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1.
The complexity of metabolites in traditional Chinese medicine (TCM) hinders the comprehensive profiling and accurate identification of metabolites. In this study, an approach that integrates enhanced column separation, mass spectrometry post-processing and result verification was proposed and applied in the identification of flavonoids in Dalbergia odorifera. Firstly, column chromatography fractionation, followed by liquid chromatography–tandem mass spectrometry was used for systematic separation and detection. Secondly, a three-level data post-processing method was applied to the identification of flavonoids. Finally, fragmentation rules were used to verify the flavonoid compounds. As a result, a total of 197 flavonoids were characterized in D. odorifera, among which seven compounds were unambiguously identified in level 1, 80 compounds were tentatively identified by MS-DIAL and Compound Discoverer in level 2a, 95 compounds were annotated by Compound discoverer and Peogenesis QI in level 2b, and 15 compounds were exclusively annotated by using SIRIUS software in level 3. This study provides an approach for the rapid and efficient identification of the majority of components in herbal medicines.  相似文献   

2.
Dalbergia sissoo is a woody plant with economic and medicinal value. As the pharmacological qualities and properties of the wood from this plant primarily depend on its extractives, in this study, the metabolomic analysis of extractives from its stems was carried out using UPLC-MS/MS. A total of 735 metabolites were detected from two groups of samples, heartwood and sapwood, with the largest number of terpenoids in type and the largest number of flavonoids in quantity. The PCA and cluster analysis showed significant differences in the metabolite composition between the two groups. The differential metabolites were mainly organic oxygen compounds, flavonoids, and isoflavones. Among the 105 differential metabolites, 26 metabolites were significantly higher in relative content in sapwood than in heartwood, while the other 79 metabolites were significantly higher in relative content in heartwood than in sapwood. KEGG metabolic pathway enrichment analysis showed that these differential metabolites were mainly enriched in three metabolic pathways: Flavonoid biosynthesis, isoflavonoid biosynthesis, and flavonoid and flavonol biosynthesis. This study provides a reference for metabolomics studies in Dalbergia and other woody plants.  相似文献   

3.
Seven novel bis-N-substituted-hydrazinecarboxamide receptors were synthesized in good to excellent yields by reacting chiral dicarbohydrazides, obtained from commercially available tartaric acid, with substituted aromatic isocyanates. The newly synthesized hydrazinecarboxamides formed structurally unique supramolecular aggregates, which have been confirmed by ESI-TOF/MS and tandem ESI-MS. They also showed molecular recognition to a selection of chiral carboxylic guests and oligopeptides, which mimic the backbone structure of the bacterial cell wall. The structures of the novel compounds were verified by various spectroscopic techniques including FTIR, 1H NMR, 13C NMR, ESI-TOF/MS, tandem ESI-MS, 2D ROESY NMR, and CD spectroscopy.  相似文献   

4.
A rapid and accurate HPLC method has been developed for the simultaneous determination of nine major flavonoids, namely 3-hydroxymelanettin, melanettin, stevenin, butein, isoliquiritigenin, dalbergin, 2,4-dihydroxy-5-methoxybenzophenone, pinocembrin, 4-methoxydalbergione in Dalbergia odorifera. The samples were separated on an Aglient Zorbax SB-C18 column (250 × 4.6 mm, 5 m) with a gradient of acetonitrile and 1% aqueous acetic acid (/) at a flow rate of 1.0 mL min–1 and detected at 350 nm. The complete separation was obtained within 30 min for the nine target flavonoids. All calibration curves showed good linearity (r2 > 0.999) within test ranges. The repeatability was evaluated by intra- and inter-day assays and RSD values were less than 4.0%. The recoveries were between 92.0% and 104.5%. The developed method was successfully applied to the analysis of 32 commercial samples of D. odorifera.  相似文献   

5.
Two methoxylated isoflavones were isolated form the roots of Dalbergia horrida. These compounds show great promise as pharmaceutical agents. The 1H and 13C NMR spectra of the compounds were completely assigned by using a combination of 2D NMR experiments which included 1H–1H COSY, HMQC and HMBC studies. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

6.
An off‐line 2‐D RPLC/RPLC system incorporating a β‐CD based column and a BEH C18 column was developed in the separation of components in Dalbergia odorifera T. Chen. (Jiang Xiang). Both orthogonality and van Deemter curves of the two columns were investigated. The orthogonality was about 57%, which was evaluated with 40 standard solutes. Optimized column efficiency could be achieved under optimal linear velocity (0.04 cm/s) on the CD column or under high linear velocity (0.32 cm/s) on the BEH C18 column. With the 2‐D LC system, totally 637 peaks were separated in 114 fractions from the extraction of Jiang Xiang. Meanwhile, 19 flavanoids were tentatively identified from 114 fractions with Q‐TOF MS. The results demonstrated the separation power of this 2‐D LC system and further proved the high orthogonality between CD and C18 columns.  相似文献   

7.
The triazinone herbicides metamitron and metribuzin are degraded by desamination. After a derivatization step with ethereal diazomethane solution, different structures of the metabolites were determined by GC/MS. The assumption that this is based on a ketoenol-tautomery was confirmed by GC/FTIR and 1H-NMR spectroscopy. This fact has to be considered for carrying out definite metabolite identification.  相似文献   

8.
An analytical protocol based on optical microscopy, Fourier transforms infrared spectroscopy (FTIR), analytical pyrolysis in the presence of hexamethyldisilazane followed by gas chromatographic/mass spectrometric analysis (Py-GC/MS) and gas chromatography/mass spectrometry after alkaline hydrolysis, solvent extraction and trimethylsilylation (GC/MS) was used in the chemical characterisation of the original adhesives used to fix monochrome and mosaic glass and stone plaques coming from the Late Roman archaeological site of Antinoopolis (Egypt).FTIR analysis demonstrated the presence of calcite fragments, and Py-GC/MS and GC/MS analyses provided detailed molecular compositions, highlighting the presence of a wide range of compound classes including diterpenoid acids, tricyclic abietanes with a high degree of aromatisation, mid- and long-chain monocarboxylic fatty acids, mono- and di-hydroxy acids, α,ω-dicaboxylic fatty acids, n-alkanols, and n-alkanes. Characteristic biomarkers and their distribution patterns indicated the presence of pine pitch in all the adhesives, which in some cases was admixed with beeswax and brassicaceae seed oil.The results provided new insights into the complex recipes used by artisans in ancient Egypt in the production of adhesives and in the sophisticated manufacture of opus sectile decorations.  相似文献   

9.
Complex formation between N‐butylboronic acid and D ‐(+)‐glucose, D ‐(+)‐mannose, methyl‐α‐D ‐glucopyranoside, methyl‐β‐D ‐galactopyranoside and methyl α‐D ‐mannopyranoside under neutral conditions was investigated by 1H, 13C and 11B NMR spectroscopy and gas chromatography–mass spectrometry (GC–MS) D ‐(+)‐Glucose and D ‐(+)‐mannose formed complexes where the boronates are attached to the 1,2:4,6‐ and 2,3:5,6‐positions of the furanose forms, respectively. On the other hand, the boronic acid binds to the 4,6‐positions of the two methyl derivatives of glucose and galactose. Methyl α‐D ‐mannopyranoside binds two boronates at the 2,3:4,6‐positions. 11B NMR was used to show the ring size of the complexed sugars and the boronate. GC–MS confirmed the assignments. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

10.
Prodigiosin is a secondary metabolite produced in several species of bacteria. It exhibits antimicrobial and anticancer properties. Methods for the extraction and identification of prodigiosin and their related derivatives from bacterial cultures typically depend on solvent-based extractions followed by NMR spectroscopy. The estuarine bacterium, V. gazogenes PB1, was previously shown to produce prodigiosin. This conclusion, however, was based on analytical data obtained from ultraviolet-visible absorption spectrophotometry and infrared spectroscopy. Complete dependence on these techniques would be considered inadequate for the accurate identification of the various members of the prodiginine family of compounds, which possess very similar chemical structures and near-identical optical properties. In this study, we extracted prodigiosin from a culture of Vibrio gazogenes PB1 cultivated in minimal media, and for the first time, confirmed the synthesis of prodigiosin Vibrio gazogenes PB1 using NMR techniques. The chemical structure was validated by 1H and 13C NMR spectroscopy, and further corroborated by 2D NMR, which included 1H-1H-gDQFCOSY, 1H-13C-gHSQC, and 1H-13C-gHMBC, as well as 1H-1H-homonuclear decoupling experiments. Based on this data, previous NMR spectral assignments of prodigiosin are reaffirmed and in some cases, corrected. The findings will be particularly relevant for experimental work relating to the use of V. gazogenes PB1 as a host for the synthesis of prodigiosin.  相似文献   

11.
A dipyrromethane functionalized monomer; 5-(4-tert-butylphenyl)dipyrromethane (BPDP) was synthesized. The structure of the monomer was characterized by nuclear magnetic resonance (1H NMR and 13C NMR) and Fourier transform infrared (FTIR) spectroscopies. Electrochemical polymerization of BPDP was performed in acetonitrile (AN)/LiClO4. The resulting conducting polymer was characterized by FTIR spectroscopy and electrical conductivity measurements. Spectroelectrochemical behavior and switching ability of P(BPDP) film were investigated by UV-Vis spectroscopy. P(BPDP) revealed color changes between yellow and blue in the reduced and oxidized states, respectively. In order to investigate electrochromic properties and stability of the P(BPDP) in electrochromic device (ECDs) application, dual type polymer ECD based on P(BPDP) and poly(ethylene dioxythiophene) (PEDOT) were constructed. Spectroelectrochemistry, switching ability and stability of the devices were investigated by UV-Vis spectroscopy and cyclic voltammetry.  相似文献   

12.
Three novel donor–π–acceptor (D–π–A) chromophores, with dipicolinate as acceptor, have been synthesized. All the compounds were characterized by 1H NMR, infrared (IR) spectroscopy, mass spectrometry (MS), and elemental analysis.  相似文献   

13.
Fourier transform infrared spectrometry (FTIR) and mass spectrometry (MS) have been combined with gas chromatography (GC) for the identification of eluted components in a complex mixture. The combined technique, GC—FTIR—MS, provides simultaneous GC—FTIR and GC—MS data from a single injection.  相似文献   

14.
The phytochemical analysis of the butanolic extract from the leaves of date palm of Saudi origin resulted in the isolation of three major constituents, oleanolic acid (1), vanillyl alcohol (2), and β-sitosterol-3-O-β-d-glucoside (3), which had not been isolated from this plant or previously reported. Together, compounds 1 and 2 account for 1.0% of the butanol extract, which represents 0.4% of the mass of the dried leaves. The isolation of other known compounds for this plant such as fatty acids, lutein, and sucrose was also achieved in this study. The characterization and identification of the isolated compounds were conducted on the basis of Fourier-transform infrared spectroscopy (FTIR), 1H and 13C nuclear magnetic resonance (NMR), liquid chromatography–mass spectrometry (LC–MS), and gas chromatography–mass spectrometry (GC–MS) analyses. The findings of the current study will definitely increase the knowledge about the contribution of the constituents of this plant to its well-known nutrition, corrosion inhibition, and antimicrobial properties.  相似文献   

15.
A set of impurities (specks) occurring in a TCF (totally chlorine free)-bleached Kraft pulp of Eucalyptus globulus wood was studied. The impurities were Soxhlet extracted with acetone, and the extracts subsequently analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) using high-temperature capillary columns. The lipophilic fraction isolated from E. globulus wood extractives was also analyzed for comparison. The composition of the acetone extracts was very similar to that of E. globulus wood. Fatty acids, steroid hydrocarbons, sterols, steroid ketones and sterol esters, arising from E. globulus wood extractives survived the cooking and bleaching processes and accumulated in the pulp. On the other hand, the residue left after acetone extraction was studied by pyrolysis–GC–MS. The results indicated that it was composed of small particles of polyisoprene rubber. In conclusion, the speck impurities studied here seems to be composed of two different moieties, a lipophilic part arising from wood extractives and a core of small particles of synthetic polymers (polyisoprene rubber).  相似文献   

16.
Novel transesterification of acetylated maritime pine sapwood (Pinus pinaster Soland) reaction was performed with tetramethoxysilane (TMOS) in presence of dibutyltin oxide as a catalyst. Transesterification was confirmed by weight percent gain calculations (WPG), infrared spectroscopy (FTIR) as well as 13C and 29Si NMR CP-MAS analysis. The results showed that transesterification indeed occurs via exchange of acetate groups from acetylated wood and methoxysilane groups from TMOS. The effect of temperatures and reaction time upon transesterification efficiency was also investigated.  相似文献   

17.
A new route was developed to design esters of gem-dicarboxylic acids of cyclopentene series by CH alkylation of diethyl malonate with cis-1,4-dichlorobutene. Diethyl cyclopent-3-ene-1,1-dicarboxylate was reacted with dichlorocarbene. The structures of the isolated compounds were described in detail by 1H, 13C NMR spectroscopy and GC–MS.  相似文献   

18.
红外光谱反应出的是特征化学基团的振动 ,对于高聚物的具体单体组成分析 ,只能借助于紫外光谱、核磁共振及质谱进行综合判断才能得到圆满的鉴定结果[1,2 ] 。本工作针对在红外光谱仪不能分辨的情况下通过气相色谱 质谱联用技术进行综合分析鉴定 ,结果可为其它高聚物分析研究提供实验依据。1 实验1 1 仪器及试验条件未知高聚物试样为白色颗粒状 (晨光化工二厂 )。SYSTEM2 0 0 0FTIR ,PE公司造IR谱仪 ;CDS2 0 0 0铂金丝裂解器 ,裂解室温度 2 5 0℃ ,裂解温度 6 0 0℃ ,升温速率 1 40℃ ms;HP6 890型 ,Compond…  相似文献   

19.
Doumenq P  Guiliano M  Mille G 《Talanta》1992,39(2):149-154
Reference infrared vapour phase spectra of 20 polychlorobiphenyls (PCBs) have been obtained by gas chromatography/Fourier transform infrared spectroscopy (GC/FTIR). These spectra are consistent with those of PCB obtained by diffuse reflectance IR spectroscopy (DRIFT) and with those of more simple molecular structures (iodochlorobenzenes, 1-bromodichlorobenzenes). The IR frequencies of the GC/FTIR spectra of PCB are assigned in terms of substitution patterns. This work shows that GC/FTIR can be a good approach for differentiation and identification of PCB in complex mixtures.  相似文献   

20.
Using Cu(1)-catalyzed [3+2] Huisgen ‘click’ cycloaddition, a rigid rod - like oligo(p-phenylene vinylene) (OPV) was functionalized at both ends with biotin ligands, combining the valuable electro-optical properties of conjugated organic molecules with the biological recognition capability of biotin. Biotin can be placed at variable distances from the oligomer via appropriate length of a hydrophilic spacer, which also serves to regulate the binding capabilities of the two terminal biotin units. To demonstrate this binding potential, networks were formed with streptavidin-coated quantum dots. The synthetic conditions are presented, together with representative optimizations of the key reactions. The organic compounds were analyzed by means of ATR/FTIR, 1H NMR (200 or 600 MHz), 13C NMR, 2D NMR (HMBC, HMQC experiments), MS (ESI or MALDI-TOF), and optical spectroscopy. Networks were imaged with TEM.  相似文献   

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