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91.
In this paper, for the first time, an inorganic–organic hybrid material based on ZnO nanoparticles was anchored to a composite made from polythiophene and hexagonally ordered silica (ZnO/PT/SBA-15) for use in solid-phase fibre microextraction (SPME) of medicinal plants. A homemade SPME apparatus was used for the extraction of volatile components of Ziziphora tenuior L. A simplex method was used for optimisation of five different parameters affecting the efficiency of the extraction. The main constituents extracted by ZnO/PT/SBA-15 and PDMS fibres and hydrodistillation (HD) methods, respectively, included pulegone (51.25%, 53.64% and 56.68%), limonene (6.73%, 6.58% and 8.3%), caryophyllene oxide (5.33%, 4.31% and 4.53%) and 1,8-cineole (4.21%, 3.31% and 3.18%). In comparison with the HD method, the proposed technique could equally monitor almost all the components of the sample, in an easier way, in a shorter time and requiring a much lower amount of the sample. 相似文献
92.
A novel triterpenoid 3α,16β,23,24-tetrahydroxy-28-nor-ursane-12,17,19,21-tetraen (1) was isolated from the fruits of Gardenia jasminoides var. radicans Makino. The structure of the new compounds was elucidated on the basis of spectroscopic analysis including MS and NMR data. Compound 1 was in vitro tested for cytostatic activity on human throat cancer (Hep-2) cell line by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide method and showed mild anticancer activity with the IC50 of 31.2 μM. 相似文献
93.
Chloroform extract of bark of Artabotrys crassifolius Hook.f. & Thomson exhibited antibacterial activities against both American Type Culture Collection and clinical bacterial strains in vitro with zones of inhibition ranging from 7 to 14 mm. Further analysis of this extract yielded artabotrine, liridine, lysicamine and atherospermidine. Artabotrine displayed a broad array of antibacterial activity mostly against Gram-positive bacteria with minimum inhibitory concentration (MIC) values ranging from 1.25 μg/mL to 5 μg/mL. Of note, artabotrine, liridine and lysicamine are bactericidal against Gram-negative extended-spectrum beta-lactamase-producing Klebsiella with MIC values equal 2.5, 2.5 and 10 μg/mL, respectively, and minimum bactericidal concentrations values equal to 2.5, 5 and 20 μg/mL. 相似文献
94.
Saoussen Hammami Ridha El Mokni Khaled Faidi Danilo Falconieri Alessandra Piras Silvia Procedda 《Natural product research》2015,29(24):2336-2340
The objectives of this study were to chemically characterise and evaluate the antioxidant potential of the essential oil from Teucrium flavum L. subsp. flavum growing spontaneously in Tunisia. The volatile oil was extracted by hydrodistillation of the aerial parts in a Clevenger type apparatus. Forty constituents were identified via GC and GC-MS analysis. β-caryophyllene (32.5%) and α-humulene (17.8%) were the most abundant components. The evaluation of free radical scavenging activity using stable DPPH free radical showed that the volatile oil exhibits a moderate antioxidant activity and reduces DPPH to 50% at EC50 value of 1230 μg mL? 1. 相似文献
95.
Separation of five compounds from leaves of Andrographis paniculata (Burm. f.) Nees by off‐line two‐dimensional high‐speed counter‐current chromatography combined with gradient and recycling elution 下载免费PDF全文
Li Zhang Qi Liu Jingang Yu Hualiang Zeng Shujing Jiang Xiaoqing Chen 《Journal of separation science》2015,38(9):1476-1483
An off‐line two‐dimensional high‐speed counter‐current chromatography method combined with gradient and recycling elution mode was established to isolate terpenoids and flavones from the leaves of Andrographis paniculata (Burm. f.) Nees. By using the solvent systems composed of n‐hexane/ethyl acetate/methanol/water with different volume ratios, five compounds including roseooside, 5,4′‐dihydroxyflavonoid‐7‐O‐β‐d ‐pyranglucuronatebutylester, 7,8‐dimethoxy‐2′‐hydroxy‐5‐O‐β‐d ‐glucopyranosyloxyflavon, 14‐deoxyandrographiside, and andrographolide were successfully isolated. Purities of these isolated compounds were all over 95% as determined by high‐performance liquid chromatography. Their structures were identified by UV, mass spectrometry, and 1H NMR spectroscopy. It has been demonstrated that the combination of off‐line two‐dimensional high‐speed counter‐current chromatography with different elution modes is an efficient technique to isolate compounds from complex natural product extracts. 相似文献
96.
Development of a method to screen and isolate potential α‐glucosidase inhibitors from Panax japonicus C.A. Meyer by ultrafiltration,liquid chromatography,and counter‐current chromatography 下载免费PDF全文
A new assay based on ultrafiltration, liquid chromatography and mass spectrometry was developed for the rapid screening and identification of the ligands for α‐glucosidase from the extract of Panax japonicus. Six saponins were identified as α‐glucosidase inhibitors. Subsequently, the specific binding ligands, namely, notoginsenoside R1, ginsenoside Rb1, chikusetsusaponin V, chikusetsusaponin IV, chikusetsusaponin IVa, and ginsenoside Rd (the purities were 94.18, 95.43, 96.09, 93.26, 94.50, 93.86%, respectively) were separated by counter‐current chromatography using two‐phase solvent systems composed of tert‐butyl methyl ether, acetonitrile, 0.1% aqueous formic acid (3.8:1.0:4.4, v/v/v) and the solvent system composed of methylene chloride, isopropanol, methanol, 0.1% aqueous formic acid (5.8:1.0:6.0:2.2, v/v/v). The results demonstrate that ultrafiltration, liquid chromatography and mass spectrometry combined with high‐speed counter‐current chromatography might provide not only a powerful tool for screening and isolating α‐glucosidase inhibitors in complex samples but also a useful platform for discovering bioactive compounds for the prevention and treatment of diabetes mellitus. 相似文献
97.
High-performance liquid chromatography (HPLC) has been commonly used as method of separating and identifying photosynthetic pigments such as chlorophylls and carotenoids because of such advantages as speed, high resolution and sensitivity. In this technique, high separation relies largely on the type of column material. This study compared the efficiency of five reverse-phase columns, C8, C18, C18 monolithic, π-NAP, and cholester, for separation of photosynthetic pigments at several fixed conditions of mobile phase and temperature. This investigation also analysed the parameters of ΔtR and tR ratio for selected pigments and resolution for structural isomers, such as α- and β-carotene. Among above columns tested, cholester column is suitable for separation of pigments not only for a broad range of polarity, but also for hydrophobic pigments in a simple mobile phase. This finding can help in the selection of column and HPLC parameters in separating photosynthetic pigments. 相似文献
98.
Large quantity of aged petroleum oil contamination such as dehydrated oil sludge, generated in the disposal process of oil-containing sewage in Indonesia. This study aims to investigate the OSCS removal by mean of bioremediation technique. Results found that petrofilic consortia and biosurfactants addition increased the removal efficiency up to 46% and 85%, respectively. At full scale application, this technique succeed in removing of 46 g TPH per kg soil from 4 883 m3 of OSCS during 16 mo of treatment. These results suggest that petrofilic consortia and biosurfactants addition stimulate the biodegradation and overcome the limitation of OSCS degradation process. 相似文献
99.
Hippocampus trimaculatus are highly valued and the most heavily traded seahorse species for traditional medicine purposes in many Asian countries. One of the main interesting features in H.trimaculatus is their richness in protein which can be hydrolyzed into bioactive peptides. In the previous study, H. trimaculatus was hydrolyzed using commercial enzymes, the peptides responsible for neuroprotective activity was identified as HTP-1. In the present study, in vitro co-culture system of neuronal (PC12) cells and Aβ42 oligomer-stimulated murine microglia cells (BV2 cells) were used to test neuroprotective effects of HTP-1. The co-culture system showed that HTP-1 protected PC12 cells from BV2 neurotoxic responses. In addition, the activation of PI3K/Akt signaling pathway by HTP-1 were confirmed. The PI3K/Akt activation was found to be mediated through transforming growth factor-β (TGF-β) induction by HTP-1. Furthermore, this signaling pathway was found to up-regulate the expression of pro survival protein expression in PC12 cells. Collectively, HTP-1 has potent protective effect against neuronal cells death in in vitro model of Alzheimer's disease. 相似文献
100.