含硫杯[4]芳烃银系配合物在织物上的抗菌性能

为提高银系抗菌剂的稳定性,用银的络合离子替代银离子,将杯芳烃应用在纺织品抗菌整理中。利用含硫杯[4]芳烃具有可修饰性和对银离子有很好的络合作用等特点,制备了一系列新型杯芳烃银系配合物,并证明其对大肠埃希菌ATCC25922、铜绿假单胞菌ATCC27853、金黄色葡萄球菌ATCC29213和白色念珠菌ATCC10231有良好的抗菌性能。将杯芳烃含银配合物作为抗菌剂整理到棉织物上,整理后的棉织物经10次水洗后,对大肠埃希菌ATCC25922、金黄色葡萄球菌ATCC29213和白色念珠菌ATCC10231仍有良好的抗菌效果。     

Biotin-containing phospholipid vesicle layer formed on self-assembled monolayer of a saccharide-terminated alkyl disulfide for surface plasmon resonance biosensing

We describe a technique to form a biotin-containing phospholipid vesicle layer on a self-assembled monolayer (SAM) deposited on a gold surface to immobilize biotinylated receptor proteins for a surface plasmon resonance (SPR) biosensor. The adsorption of vesicle of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) was examined by SPR on the SAMs of dithiobis(1-deoxy-glucitol-1-carbamoyl pentane) (DDGP), 11-mercaptoundecanoic acid, 11-mercaptoundecanol, 11-amino-1-undecanethiol, and 12-mercaptododecane, and it was found that the DOPC vesicle rapidly adsorbed on the DDGP SAM to achieve the highest coverage of the surface. By quartz crystal microbalance with dissipation monitoring (QCM-D), the DOPC layer formed on the DDGP SAM was shown to be a vesicle layer, in which intact DOPC vesicles physisorbed on the SAM surface. To immobilize a biotinylated receptor protein, one of three biotinylated phospholipids, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(biotinyl) (biotin-DOPE), N-((6-(biotinoyl)amino)hexanoyl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (biotin-X-DHPE) and N-(biotinoyl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (biotin-DHPE), was mixed with DOPC to form a biotin-containing vesicle layer on the DDGP SAM. A comparative binding study of NeutrAvidin and the biotin-containing vesicle layers showed that the use of biotin-X-DHPE achieved the most rapid immobilization of NeutrAvidin on the vesicle layer at the highest surface density. Furthermore, biotinylated protein A, as a receptor protein, could be immobilized through NeutrAvidin on the vesicle layer containing DOPC and biotin-X-DHPE, and its reaction with immunoglobulin G, as an analyte, was successfully observed by SPR. The results demonstrate that the biotin-containing vesicle layer on the DDGP SAM must be a useful component for SPR biosensor surfaces.     

三甲胺柱[5]芳烃的合成及其抑菌性能

本研究合成基于三甲胺的柱[5]芳烃,并以金黄色葡萄球菌（Staphylococcus aureus ATCC 6538）和大肠杆菌（Escherichia coli DH5α）为供试菌对三甲胺柱[5]芳烃的抑菌性能和抑菌机制进行分析。通过抑菌实验确定三甲胺柱[5]芳烃最小抑菌浓度（minimal inhibit concentration,MIC）和最小杀菌浓度（minimal bactericidal concentration,MBC）,并探讨其对细菌生物被膜形成的影响;利用透射电子显微镜（transmission electron microscopy,TEM）观察三甲胺柱[5]芳烃对细菌细胞膜的损伤情况,并通过噻唑蓝（3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide,MTT）法测定其细胞毒性。结果显示,三甲胺柱[5]芳烃对S. aureus ATCC 6538的MIC和MBC分别为0.125 mg/mL和1.000 mg/mL,对E. coli DH5α的MIC和MBC分别为0.250 mg/mL和＞1.000 mg/mL;三甲胺柱[5]芳烃对S. aureus ATCC 6538生物被膜形成的抑制效果优于对E. coli DH5α。TEM观察结果表明三甲胺柱[5]芳烃对不同菌株细胞膜的损伤不同;MTT实验结果表明MIC范围内三甲胺柱[5]芳烃无毒。本研究结果明确了三甲胺柱[5]芳烃的具体抑菌性能,可为其在食品领域的进一步开发利用提供一定的理论依据。     

光度法研究八元瓜环与食用色素-日落黄和靛蓝的相互作用

利用紫外可见吸收光谱法研究了八元瓜环(Q[8])与食用色素靛蓝(g2)和日落黄(g3)的相互作用情况。考察了溶液的酸度对作用体系的影响。计算了稳定常数,测定了作用体系的校正曲线。结果表明,八元瓜环与客体的相互作用随客体及溶液pH的不同而有所改变。pH>5.3,Q[8]与日落黄(g3)能够发生明显的相互作用,形成作用比为2∶1的稳定配合物,而Q[8]与靛蓝(g2)则在pH<10.8时,才能形成配比为1∶2的稳定配合物。这对于研究瓜环与食用色素的包结和缓释等在食品添加剂的开发和应用方面具有重要的研究价值。      

四氮杂杯[2]芳烃[2]三嗪键合硅胶固相萃取/HPLC-MS/MS法测定家兔血浆中的TSNAs

为了准确测定家兔血浆中的烟草特有N-亚硝胺(TSNAs),制备了四氮杂杯[2]芳烃[2]三嗪键合硅胶(NCS)固相萃取柱,并通过对NCS固相萃取、色谱及质谱条件的优化,建立了测定家兔血浆中的N-亚硝基降烟碱(NNN)、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮(NNK)、4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁醇(NNAL)、N-亚硝基新烟草碱(NAT)和N-亚硝基假木贼碱(NAB)5种TSNAs的NCS固相萃取/HPLC-MS/MS方法.结果表明:NCS固相萃取柱对家兔血浆中5种TSNAs的萃取效率优于商品化的C18固相萃取柱;5种TSNAs的检测限为0.0092～0.0590 ng/mL,回收率和相对标准偏差(RSD)分别为90.1％～113.3％和0.95％～7.22％.该方法简单、准确,适合于家兔血浆中TSNAs的检测.     

食品中有害物苯并[a]芘诱导结肠毒性的研究进展

苯并[a]芘是多环芳烃类物质,广泛存在于高温加工食品中,且工业生产和生活中燃料不完全燃烧也会产生大量苯并[a]芘,进而通过水源、空气和土壤等污染食物.流行病学调查显示,苯并[a]芘与结肠癌、结肠炎症等肠道疾病的发生密切相关.作者详细综述了不同食品中苯并[a]芘的含量,及其诱发结肠癌、结肠氧化损伤、结肠炎症、肠道菌群失调...     

食品污染物苯并[a]芘致细胞损伤作用的研究

目的:对食品污染物苯并[a]芘所致细胞损伤作用进行研究。方法:用不同浓度的苯并[a]芘(1、5、10、50、100μmol/L)对肺腺癌细胞A549染毒24h,MTT法测定细胞存活率、单细胞琼脂糖凝胶电泳检测细胞DNA损伤,用溶剂二甲基亚砜处理细胞组作为未染毒细胞组。结果:苯并[a]芘染毒作用时,随染毒浓度的增加,A549细胞存活率呈下降趋势;A549细胞的DNA损伤程度也随染毒浓度增加而增加,与未染毒A549细胞相比,染毒A549细胞的Olive尾矩值均有明显增加(p<0.05)。结论:食品污染物苯并[a]芘致A549细胞明显的损伤作用。     

miRNA影响苯并[a]芘诱发毒性的机制研究进展

苯并[a]芘（B[a]P）作为多环芳烃类化合物（PAHs）中毒性最大的一种强致癌物,广泛存在于高温加工食品中。大量流行病学研究表明,B[a]P与许多疾病的发生发展密切相关。微小RNA（miRNA）是短的（17–25个核苷酸）非编码RNA,通过mRNA降解或翻译抑制负调控特定的靶基因。miRNA在B[a]P诱发致癌性、生殖毒性、神经毒性等过程中发挥重要作用。本文根据现有的研究发现,对miRNA在B[a]P毒性过程中的作用机制作一综述,旨在深入揭示B[a]P的毒理机制并为其疾病预防和食品安全控制提供新的研究方向和思路。     

Atomic force microscopy observation of highly arrayed phospholipid bilayer vesicle on a gold surface

Tapping mode atomic force microscopy (TM-AFM) imaging of a phospholipid bilayer vesicle (liposome) immobilized on a gold surface was performed to investigate morphologies of the electrode surfaces produced through application of three different sample preparation methods. We compared both methods from a morphological viewpoint using TM-AFM images. Liposomes, composed of zwitterionic and anionic phospholipids, were prepared by extrusion. Results indicate that the surface with immobilized L1-liposome, which was fabricated by the amino coupling method, seemed to form large amounts of aggregated or fused liposomes. In contrast, L2-liposome-containing 1-octadecanthiol that was directly attached on the gold surface using thiol-gold binding force was immobilized as a uniform surface topology without liposome aggregation. Finally, we attempted to arrange individual L3-liposome, prepared by mixing zwitterionic and anionic phospholipids, onto the gold layer by electron-beam (e-beam) lithography technique. A third method, L3-liposome formation on the sensor surface, is greatly anticipated for biosensor applications.     

高效液相色谱法测定反应香精中的3,4-苯并□

建立高效液相色谱测定反应香精中3,4-苯并芘的方法,考察前处理方法及色谱条件对实验回收率的影响,确定了C18固相萃取柱为前处理工艺,萃取剂为甲醇,色谱流动相为甲醇∶水=90∶10,流速为1.0 mL/min,DAD检测波长为UV-290 nm.测定反应样品不合3,4-苯并芘,加标实验回收率为76.66%～79.44%.相对平均偏差为1.28%.     

卷烟主流烟气中苯并[a]芘的HPLC测定

先用乙醇 +乙醚混合溶剂萃取卷烟烟气总粒相物 (TPM) ,再用中性氧化铝柱层析 ,然后 ,利用配有ODS -C18色谱柱的高效液相色谱仪 ,在以 90 %甲醇 + 10 %水为流动相 ,流速为 1mL min ,激发波长 2 86nm和发射波长 4 30nm的条件下测定了TPM中的苯并 [a]芘含量。苯并 [a]芘的回收率≥ 91.2 % ,方法的RSD <5 %。并采用该方法测定了 10种不同焦油量卷烟主流烟气中的苯并 [a]芘含量。结果表明 ,就所测定的卷烟而言 ,①在焦油量相近的情况下 ,混合型卷烟烟气中的苯并 [a]芘含量较烤烟型卷烟的低 8.2 9%～ 19.5 9% ;②无论是烤烟型还是混合型卷烟 ,随着卷烟焦油量的降低 ,虽然焦油中的苯并[a]芘总量明显降低 ,但单位量焦油中的苯并 [a]芘含量却明显增大。     

内标校准液相色谱荧光法测定食用油中苯并（a）芘

采用内标苯并（b）屈校正,建立了正相固相净化-反相液相色谱-荧光分光光度法测定食用油中苯并（a）芘的方法。正相Plus Silica固相萃取柱作为净化柱,反相C18柱作为分离柱。以苯并（b）屈作为内标,测定了苯并（a）芘的校正因子。使用本方法,苯并（a）芘在液态食用油和固态食用油中的检出限分别为0.01和0.03μg/kg。苯并（a）芘在不同食用油回收率在83%～108%之间,方法的日内精密度和日间精密度分别小于7.7%和13.2%。     

高效液相色谱法测定卷烟主流烟气中的苯并[a]芘

为了测定卷烟主流烟气中苯并[a]芘,考察了萃取条件、弗罗里硅土净化条件和色谱分离条件,建立了测定卷烟主流烟气中苯并[a]芘的高效液相色谱-荧光检测法,并采用该方法和国标法测定了肯塔基参考卷烟3R4F和国内参比烤烟以及国内50个牌号卷烟样品烟气中的苯并[a]芘。结果表明:①用环己烷超声萃取40 min效果较好;②用Agilent ZORBAX Eclipse PAH作色谱柱,乙腈和水为流动相,梯度洗脱,流速2.0 mL/min,30 min内苯并[a]芘色谱峰可以和杂质峰有效分开;③该法的平均回收率在98.13%～101.36%之间,RSD在1.29%～4.32%之间;④该方法的测定结果与国标法较为一致,二者不存在显著性差异。该方法适合卷烟主流烟气中苯并[a]芘的检测。     

Towards Understanding Formation and Stability of Cyclodextrin Inclusion Complexes: Computation and Visualization of their Molecular Lipophilicity Patterns[1]

Five cyclodextrin inclusion complexes - typical examples for their solid state as well as exemplary „frozen molecular images”︁ of their status in solution - were subjected to a molecular modelling study comprising the computer-assisted generation of the molecular lipophilicity patterns (MLP's), i. e. the p-iodoaniline inclusion into α-CD, the complexes of β-CD with 1,4-butanediol, adamantane-1-carboxylic acid, and adamantane-1-methanol, and the unique 12-crown-4 ether inclusion compound of γ-CD. Based on their solid state structures, the „solvent-accessible”︁ contact surfaces were generated by the MOLCAD program. Calculation and color-coded projection of the MLP's onto these surfaces easily allows to locate the hydrophobic and hydrophilic surface regions of CD-host and guest alike. Their detailed analysis revealed a far-reaching, mostly complete conformity between the hydrophobic surface areas of the guest and the hydrophobic domains in the CD cavity. This striking tendency to optimize the reciprocal concurrence of lipophilic as well as hydrophilic domains at the guest-host-interface may accordingly be concluded to be an important, if not the decisive element in orienting the guest into the cavity and in determining the stability of the complex, particularly in cases where the guest is devoid of polar groups; if these are present, dipole-dipole alignments and the need for their solvation may diminish the importance of hydrophobic attractions for orienting and stabilizing the guest in the CD cavity.     

In vitro and in vivo modulation of testosterone mediated alterations in apoptosis related proteins by [6]-gingerol

Ginger (Zingiber officinale, Zingiberaceae) has been widely used as a dietary spice, and as a traditional oriental medicine. The rhizome of ginger contains pungent vanillyl ketones, including [6]-gingerol and [6]-paradol, and have been credited with therapeutic and preventive health benefits, including anti-cancer activity. Prostate cancer is an attractive target for chemoprevention because of its ubiquity, treatment-related morbidity, long latency between premalignant lesions and clinically evident cancer, and defined molecular pathogenesis. Here we are reporting the modulatory effects of [6]-gingerol on testosterone-induced alterations on apoptosis related proteins in both in vitro, androgen sensitive LNCaP cells and in vivo, ventral prostate of Swiss albino mice. [6]-gingerol treatment resulted apoptosis in LNCaP cells, as indicated by depolarization of mitochondrial membrane potential, increase in sub G1 cell population by flow cytometry and the appearance of DNA laddering pattern in agarose gel electrophoresis. Results of western blot analysis showed that [6]-gingerol upregulated the testosterone depleted levels of p53 in mouse prostate and upregulated its downstream regulator Bax and further activated Caspase-9 and Caspase-3 in both LNCaP cells and in mouse prostate. We also found downregulation of testosterone induced antiapoptotic proteins, Bcl-2 and Survivin expression by [6]-gingerol in both LNCaP cells and in mouse ventral prostate. Thus, [6]-gingerol shows its protective effects in both in vivo and in vitro prostate cancer models by modulation of proteins involved in apoptosis pathway.     

In vitro antioxidant and anti-inflammatory activities of 1-dehydro-[6]-gingerdione, 6-shogaol, 6-dehydroshogaol and hexahydrocurcumin

Hexahydrocurcumin, 1-dehydro-[6]-gingerdione, 6-dehydroshogaol and 6-shogaol were evaluated for their antioxidant and anti-inflammatory activities in the present study. The relative antioxidant potencies of ginger compounds decreased in similar order of 1-dehydro-[6]-gingerdione, hexahydrocurcumin>6-shogaol>6-dehydroshogaol in both 1,1-diphenyl-2-picyrlhydrazyl (DPPH) radical-scavenging and trolox equivalent antioxidant capacity (TEAC) assays. All tested compounds could attenuate lipopolysaccharide (LPS)-elicited increase of prostaglandin E2 (PGE(2)) in murine macrophages (RAW 264.7) in a concentration-dependent manner but hexahydrocurcumin of 7μM and 6-shogaol of 7μM. The strongest inhibitory effect was observed for 6-dehydroshogaol and 6-shogaol at 14μM with the inhibition of 53.3% and 48.9%, respectively. Furthermore, both 6-dehydroshogaol and 1-dehydro-[6]-gingerdione significantly suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in a concentration-dependent fashion. These results contribute to our theoretical understanding of the potential beneficial effects of consuming ginger as a food and/or dietary supplement.     

二甲亚砜提取—冷冻离心净化测定食品中苯并[a]芘及苯并[e]芘

建立以二甲基亚砜作为提取溶剂,冷冻离心提取净化食品中的苯并[a]芘和苯并[e]芘,高效液相色谱—荧光法检测的方法。替代传统的固相萃取小柱净化方式,能更快速、高效、准确检测食品中苯并[a]芘和苯并[e]芘的含量。2种目标物在0.5~1 000 ng/mL范围内呈现良好线性关系,在1~100 ng/g添加量下,回收率为89.0%~91.3%,相对标准偏差为1.19%~1.29%;仪器检出限为0.01 ng/mL,植物油脂方法检出限为0.05 ng/g,肉制品和动物油脂方法检出限为0.02 ng/g。该方法测定动植物油脂和肉制品中的苯并[a]芘和苯并[e]芘方便、快捷,适用于批量化检测。     

表面增强拉曼光谱(SERS)快速检测食用油中的苯并[a]芘

苯并(a)芘广泛存在于煤焦油、炼油等工业污水中,多次使用的高温植物油、烧焦的食物都可能含有苯并(a)芘。我国目前对食用植物油类产品中苯并(a)芘的限量标准是10μg/kg。检测食品中苯并(a)芘的方法中使用较多的是高效液相色谱法、气相色谱-质谱联用法等方法,但检测过程样品的前处理复杂、检测耗时长、检测效率低,尚不能满足实时、现场检测的要求。本文使用纳米金修饰的多孔材料作为SERS基底,利用SERS对食用油中的苯并(a)芘的含量进行快速检测。苯并(a)芘在0~200μg/L范围内与SERS的信号值呈线性关系,线性方程为y=134.98x-571.77,R2=0.9942;在10μg/kg含量水平下,样品回收率为93.2~125.7%,相对标准偏差为10~18%,方法检出限为5.6μg/L。SERS可使用便携式拉曼光谱仪进行现场检测,测试时间短(一般为数十秒至一两分钟)。在检测灵敏度满足要求的情况下,SERS方法为快速筛查食用油中苯并(a)芘含量提供了一种新的选择。     

Determination of benzo[a]pyrene in some Spanish commercial smoked products by HPLC-FL

In order to investigate the levels of the potently carcinogenic benzo[a]pyrene (BP), 31 samples of smoke foods were analysed. The samples tested included five samples of meat products, three samples of cheese and 22 samples of fish. A liquid chromatographic method was developed using a fluorescence detector. BP was found in 74% of the samples analysed. The levels varied from not detected to 2.46 mug/kg. Only one sample showed a BP level above 1 mug/kg, the maximum level that the EU intends to set for smoked foods.