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31.
Hua Zhou Hong‐Ping He Ning‐Chuan Kong Tie‐Jun Wang Xiao‐Jiang Hao 《Helvetica chimica acta》2008,91(11):2148-2152
Anthocephalusine A ( 1 ) and 3β‐isodihydrocadambine 4‐oxide ( 2 ) were isolated from the leaves of Anthocephalus chinensis (Rubiaceae), together with five known compounds. The structures were established by spectroscopic methods including 2D‐NMR analyses. 相似文献
32.
The in‐capillary DPPH‐capillary electrophoresis‐the diode array detector combined with reversed‐electrode polarity stacking mode for screening and quantifying major antioxidants in Cuscuta chinensis Lam
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Jiao Liu Ji Tian Jin Li John Teye Azietaku Bo‐li Zhang Xiu‐mei Gao Yan‐xu Chang 《Electrophoresis》2016,37(12):1632-1639
An in‐capillary 2, 2‐diphenyl‐1‐picrylhydrazyl (DPPH)‐CE‐the DAD (in‐capillary DPPH‐CE‐DAD) combined with reversed‐electrode polarity stacking mode has been developed to screen and quantify the active antioxidant components of Cuscuta chinensis Lam. The operation parameters were optimized with regard to the pH and concentration of buffer solution, SDS, β‐CDs, organic modifier, as well as separation voltage and temperature. Six antioxidants including chlorogenic acid, p‐coumaric acid, rutin, hyperin, isoquercitrin, and astragalin were screened and the total antioxidant activity of the complex matrix was successfully evaluated based on the decreased peak area of DPPH by the established DPPH‐CE‐DAD method. Sensitivity was enhanced under reversed‐electrode polarity stacking mode and 10‐ to 31‐fold of magnitude improvement in detection sensitivity for each analyte was attained. The results demonstrated that the newly established in‐capillary DPPH‐CE‐DAD method combined with reversed‐electrode polarity stacking mode could integrate sample concentration, the oxidizing reaction, separation, and detection into one capillary to fully automate the system. It was considered a suitable technique for the separation, screening, and determination of trace antioxidants in natural products. 相似文献
33.
Wang J Chen Y Lin M Fan G Zhao W Wu Y Yan C Wang J 《Journal of separation science》2007,30(3):381-390
A pressurized CEC (pCEC) method with postcolumn detection cell had been developed for quantifying the lignans from Fructus schisandrae extracts. The effects of different experimental conditions, such as the ACN content of the mobile phase, the concentration and pH of the buffer, the applied voltage, and the supplementary pressure were studied. Five lignans (schisandrin, gomisin A, schisantherin C, deoxyschizandrin, schisandrin B) were baseline separated using a mobile phase of ACN-phosphate buffer (pH 5.4; 5 mM) (40:60 v/v) under -4 kV applied voltage. The method showed the satisfactory retention time and peak area repeatability. The calibration curves were linear in the range 50.0-1000.0 microg/mL for schisandrin, 20.0-500.0 microg/mL for gomisin A, 10.0-200.0 microg/mL for schisantherin C, 20.0-500.0 microg/mL for deoxyschizandrin, and 20.0-500.0 microg/mL for schisandrin B. The correlation coefficients were between 0.9978 and 0.9989. With this pCEC system, fingerprints of F. schisandrae were preliminarily established to distinguish two members S. chinensis (Turcz.) Baill. and S. sphenanthera Rehd. Et Wils. of F. schisandrae by characteristic peaks, and evaluate the quality of various sources of raw materials by determining the contents of the five lignans. 相似文献
34.
Zhi-jun Guo Wei Zhang Jin-guo Xu Xiao-man Li Jiu-ba Zhang Yu Li De Ji Lin Li Wei Huang Lian-lin Su 《Biomedical chromatography : BMC》2024,38(3):e5811
In this study, infrared spectroscopy, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) technology were applied to systematically explain the Schisandra chinensis’s polysaccharide transformation in configuration, molecular weight, monosaccharide composition, and anti-ulcerative colitis (UC) activity after vinegar processing. Scanning electron microscopic results showed that the appearance of S. chinensis polysaccharide changed significantly after steaming with vinegar. The MALDI-TOF-MS results showed that the mass spectra of raw S. chinensis polysaccharides (RSCP) were slightly lower than those of vinegar-processed S. chinensis polysaccharides (VSCP). The RSCP showed higher peaks at m/z 1350.790, 2016.796, and 2665.985, all with left-skewed distribution, and the molecular weights were concentrated in the range of 1300–3100, with no higher peak above m/z 5000. The VSCPs showed a whole band below m/z 3000, with m/z 1021.096 being the highest peak, and the intensity decreased with the increase of m/z. In addition, compared to RSCPs, VSCPs can significantly increase the content of intestinal short-chain fatty acids (SCFAs). This study showed that the apparent morphology and molecular weight of S. chinensis’s polysaccharides significantly changed after steaming with vinegar. These changes directly affect its anti-UC effect significantly, and its mechanism is closely related to improving the structure and diversity of gut microbiota and SCFA metabolism. 相似文献
35.
Jin Woo Lee Jun Gu Kim Jae Sang Han Yong Beom Cho Yu Jin Lee Dongho Lee Dae Hwan Shin Jin Tae Hong Mi Kyeong Lee Bang Yeon Hwang 《Molecules (Basel, Switzerland)》2021,26(23)
Orbitides are plant-derived small cyclic peptides with a wide range of biological activities. Phytochemical investigation of the whole plants of Dianthus chinensis was performed with the aim to discover new bioactive orbitides. Five undescribed proline-containing orbitides, dianthiamides A–E (1–5), were isolated from a methanolic extract of Dianthus chinensis. Their structures were elucidated by extensive analysis of 1D and 2D NMR and HRESI–TOF–MS as well as ESI–MS/MS fragmentation data. The absolute configuration of the amino acid residues of compounds 1–5 was determined by Marfey’s method. All compounds were tested for their cytotoxic activity, and dianthiamide A (1) exhibited weak activity against A549 cell line with IC50 value of 47.9 μM. 相似文献
36.
月季花抗氧化活性成分研究 总被引:2,自引:0,他引:2
以活性追踪为指导分离和纯化了月季花中具有1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除活性的成分. 从月季花中分离得到了10个黄酮类化合物, 采用光谱法对其结构进行了表征, 并对它们的自由基清除活性进行了评价. 结果表明, 化合物1为新化合物, 化合物1, 2, 4和9具有较强的清除DPPH自由基的活性. 相似文献
37.
38.
摘要:采用遮荫的方式设置3个光照梯度:全光照(CK)、37%全光照(37%RI)和10%全光照(10%RI),于2007年7月中旬,对上述光环境中的夏蜡梅(Sinocalycanthus chinensis)幼苗的光合作用参数、叶绿素荧光参数进行测定,结果表明:3种光环境下,夏蜡梅的净光合速率日变化均为“双峰”曲线,CK和37%RI光环境下,午休现象明显;最大净光合速率的大小是37%RI>CK>10%RI;日均净光合速率的大小是37%RI>10%RI>CK.叶绿素荧光参数的日变化表明,10%RI光环境下光抑制现象不明显;37%RI光环境下在午间发生了明显的光抑制,但是光合机构可以恢复.全光照环境下发生了长期的光抑制,光合机构受到不可恢复的伤害.在夏蜡梅自然群落中,于2006年7月、10月和2007年4月下旬的晴朗天气,测定了群落冠层和林下2种光环境下夏蜡梅的净光合速率日进程,并与其主要伴生植物进行比较.7月夏蜡梅冠层的净光合速率日进程呈“双峰”曲线,有明显的“午休”现象;林下夏蜡梅则表现为“单峰”曲线;在4月和10月夏蜡梅及其伴生植物净光合速率日进程均呈“单峰”曲线.夏蜡梅3个季节的日均净光合速率的平均值比其它伴生植物低,在群落内种间竞争中将处于不利地位. 相似文献
39.
WD Zhang Q Wang Y Wang XJ Wang JX Pu Y Gu R Wang 《Journal of separation science》2012,35(17):2203-2209
Lignans in the drug Fructus Schisandrae chinensis (FSC) exhibit potent biological activities such as antihepatotoxic, antiasthmatic, and antigastric ulcer. An ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method has been developed to evaluate the quality of FSC through simultaneous qualitative and quantitative analysis of 15 lignans, including schizandrin A, B, and C; schizandrol A and B; gomisin B, C, D, E, G, H, J, and N; tigloylgomisin H; and angeloylgomisin H. The compounds were separated on a Zorbax Eclipse Plus C(18) (2.1 × 100 mm, 1.8 μm) column with a gradient elution of acetonitrile and 0.1% formic acid. Lignans were identified through their retention times, accurate mass data, and characteristic ions by comparison with a reference substance. All calibration curves showed perfect linear regression (r(2) > 0.99) within the test range. The limits of detection and quantitation fell in the ranges of 0.1-4 ng/mL for all the analytes with an injection of 10 μL. Good results were obtained with respect to repeatability (relative standard deviation <4.6%) and recovery (85.58-105.82%). Meanwhile, the entire sample analysis time was less than 10 min. This developed method provided a new basis for the overall assessment of the quality of FSC. 相似文献
40.
Monchanok Tuntipaleepun Suda Chakthong Chanita Ponglimanont Patimaporn Plodpai Supayang P.Voravuthikunchai 《中国化学快报》2012,23(5):587-590
Isounonal-7-methyl ether(1) and chinendihydrochalcone(2) together with 8 known compounds were isolated from the stem barks of Desmos chinensis.Their structures were determined on the basis of spectroscopic data.Compound 2 exhibited cytotoxic activity against MOLT-3 cancer cell line(IC50 7.16μg/mL) and antifungal activity against Pyricularia oryzae and Rhizoctonia solani with MIC values of 15.6 and 31.2μg/mL,respectively. 相似文献