尿素柱层析结合重结晶制备高纯度茄尼醇

为制备高纯度的茄尼醇,进行了尿素柱层析结合重结晶分离茄尼醇试验,考察了尿素柱层析固定相尿素与硅胶的比例、洗脱溶剂、上样量对茄尼醇纯度和收率的影响。结果表明:尿素柱层析固定相尿素与硅胶质量比1∶1,洗脱剂石油醚与乙酸乙酯体积比60∶1,上样量0.4 g,茄尼醇的纯度和收率分别为74.8%和89.8%。再经过甲醇、乙腈各结晶一次,茄尼醇的纯度达96.7%,总收率0.1248%。该方法可以用于浸膏中茄尼醇的精制。     

樟芝发酵产物中安卓奎诺尔的提取纯化

对樟芝发酵产物中的生理活性物质安卓奎诺尔的提取纯化工艺技术进行了研究。结果表明,安卓奎诺尔的最佳的提取条件为:提取溶剂为95%乙醇,料液比1∶25(g/m L),提取温度为35℃,提取时间为85 min。提取液再经过二次柱层析进一步纯化。第一次硅胶柱层析最佳条件为:上样量1∶40(w样品∶w硅胶),径高比1∶30,洗脱流速2.0 BV/h,产物中安卓奎诺尔的纯度为70.2%;第二次硅胶柱层析最佳条件为:洗脱剂v苯∶v丙酮=7∶3,上样量w样品∶w硅胶=1∶30,径高比1∶10,洗脱流速1.0 BV/h,最终产品中安卓奎诺尔的纯度达到91.0%。     

黑树莓花色苷分离、纯化与抗氧化活性

采用AB-8大孔树脂和硅胶柱层析技术纯化并分离黑树莓花色苷,分别通过DPPH自由基、ABTS自由基和羟自由基清除试验评价花色苷组分的抗氧化活性。结果表明:经过大孔树脂纯化后的花色苷的纯度从17.18%提高到85.21%,得率为0.60%;硅胶柱层析参数为洗脱液配比为正丁醇∶乙酸∶水的体积比为4∶2∶0.5,流速为0.5 mL/min,树莓花色苷粗品与硅胶的质量比为1∶550;得到黑树莓花色苷产物组分分别为BRA1和BRA2,纯度分别为94.53%和92.14%。组分BRA1的抗氧化活性优于组分BRA2,两者均呈现出良好的抗氧化活性。     

大孔树脂-硅胶柱层析法纯化花生根中白藜芦醇

研究了大孔树脂-硅胶柱层析法分离纯化花生根中白藜芦醇的工艺。通过动静态解吸附试验确立大孔树脂最佳分离工艺为:大孔树脂为聚酰胺,上样质量浓度26.58μg/mL,解吸剂为80%乙醇,洗脱流速2 BV/h。通过薄层色谱与硅胶柱层析试验,确定最佳纯化条件为:洗脱剂V(氯仿)∶V(甲醇)=40∶1、流速30 mL/min、m(硅胶)∶m(样品)=1∶1。产物经V(甲醇)∶V(氯仿)=3∶1重结晶后,采用高效液相色谱测定其纯度为97.01%。     

硅胶柱分离纯化亚麻木脂素工艺的研究

依据薄层层析法确定了硅胶柱层析纯化亚麻木脂素的最佳洗脱液为以氯仿、甲醇、醋酸和水的比例为8∶4∶0.5∶0.5组成的体系;硅胶柱上样浓度最佳值为15 mg/m L,洗脱流速为1.0 m L/min分离效果最好;在上述条件下,得到亚麻木脂素纯度可以达到80.13%;检测结果显示:亚麻木脂素粗品经硅胶柱纯化后,通过薄层层析检测显示出现亚麻木脂素单一点,HPLC检测表明经硅胶柱纯化后出现单一峰且其保留时间与标准品保留时间相同,说明纯化后纯度较高。     

艾纳香叶中花椒油素的制备

提出从艾纳香叶中制取花椒油素的方案。通过同时蒸馏萃取法(SDE)提取花椒油素,利用硅胶柱层析分离粗品,经过重结晶纯化得高纯产品,通过气相色谱(GC)和核磁共振(NMR)对花椒油素进行定量和定性分析。在料水比1∶8,溶剂(无水乙醚)体积60 m L,提取时间2.5 h的参数下通过SDE法提取花椒油素,GC测定显示粗提物中含量达20.26%。硅胶柱参数为洗脱液配比[V(乙酸乙酯)∶V(石油醚)=1∶19]、径高比1∶14、样品与硅胶质量比(上样量)1∶40、洗脱液流速3.5 m L/min时,可分离到花椒油素粗品(纯度72.09%),回收率为99.04%。经过3次重结晶得到高纯度产品(98.37%),总回收率为91.92%,得率为0.28%。NMR结果证实产品为花椒油素。     

化学合成香叶醇-β-D吡喃葡萄糖苷的分离纯化

为实现化学合成的香叶醇-β-D-吡喃葡萄糖苷的高效、系统分离纯化,采用改进的Koenigs-Knorr法,以硅胶担持碳酸银催化剂提高合成收率,利用硅胶柱层析及高效液相(HPLC)对粗样品进行分离纯化,硅胶柱层析通过薄层层析选择较佳的流动相配比,即乙酸乙酯和乙醇按照50:1,40:1,30:1依次进行梯度洗脱,利用HPLC技术的高精密性,其流动相乙腈:水为55:45,分别纯化合成的粗品。结果表明:采用新型的催化剂使产物收率由56.1%提高到75%,收率得以较为显著的提高;且硅胶柱层析得到产物纯度为90.12%,HPLC纯化得到的产物纯度为98.66%,两种层析方法均可得到纯度较佳的香叶醇糖苷;为香叶醇吡喃葡萄糖苷合成及纯化提供一定的借鉴。     

硅胶柱层析法分离大豆异黄酮苷元的研究

利用硅胶柱层析分离大豆异黄酮苷元.通过丙酮萃取大豆异黄酮后,经硅胶柱层析可以分离得到染料木素、大豆素、黄豆黄素3种大豆异黄酮苷元异构体.经HPLC检测3种物质的纯度均超过90%.     

肽类生物表面活性剂中消泡剂的分离研究

本研究首次建立硅胶柱层析两步法以去除抗菌脂肽粗品中所含有的大豆油消泡剂成分,实验中采用高效液相色谱(HPLC)检测抗菌脂肽的含量,薄层色谱-可见光分光光度法定量分析消泡剂中甘油三酯含量,TLC法筛选大豆油的洗脱流动相。研究结果表明:使用200~300目的硅胶作为层析材料,硅胶的总负载量为12.5mg/g时,采取混合液(石油醚∶乙酸乙酯∶乙酸=20∶2∶1,体积比)为流动相,以1m L/min流速进行洗脱,可将97.97%的大豆油成分去除;第二阶段采用流动相为100%的乙醇以1m L/min流速进行洗脱可将抗菌脂肽解吸,抗菌脂肽的总回收率达到91.52%,纯度从34.07%提高到93.12%。本研究为肽类生物表面活性剂工业化生产和应用提供实验依据。     

尿素包合法分离欧李仁油中油酸的研究

以我国特有的天然固沙植物欧李的种子油为原料 ,采用正交试验设计分析方法 ,用尿素包合分离法纯化、制备高纯油酸 ,对欧李仁油油酸的分离工艺条件进行了优化 ,得到的最佳工艺条件为 :结晶温度T1为 10℃ ,结晶温度T2 为 - 10℃ ,尿素∶脂肪酸 (W/W )为 1 5∶1,甲醇浓度90 % ,在优化工艺条件下 ,油酸提取率 :87 3% ,纯度 :97 6 % ;油酸样品硅胶柱层析处理后 ,总提取率为 76 9% ,油酸含量为 99 3%。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press     

INFOPRINT 2014 was Successfully Held in Dongguan

Sponsored by Printing and Printing Equipment Industries Association of China （PEIAC） and organized by Print China magazine, the Seventeenth Beijing International Printing Information Conference （INFOPRINT 2014） was successfully held on 11th Dec. 2014 at Dongguan Exhibition International Hotel.