五味子助眠成分的分离鉴定

通过高效液相色谱法(HPLC)对小鼠大脑皮层中多巴胺(DA)含量进行检测和直接观察睡眠法对五味子助眠作用进行研究;用大孔树脂柱、MCI柱、ODS柱等方法分离出具有助眠作用的有效成分;利用核磁共振(NMR)对有效成分中分离得到的化合物进行结构鉴定。结果表明:五味子水洗脱部分和95%乙醇洗脱部分能显著提高小鼠睡眠率和睡眠时间,水洗脱部分得到化合物α-氨基-β-羟基异丁酸、β-乙氧基氨基丙酸,95%乙醇洗脱部分分离得到戈米辛N。五味子中氨基酸和木质素一样具有较好的助眠功效。     

佤药远志醇提物对斑马鱼的助眠作用

该研究以佤药远志（娘母良）为试材，研究其改善睡眠的功效。采用高效液相色谱法（HPLC）检测佤药远志醇提物的主要活性成分及含量，以斑马鱼为实验动物，建立戊四唑（PTZ）斑马鱼失眠模型。实验设置正常对照组、模型组和处理组，处理组设置5个质量浓度，分别为125、250、500、1 000、2 000 μg/mL，28 ℃处理1 d后，观察统计各组斑马鱼死亡数量和死亡率，测定远志醇提物对正常斑马鱼的最大耐受浓度（Maximum Talerated Concentration，MTC）；根据MTC给予PTZ模型斑马鱼不同质量浓度的远志醇提物，设置阳性对照组（褪黑素组）和正常对照组，通过行为分析仪检测斑马鱼的觉醒活动时间和觉醒活动量。结果表明，MTC为1 000 μg/mL；观察时间内，阳性褪黑素组改善睡眠作用为29.00%，远志醇提物4个质量浓度处理组（125、250、500、 1 000 μg/mL）改善睡眠作用依次为6.97%、22.78%、33.14%、47.26%，其中质量浓度为500 μg/mL和1 000 μg/mL的远志醇提物改善睡眠作用明显优于阳性褪黑素组。以上结果显示远志醇提物对PTZ诱导的斑马鱼失眠症状具有一定的改善作用，但是在一定浓度范围内，呈剂量依赖性，浓度越高，作用越明显。     

百合助眠活性组分的筛选和分析

对百合助眠的活性组分进行筛选并对有效成分进行分析。用直接睡眠实验和延长戊巴比妥钠睡眠时间实验对百合助眠作用的有效成分进行研究;用大孔树脂、MCI等方法分离具有助眠作用的有效成分;用核磁共振对有效成分进行结构鉴定。百合的正丁醇提取物能显著增加小鼠睡眠率、睡眠时间,促进小鼠更快进入睡眠。经分离,得到的主要物质结构为(25R)-3β,17α-二羟基-5α-螺甾烷-6-酮-3-O-α-L-鼠李糖基-(1→2)-β-D-葡萄糖苷和(25R)-3β-羟基-5α-螺甾烷-6-酮-3-O-α-L-鼠李糖基-(1→2)-β-D-葡萄糖苷。百合的正丁醇提取物具有显著助眠作用,其中具有助眠作用的主要物质为甾体皂苷。     

8种葡萄糖苷配糖体在卷烟主流烟气粒相物中的转移率测定

对8种葡萄糖苷配糖体化合物在红塔集团某牌号卷烟主流烟气中的转移率进行了测定.通过收集主流烟气中的粒相物,并用二氯甲烷萃取粒相物中的配糖体,然后进行GC-MS分析,采用内标标准曲线法测定各配糖体的含量,进一步计算配糖体的转移率.结果表明:①用所建立的测定方法测定的8种配糖体回收率在81.31％ -89.86％之间,相对标准偏差小于3.14％,线性相关系数(r)大于0.9995;②8种葡萄糖苷配糖体化合物向主流烟气粒相物中的转移率为0.43％ -2.37％.     

罗莱家纺联合迈迪加和京东智能发布首款助眠灯

正近日,罗莱家纺联合深圳市迈迪加科技发展有限公司、京东智能集团在北京举行了新品发布会,首发智能睡眠旗舰产品——Nox智能助眠灯。据深圳市迈迪加科技发展有限公司透露,该产品融入了最新的助眠科技,能为用户提供高质量的睡眠体验。同时,该产品还可以通过准确获取人体在整个卧室睡     

基于气相色谱-串联质谱技术测定植物组织中糖与糖醇

该研究以植物组织中含量极少的侧金盏花醇作为内标物,建立气相色谱-串联质谱联用法(gas chromatography-tandem mass spectrometry,GC-MS/MS)同时检测植物组织中葡萄糖、半乳糖、肌醇、甘露醇、山梨醇、蔗糖的分析方法。样品采用氯仿-甲醇水溶剂提取法,加入吡啶、盐酸羟胺和乙酸酐衍生化,经HP-5MS毛细管色谱柱分离后使用电子轰击离子源以多重反应监测(multiple reaction monitoring,MRM)模式进行质谱检测。结果表明,各目标化合物在15 min内完成分离分析,6种乙酰化糖和糖醇检测响应呈现良好的线性关系,相关系数(correlation coefficients,R 2)均在0.997以上,方法定量限(limits of quantitation,LOQs)为0.045~0.37 mg/L,检出限(limits of detection,LODs)为0.013~0.12 mg/L。植物样品加标回收率为95.38%~102.6%,相对标准偏差为1.28%~3.42%。该方法样品用量少,准确度高,精密度好,适合植物组织中微量糖和糖醇化合物含量的快速检测。     

新疆药桑叶中黄酮类化合物的分离与鉴定

采用色谱分离技术从药桑叶醇提物的乙酸乙酯萃取部分分离黄酮类化合物,通过核磁共振(NMR)和高效液相-串联质谱(HPLC-MS-MS)鉴定其结构。分离得到四个黄酮类化合物,结构表征为芦丁(1)、槲皮素-3-O-葡萄糖苷(2)、金丝桃苷(3)、山奈酚-3-O-β-D-吡喃葡萄糖(4)。其中化合物(3)、(4)首次从新疆药桑叶中分离得到。     

猪肉、猪肝中 17 种全氟烷基化合物的HPLC-MS/MS 测定

目的建立猪肉、猪肝中17种全氟烷基化合物(perflurorinated alkylated substances,PFASs)的高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。方法样品经酸化乙腈提取、混合吸附剂纯化后,应用HPLC-MS/MS技术检测,以Poroshell 120 EC-C18为色谱柱,甲醇-5 mmol/L乙酸铵水溶液梯度洗脱,多反应监测负离子模式扫描,同位素内标法定量,内标物为经13C或者18O标记的相应外标物。结果应用该方法检测猪肉样品中17种全氟烷基化合物的检出限(LOD,S/N=3)为0.009~0.047μg/kg,在猪肝样品中的检出限(LOD,S/N=3)为0.003~0.031μg/kg;在0.5μg/kg、1.0μg/kg、1.5μg/kg三个加标浓度下,该方法的平均加标回收率约为80%~110%,平均相对标准偏差(RSD)小于10%。结论该方法可有效应用于猪肉、猪肝中17种全氟烷基化合物的检测。     

百事将推助眠饮料 谋求新的业绩增长点

正有史以来最快时间推出助眠饮料,百事开始焦虑了吗?9月15日,百事宣布将推出助眠饮料Driftwell,这也是百事有史以来推出速度最快的新产品。百事急于入局助眠饮料市场的背后,是逐渐扩大的市场份额以及娃哈哈、新希望、可口可乐等巨头的提前布局。不过,在业内人士看来,"睡眠经济"催生下的助眠饮品更像是一种噱头。作为"迟到者",百事的助眠产品能为其业绩带来多少帮助还不好说。     

金樱子酒中还原糖的分光光度法测定

发酵液中还原糖浓度是酿酒工艺的重要控制参数之一。利用还原糖与3,5-二硝基水杨酸(DNS)的专一性显色反应,通过考察检测波长、显色剂用量、反应时间和样品pH等条件对反应的影响,确定了还原糖的DNS-分光光度法检测条件。为克服金樱子浸出液中干扰物对显色反应的影响,建立了一种基于校正工作曲线的还原糖显色检测方法,该方法简便、准确,样品回收率达99.8%。     

As(III) oxidation by active chlorine and subsequent removal of As(V) by Al13 polymer coagulation using a novel dual function reagent

An electrochemically prepared water treatment reagent containing a high concentration of Al(13) polymer and active chlorine (PACC) showed promising potential for the removal of As(III) due to the combined function of oxidation and coagulation. The results indicated that PACC was effective for As(III) removal through oxidation by the active chlorine and subsequent removal of As(V) by coagulation with the Al(13) polymer. The As(III) was oxidized to As(V) by active chlorine in PACC, with a stoichiometric rate of 0.99 mg Cl(2)/mg As(III). The Al(13) polymer was the most active Al species responsible for As(V) removal in PACC. To meet As drinking water standards the stoichiometric weight ratio of Cl(2)/Al within PACC was 0.09 for the treatment of As(III). Considering the process of As(III) oxidation and As(V) coagulation together, the optimal pH conditions for the removal of As by PACC was within the neutral range, which facilitated the reaction of As(III) with active chlorine and favored the formation of Al hydroxide flocs. The presence of humic acid reduced the As(III) removal efficiency of PACC due to its negative influence on subsequent As(V) coagulation, and disinfection byproduct yields were very low in the presence of insufficient or stoichiometric active chlorine.     

The determination of the antiperspirant activity of aluminium-chlorhydrate by digital image-analysis

The method of Minor to visualize by iodine–starch–reaction the activity of sweat glands was used in combination with image-analysis to quantify sweat-secretion. Aqueous aluminium chlorohydrate solutions (ACH) (1, 2, 4, 8, 16%) were applied twice daily for 6 days to defined areas of the lower volar forearms. After 3 and 6 days of treatment perspiration was induced by thermal stress. The dark blue spots on top of active glands which are formed by iodine–starch–complexes were counted and their projection area was measured by an image analysing system. Increasing concentrations of ACH lower the number of active sweat glands, while the size of the dark spots is not dependent on the concentration of the active ingredient.     

不同干酵母对甘蔗汁酿酒特性的影响

为研究不同酵母对甘蔗果酒的发酵影响,以新鲜的甘蔗压榨汁为原料,常温下选用葡萄酒高活性干酵母、耐高温高活性干酵母和发利干酵母三种商业活性干酵母进行液态发酵酿制甘蔗果酒。研究探讨了三种酵母菌的生长曲线、凝聚性、发酵度、发酵力、酸化力和产酒精能力等酿酒发酵特性。结果表明,三种酵母菌作用甘蔗汁的发酵过程中,酵母菌生长曲线趋势基本一致,三种酵母菌的凝聚值F<20%,均为非凝聚性酵母。三种酵母菌的发酵力基本相当的,最终产酒精的能力差距不大,其中葡萄酒高活性干酵母最终产酒精为12.2% vol,耐高温高活性干酵母和发利干酵母均为12.0% vol。从三种商用酵母菌对甘蔗汁酿酒的各发酵特性来看,葡萄酒高活性干酵母略优于耐高温高活性干酵母和发利干酵母。研究结果为甘蔗汁发酵酿制风味甘蔗果酒提供了技术参考。     

Improvement of productivity of active horseradish peroxidase in Escherichia coli by coexpression of Dsb proteins

Coexpression of two classes of folding accessory proteins, molecular chaperones and foldases, can be expected to improve the productivity of soluble and active recombinant proteins. In this study, horseradish peroxidase (HRP), which has four disulfide bonds, was selected as a model enzyme and overexpressed in Escherichia coli. The effects of coexpression of a series of folding accessory proteins (DnaK, DnaJ, GrpE, GroEL/ES, trigger factor (TF), DsbA, DsbB, DsbC, DsbD, and thioredoxin (Trx)) on the productivity of active HRP in E. coli were examined. Active HRP was produced by very mild induction with 1 microM isopropyl-beta-D-thiogalactopyranoside (IPTG) at 37 degrees C, whereas the amount of active HRP produced by the induction with 1 mM IPTG was negligibly small. Active HRP production was increased significantly by coexpression of DsbA-DsbB (DsbAB) or DsbC-DsbD (DsbCD), while coexpression of molecular chaperones did not improve active HRP production. The growth of E. coli cells was inhibited significantly by the induction with 1 mM IPTG in a HRP single expression system. In contrast, when HRP was coexpressed with DsbCD, the growth inhibition of E. coli was not observed. Therefore, coexpression of Dsb proteins improves both the cell growth and the productivity of HRP.     

聚酯/二氧化硅/橙活性成分改性纤维的制备及其性能

为解决天然活性成分改性聚酯纤维生产过程中,天然成分不耐高温易损失导致功能下降的问题,通过分子巢技术将超临界CO₂萃取获得的橙活性成分装载入介孔SiO₂载体中,进而制备具有良好抑菌、抗病毒效果的聚酯/二氧化硅/橙活性成分改性纤维。对改性纤维的形貌结构、化学结构、力学性能、活性成分含量、抗菌性能和抗病毒性能等进行测试与分析。结果表明:制备的介孔SiO₂的尺寸为(100±5) nm,比表面积为729.7 m²/g,平均孔径为 2.55 nm;聚酯/二氧化硅/橙活性成分改性纤维的断裂强度为3.22 cN/dtex,纤维中橙活性成分柚皮甙含量为(0.41±0.05) mg/kg,抑菌率大于或等于91%,抗病毒率大于或等于99%,均显著优于普通聚酯纤维(p<0.01)。     

斑点叉尾(鱼回)鱼皮明胶的风味成分及其脱腥的研究

采用顶空固相微萃取和气质联用技术,分析了斑点叉尾(鱼回)鱼皮明胶的风味成分,比较了活性炭、β-环糊精和酵母3种脱腥剂对明胶的脱腥效果。结果表明:斑点叉尾(鱼回)鱼皮明胶的风味成分主要是一些含有羰基的饱和或不饱和的醛类和酮类;(鱼回)鱼皮明胶腥味最为相关的成分为正己醛、正庚醛、2,4-庚二烯醛、2,6-壬二烯醛。活性炭、β-环糊精和酵母都有一定的脱腥效果,其中活性炭脱腥效果最好。活性炭脱腥前醛、酮种类个数分别为13和6,脱腥后减少为5和4;活性炭脱腥前醛、酮含量为27.89%,脱腥后降至10.92%。尤其与腥味相关的正己醛、正庚醛、2,4-庚二烯醛、2,6-壬二烯醛等成分在脱腥后,均未被检出。     

山葡萄酒发酵过程中活性物质、抗氧化能力及有机酸的变化

本文探究了山葡萄酒的功能活性物质和抗氧化能力变化规律和相关性,并分析了山葡萄酒中有机酸的变化规律。利用比色法和高效液相色谱法（HPLC）对发酵过程中山葡萄酒中的功能活性物质、抗氧化能力和有机酸含量进行了动态检测。结果表明:山葡萄酒中的总酚和黄酮含量较丰富,分别可达（5482±36）和（1075±2） mg/L,花青素含量（334.8±7） mg/L;三种功能活性物质与Fe3+还原力、DPPH·清除率及ABTS+·清除率的抗氧化能力进行相关性分析,表明山葡萄酒中的功能活性物质和抗氧化能力呈极显著正相关（P<0.01）;随着发酵时间的增加,酒石酸下降明显,柠檬酸和乙酸有少量增加,乳酸增加明显且168 h后含量达2.22 g/L。综上,山葡萄中的活性物质在发酵过程中能充分溶出,增强山葡萄酒的抗氧化能力,突出山葡萄酒的营养价值;有机酸中的酒石酸降低,增加了口感柔和的乳酸含量,使山葡萄酒口感明显改善,从而提高酒体品质。     

Importance of disulfide bridge formation on folding of phospholipase D from Streptomyces antibioticus

The effects of redox conditions on the folding of phospholipase D (PLD) of Streptomyces antibioticus were investigated. Although the enzyme was very stable even in the presence of 1.0 M guanidinehydrochloride (Gdn-HCl), the coexistence of dithiothreitol (DTT) and Gdn-HCl inactivated the enzyme completely. The inactivated enzyme recovered its activity by dialysis in which DTT was removed prior to Gdn-HCl, whereas its activity was not recovered when Gdn-HCl was removed prior to DTT. In vitro protein synthesis was used for further analyses of the folding process. Active PLD was synthesized in the absence of DTT. The activity increased as the protein synthesis proceeded. In contrast, inactive PLD was synthesized in the presence of DTT. The inactive PLD could not be effectively activated by simple removal of the reductant, while incubation with Gdn-HCl and subsequent removal of DTT followed by that of Gdn-HCl was a much more effective method for the synthesis of active enzymes. From these results, it is suggested that: (i) PLD contains disulfide bridge(s), which is (are) necessary for maintaining its tertiary structure, (ii) correct formation of the disulfide bridge(s) is a critical step in the early stage of the (re)folding process, and (iii) the disulfide bridge(s) further facilitate the folding process, resulting in the synthesis of the active enzymes with the correct structure.     

Assessment of the effectiveness of biologically active food additives based on zeolites in experimental animals

The aim of present study was an investigation of effective of product from ceolites which is suggested as biologically active food additive. The high-calorie, high-fat, high-cholesterol diet was developed. The rats (female and male) were fed with the biologically active food additive during 1 month at dose 70 mg per kg of body weight. Their blood and liver were investigated to measure total lipids, total cholesterols, phospholipid, triglycerides. Morphologic parameters of liver was studied. Cholesterol lowering effect of biologically active food additive in rat (female) has been shown.     

Improvement of productivity of active horseradish peroxidase in Escherichia coli by coexpression of Dsb proteins

Coexpression of two classes of folding accessory proteins, molecular chaperones and foldases, can be expected to improve the productivity of soluble and active recombinant proteins. In this study, horseradish peroxidase (HRP), which has four disulfide bonds, was selected as a model enzyme and overexpressed in Escherichia coli. The effects of coexpression of a series of folding accessory proteins (DnaK, DnaJ, GrpE, GroEL/ES, trigger factor (TF), DsbA, DsbB, DsbC, DsbD, and thioredoxin (Trx)) on the productivity of active HRP in E. coli were examined. Active HRP was produced by very mild induction with 1 μM isopropyl-β- -thiogalactopyranoside (IPTG) at 37°C, whereas the amount of active HRP produced by the induction with 1 mM IPTG was negligibly small. Active HRP production was increased significantly by coexpression of DsbA-DsbB (DsbAB) or DsbC-DsbD (DsbCD), while coexpression of molecular chaperones did not improve active HRP production. The growth of E. coli cells was inhibited significantly by the induction with 1 mM IPTG in a HRP single expression system. In contrast, when HRP was coexpressed with DsbCD, the growth inhibition of E. coli was not observed. Therefore, coexpression of Dsb proteins improves both the cell growth and the productivity of HRP.