory components in this species. The differences in gingerol content were verified by HPLC. The metabolic profiles of other Zingiber species were very different, both qualitatively and quantitatively, when compared to Z. officinale and to each other. Comparative DNA sequence/chemotaxonomic phylogenetic trees showed that the chemical characters of the investigated species were able to generate essentially the same phylogenetic relationships as the DNA sequences. This supports the contention that chemical characters can be used effectively to identify relationships between plant species. Anti-inflammatory in vitro assays to evaluate the ability of all extracts from the Zingiber species examined to inhibit LPS-induced PGE(2) and TNF-alpha production suggested that bioactivity may not be easily predicted by either phylogenetic analysis or gross metabolic profiling. Therefore, identification and quantification of the actual bioactive compounds are required to guarantee the bioactivity of a particular Zingiber sample even after performing authentication by molecular and/or chemical markers.     

Rapid techniques for the extraction of vitamin E isomers from Amaranthus caudatus seeds: ultrasonic and supercritical fluid extraction

Supercritical fluid extraction (SFE) of seeds of Amaranthus caudatus (Amaranthaceae) and the use of ultrasound as a co-adjuvant in the extraction process were compared with methods traditionally used in the extraction of tocopherols and fatty acids. The use of readily available ultrasound equipment as an adjunct to the classical methods employed for the extraction of tocols provided qualitatively acceptable results more rapidly and more economically. SFE gave quantitatively better yields in shorter times, with solvent-free extracts obtained under conditions that minimised the degradation of thermolabile components. No significant variations were observed in the profile of the fatty acids extracted from amaranth oil by SFE or other methods, thus confirming the qualitative comparability of the faster supercritical extraction with the more time-consuming classical techniques even when processed with the aid of ultrasound.     

Liquid chromatographic analysis of supercritical carbon dioxide extracts of Schizandra chinensis

Six major lignans (schizandrin, gomisin A, deoxyschizandrin, y-schizandrin, gomisin N, wuweizisu C) in the caulomas and leaves of Schizandra chinensis (Turcz.) Baill., and cinnamic acid in the leaves of the plant, were quantitatively analysed by high-performance liquid chromatography in reversed-phase mode with UV detection. Resolution of the determined lignans was evaluated for two multistep gradients applied. Samples for HPLC analysis were prepared by extraction with supercritical carbon dioxide at pressures of 20-27 MPa and temperatures of 40-60 degrees C. Kinetics of the extraction of individual components was measured and simulated with a model.     

Evaluation of the influence of decellularization on the changes in biomechanical properties of primate lungs

The effect of decellularization on the biomechanical properties of macaque lungs was studied. The quality of the biological scaffold was additionally assessed by morphological methods, and the contents of extracellular matrix (ECM) fibers were determined both qualitatively and quantitatively. Histological analysis revealed no damage of structural integrity of ECM components, but the scaffold elasticity significantly decreased, which was confirmed by the changes in the hysteresis loop without a concomitant decrease in peak loads, with the mechanical strength of the samples being retained. These changes require taking additional measures to prevent a decrease in the effective lung volume.     

QUALITATIVE AND QUANTITATIVE MORPHOLOGICAL CHANGES IN SUBCELLULAR FRACTIONS FROM MOUSE CEREBRAL CORTEX DURING POSTNATAL DEVELOPMENT

Discontinuous Ficoll-sucrose gradients were used to prepare subcellular fractions from mouse cerebral cortex at various stages of postnatal development. Representative samples of each subcellular fraction were obtained by sedimentation in an analytical ultracentrifuge and each fraction was examined quantitatively and qualitatively by electron microscopy. The amount of synaptosomal material was determined for each fraction on the basis of volume percentage, obtained from a series of contiguous micrographs, to circumvent any sampling error. This allowed an accurate appraisal of synaptosomal distribution during neural development and a direct comparison of the Ficoll-sucrose gradient fractions to the original crude mitochondrial preparations. The distribution of synaptosomal material was shown to be quantitatively altered during neural development, and maturation-dependent changes, at a qualitative level, were described. In addition, the relationship between neural maturation and the relative proportion and distribution of subcellular particles which contain processes tentatively identified as growth cones were characterized.     

Distribution of tightly bound non-histone proteins in chromatin fractions obtained by DNAase II digestion

Digestion of pig liver chromatin with DNAse II afforded three different fractions which were characterized in terms of their DNA, RNA and tightly bound non-histone protein content, their DNA fragment size and their template activity. Two of these fractions are soluble after digestion with DNAase II and have been separated on the basis of their different solubility in MgCl2. A third fraction is not solubilized even after extensive digestion, although the size of its DNA is comparable to that of the enzyme solubilized fractions. The three fractions show qualitatively and quantitatively different distribution of tightly bound non-histone proteins, with specific protein components in each fraction; furthermore the non-solubilized fraction is greatly enriched in proteins tightly bound to DNA. From all the data obtained it can be suggested that the tightly bound proteins of the insoluble fraction may play, directly or indirectly, a role in maintaining an organized chromatin structure.     

Qualitative Characterization of the Aqueous Fraction from Hydrothermal Liquefaction of Algae Using 2D Gas Chromatography with Time-of-flight Mass Spectrometry

Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in complex mixtures. It is often used to analyze gasoline, jet fuel, diesel, bio-diesel and the organic fraction of bio-crude/bio-oil. In most of those analyses, the first dimension of separation is non-polar, followed by a polar separation. The aqueous fractions of bio-crude and other aqueous samples from biofuels production have been examined with similar column combinations. However, sample preparation techniques such as derivatization, solvent extraction, and solid-phase extraction were necessaryprior to analysis. In this study, aqueous fractions obtained from the hydrothermal liquefaction of algae were characterized by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry without prior sample preparation techniques using a polar separation in the first dimension followed by a non-polar separation in the second. Two-dimensional plots from this analysis were compared with those obtained from the more traditional column configuration. Results from qualitative characterization of the aqueous fractions of algal bio-crude are discussed in detail. The advantages of using a polar separation followed by a non-polar separation for characterization of organics in aqueous samples by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry are highlighted.     

Analysis of Rhioxma Curcumae Aeruginosae volatiles by solid-phase microextraction with gas chromatography-mass spectrometry

In this paper, a headspace solid-phase microextraction (HS-SPME) method was applied to analyse the volatile compounds in a traditional Chinese medicine (TCM), Rhioxma Curcumae Aeruginosae. SPME parameters such as fibers, extraction temperature, extraction time and desorption time were investigated. Thirty-five volatile compounds were separated and identified. Relative standard deviations (RSDs) were less than 8.4%, showing that the method has a good reproducibility. The volatile constituents were also analyzed by steam distillation (SD) and thirty-seven compounds were identified. The similar results obtained by the two methods showed that SPME is a good alternative for the analysis of volatile constituents in Rhioxma Curcumae Aeruginosae samples and it is a relatively simple, rapid and solvent-free method.     

Combination of HPLC chromatogram and hypoglycemic effect identifies isoflavones as the principal active fraction of Belamcanda chinensis leaf extract in diabetes treatment

In previous study, we demonstrated the hypoglycemic effect of aqueous extract of Belamcanda chinensis leaves in rats. Here, we separated the aqueous extract of B. chinensis leaves and investigated the spectrum-effect relationships between HPLC chromatograms and hypoglycemic activities of different isolates from B. chinensis leaf extract. Sequential solvent extraction with petroleum ether, chloroform, acetic ester and n-butanol provided several isolates showing similar hypoglycemic activities, making it difficult to discriminate the active fractions. Stepwise elution through HP20 macroporous resin by water, 40% and 95% ethanol provided isolates with distinct hypoglycemic activities, representing a simple, rapid and efficient preparative separation method. Combination of HPLC chromatogram and pharmacological effect targeted a hypoglycemic activity-related region in HPLC chromatogram. Each peak in this region was analyzed by UV spectrum scan. Most of them were flavonoids in which tectoridin and swertisin were known flavonoids with anti-diabetic activities. In together, this work provides a general model of combination of HPLC chromatography and pharmacological effect to study the spectrum-effect relationships of aqueous extract from B. chinensis leaves, which can be used to find principle components of B. chinensis on pharmacological activity.     

超声提取枸杞叶总黄酮的工艺研究

目的：优选超声辅助提取枸杞叶总黄酮的提取工艺并探讨枸杞叶的合理采收时期。方法：分别研究乙醇浓度、乙醇用量、超声提取时间、超声时温度四个单因素对提取效果的影响,设计正交试验,所得结果采用方差分析。利用优选出的最佳超声提取工艺测定比较不同采收时期枸杞叶中的总黄酮含量。结果：确定了最佳单因素水平,通过正交试验法优选出超声辅助提取枸杞叶总黄酮的最佳工艺条件为乙醇浓度75％、乙醇用量1：40、超声提取时间30min、超声时温度50℃。结论：通过比较不同采收时期枸杞叶总黄酮的含量,发现总黄酮的含量随枸杞叶生长而下降,结合枸杞果园生产探讨得出枸杞叶合理采摘时期为4月上旬和11月中旬。