山茱萸中生物活性物质的分离、鉴定及其神经保护作用

研究山茱萸乙醇提取物中生物活性成分的化学组成及其对神经的保护作用。采用正相常压硅胶、Sephadex LH-20凝胶、大孔吸附树脂、闪式低压正反相硅胶和氰基、反相高压液相等色谱方法对显示具有神经保护活性的组分进行分离纯化,根据核磁共振谱、质谱,同时结合已知文献数据对比鉴定化合物结构;再采用H 2 O 2诱导的SH-SY5Y细胞氧化损伤模型对分离鉴定的化合物进行体外神经保护活性测定。结果表明,从山茱萸显示神经保护活性的组分中分离鉴定了9个化合物,分别为7-β-莫诺苷(1)、7-β-O-甲基莫诺苷(2)、7-α-O-甲基莫诺苷(3)、金吉苷(4)、cornolactones D(5)、pollenfuran A(6)、threo-2,3-bis(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol(7)、5-羟甲基糠醛(8)和3,4-二羟基苯甲酸(9);其中化合物pollenfuran A(6)和threo-2,3-bis(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-ol(7)为首次从山茱萸属植物中分离得到,化合物cornolactones D(5)为首次从山茱萸中分离得到;化合物7-β-莫诺苷(1)、7-β-O-甲基莫诺苷(2)、7-α-O-甲基莫诺苷(3)具有神经保护活性。     

黑豆乙醇萃取物中抗氧化成分的分离与鉴定

目的：研究黑豆抗氧化活性成分。方法：采用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）法筛选黑豆乙醇提取物抗氧化活性部分,并综合运用硅胶柱色谱、聚酰胺柱色谱、D-101大孔吸附树脂柱色谱、凝胶柱色谱等方法对黑豆乙醇提取物具有较强抗氧化活性部分进行分离纯化,并根据理化性质和波谱数据对化合物进行结构鉴定。结果：采用DPPH法筛选表明黑豆乙醇提取物乙酸乙酯萃取部分和正丁醇萃取部分具有较强抗氧化活性,并从黑豆乙酸乙酯萃取部分、正丁醇萃取物经大孔吸附树脂体积分数30%乙醇洗脱部分中分离鉴定了10 个化合物,其中包括7 个黄酮类化合物：染料木素（1）、大豆素（2）、黄豆黄苷（3）、大豆苷（4）、染料木苷（5）、槲皮素-3-O-葡萄糖苷（6）、3’-甲氧基-表儿茶素-7-O-葡萄糖苷（7）,以及胡萝卜苷（8）,麦芽酚（9）、岩白菜素（10）。结论：化合物6、7、9、10为首次从大豆植物中分离得到,黑豆的抗氧化活性与其含较多酚类化合物有关。     

山茱萸中具有抗氧化活性的环烯醚萜类成分

采用正相硅胶柱色谱、Sephadex LH-20凝胶柱色谱、大孔吸附树脂柱色谱、氰基柱色谱和高效液相色谱等方法对山茱萸乙醇提取物中具有抗氧化活性的环烯醚萜类组分进行分离纯化;采用核磁共振波谱技术和质谱技术鉴定其结构;通过总抗氧化能力FRAP法测定其抗氧化活性。结果表明：共分离并鉴定出4个具有抗氧化活性的环烯醚萜类成分,分别为：马钱子苷（1）、马钱素-7-酮（2）、1-β-甲氧基马钱子苷元（3）和1-去羟基马钱子苷元（4）,其中化合物3和4是首次从山茱萸属中分离得到的新的天然产物。     

肉苁蓉苯乙醇苷的纯化及其抗氧化活性研究

本实验分别运用有机溶剂萃取法和大孔吸附树脂分离法对肉苁蓉苯乙醇苷(PEG)粗提液进一步分离纯化.通过比较分析确定合适的分离纯化方法;并对经分离纯化的苯乙醇苷从还原能力、1,1-二苯基苦基苯肼(DPPH)自由基清除能力和亚油酸体系抗脂质过氧化能力三方面进行抗氧化活性评价研究.结果表明:D101大孔吸附树脂柱层析较适合苯乙醇苷的纯化工艺,苯乙醇苷抗氧化活性高于阳性对照VE.     

红凤菜抗氧化成分提取分离研究

目的有效地从红凤菜中提取分离抗氧化活性成分。方法以"乙醇提取-NKA大孔树脂柱层析-聚酰胺柱层析-重结晶"的方法进行分离,测定各阶段样品的DPPH IC50、ABTS IC50、总酚及总黄酮含量,并作相关性分析。结果大孔树脂的30%乙醇洗脱物抗氧化活性最高(DPPH IC50为31.5μg/m L,ABTS IC50为15.1μg/m L)、总酚含量较高(22.8%)、未检出黄酮苷元成分,50%乙醇洗脱物抗氧化活性较高(DPPH IC50为42.1μg/m L,ABTS IC50为33.2μg/m L)、总酚含量最高(26.3%)、总黄酮苷元及总黄酮含量均最高(分别为18.7%和33.7%);50%乙醇洗脱物经聚酰胺柱层析得到的黄酮苷结晶Ⅰ、Ⅱ及其母液干燥物,其抗氧化活性、总酚及总黄酮含量均提高;DPPH IC50与总酚含量间存在显著负相关(r=-0.883*)。结论红凤菜提取物清除DPPH自由基的活性与其总酚含量显著相关,依次采用NKA大孔树脂和聚酰胺柱层析可有效地富集抗氧化活性成分。     

桉叶提取物中抗氧化活性物分离纯化、结构鉴定及其活性的研究

为进一步探索桉叶提取物抗氧化活性的物质基础,本文采用反相硅胶和制备液相等方法对桉叶提取物中高醇组分进行分离纯化得到4个化合物。接着应用~1H-NMR和~(13)C-NMR光谱分析鉴定化合物的结构,最终鉴定出3个化合物,分别为金丝桃苷、番石榴苷和槲皮素-3-O-α-吡喃阿拉伯糖-2"-棓酸盐。最后采用DPPH·、ABTS+·和ORAC三种体外检测体系进行抗氧化活性的研究。在DPPH·和ORAC方法中,番石榴苷的抗氧化能力最强,槲皮素-3-O-α-吡喃阿拉伯糖-2"-棓酸盐的抗氧化能力最低。在ABTS·+方法中金丝桃苷的抗氧化能力最强,番石榴苷的抗氧化能力最低。但与抗氧化剂Trolox相比,三者都表现出更强的抗氧化能力,是有较好发展前景的天然抗氧化剂。本文为桉叶资源的综合开发提供理论指导作用。     

桉叶提取物中抗氧化活性物分离纯化、结构鉴定及其活性的研究

为进一步探索桉叶提取物抗氧化活性的物质基础,本文采用反相硅胶和制备液相等方法对桉叶提取物中高醇组分进行分离纯化得到 4 个化合物。接着应用1H-NMR 和13C-NMR 光谱分析鉴定化合物的结构,最终鉴定出 3 个化合物,分别为金丝桃苷、番石榴苷和槲皮素-3-O-α-吡喃阿拉伯糖-2”-棓酸盐。最后采用 DPPH·、ABTS·+和 ORAC 三种体外检测体系进行抗氧化活性的研究。在DPPH·和 ORAC 方法中,番石榴苷的抗氧化能力最强,槲皮素-3-O-α-吡喃阿拉伯糖-2”-棓 酸盐的抗氧化能力最低。在 ABTS·+方法中金丝桃苷的抗氧化能力最强,番石榴苷的抗氧化能力最低。但与抗氧化剂 Trolox 相比,三者都表现出更强的抗氧化能力,是有较好发展前景的天然抗氧化剂。本文为桉叶资源的综合开发提供理论指导作用。     

油茶粕中黄酮化合物的分离鉴定及抗氧化性研究

为了探索油茶粕中黄酮化合物的分子组成及其抗氧化活性,本研究运用优化的分离纯化方法对油茶粕中黄酮进行粗提和HZ816大孔吸附树脂富集纯化,然后再经硅胶柱对其黄酮化合物层析,得到2种黄酮化合物,分别记为化合物Ⅰ和化合物Ⅱ。随后利用核磁共振、质谱、红外和紫外光谱对上述分离得到的2种黄酮化合物进行结构鉴定。结果表明:这2种物质分别为山奈酚3-O-[2-O-β-D-木糖-6-O-α-L-鼠李糖]-β-D-葡萄糖苷(化合物Ⅰ)和山奈酚3-O-[2-O-β-D-半乳糖-6-O-α-L-鼠李糖]-β-D-葡萄糖苷(化合物Ⅱ)。对分离的黄酮化合物采用1,1-二苯基-3-硝基苯肼自由基清除法(DPPH法)、邻苯三酚自氧化法在体外进行抗氧化实验,结果显示总黄酮、化合物Ⅰ和化合物Ⅱ清除DPPH自由基半抑制浓度(IC_(50))分别为0.44、1.88、2.41 mg/m L,清除超氧阴离子IC_(50)分别为1.38、1.13、1.29 mg/m L。     

厚朴叶不同溶剂提取物抗氧化活性比较分析

采用1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除法,2,2-联氮基-双-(3-乙基苯并噻唑啉-6-磺酸)二铵盐[2,2/-azino-bis(3-ethylbenzthiazoline-6-sulonic acid),ABTS]自由基清除法以及铁离子还原能力(ferric reducing antioxidant power,FRAP)测定,评价厚朴叶7种不同溶剂提取物的抗氧化活性,并考察总酚含量与抗氧化活性的关系。结果表明,厚朴叶不同溶剂提取物具有良好的抗氧化活性,但抗氧化能力存在一定差异。其中正丁醇提取物的DPPH自由基清除率和ABTS自由基清除率最高,EC50值分别为40.67μg/m L和26.67μg/m L;乙醇提取物的铁离子还原能力最强,在浓度为0.1 mg/m L时,其FRAP值为24.54%;含量测定显示,乙醇提物中总酚含量最高,为174.14 mg/g;相关系数表明,总酚含量与抗氧化能力具有较好的相关性,提示乙醇可以作为厚朴叶抗氧化活性物质提取的优选溶剂。     

番木瓜中皂苷类成分的研究

目的：研究番木瓜果肉的化学成分,寻找活性物质。方法：用85% 乙醇提取,大孔吸附树脂、ODS、MCI 柱层析进行分离,NMR 波谱法鉴定化合物的结构。结果：从番木瓜果肉乙醇提取物中分离到3 种化合物,分别为2β,3β - 二羟基- 乌苏酸(Ⅰ)、3-O- 葡萄糖- 甾苷(Ⅱ)、薯蓣皂苷元-3-O- β -D- 吡喃葡萄糖基(1 → 3)- β -D- 吡喃葡萄糖基(1 → 4)-[α -L- 吡喃鼠李糖基(1 → 2)]- β -D- 吡喃葡萄糖苷(Ⅲ)。     

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.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

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