Helicase-dependent amplification is effective in distinguishing Asian ginseng from American ginseng

This study describes for the first time the application of helicase-dependent amplification (HDA) to authenticate botanical species and processed products. Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius) are consumed worldwide as functional food and health remedies. The two herbs share similar morphological appearance but have different pharmacological effects. In this work, a novel isothermal amplification mediated DNA method was applied to authenticate the two ginseng species. Internal control and P. ginseng specific primers were designed based on the ribosomal external transcribed spacer (ETS) region. The amplification results were confirmed by real-time monitoring, gel electrophoresis and DNA sequencing. The screened retail samples included dried ginseng root, ginseng powder, ginseng tea granules as well as a four-herb formulation. Our HDA protocol worked well on both purified DNA and crude water extract. In conclusion, HDA is a highly sensitive and specific approach for differentiating Asian ginseng from American ginseng and it has the potential for on-site authentication of herbal products.     

微流控芯片联用高效液相色谱-荧光检测器同时测定肉类食品中4种磺胺类药物残留

目的 建立一种使用微流控芯片进行肉类食品前处理,并结合高效液相色谱-荧光检测器(high performance liquid chromatography-fluorescence detector, HPLC-FLD)同时测定肉类食品中4种磺胺残留的方法。方法 样品先用乙酸乙酯提取后,在微流控芯片中用2 mol/L盐酸溶液反萃取和正己烷脱脂,收集盐酸流出液100μL,与0.5 g/mL醋酸钠溶液按照1:1(V:V)混合,加入0.2 g/L荧光胺50μL进行衍生化反应,采用岛津ODS-3色谱柱进行分离,流动相为乙腈-2%乙酸水溶液。结果 4种磺胺完全分离且在0.01～1.00mg/L呈良好的线性关系,在50、100、200μg/kg3个添加水平下,平均回收率为72.1%～91.6%,相对标准偏差为4.7%～13.6%,方法检出限为1～5μg/kg。结论 该方法具有快速、方便、经济、除脂效果好、环保等优点,适合肉类食品中4种磺胺类药物残留分析,并且提供了一个新的样品前处理思路。     

太子参化学成分及生物活性研究进展

太子参为石竹科植物孩儿参的干燥块根,味甘、微苦,性平,归脾肺经,具有益气健脾、生津润肺之功效,常用于气虚津伤的肺虚燥咳,被国家卫生健康委员会批准用于保健食品。现代药理和临床研究表明,太子参中特征性化学成分多糖和环肽具有免疫调节、抗炎、改善记忆等作用。近年来对太子参的化学成分、结构和药理作用的综述仅局限于特征成分,对其他成分还鲜有系统梳理报道。因此本文系统梳理了太子参的化学成分及生物活性研究进展,以期为太子参的开发利用提供参考和依据。     

Real-time TaqMan PCR for quantitative detection of cows’ milk in ewes’ milk mixtures

A real-time PCR based on the amplification of a fragment of the mitochondrial 12S ribosomal RNA gene was developed and evaluated for the detection and quantification of cows’ milk in raw and heat-treated cow/sheep milk mixtures. The method combines the use of cow-specific primers that amplify a 252 bp fragment from cow DNA, and mammalian-specific primers amplifying a 428 bp fragment from mammalian species DNA, which is used as an endogenous control. The method measures PCR product accumulation through a 6-carboxyfluorescein-labeled fluorogenic probe (TaqMan). A comparison of the cycle number at which mammalian and cow-specific PCR products were first detected, in combination with the use of reference standards of known bovine content, allowed the determination of the percentage of cows’ milk in mixtures. Experimental raw and heat-treated binary mixtures were analyzed, demonstrating the specificity and sensitivity of the assay for detection and quantification of cows’ milk in the range 0.5–10%.     

The structure of marmesinin by powder and single-crystal diffraction methods

The crystal and molecular structure of marmesinin C₂₀H₂₄O₉, a furocoumarine β-d-glucoside, an important biocontrolling compound isolated from the fruits of Ammi majus L. was determined from high-resolution powder diffraction using simulated annealing and, independently, from microcrystal diffraction. Both structural models were in good agreement. High-resolution powder diffraction patterns recorded with synchrotron radiation proved to be an efficient method for crystal structure determination of poorly-crystallizing natural products.     

Synthesis and photoluminescent properties of high-efficient color-tunable Ba3Y2B6O15: Ce3+, Tb3+ phosphors

High-efficient Ce³⁺/Tb³⁺ co-doped Ba₃Y₂B₆O₁₅ phosphors with multi color-emitting were firstly prepared, and their structural and luminescent properties were studied by XRD Rietveld refinement, emission/excitation spectra, fluorescence lifetimes as well as temperature-variable emission spectra. Upon 365?nm excitation, the characteristic blue Ce³⁺ band along with green Tb³⁺ peaks were simultaneously found in the emission spectra. Moreover, by increasing concentration of Tb³⁺, a blue-to-green tunable emitting color could be realized by effective Ce³⁺→Tb³⁺ energy transfer. Furthermore, all Ba₃Y₂B₆O₁₅: Ce³⁺, Tb³⁺ phosphors exhibit high internal quantum efficiency of ~?90%, while the temperature-variable emission spectra reveal that the phosphors possess impressive color stability as well as good thermal stability (T₅₀ =?~?120?°C). The results indicate that these efficient color-tuning Ba₃Y₂B₆O₁₅: Ce³⁺, Tb³⁺ might be candidate as converted phosphor for UV-excited light-emitting diodes.     

Disabling partners in crime: Gold nanoparticles disrupt multicellular communications within the tumor microenvironment to inhibit ovarian tumor aggressiveness

The tumor microenvironment (TME) plays a key role in the poor prognosis of many cancers. However, there is a knowledge gap concerning how multicellular communication among the critical players within the TME contributes to such poor outcomes. Using epithelial ovarian cancer (EOC) as a model, we show how crosstalk among cancer cells (CC), cancer associated fibroblasts (CAF), and endothelial cells (EC) promotes EOC growth. We demonstrate here that co-culturing CC with CAF and EC promotes CC proliferation, migration, and invasion in vitro and that co-implantation of the three cell types facilitates tumor growth in vivo. We further demonstrate that disruption of this multicellular crosstalk using gold nanoparticles (GNP) inhibits these pro-tumorigenic phenotypes in vitro as well as tumor growth in vivo. Mechanistically, GNP treatment reduces expression of several tumor-promoting cytokines and growth factors, resulting in inhibition of MAPK and PI3K-AKT activation and epithelial-mesenchymal transition - three key oncogenic signaling pathways responsible for the aggressiveness of EOC. The current work highlights the importance of multicellular crosstalk within the TME and its role for the aggressive nature of EOC, and demonstrates the disruption of these multicellular communications by self-therapeutic GNP, thus providing new avenues to interrogate the crosstalk and identify key perpetrators responsible for poor prognosis of this intractable malignancy.     

Nutrient composition and food potential of Parkia roxburghii,a less known tree legume from northeast India

The nutrient compositions of Parkia roxburghii kernels and pods (i.e. tender, immature and mature) were determined. Protein content of the kernel was 29% and that of pods 13–19%. Similarly, fat content was highest (34%) in the kernel and ranged from 1–16% in the pods. Unsaturated acids Oleic, linoleic and linolenic acids made up 63–68% of the total fat in the pods as well as the kernels. The total essential amino acids amounted to 33%, 36% and 39% in the tender, immature, mature pods, respectively, and 42% in the kernels. The essential amino acid pattern of the kernel was comparable to the FAO/WHO/UNU (1985) amino acid requirement for preschoolers. However, the amino acid scores of the tender, immature and mature pods were 64, 84 and 92, respectively, with sulphur amino acids as the limiting amino acids in all the pod samples.     

微波辅助合成4-苯基氨基-7-氨基喹唑啉

以2-氨基-4-硝基苯甲酸和甲酰胺为原料,经Niementowski、氯代、烃化反应合成4-苯基氨基-7-硝基喹唑啉盐酸盐,再经铁粉还原得4-苯基氨基-7-氨基喹唑啉。目标化合物的结构经1HNMR、IR、MS谱表征。前三步反应采用微波辐助合成,大大缩短了反应时间,提高了反应速率和收率。