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311.
A chromatographic method using 12% cross-linked agarose gel Superose 12 as the separation medium was developed for isolation and purification of the chemical constituents from the pericarp of Sophora japonica L. The mobile phase used for the separation was 2% acetic acid and 7% acetic acid in gradient elution. As a result, eight compounds including four kinds of flavonoids and four kinds of isoflavonoids were obtained in a one-step separation. A straightforward explanation of the separation mechanism of flavonoids and isoflavonoids on Superose 12 is also given. The flavonoids and isoflavonoids are retained on Superose 12 by a combination of hydrogen bonding and hydrophobic interactions between the hydroxyl groups of aglycone and the residues of the cross-linking reagents used in the manufacture of Superose 12. 相似文献
312.
High-speed counter-current chromatography combined with macroporous resin column separation was applied to the isolation and purification of genistein-7,4'-di-O-beta-D-glucoside (I), genistein-7-O-beta-D-glucopyranoside-4'-O-[(alpha-L-rhamnopyransoyl)-(1-2)-beta-D-glucopyranoside] (II), kaempferol-3-O-beta-D-sophoroside(III), quercetin-3-O-beta-L-ramnopyranosyl-(1 - 6)-beta-D-glucopyranoside (IV), genistein-4'-beta-L-rhamnopyransoyl-(1 - 2)-alpha-D-glucopyranoside (V), and kaempferol-3-O-beta-L-ramnopyranosyl-(1 - 6)-beta-D-glucopyranoside (VI) from the Chinese medicinal herb Sophora japonica L. The crude extracts from the pericarps of Sophora japonica L. were pre-separated on a D-101 macroporous resin column and divided into two parts as sample 1 and sample 2. An 80-mg portion of sample 1 was separated by using n-butanol-acetic acid (1%) (5:5, v/v) as the two-phase solvent system and yielded 30.1 mg of compound I, 23.3 mg of compound II. A 120 mg portion of sample 2 was separated by using ethyl acetate-n-butanol-acetic acid (1%) (5:0.8:5, v/v) as the two-phase solvent system and yielded 5.5 mg of compound III, 31.7 mg of compound IV, 37.4 mg of compound V, and 6.2 mg of compound VI. The purities of compounds I, II, III, IV, V, and VI were 98.7, 98.2, 97.8, 98.5, 99.3, and 98.9%, respectively, as determined by HPLC. The chemical structures of these components were identified by 1H-NMR and 13C-NMR. 相似文献
313.
Luteoloside is a potential anticarcinogenic component isolated from Lonicera japonica, a traditional Chinese medicine (TCM). This study details the development and validation of a sensitive and accurate HPLC‐ESI‐MS/MS method for the quantification of luteoloside in dog plasma. Sample pretreatment includes simple protein precipitation using methanol–acetonitrile (1:1, v/v). A Phenomenex Gemini C18 column (2.0 × 50 mm, i.d., 3.5 µm) was used to separate luteoloside and internal standard by gradient mode with mobile phase consisting of water containing 0.1% formic acid and methanol containing 0.1% formic acid at a flow rate of 0.40 mL/min with a column temperature of 25°C. The detection was performed by positive ion electrospray ionization (ESI) in multiple reaction monitoring mode. The calibration curves were linear (R > 0.995) over the concentration range 1.0–2000 ng/mL and the lower limit of quantification was 1.0 ng/mL. The intra‐day and inter‐day precisions (RSD) were all <15%, accuracies (RE) were within the range of ±15%, and recoveries were between 85.0 and 115%. The validated HPLC‐ESI‐MS/MS method was successfully applied to determine plasma concentrations of luteoloside after intravenous administration of luteoloside at a dose level of 20 mg/kg. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
314.
Phosphodiesters quaternary ammonium salt (PQAS) displayed quite intense light scattering in aqueous solution under the optimum condition. In addition, the resonance light scattering (RLS) signal of PQAS was remarkably decreased after adding trace amount polysaccharide with the maximum peak located at 391 nm. It was found that the decreased RLS intensity of the PQAS − PPGL system (ΔIRLS) was in proportion to PPGL concentration in the range of 0.1-30 ng mL−1, with a lower detection limit of 0.05 ng mL−1. Based on this rare decreased RLS phenomenon, the novel method of the determination of purified polysaccharide of Gracilaria Lemaneiformis (PPGL) at nanogram level was proposed in this contribution. The proposed approach was used to determine purified polysaccharide extracted from Gracilaria Lemaneiformis with satisfactory results. Compared with the reported polysaccharide assays, this proposed method has good selectivity, high sensitivity and is especially simple and convenient. Moreover, the mechanism of the reaction between PQAS and polysaccharide was investigated by RLS, fluorescence, and fluorescence lifetime spectra. 相似文献
315.
为了解氮(N)、磷(P)水平对细基江蓠(Gracilaria tenuistipitata)植物营养生理生态特征的影响,以亚热带大型海藻细基江蓠为原材料,研究不同N、P浓度条件下细基江蓠的生长,净化吸收N、P及其之间的相互关系。结果表明:细基江蓠的相对生长速率随着N、P浓度的增加而升高,但藻体增重幅度跟营养盐浓度不成正比,在N和P初始浓度分别为160 μmol·L-1和10 μmol·L-1时增幅最大,N、P水平和N/P明显影响细基江蓠的生长。在低N、P浓度条件下细基江蓠对N、P的去除率更高,P4组(N=64 μmol·L-1、P=4 μmol·L-1)对PO43--P去除率高达96.8%,对NH4+-N和NO3--N的去除率也表现出类似特征。细基江蓠在高N/P组对P的去除率高,在低N/P组对N的去除率高,N、P胁迫对细基江蓠的营养盐去除率有明显影响。各实验组中细基江蓠对PO43--P、NO3--N和NH4+-N的吸收速率随着初始营养盐浓度的增加而升高,分别在PO43--P初始浓度为25 μmol·L-1,无机氮(NO3--N:NH4+-N浓度比为1:1)初始浓度为200 μmol·L-1时吸收速率最大。适应富营养环境的细基江蓠倾向于按Redfield比吸收N、P,偏离Redfield比则对细基江蓠的生长有明显的抑制效应。细基江蓠对N、P高去除率的特性使其成为富营养化水质修复的潜在优良种类。 相似文献
316.
日本三角涡虫组织结构嗜银反应观察 总被引:1,自引:0,他引:1
涡虫在动物系统演化史上占有十分重要的地位,雌雄同体,具有很强的再生能力,因此,对其组织结构嗜银反应进行研究具有重要的意义.本文用Grimellus还原银法显示了日本三角涡虫(Dugesia japonica)嗜银反应阳性的组织结构.结果表明:肠上皮细胞内有很多染成棕褐色的圆形泡状结构,肠上皮下的实质组织细胞中分布很多黑色颗粒;交配囊上皮细胞可见染成棕褐色的颗粒;在雄腔和交配囊柄两侧和后部可见染成棕褐色的三角形区域;纵神经索嗜银反应较弱,呈浅褐色.因此,可以确定肠上皮下实质组织中存在APUD系统. 相似文献
317.
良种白沙枇杷"冠玉"的组织培养和快繁技术研究 总被引:4,自引:0,他引:4
良种白沙枇杷“冠玉”茎尖在MS (6-BA,1.2mg/L) (NAA,0.4mg/L) (GA3,0.5mg/L)培养基上展叶,在MS (6-BA,1.75mg/L) (NAA,0.3mg/L)培养基上增殖,在1/2MS (NAA,0.5mg/L)培养基上生根。培养温度24℃-26℃,光照1500-2000lux,光照时间每天12小时。 相似文献
318.
李相敢 《南京大学学报(自然科学版)》1988,(2)
本文应用聚类方法对溫带山地灌草丛群落进行定量分析,过程如下:(1)计算群落的相关矩阵R;(2)求模糊等价矩阵B~*;(3)用不同水平截距APH将群落逐步聚类;当APH=0.425时,将溫带山地灌草丛群落划分成10个群丛。它们是细柄草+黄背草群丛,野青茅+白颖苔草群丛,黄背草+获群丛;黄背草+绿毛鹅观草群丛;黄背草+白羊草群丛;白羊草+隐子草群丛;白羊草+大穗结缕草群丛;白羊草+南牡蒿群丛;白羊草+百里香群丛;白羊草+长芒草群丛。同时详细分析了灌草丛性质、成因、演替及利用问题。 相似文献
319.
金银花叶提取物的抗氧化活性和抑菌作用研究 总被引:8,自引:0,他引:8
用POV测定法和过氧化氢氧化法考察了金银花叶提取物的抗氧化活性 ,最小抑菌浓度试验考察了提取物对金黄色葡萄球菌和大肠杆菌的抑制作用。结果表明 ,绿原酸粗提物和粗黄酮对油脂的过氧化反应均有一定的抑制作用 ,两者的氧化还原容量分别是化学合成抗氧剂BHA的 2 .0和 2 .8倍 ;分离物最小抑菌浓度试验表明 ,金银花叶中的黄酮类物质对金黄色葡萄球菌和大肠杆菌的抑制作用分别是绿原酸的 4和 2倍。 相似文献
320.
Guangce Wang 《Chromatographia》2002,56(7-8):509-513
Summary R-phycoerythrin was isolated and purified fromGracilaria verrucosa on an expanded-bed adsorption column combined with ion-exchange chromatography, which can effectively solve the problem of
blockage of chromatographic column due to polysaccharides during isolation and purification of phycobiliproteins. 0.1 M (NH4)2SO4 proved best to elute R-phycoerythrin from the expanded-bed column, and desalted 0.1 M (NH4)2SO4 eluate was used on an ion-exchange column to purify the R-phycoerythrin. Using this two-stage chromatography, the purity
(OD565/OD280) of the R-phycoerythrin fromG. verrucosa is increased to 4.4, and the yield of purified R-phycoerythrin can reach 0.141 mg·g−1 of the frozen alga. 相似文献