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A new labeling reagent, 1-(2-naphthyl)-3-methyl-5-pyrazolone (NMP), coupling with liquid chromatography (LC) with electrospray ionization mass spectrometry (ESI-MS) for the detection of carbohydrates from a famous Tibetan medicine is reported. Carbohydrates were derivatized to their bis-NMP-labeled derivatives. The method, in conjunction with a gradient elution, offered a baseline resolution of carbohydrate derivatives on a reversed phase Hypersil ODS-2 column. The carbohydrates such as mannose, galacturonic acid, glucuronic acid, rhamnose, glucose, galactose, xylose, arabinose, and fucose could be successfully detected by UV and ESI-MS. Derivatives showed intense protonated molecular ion at m/z [M + H]+ in positive ion mode. The mass to charge ratios of characteristic fragment ions at m/z 473.0 could be used for the accurately qualitative identification of carbohydrates; this characteristic fragment ion was from the cleavage of C2-C3 bond in the carbohydrate chain giving the specific fragment ions at m/z [MH-CmH2m+1Om-H2O]+ for pentose, hexose, and glyceraldehydes, and at m/z [MH-CmH2m-1Om+1-H2O]+ for alduronic acids, such as galacturonic acid and glucuronic acid (m = n - 2, n is carbon atom number of carbohydrate). Compared with the traditional 1-phenyl-3-methyl-5-pyrazolone (PMP) reagent, currently synthesized NMP show the advantage of higher sensitivity to carbohydrate compounds with UV and ESI-MS detection.
A method that involved the combination of pH-zone-refining counter-current chromatography and semipreparative reversed-phase liquid chromatography has been established for the preparative separation of alkaloids from Hypecoum leptocarpum. From 1.2 g of crude sample, 31 mg N-feruloyltyramine, 27 mg oxohydrastinine, 47 mg hydroprotopine, 25 mg leptopidine, and 18 mg hypecocarpine have been obtained. The structure of the new compound, hypecocarpine, is confirmed based on the analysis of spectroscopic data, including NMR, UV, and IR spectroscopy and positive electrospray ionization mass spectrometry. The known chemical structures were characterized on the basis of (1) H and (13) C NMR spectroscopy. The purities of the five alkaloids are all over 92.7% as determined by high-performance liquid chromatography. The alkaloids' cytotoxicity in breast cancer cells is assessed by using a Cell Counting Kit assay and their inhibitory effect on fatty acid synthase expression is assessed by a Western blot assay. These results suggest that leptopidine could suppress growth and induce cytotoxicity in breast cancer cells and that the cytotoxicity of leptopidine may be related to its inhibitory effect on fatty acid synthase expression.
<p>A simple and sensitive method for the determination of free fatty acids (FFAs) using acridoné9́ethyĺṕtoluenesulfonate (AETS) as a fluorescence derivatization reagent by high performance liquid chromatography (HPLC) has been developed. Free fatty acid derivatives were separated on an Eclipse XDB́C<sub>8</sub> column with a good baseline resolution and detected with the fluorescence of which excitation and emission wavelengths of derivatives were set at <sub>ex</sub>=404 and <sub>em</sub>=440 nm, respectively. Identification of 19 fatty acid derivatives was carried out by online post́column mass spectrometry with an atmospheric pressure chemical ionization (APCI) source under positivéion detection mode. Nineteen FFAs from the extract of <i>Lomatogonium rotatum</i> are sensitively determined. The results indicate that the plant <i>Lomatogonium rotatum</i> is enriched with an abundance of FFAs and FFAs of higher contents, which mainly focus on even carbon atoms, C<sub>14</sub>, C<sub>16</sub>, and C<sub>18</sub>. The validation of the method including linearity, repeatability, and detection limits was examined. Most linear correlation coefficients for fatty acid derivatives are >0.9989, and detection limits (at signaĺtónoise of 3:1) are 12.3-43.7 fmol. The relative standard deviations (RSDs) of the peak areas and retention times for 19 FFAs standards are <2.24% and 0.45%, respectively. The established method is rapid and reproducible for the separation determination of FFAs from the extract of <i>Lomatogonium rotatum</i> with satisfactory results.</p>
High-speed counter-current chromatography (CCC) was firstly and successfully applied for the preparative separation and purification of alkaloids from crude extract of Hypecoum leptocarpum. After the measurement of partition coefficient of five target alkaloids in the two-phase solvent systems, the CCC was performed well with a two-phase solvent system composed of tetrachloromethane-chloroform-methanol-0.1 M HCl at a volume ratio of 1.5 : 2.5 : 3 : 2 (V/V/V/V). The upper phase was used as the stationary phase, and the lower phase was used as the mobile phase. From 120 mg crude extract, 5 mg leptopidine, 32 mg oxohydrastinine, 27 mg (-)-N-methylanadine, 7 mg N-feruloyltyramine and 3 mg hypecoleptopine could be successfully separated. The amides alkaloid, N-feruloyltyramine, was firstly separated from H. leptocarpum. High-performance liquid chromatography analysis showed that the purity of each of the five target alkaloids was over 92%. Their chemical structures were confirmed by (1)H-NMR and (13)C-NMR data.
High-speed counter-current chromatography (HSCCC) was successfully applied for the first time to isolate and purify four cis-trans isomers of coumaroylspermidine analogs from Safflower. HSCCC separation was achieved with a two-phase solvent system composed of chloroform-methanol-water (1:1:1, v/v/v) with the upper phase as the mobile phase. In a single run, a total of 1.3mg of N(1), N(5), N(10)-(E)-tri-p-coumaroylspermidine (EEE), 4.4mg of N(1)(E)-N(5)-(Z)-N(10)-(E)-tri-p-coumaroylspermidine (EZE), 7.2mg of N(1)(Z)-N(5)-(Z)-N(10)-(E)-tri-p-coumaroylspermidine (ZZE), and 11.5mg of N(1),N(5),N(10)-(Z)-tri-p-coumaroylspermidine (ZZZ) were obtained from 100mg of crude sample. High Performance Liquid Chromatography (HPLC) analysis showed that the purities of these four components are 95.5%, 98.1%, 97.5% and 96.2%, respectively. The chemical structures were identified by ESI-MS, (1)H NMR and (13)C NMR.
NSM-<i>g</i>-P(MMA-<i>co</i>-BA) resin with super oil-absorbent capability was prepared by grafting co-polymerization using Nitraria seeds meal as filler, methyl-meth-acrylate (MMA) and butyl-acrylate (BA) as monomers, <i>N,N′</i>-methylene-bis-acrylamide (MBA) as crosslinker and peroxide-benzoyl (BPO) as initiator. The structure of obtained products was analyzed using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. The oil absorbency, reusability, oil-retention capacity, thermodynamics, and the removal of oil from the surface of 0.9 wt% NaCl solutions were examined further. The results showed that NSM-<i>g</i>-P(MMA-<i>co</i>-BA) can absorb lubrication up to 29.6 times of its weight, 24.3 times for colza oil, 22.7 times for diesel, and 21 times for gasoline. The exhausted NSM-<i>g</i>-P(MMA-<i>co</i>-BA) can be recollected and recovered through extraction or drying approach. More importantly, the oil sorption capacity of recovered NSM-<i>g</i>-P(MMA-<i>co</i>-BA) only has a slight decline after six sorption cycles. The thermodynamic studies indicated that adsorption procedure with complex physical and chemical sorption is spontaneous and exothermic. In general, the present composite resins have exhibited potential applications in cleanup of oil spills because of their good hydrophobicity, lipophilicity, and excellent network structure. Also, the findings of this study might provide a convenient and economic method for fast and selective removal of oil from surface of wastewater. POLYM. COMPOS., 39:1051-1063, 2018. © 2016 Society of Plastics Engineers
A method of using high-speed counter-current chromatography (HSCCC) for preparative isolation and purification of oligostilbenes from the ethanol extracts of seed kernel of Iris lactea Pall. var. chinensis (Fisch.) Koidz was established in this study. Four oligostilbenes were successfully separated and purified by HSCCC with two sets of two-phase solvent system, n-hexane-ethyl acetate-methanol-water (3:6:4.2:5.5, v/v/v/v) in the head-to-tail elution mode for the first separation to mainly isolate vitisin A (58 mg), ɛ-viniferin (76 mg) and peak II (43 mg) from 300 mg of the crude ethanol extracts, and then light petroleum-ethyl acetate-methanol-water (5:5:3:6, v/v/v/v) in the tail-to-head elution mode for the second separation to isolate vitisin B (52 mg) and vitisin C (11 mg) from 100mg of peak II. The purities of the isolated four oligostilbenes were all over 95.0% as determined by HPLC. Vitisin A, vitisin B and vitisin C, resveratrol tetramers, were isolated from Iris lactea for the first time. The preparation of crude sample was simple and the HSCCC method for the isolation and purification of four oligostilbenes was rapid, efficient and economical.
Two novel organic amide alkaloids, 4-[(<i>E</i>)-<i>p</i>-coumaroylamino]butan-1-ol (<b>1</b>) and 4-[(<i>Z</i>)-<i>p</i>-coumaroylamino]butan-1-ol (<b>2</b>), together with a rare pyridoindole alkaloid, hippophamide (<b>3</b>), were isolated from the seed residue of <i>Hippophae rhamnoides</i> Linn. subsp. <i>sinensis</i> Rousi. Their structures were determined by spectroscopic means. The results show that compounds <b>1</b> and <b>2</b> are (<i>E</i>/<i>Z</i>)<i>-</i>isomers, compound <b>3</b>, a pyridoindole alkaloid concerted with <i>γ</i>-lactam ring.
Anthocyanins are the main compounds in Nitraria tangutorun Bobr. The enrichment and purification of anthocyanins on macroporous resins were investigated. Regarding anthocyanin purification, static adsorption and desorption were studied. The optimal experimental conditions were the following: resin type: X-5; static adsorption time: 6h; desorption solution: ethanol-water-HCl (80:19:1, V/V/V; pH 1); desorption time: 40min. Furthermore, the in vitro and in vivo biological activities of the anthocyanins were evaluated. The anthocyanins showed ideal scavenging effects on free radicals in vitro, especially on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl free radical (OH). In the animal experiment, blood lipid metabolism of hyperlipidemia rats was regulated by anthocyanin contents. The superoxide dismutase (SOD) activity and the total antioxidant capacity (TAC) of hyperlipidemia rats were also improved by anthocyanins. These results showed that anthocyanins from N. tangutorun Bobr. fruits had potential biological activities in vivo as well as in vitro.