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111.
Geng P Zhang R Aisa HA He J Qu K Zhu H Abliz Z 《Rapid communications in mass spectrometry : RCM》2007,21(12):1877-1888
A method of fast profiling the constituents in an active herbal extract and their metabolites in biological fluids based on the combination of fragmentation behavior and metabolic pathways is described. The complementary information from fragmentation behavior and metabolic pathways helped not only to identify the structure of parent constituents and metabolites, but also to correlate metabolites back to their parent forms. An active fraction obtained from Gossypium herbaceam L., named AB-8-2, and bile samples from rats administered it orally and intravenously were analyzed using high-performance liquid chromatography/multi-stage tandem mass spectrometry (HPLC-MSn) in a single chromatographic run. Fifty-eight flavonols comprising mixed sulfate, methyl, glucuronide and glycoside derivatives of quercetin or kaempferol were detected, including several groups of isomers. By contrasting the analytical results from AB-8-2 and from bile samples derived from different administration routes, a profile of the biotransformation of the flavonols in AB-8-2 was obtained. The results should be of benefit in targeting potential active ingredients in complex mixtures, such as herbs or their active extracts. 相似文献
112.
A 2-phenoxychromone, 6-demethoxy-4′-O-methylcapillarisin, was isolated from Artemisia rupestris L. The structure of this compound was established by analysis of the spectroscopic data. A single-crystal diffraction analysis
was performed in order to confirm the proposed structure.
Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 14–15, January–February, 2006. 相似文献
113.
114.
An efficient method for bioassay-guided preparative isolation of antioxidants from the n-butanol extract of Astragalus altaicus Bunge was ingeniously developed by combination of silica gel column chromatography and high-speed counter-current chromatography. Under the bioassay-guidance of antioxidant activities, the antioxidants were gradually separated from the crude sample of Astragalus altaicus Bunge by silica gel column chromatography and high-speed counter-current chromatography. Silica gel column chromatography separation was performed with chloroform, chloroform-methanol (100:1~5:1, v/v) and chloroform-methanol-water (5:1:0.1~2:1:0.1, v/v/v). High-speed counter-current chromatography separation was performed with a two-phase solvent system composed of ethyl acetate-n-butanol-water (2:1:6, v/v/v), which was successfully selected by thin layer chromatography analysis, at a flow rate of 1.5 mL/min. As a result, isorhamnetin-3-gentiobioside (20.8 mg), rutin (82.0 mg), and narcissin (12.8 mg) were obtained for the first time from 200 mg of the crude sample, ABS-5 of Astragalus altaicus Bunge. The purities were all at over 95% by high-performance liquid chromatography analysis, and their structures were unambiguously identified by mass spectroscopy, (1) H, and (13) C nuclear magnetic resonance spectroscopy. Antioxidant activities of the three compounds were also assayed by in vitro ABTS [2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diamonium salt] radical cation scavenging activity. Among them, rutin possessed the highest antioxidant capacity with SC(50) value of 22.15 μg/mL. 相似文献
115.
8, 8-Dimethyl-5, 6, 7,8-tetrahydrophenanthrene-3, 4-dione (3) and 8, 8-dimethyl-2- ( 1-hydroxy ethyl) -5,6, 7, 8-tetrahydrophenanthrene-3,4-dione (4), two analogues of the antitumor active tanshinone, were synthesized from anisole. The synthesized compounds 3 and 4 were shown to be highly active against leukemia P-388 cell fine as assayed by in vitro MTT method. 相似文献
116.
Rupestonic acid was purified for the first time by high-speed counter-current chromatography from a dichloromethane extract of the traditional Chinese medicinal plant Artemisia rupestris L. The separation was performed in two steps with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (6:4:3.5:6.5, v/v) with 0.5% acetic acid in stationary-phase. From 200 mg of the crude extract, 27.9 mg of rupestonic acid was obtained at over 98% purity as determined by HPLC analysis, and its chemical structure was confirmed by MS, 1H and 13C nuclear magnetic resonance. 相似文献
117.
High-Speed Counter-Current Chromatography Combined with Column Chromatography for Isolation of Methyllycaconitine from Delphinium pseudocyanthum 总被引:1,自引:0,他引:1
Preparative high-speed counter-current chromatography (HSCCC) combined with conventional column chromatography (CC) has been used for isolation and purification of methyllycaconitine from Delphinium pseudocyanthum. n-Hexane-ethyl acetate-methanol-water, 1:1:1:2 (v/v), was used as the solvent system for HSCCC. Separation of methyllycaconitine from an HSCCC fraction was successfully achieved by CC on silica gel using chloroform-methanol, 7:1 (v/v), as mobile phase. A total of 113.45 mg methyllycaconitine of purity >95% was obtained from 1.044 g extract of D. pseudocyanthum. Its structure was identified by MS and NMR. 相似文献
118.
Zareen Akhter Asifa Nigar Muhammad Y. Razzaq Humaira M. Siddiqi 《Journal of organometallic chemistry》2007,692(16):3542-3546
A series of ferrocenyl Schiff base derivatives was synthesized by condensation reactions of 1,1′-ferrocenedicarboxaldehyde and aromatic amines containing long chain alkyl groups as free ends which were characterized by their physical properties, elemental, FTIR, 1H NMR, 13C NMR spectral and thermal analysis. The thermal behaviour of the synthesized compounds was studied by differential scanning calorimetry (DSC) which revealed that these compounds may exhibit mesomorphic properties. The DSC results of aromatic amines and ferrocenyl Schiff bases were compared to study the effects of structure, i.e. rigid core and terminal chain length, on the phase transition behaviour. 相似文献
119.
Muhammad Kashif Erdawaty Jaafar Poonam Bhadja Foo Wah Low Siti Kudnie Sahari Shahid Hussain Foo Kai Loong Awais Ahmad Tahani Saad AlGarni Muhammad Shafa Humaira Asghar Saad A. Al-Tamrah 《Arabian Journal of Chemistry》2021,14(2):102953
This work investigated the effect of Potassium Permanganate (KMnO4) on graphene oxide (GO) properties, especially on electrical properties. The GO thin films were deposited on a glass substrate using drop casting technique and were analysed by using various type of spectroscopy (e.g. Scanning Electron Microscopy (SEM), Ultra- Violet Visible (UV–VIS), Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD), optical band gap, Raman Spectroscopy). Furthermore, the electrical experiments were carried out by using current–voltage (I-V) characteristic. The GO thin film with 4.5 g of KMnO4 resulted in higher conductivity which is 3.11 × 10?4 S/cm while GO with 2.5 g and 3.5 g of KMnO4 achieve 2.47 × 10?9 S/cm and 1.07 × 10?7 S/cm, respectively. This further affects the morphological (SEM), optical (band gap, UV–Vis, FTIR, and Raman), and crystalline structural (XRD) properties of the GO thin films. The morphological, elemental, optical, and structural data confirmed that the properties of GO is affected by different amount of KMnO4 oxidizing agent, which revealed that GO can potentially be implemented for electrical and electronic devices. 相似文献
120.
Fareena Shahid Noreen Roshan Ali Syed Lal Badshah Syed Babar Jamal Riaz Ullah Ahmed Bari Hafiz Majid Mahmood Muhammad Sohaib Siddique Akber Ansari 《Molecules (Basel, Switzerland)》2021,26(5)
Hepatitis C is affecting millions of people around the globe annually, which leads to death in very high numbers. After many years of research, hepatitis C virus (HCV) remains a serious threat to the human population and needs proper management. The in silico approach in the drug discovery process is an efficient method in identifying inhibitors for various diseases. In our study, the interaction between Epigallocatechin-3-gallate, a component of green tea, and envelope glycoprotein E2 of HCV is evaluated. Epigallocatechin-3-gallate is the most promising polyphenol approved through cell culture analysis that can inhibit the entry of HCV. Therefore, various in silico techniques have been employed to find out other potential inhibitors that can behave as EGCG. Thus, the homology modelling of E2 protein was performed. The potential lead molecules were predicted using ligand-based as well as structure-based virtual screening methods. The compounds obtained were then screened through PyRx. The drugs obtained were ranked based on their binding affinities. Furthermore, the docking of the topmost drugs was performed by AutoDock Vina, while its 2D interactions were plotted in LigPlot+. The lead compound mms02387687 (2-[[5-[(4-ethylphenoxy) methyl]-4-prop-2-enyl-1,2,4-triazol-3-yl] sulfanyl]-N-[3(trifluoromethyl) phenyl] acetamide) was ranked on top, and we believe it can serve as a drug against HCV in the future, owing to experimental validation. 相似文献