十字花科植物中的芥子碱对大麦和小麦萌发种子的辐射保护作用

本文证明许多十字花科植物对电离辐射都有很强的抗性。用油菜、青菜和芥菜幼芽提取液预处理大麦萌发种子,以及用油菜、青菜、芥菜、雪里蕻、甘蓝、萝卜的幼芽提取液和蔊菜的花序和叶提取液预处理小麦萌发种子,均能减轻X射线对生长的抑制作用。说明这些十字花科植物抗辐射的能力可能与其体内存在天然的辐射保护物质有关。芥子碱普遍存在于十字花科植物,油菜提取液的定性反应与芥子碱的反应相同。从油菜中提取到的芥子碱硫氰酸盐结晶的溶液对小麦和大麦也有同样的辐射保护作用。ESR的研究表明芥子碱能对胸腺嘧啶起辐射保护作用。芥子碱是存在于十字花科植物中的一种天然辐射保护物质。     

用高效液相色谱法测定灯盏花中槲皮素的含量

分别采用溶剂回流提取和超声提取两种方法对灯盏花样品中的槲皮素进行提取,优化了提取条件,并用高效液相色谱进行了定量分析,采用扫描电镜分析了提取样品的表面形貌.结果表明:两种方法的提取率分别为0.048 7mg/g和0.042 3mg/g,溶剂回流的提取效果略优于超声提取;回流提取时的高温有利于提取物的溶出,而超声提取节能、快速.与此同时,采用两种方法提取的样品表面都受到明显的侵蚀,且回流提取时的机械搅拌促进样品的破碎,这些都有利于槲皮素的溶出.     

芥子酸及其衍生物对酪氨酸酶抑制作用的电化学研究

采用电化学方法研究了芥子酸、芥子酸甲酯及芥子碱对酪氨酸酶的抑制作用. 结果发现, 酪氨酸酶电极对其底物邻苯二酚有良好的电催化作用, 电流响应在底物1.0×10-7~6.0×10-5 mol/L的浓度范围内呈线性关系, 并具有较高的灵敏度(60.93 nA·L/μmol); 芥子酸及其衍生物都对酪氨酸酶的活性有抑制作用, 抑制能力大小的顺序为芥子酸>芥子酸甲酯>芥子碱. 通过对这3种物质的抑制参数的计算结果表明, 芥子碱是非竞争型抑制, 而芥子酸和芥子酸甲酯是混合型抑制. 这3种物质对酪氨酸酶可能的抑制机理一是抑制物与底物竞争酶的双铜活性中心; 二是抑制物具有抗氧化活性, 因而抑制酶对底物的催化反应.     

超声辅助皂化提取禾谷镰孢菌中麦角甾醇及其HPLC分析

采用超声辅助皂化法提取禾谷镰孢菌中的麦角甾醇,通过单因素和响应面分析,对影响麦角甾醇提取效果的主要因素包括皂化碱含量、提取温度、液固比及超声时间进行优化,并建立其HPLC测定方法。结果表明,禾谷镰孢菌中麦角甾醇超声提取最佳条件为碱含量0. 034 g/mL、温度36℃、液固比200 mL/g、超声时间8 min,禾谷镰孢菌中麦角甾醇提取量为0. 88 mg/g,与模型预测基本一致。麦角甾醇的线性范围为3. 125～200μg/mL,相关系数0. 9997,平均回收率在82%以上。     

Comparation of Different Extraction Methods for Trace Elements Fe, Mn and Mg

为比较不同提取方法对菟丝子中微量元素含量的影响,采用酸式提取法、碱式提取法、沸水提取法及超声提取法对中药菟丝子中的微量元素进行提取,用原子吸收分光光度法测定了提取液中微量元素铁、锰和镁的含量并进行了比较.结果表明,4种提取方法对微量元素的溶出率由高到低顺序为:铁—酸提,超提,碱提,沸提;锰—酸提,超提,沸提,碱提.镁—酸提,沸提,超提,碱提.     

景天三七总多酚提取工艺的优化及活性研究

采用超声提取景天三七中的多酚,并利用Box-Behnken响应面法对影响景天三七总多酚提取率的因素(液料比、乙醇浓度、超声时间、超声温度)进行了优化,并以DPPH自由基和ABTS自由基清除能力为评价指标,研究景天三七总多酚体外抗氧化活性.结果显示,最佳的提取条件为乙醇浓度63％,液料比36:1(mL·g-1),超声温度...     

常用十字花科药用植物中芥子碱的分布研究

十字花科植物中的芥子碱是一种非常有价值的天然抗氧剂,在抗衰老药物的研究中受到了许多学者的重视。为了考察芥子碱在我国药用植物中的分布情况,采用反相高效液相色谱法测定了我国常用的4种十字花科药用植物白芥子、莱菔子、葶苈子、黄芥子中该成分的含量。采用的色谱柱为Alltima Phenyl柱(250 mm×4.6 mm i.d.,5 μm);流动相:3%醋酸溶液和乙腈的混合溶液,梯度洗脱;检测波长:326 nm;柱温:25 ℃。该法快速,准确度高,重现性好,方法的建立不仅为上述4种药材的质量监测提供了有效的定量分析方法,而且对于芥子碱的深入研究具有重要意义。     

超声波提取含羞草种子中总黄酮工艺条件优化研究

采用超声提取法对含羞草种子中黄酮类物质进行提取,对提取工艺条件如溶剂、配料比、浸泡时间、提取温度、提取时间进行了优化。在单试验的基础上进行正交试验,得出黄酮类物质的最佳提取工艺条件:乙醇体积分数为60%,含羞草种子与60%乙醇配料比(g∶m L)为1∶8,超声温度范围40~44℃,超声时间为50 min。该方法操作简单,提取时间短,提取效率较高。     

石榴皮单宁的超声波-半仿生法提取及抗氧化性分析

采用超声波辅助半仿生法提取石榴皮单宁。利用正交实验方法对提取工艺进行优化,并进行了红外光谱分析和研究抗氧化能力检测。在提取液的pH值分别:1.2、7.6、8.4,溶剂质量分数50%、提取时间45 min、提取温度50℃、超声波功率320 W和超声波频率25KHz的条件下,单宁提取量可达234.6 mg.g-1,远高于无超声波辅助的试样。红外光谱分析表明:石榴皮单宁中含有大量的无色花翠素-3-葡萄糖苷分子结构式类物质;抗氧化能力检测显示:采用超声波辅助半仿生法能够提高单宁对OH.、DPPH.和ABTS+.等自由基的清除能力,与水回流提取法相比,其IC50值分别降低了0.26、0.022和0.41 mg.mL-1。     

不同方法提取菟丝子微量元素Fe，Mn和Mg的比较研究

为比较不同提取方法对菟丝子中微量元素含量的影响,采用酸式提取法、碱式提取法、沸水提取法及超声提取法对中药菟丝子中的微量元素进行提取,用原子吸收分光光度法测定了提取液中微量元素铁、锰和镁的含量并进行了比较。结果表明,4种提取方法对微量元素的溶出率由高到低顺序为：铁-酸提,超提,碱提,沸提;锰-酸提,超提,沸提,碱提。镁酸提,沸提,超提,碱提。     

Selective Extraction of Sinapic Acid Derivatives from Mustard Seed Meal by Acting on pH: Toward a High Antioxidant Activity Rich Extract

The aim of this paper is to study the effect of the pH on the extraction of sinapic acid and its derivatives from mustard seed meal. Solutions of acidic pH (pH 2), basic pH (pH 12) and distilled water (uncontrolled pH ~ 4.5) were tested at different percentages of ethanol. The maximum extraction yield for sinapic acid (13.22 µmol/g of dry matter (DM)) was obtained with a buffered aqueous solution at pH 12. For ethyl sinapate, the maximum extraction yield reached 9.81 µmol/g _DM with 70% ethanol/buffered aqueous solution at pH 12. The maximum extraction yield of sinapine (15.73 µmol/g _DM) was achieved with 70% ethanol/buffered aqueous solution at pH 2. The antioxidant activity of each extract was assessed by DPPH assay; the results indicated that the extracts obtained at pH 12 and at low ethanol percentages (<50%) exhibit a higher antioxidant activity than extracts obtained at acidic conditions. Maximum antioxidant activity was reached at pH 12 with buffer solution (11.37 mg of Trolox Equivalent/g _DM), which confirms that sinapic acid-rich fractions exhibit a higher antioxidant activity. Thus, to obtain rich antioxidant extracts, it is suggested to promote the presence of sinapic acid in the extracts.     

Optimization of ultrasonic-assisted extraction of 3-monochloropropane-1,2-diol (MCPD) and analysis of its esters from edible oils by gas chromatography-mass spectrometry

In this paper, ultrasonic-assisted extraction of 3-chloropropane-1,2-diol and its esters from edible oils was studied with isotope dilution GC-MS. Effects of several experimental parameters, such as types and concentrations of extracting solvent, ratios of liquid to material, extraction temperature, time of ultrasonic treatment on the extraction efficiency of 3-chloropropane-1,2-diol and its esters from edible oils and sample preparation for calibration were compared and optimized. The optimal extraction conditions were suggested as 66 mg oil sample in mixture of 0.5 mL MTBE/ethyl acetate (20% v/v) and 0.5 mL of sulfuric acid/n-propanol (0.3% v/v), being extracted for 30 min at 45°C under ultrasonic irradiation. Good linearity was gained in the range of 0.020-5.000 μg/g with the limit of detection (LOD) of 0.006 μg/g (S/N = 3) and the limit of quantification (LOQ) of 0.020 μg/g (S/N = 10). The recoveries at five spiked concentrations were ranged from 91.9 to 109.3% with RSD less than 9.4%. The method was successfully applied to the determination of 3-chloropropane-1,2-diol and its esters amounts in rapeseed, sesame, peanut, camellia, and soybean oils.     

A Potential Commercial Source of Fucoxanthin Extracted from the Microalga <Emphasis Type="Italic">Phaeodactylum tricornutum</Emphasis>

Fucoxanthin, one of the main marine carotenoids, is abundant in macro- and microalgae. Here, fucoxanthin was isolated and structurally identified as the major carotenoid in the diatom Phaeodactylum tricornutum through chromatographic and spectroscopic methods, such as liquid chromatography–positive-ion atmospheric pressure chemical ionization/mass spectroscopy and nuclear magnetic resonance. This pigment was quantified by reverse-phase high-performance liquid chromatography, and a number of extraction procedures were assessed to investigate the effect of solvent type, extraction time, temperature, and extraction method (maceration, ultrasound-assisted extraction, Soxhlet extraction, and pressurized liquid extraction). Among the investigated solvents, ethanol provided the best fucoxanthin extraction yield (15.71 mg/g freeze-dried sample weight). Fucoxanthin content in the extracts produced by the different methods was quite constant (15.42–16.51 mg/g freeze-dried sample weight) but increased steeply based on the percentage of ethanol in water, emphasizing the importance of ethanol in the extraction. The results indicate that P. tricornutum is a rich source of fucoxanthin (at least ten times more abundant than that in macroalgae) that is easily extracted with ethanol, suggesting potential applications in human and animal food, health, and cosmetics.     

昆仑雪菊中黄酮类化合物提取与纯化

用超声法提取昆仑雪菊中黄酮类化合物,通过大孔树脂对提取液进行纯化,纯化物经聚酰胺层析柱梯度洗脱得到初步分离物,通过颜色反应和紫外光谱扫描进行定性分析。设计正交实验得到超声法提取的最佳工艺条件是65%乙醇、料液比为1∶40、超声时间60 min,此条件下提取3次,总黄酮得率可达132.6 mg/g。通过聚酰胺柱层析法分离出五个组分,初步判断它们属于不同的黄酮类物质。超声法提取总黄酮,提取率较高,聚酰胺树脂对黄酮类化合物的分离效果较好。     

Isolation and determination of p-hydroxybenzoylcholine in traditional Chinese medicine Semen sinapis Albae

A special component is isolated from Semen sinapis Albae (white mustard seed), a traditional Chinese medicine. According to the physical and chemical investigation and spectroscopic identification, this component can be known as p-hydroxybenzoylcholine bisulfate, a choline base. This component in the drug is also determined by RP-HPLC. A reversed-phase C₁₈ column is used to separate the p-hydroxybenzoylcholine with an eluent of methanol–0.05 mol/L monopotassium phosphate solution (30:70) (adjusted by phosphoric acid to pH 3.6) at the flow rate of 0.5 mL/min. Detection is carried out with a UV detector operated at 285 nm, and the column temperature is 25 °C. It reveals that there is 0.021% (w/w) of p-hydroxybenzoylcholine bisulfate in Semen sinapis Albae and 0.037% (w/w) in stir-baked Semen sinapis Albae.     

Antioxidant activity of various parts of Cinnamomum cassia extracted with different extraction methods

The aim of this study was to investigate the antioxidant activities of various parts (barks, buds, and leaves) of Cinnamomum cassia extracted with ethanol and supercritical fluid extraction (SFE). For the antioxidant activity comparison, IC50 values of the SFE and ethanol extracts in the DPPH scavenging assay were 0.562-10.090 mg/mL and 0.072-0.208 mg/mL, and the Trolox equivalent antioxidant capacity (TEAC) values were 6.789-58.335 mmole Trolox/g and 133.039-335.779 mmole Trolox/g, respectively. In addition, the total flavonoid contents were 0.031-1.916 g/ 100 g dry weight of materials (DW) and 2.030-3.348 g/ 100 g DW, and the total phenolic contents were 0.151-2.018 g/ 100 g DW and 6.313-9.534 g/ 100 g DW in the SFE and ethanol extracts, respectively. Based on the results, the ethanol extracts of Cinnamon barks have potential value as an antioxidant substitute and this study also provide a better technique to extract the natural antioxidant substances from C. cassia.     

Study on optimizing dyeing of cotton using date pits extract as a combined source of coloring matter and bio-mordant

In this research, extraction of colouring matter from date pits powder was conferred by conventional and ultrasonic methods. Phenolic compounds present in the resulted extract were identified by HPLC analysis. Total phenolic, total flavonoid and total metallic contents were quantified; and the highest levels were obtained in case of ultrasonic extraction process at a frequency of 25 kHz. The different resultant extracts were diluted with distilled water and unified to a polyphenolic content of 48 mg per 100 mL. Dyeing results have been discussed as a function of the bio-metallic contents present in the extract. It was found that the highest colour strengths and the better fastness properties were registered in case of dyeing experiments developed using the ultrasonic extracts. Those above results could be due to the highest metallic content present in the ultrasonic extracts, which has functioned as a bio-mordant properly extracted from date pits powder.     

Multi‐criteria optimization for ultrasonic‐assisted extraction of antioxidants from Pericarpium Citri Reticulatae using response surface methodology,an activity‐based approach

An activity‐based approach to optimize the ultrasonic‐assisted extraction of antioxidants from Pericarpium Citri Reticulatae (Chenpi in Chinese) was developed. Response surface optimization based on a quantitative composition‐activity relationship model showed the relationships among product chemical composition, antioxidant activity of extract, and parameters of extraction process. Three parameters of ultrasonic‐assisted extraction, including the ethanol/water ratio, Chenpi amount, and alkaline amount, were investigated to give optimum extraction conditions for antioxidants of Chenpi: ethanol/water 70:30 v/v, Chenpi amount of 10 g, and alkaline amount of 28 mg. The experimental antioxidant yield under the optimum conditions was found to be 196.5 mg/g Chenpi, and the antioxidant activity was 2023.8 μmol Trolox equivalents/g of the Chenpi powder. The results agreed well with the second‐order polynomial regression model. This presented approach promised great application potentials in both food and pharmaceutical industries.